GERM Reservoir Database
Development and Maintenance by the EarthRef.org Database Team

GERM Database Search Results        
Reservoir Z Element Value Median SD Low High N Unit Info Reference Source(s)
Active Continental Rifts 73 Ta 0.7           ppm Lower crustal rocks are combined in proportions as indicated in Figure 2. Average compositions were calculated using mafic granulitic xenoliths since these xenoliths are believed to represent the lowermost continental crust. Rudnick & Fountain 1995
Active Continental Rifts 73 Ta 1.3           ppm Rudnick & Fountain 1995
Alaska Trench 73 Ta 0.522           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 3 or moderate. Plank & Langmuir 1998
Aleutian Basalts 73 Ta 0.25         12 ppm Average major and trace element values for Aleutian Arc Basalts given in weight percent and parts per million respectively. Kelemen et al. 2004
Aleutian Trench 73 Ta 0.545           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 1 or highest. Plank & Langmuir 1998
ALH 77005 Meteorite 73 Ta 33   7       ppb Mars elemental abundances as given by ALH77005 meteorite, which is a lherzolitic shergottite, as given in Lodders 1988. McSween, Jr. 2004 Lodders 1998
ALH 84001 Meteorite 73 Ta 32           ppb Mars elemental abundances as given by ALH84001 meteorite, which is an orthopyroxenite, as given in Lodders 1988. McSween, Jr. 2004 Lodders 1998
ALHA77081 Acapulcoite 73 Ta 50           ng/g Trace element compositional data on Acapulcoite ALHA77081. Mittlefehldt 2004 Schultz et al. 1982
Amazon River Particulates 73 Ta 2           µg/g Elemental particulates in major South American rivers. Averages for major elements are weighted according to the suspended load prior to the construction of dams, for trace elements the average contents are mean values. Martin & Meybeck 1979
Amphibolites 73 Ta 0.41         189 ppm Average of 165 subsamples and 24 composites. Gao et al. 1998
Andaman Trench 73 Ta 0.714           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 4 or low. Plank & Langmuir 1998
Andes Basalt 73 Ta 0.99         20 ppm Average major and trace element values for Andean Arc Basalts given in weight percent and parts per million respectively. Kelemen et al. 2004
Andesites 73 Ta 0.292         50 ppm Average Aleutian Andeiste major and minor element composition taken from Plank and Langmuir 1988. Andesite was used in this case to correct for the ash layer which was omitted from sampling of the upper unit of the Aleutian trench. Plank & Langmuir 1998 Plank & Langmuir 1988
Andesites 73 Ta 0.5           ppm Condie 1993
Andesites 73 Ta 0.4           ppm Condie 1993
Andesites 73 Ta 0.25         20 ppm Average major and trace element values from Primitive Aleutian Arc Andesites given by Kelemen et al. 2004. All major element oxide values are given in wt. % and trace elements in ppm. Kelemen et al. 2004
Andesites 73 Ta 0.5           ppm Condie 1993
Andesites 73 Ta 0.5           ppm Condie 1993
Andesites 73 Ta 0.53           ppm Condie 1993
Andesites 73 Ta 0.5           ppm Condie 1993
Andesites 73 Ta 0.35           ppm Condie 1993
Angrite Angra Dos Reis 73 Ta 350           ng/g Trace element compositional data on Angra dos Reis Angrite. Mittlefehldt 2004 Mittlefehldt & Lindstrom 1990
Angrite LEW 87051 73 Ta 110           ng/g Trace element compositional data on Angrite LEW 87051. Mittlefehldt 2004 Mittlefehldt & Lindstrom 1990
Antilles Trench   Nb/Ta 16.4         3   Plank & Langmuir 1998 Stolz et al. 1996
Archean Terrains 73 Ta 0.6           ppm Rudnick & Fountain 1995
Arenaceous Rocks 73 Ta 0.81         121 ppm Average of 110 subsamples and 11 composites. Gao et al. 1998
Arenaceous Rocks 73 Ta 0.88         2754 ppm Average of 2628 subsamples and 126 composites. Gao et al. 1998
Ashy Clay 73 Ta 0.299         4 ppm Average of 4 ashy clays after Peate et al. (1997) that have been diluted by the percentages of pure SiO2 and CaCO3 in the drill cores. The biogenic diluent is minor at 1.7% pure silica and 2.5% CaCO3 in this 85 m deep unit. Plank & Langmuir 1998
Australian Granite 73 Ta 2.9           ppm Analysis of A-type Lachlan Fold Belt Granite represented in major and minor element abundances as well as slected trace element ratios given by Martin 1995 but plotted in Figure 5 of Kemp & Hawkesworth 2004. Kemp & Hawkesworth 2004 Collins et al. 1982
Australian Granite 73 Ta 0.88         8 ppm Analysis of Oceanic Arc Granite represented in major and minor element abundances as well as slected trace element ratios given by Martin 1995 but plotted in Figure 5 of Kemp & Hawkesworth 2004. Kemp & Hawkesworth 2004 Whalen 1985
Barea Mesosiderite 73 Ta 54           ng/g Trace element compositional data on Barea Mesosiderite. Mittlefehldt 2004 Mason & Jarosewich 1973
Mittlefehldt in press
Basalts 73 Ta 4         3 ppm Average major and trace element values for Taiwanese Cenozoic continental sodic alkali basalt as well as selected elemental and isotopic ratios. Farmer 2004 Chung et al. 1995
Basalts 73 Ta 0.62         27 ppm Average major and trace element compositions for Western U.S. Sierra Nevada Low Ti Cenozoic continental potassic alkali basalt along with selected elemental and isotopic ratio abundances associated with these provinces. Farmer 2004 Farmer et al. 2002
Basalts 73 Ta 0.3         7 ppm Average major and trace element compositions for Italian Roman V.F. Low Ti Cenozoic continental potassic alkali basalt along with selected elemental and isotopic ratio abundances associated with these provinces. Farmer 2004 Conticelli et al. 1997
Basalts 73 Ta 0.88         10 ppm Average major and trace element compositions for Taiwanese Mt. Tsaoling Low Ti Cenozoic continental potassic alkali basalt along with selected elemental and isotopic ratio abundances associated with these provinces. Farmer 2004 Chung et al. 2001
Basalts 73 Ta 2.48         6 ppm Average major and trace element compositions for Chinese Tibetan Plateau Low Ti Cenozoic continental potassic alkali basalt along with selected elemental and isotopic ratio abundances associated with these provinces. Farmer 2004 Turner et al. 1996a
Basalts 73 Ta 0.3           ppm Condie 1993
Basalts 73 Ta 0.3           ppm Condie 1993
Basalts 73 Ta 0.27           ppm Condie 1993
Basalts 73 Ta 0.25           ppm Condie 1993
Basalts 73 Ta 0.25           ppm Condie 1993
Basalts 73 Ta 0.24           ppm Condie 1993
Basalts 73 Ta 0.23           ppm Condie 1993
Basalts 73 Ta 4.19         4 ppm Average major and trace element values for NE China Cenozoic continental sodic alkali basalt as well as selected elemental and isotopic ratios. Farmer 2004 Chung 1999
Basalts 73 Ta 1.24         13 ppm Average major and trace element compositions for Aegean Sea Dodecanese V.F. Low Ti Cenozoic continental potassic alkali basalt along with selected elemental and isotopic ratio abundances associated with these provinces. Farmer 2004 Robert et al. 1992
Basalts 73 Ta 3.77         8 ppm Average major and trace element values for SE Australian Dubbo V.F. Cenozoic continental sodic alkali basalt as well as selected elemental and isotopic ratios. Farmer 2004 Zhang & O'Reilly 1997
Basalts 73 Ta 2.64         9 ppm Average major and trace element values for Vietnamese Tholeiitic Basalts as well as selected elemental and isotopic ratios. Farmer 2004 Hoang & Flower 1998
Basalts 73 Ta 0.45         12 ppm Average major and trace element values for Taos Plateau, Rio Grande Rift Tholeiitic Basalts as well as selected elemental and isotopic ratios. Farmer 2004 Dungan et al. 1986
Basalts 73 Ta 7.36         16 ppm Average major and trace element compositions for African Virunga V.F. High Ti Cenozoic continental potassic alkali basalt along with selected elemental and isotopic ratio abundances associated with these provinces. Farmer 2004 Rogers et al. 1998
Basic Precambrian Granulites 73 Ta 1.6         25 ppm Shaw et al. 1986
Binda Eucrite 73 Ta 21           ng/g Trace element compositional data on Binda Eucrite. Mittlefehldt 2004 Barrat et al. 2000
McCarthy et al. 1973
Boninites 73 Ta 0.13         22 ppm Average major and trace element values from Primitive Arc Boninites (High-Mg Andesites) given by Kelemen et al. 2004. All major element oxide values are given in wt. % and trace elements in ppm. Kelemen et al. 2004
Brown Clay 73 Ta 0.527         4 ppm Average of 4 brown clays using DCP analyses. Plank & Langmuir 1998
Brown Clay 73 Ta 0.628         29 ppm The brown clay analyses where averaged over 10 m intervals and then averaged down-unit. Ta is calculated from the Nb/Ta = 15.2 ratio. Plank & Langmuir 1998
Carbonate 73 Ta 0.056         13 ppm The average Ca-carbonate in this unit is 80% based on Leg 67 shipboard carbonate bomb analyses. The analyses have been adjusted accordingly for 45% CaO. Ta is calculated from the Nb/Ta = 14.2 ratio. Plank & Langmuir 1998
Carbonate Turbidites   Nb/Ta 11.9   1.1     8   Plank & Langmuir 1998
Carbonate Turbidites 73 Ta 0.41         87 ppm Average of 87 Cenozoic carbonate turbidites in 100 m of the total of 500 m ODP section. Plank & Langmuir 1998
Carbonates 73 Ta 0.14         50 ppm Average of 45 subsamples and 5 composites. Gao et al. 1998
Carbonates 73 Ta 0.4         2038 ppm Average of 1922 subsamples and 116 composites. Gao et al. 1998
Cascade Basalt 73 Ta 0.48         17 ppm Average major and trace element values for Cascades Arc Basalt given in weight percent and parts per million respectively. Kelemen et al. 2004
Cascadia Trench 73 Ta 0.704           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 4 or low. Plank & Langmuir 1998
Central America Trench 73 Ta 0.127           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 1 or highest. Plank & Langmuir 1998
Central American Basalts 73 Ta 0.29         17 ppm Average major and trace element values for Central American Arc Basalts given in weight percent and parts per million respectively. Kelemen et al. 2004
Central East China Craton   Nb/Ta 17.4             Compostional estimate of the entire Central East China province. Calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
Central East China Craton   Nb/Ta 17.3             Compostional estimate of the entire Central East China province. Assuming that the lowermost crust is represented by the average mafic granulite from Archean high-grade terrains in Central East China (Appendix 1). Gao et al. 1998
Central East China Craton   Nb/Ta 17.9             Compostional estimate of the entire Central East China province. Gao et al. 1998
Central East China Craton   Nb/Ta 16.5             Compostional estimate of the entire Central East China province. Calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
Central East China Craton   Nb/Ta 19.5             Compostional estimate of the entire Central East China province. Gao et al. 1998
Central East China Craton   Nb/Ta 16.7             Compostional estimate of the entire Central East China province. Assuming that the lowermost crust is represented by the average worldwide mafic granulite xenolith using the median values of Rudnick & Fountain (1995). Gao et al. 1998
Central East China Craton   Nb/Ta 17.5             Compostional estimate of the entire Central East China province. Assuming that the lowermost crust is represented by the average mafic granulite from Archean high-grade terrains in Central East China (Appendix 1). Gao et al. 1998
Central East China Craton   Nb/Ta 14.7             Compostional estimate of the entire Central East China province. Assuming that the lowermost crust is represented by the average worldwide mafic granulite xenolith using the median values of Rudnick & Fountain (1995). Gao et al. 1998
Central East China Craton 73 Ta 0.6           ppm Compostional estimate of the entire Central East China province. Gao et al. 1998
Central East China Craton 73 Ta 0.53           ppm Compostional estimate of the entire Central East China province. Assuming that the lowermost crust is represented by the average worldwide mafic granulite xenolith using the median values of Rudnick & Fountain (1995). Gao et al. 1998
Central East China Craton 73 Ta 0.55           ppm Compostional estimate of the entire Central East China province. Average composition of granulite terrains. Gao et al. 1998
Central East China Craton 73 Ta 0.68           ppm Compostional estimate of the entire Central East China province. Includes sedimentary carbonates. Gao et al. 1998
Central East China Craton 73 Ta 0.62           ppm Compostional estimate of the entire Central East China province. Assuming that the lowermost crust is represented by the average worldwide mafic granulite xenolith (Rudnick & Fountain, 1995). Gao et al. 1998
Central East China Craton 73 Ta 0.63           ppm Compostional estimate of the entire Central East China province. Average compostion of granulite terrains and calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
Central East China Craton 73 Ta 0.58           ppm Compostional estimate of the entire Central East China province. Assuming that the lowermost crust is represented by the average mafic granulite from Archean high-grade terrains in Central East China (Appendix 1). Gao et al. 1998
Central East China Craton 73 Ta 0.55           ppm Compostional estimate of the entire Central East China province. Gao et al. 1998
Central East China Craton 73 Ta 0.52           ppm Compostional estimate of the entire Central East China province. Calculated according to 70% intermediate granulite plus 15% mafic granulite plus 15% metapelite from central East China (Appendix 1; for detailed explanation see text). Gao et al. 1998
Central East China Craton 73 Ta 0.63           ppm Average composition for Central East China. Assuming that the lowermost crust is represented by the average mafic granulite from Archean high-grade terrains in Central East China (Appendix 1). Gao et al. 1998
Central East China Craton 73 Ta 0.74           ppm Compostional estimate of the entire Central East China province. Calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
Chassigny Meteorite 73 Ta 20           ppb Mars elemental abundances as given by Chassigny meteorite (chassignite) as given in Lodders 1988. McSween, Jr. 2004 Lodders 1998
Chaunskij Mesosiderite 73 Ta 52           ng/g Trace element compositional data on Chaunskij Mesosiderite. Mittlefehldt 2004 Mittlefehldt in press
Petaev et al. 2000
Chert 73 Ta 0.182         4 ppm Average of 4 brown chert analyses. Due to the poor recovery of these notoriously hard chert beds, this chert section may be overdiluted by silica causing an underestimation of the geochemical abundances. The dilution factors have therefore been based on the down-core logging for SiO2 contents. Plank & Langmuir 1998
Chert 73 Ta 0.406         4 ppm Average of 4 brown chert analyses. Due to the poor recovery of these notoriously hard chert beds, this chert section may be overdiluted by silica causing an underestimation of the geochemical abundances. The dilution factors have therefore been based on the down-core logging for SiO2 contents. Plank & Langmuir 1998
Chert 73 Ta 0.41           ppm Compositional estimates of the second of four layers from the sediment column of DSDP Leg 129's Hole 801 according to the methods of Plank and Ludden 1992. Elliot et al. 1997
CI Chondrites   Nb/Ta 17.6             Selected ratios for C1 Chondrite averaged from various sources in an effort to compare and contrast values obtained by McDonough 1990 for spinel peridotite xenoliths and their relative associations with the composition of the Earth's Mantle. McDonough 1990 McDonough & Frey 1989
Sun & McDonough 1989
Sun 1982
CI Chondrites 73 Ta 13.6           ppb Based on measurements on 3 out of 5 carbonaceous chrondrites namely Orgueil, Ivuna and Alais. McDonough & Sun 1995
CI Chondrites 73 Ta 0.02           ppm Average calculated for volatile-free C1 chondrites after McDonough (1987). McDonough et al. 1992
CI Chondrites 73 Ta 14           ppb C1 Carbonaceous chondrite major and minor element compositions as given in Palme 1988. These values are given in an effort to accurately represent the C1 chondrites as based on an array of sources and derive a revised model for the composition of the Earth. McDonough & Sun 1995 Palme 1988
CI Chondrites 73 Ta 14.2   0.852       ppb Composition of the Primitive Mantle of the Earth as based on CI Chondritic major and trace element compositions from Chapter 1.03 Palme & Jones 2004 Treatise of Geochemistry. Palme & O'Neill 2004 Palme & Jones 2004
CI Chondrites 73 Ta -0.14   0.06         CI Meteorite derived solar system abundances of various elements. Palme & Jones 2004
CI Chondrites 73 Ta 0.0142   0.000852       ppm Abundance of elements in the solar system based off of Palme & Beer 1993 study of CI meteorites. Palme & Jones 2004 Palme & Beer 1993
Jochum et al. 2000
CI Chondrites 73 Ta 0.0142           ppm Abundance of elements in the solar system from Anders & Grevesse 1989 study of CI meteorites. Palme & Jones 2004 Anders & Grevesse 1989
CI Chondrites 73 Ta 14.2   0.26     2 ppb Mean C1 chondrite from atomic abundances based on C = 3.788E-3*H*A where C = concentration; H = atomic abundance and A = atomic weight. Values are not normalised to 100% Anders & Grevesse 1989
CI Chondrites 73 Ta 16           ppb C1 Carbonaceous chondrite major and minor element compositions as given in Wasson & Kallemeyn 1988. These values are given in an effort to accurately represent the C1 chondrites as based on an array of sources and derive a revised model for the composition of the Earth. McDonough & Sun 1995 Wasson & Kallemeyn 1988
Clastic Turbidites 73 Ta 0.704         28 ppm In this homogeneous turbidite unit 28 analyses were used to calculate an average by weighting interval height and lithology. Proportions of sand, silt and clay were estimated from core descriptions. Plank & Langmuir 1998
Colombia Trench 73 Ta 0.146           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 3 or moderate. Plank & Langmuir 1998
Congo River Particulates 73 Ta 1.1           µg/g Elemental particulates in major African rivers. Averages for major elements are weighted according to the suspended load prior to the construction of dams, for trace elements the average contents are mean values. Martin & Meybeck 1979
Continental Arc Andesite 73 Ta 0.45         83 ppm Average major and trace element values for Average Continental Arc Basalt given in weight percent and parts per million respectively. Kelemen et al. 2004
Continental Arc Andesite 73 Ta 0.85         22 ppm Average major and trace element values from Primitive Continental Arc Andesites given by Kelemen et al. 2004. All major element oxide values are given in wt. % and trace elements in ppm. Kelemen et al. 2004
Continental Arcs 73 Ta 0.6           ppm Lower crustal rocks are combined in proportions as indicated in Figure 2. Average compositions were calculated using mafic granulitic xenoliths since these xenoliths are believed to represent the lowermost continental crust. Rudnick & Fountain 1995
Continental Arcs 73 Ta 1.1           ppm Rudnick & Fountain 1995
Continental Crust   Be/Ta 2.7             Elemental ratios as found in the Continental Crust according to Rudnick and Gao 2003.  As in the text these values are used as comparisons to the Elemental ratios found in Primitive Upper Mantle from McDonough and Sun 1995. Salters & Stracke 2004
Continental Crust 73 Ta 0.8           µg/g Major and trace element compositional estimates of the Bulk Continental Crust given by Taylor and McLennan 1985 & 1995. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Taylor & McLennan 1985
Taylor & McLennan 1995
Continental Crust 73 Ta 0.7           µg/g Rudnick & Gao 2004
Continental Crust 73 Ta 1.1           ppm UCC = calculated from Nb/Ta = 17.5 (from international reference rocks) by Gladney et al. (1983); LCC = Rudnick & Presper (1990). Wedepohl 1995
Continental Crust 73 Ta 1.1           ppm Rudnick & Fountain 1995
Continental Crust 73 Ta 1           ppm Taylor & McLennan 1995
Continental Crust 73 Ta 4           ppm Simple average between the LCC and UCC estimates. The LCC is based on the mean values of estimates of the regional abundances of high metamorphic grade Precambrian rock types ad divided by SiO2 contents into ultrabasis, basic, intermediate and silica-rich (see Table 3); the UCC is given in Table 1. Shaw et al. 1986
Continental Crust 73 Ta 0.7           ppm Revised bulk continental crust (BCC) value calculated from the revised upper continental crust (UCC) as reported in Table 5. The middle and lower crust is given by Rudnick & Fountain (1995). Plank & Langmuir 1998
Continental Crust 73 Ta 1.1           ppm Major and minor element composition of the Continental Crust as based on the study by Wedepohl 1994. Major elements are given as Oxides whereas the minor elements are given in singularly in ppm. Rudnick & Fountain 1995 Wedepohl 1995
Continental Crust 73 Ta 2           µg/g Major and trace element compositional estimates of the Bulk Continental Crust given by Taylor 1964. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Taylor 1964
Continental Crust 73 Ta 0.6           µg/g Major and trace element compositional estimates of the Bulk Continental Crust given by Gao et al. 1998a. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Gao et al. 1998a
Continental Crust 73 Ta 1.1           µg/g Major and trace element compositional estimates of the Bulk Continental Crust given by Wedepohl 1995. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Wedepohl 1995
Continental Crust 73 Ta 0.7           µg/g Major and trace element compositional estimates of the Bulk Continental Crust given by Rudnick and Fountain 1995. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Rudnick & Fountain 1995
Continental Crust 73 Ta 0.7           µg/g Recommended composition of the Bulk Continental Crust where the total-crust composition is calculated according to the upper, middle and lower-crust compositions obtained in this study and corresponding weighing factors of 0.317, 0.296 and 0.388. The weighing factors are based on the layer thickness of the global continental crust, recalculated from crustal structure and areal proportion of various tectonic units given by Rudnick and Fountain 1995. Rudnick & Gao 2004 Rudnick & Fountain 1995
Continental Crust 73 Ta 1000           ppb Enrichment of elements in the bulk continental crust given by Rudnick & Gao from Chapter 3.1 of the Treatise on Geochemistry 2004. Palme & O'Neill 2004 Rudnick & Gao 2004
Continental Crust 73 Ta 0.7           ppm Major and minor element composition of the Bulk Crust of the Earth with selected trace element ratios as given by Rudnick and Gao 2004. Kemp & Hawkesworth 2004 Rudnick & Gao 2004
Continental Crust 73 Ta 4           µg/g Major and trace element compositional estimates of the Bulk Continental Crust given by Shaw et al. 1986. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Shaw et al. 1986
Continental Intraplate Xenoliths 73 Ta 0.007           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Ionov 1996
Continental Intraplate Xenoliths 73 Ta 0.001           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Bedini & Bodinier 1999
Continental Intraplate Xenoliths 73 Ta 0.04           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Ionov 1996
Continental Intraplate Xenoliths 73 Ta 6.65           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Ionov et al. 1997
Continental Intraplate Xenoliths 73 Ta 0.001           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Eggins et al. 1998
Continental Intraplate Xenoliths 73 Ta 0.002           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Bedini & Bodinier 1999
Continental Intraplate Xenoliths 73 Ta 0.002           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Bedini & Bodinier 1999
Continental Intraplate Xenoliths 73 Ta 2.79           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Gregoire et al. 2002
Continental Intraplate Xenoliths 73 Ta 0.041           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Eggins et al. 1998
Continental Intraplate Xenoliths 73 Ta 0.007           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Eggins et al. 1998
Continental Intraplate Xenoliths 73 Ta 0.0033           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Ionov 1996
Continental Intraplate Xenoliths 73 Ta 0.215           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Eggins et al. 1998
Continental Intraplate Xenoliths 73 Ta 0.37           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Ionov et al. 1997
Continental Intraplate Xenoliths 73 Ta 0.083           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Johnson et al. 1996
Continental Intraplate Xenoliths 73 Ta 0.0001           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Bedini & Bodinier 1999
Continental Intraplate Xenoliths 73 Ta 0.058           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Eggins et al. 1998
Continental Intraplate Xenoliths 73 Ta 0.12           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Bedini & Bodinier 1999
Continental Intraplate Xenoliths 73 Ta 1.33           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Glaser et al. 1999
Continental Intraplate Xenoliths 73 Ta 0.002           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Ionov 1996
Continental Shields & Platforms 73 Ta 1.1           ppm Rudnick & Fountain 1995
Continental Shields & Platforms 73 Ta 0.6           ppm Lower crustal rocks are combined in proportions as indicated in Figure 2. Average compositions were calculated using mafic granulitic xenoliths since these xenoliths are believed to represent the lowermost continental crust. Rudnick & Fountain 1995
Core 73 Ta 0           µg/g Compostioinal models for the bulk Earth, core and silicate Earth are modified after McDonough & Sun (1995). McDonough 1998
Cratonic Xenoliths 73 Ta 0.071           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004
Cratonic Xenoliths 73 Ta 40           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Gregoire et al. 2002
Cratonic Xenoliths 73 Ta 46           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Gregoire et al. 2002
Cratonic Xenoliths 73 Ta 90           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Gregoire et al. 2002
Cratonic Xenoliths 73 Ta 0.06           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Gregoire et al. 2002
Cratonic Xenoliths 73 Ta 0.01           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Gergoire et al. 2002
Cratonic Xenoliths 73 Ta 0.06           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004 Gregoire et al. 2002
Cratonic Xenoliths 73 Ta 0.039           ppm Representative trace element analyses of minerals from peridotite xenoliths from different lithologies and different regions. These minerals vary from garnet, cpx, and spinel to amphibole, phlogopite and carbonate and vary from being cratonic to 'off cratonic' generally from a region of continental intraplate xenoliths. Pearson et al. 2004
D'Orbigny Angrite 73 Ta 200           ng/g Trace element compositional data on D'Orbigny Angrite. Mittlefehldt 2004 Mittlefehldt et al. 2002
Depleted D-MORB basalts   Nb/Ta 15.19             Constant' ratios in MORB as taken from the D-MORB (Depleted MORB) compilation as explained in Salters and Stracke 2003.  This compliation of 232 ratio values represent one method of removing low degree melts from MORB data.  All values have gone thru a series of tests and must meet certain criteria to be added to the D-MORB compilation.  This in turn leads to better estimates of values for the Depleted Mantle. Salters & Stracke 2004
Depleted Mantle 73 Ta 0.0096     0.0082 0.0108   ppm Trace element composition of DMM (Depleted MORB Mantle) with minimum and maximum estimates based on assuming initiation of continuous depletion at 2.5Ga (min) and 3.5Ga (max). Workman & Hart 2005
Depleted Mantle 73 Ta 13.8   4.554       ppb Estimate for the concentrations in the Depleted Mantle of most of the elements of the Periodic Table.  Nb/Ta is the element ratio/constraint used to make this estimate. Salters & Stracke 2004
Depleted-Depleted MORB Mantle 73 Ta 0.0056           ppm Trace element composition of DDMM (Depleted Depleted MORB Mantle) in ppm. Workman & Hart 2005
Diatom Oozes & Clay 73 Ta 0.321         15 ppm Weighted average based on DCP analyses for 200 m of diatom oozes. Plank & Langmuir 1998
Diatome Clay 73 Ta 0.42         6 ppm Upper 240 m of a total section that is 335 m thick (Site 581) dominated by diatom clay. Plank & Langmuir 1998
Diatome Mud 73 Ta 0.354         6 ppm Based on smear slides an average of 35% biogenic opal (SiO2) has been estimated, which is consistent with 17 wt% biogenic opal estimated from shipboard logs. The 6 analyses have simply been averaged since the SiO2 content is consistently ~57%. Ta is calculated from the Nb/Ta = 14.2 ratio. Plank & Langmuir 1998
Diatome Ooze 73 Ta 0.391         4 ppm This ash-rich diatom ooze contains 50% diatoms and 7% ash particles. The individual analyses therefore have been diluted with 65% SiO2 based on an average 75% SiO2 in the diatoms. The analyses were further enriched by adding an average Aleutian andesite (Plank & Langmuir, 1988) to represent the ash layers in this section. Plank & Langmuir 1998
Diorite 73 Ta 1.46         260 ppm Average of 243 subsamples and 17 composites. Gao et al. 1998
DSDP/ODP Site 800 73 Ta 0.647           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 1 or highest. Plank & Langmuir 1998
DSDP/ODP Site 801 73 Ta 0.869           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 1 or highest. Plank & Langmuir 1998
DSDP/ODP Site 801 73 Ta 0.87           ppm Compositional estimates of Bulk Marianas sediment as observed from the sediment column of DSDP Hole 801. Values derived according to methods given in Plank and Ludden 1992. Elliot et al. 1997
E-MORB 73 Ta 0.77           ppm Compositie analyses on E-MORB glasses from the Mid-Atlantic Ridge as reported in the RidgePetDB database. Major and most trace elements for this E-type MORB are taken from the sample EW19309-004-002. Klein 2004 Lehnert 2000
Early Archean Upper Crust   La/Ta 41             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Early Archean Upper Crust   La/Ta 42             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Early Archean Upper Crust   Nb/Ta 12             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Early Archean Upper Crust   Nb/Ta 12             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Early Archean Upper Crust 73 Ta 0.7           ppm Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Early Archean Upper Crust 73 Ta 0.69           ppm Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Early Proterozoic Upper Crust   La/Ta 33             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Early Proterozoic Upper Crust   La/Ta 33             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Early Proterozoic Upper Crust   Nb/Ta 13             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Early Proterozoic Upper Crust   Nb/Ta 13             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Early Proterozoic Upper Crust 73 Ta 0.88           ppm Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Early Proterozoic Upper Crust 73 Ta 0.95           ppm Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
East China Craton 73 Ta 0.61           ppm Compostional estimate of East China. Assuming that the lowermost crust is represented by the average worldwide mafic granulite xenolith (Rudnick & Fountain, 1995). Gao et al. 1998
East China Craton 73 Ta 0.63           ppm Compostional estimate of East China. Assuming that the lowermost crust is represented by the average mafic granulite from Archean high-grade terrains in Central East China (Appendix 1). Gao et al. 1998
East Sunda Trench 73 Ta 0.693           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 1 or highest. Plank & Langmuir 1998
EET 84302 Acapulcoite 73 Ta 10           ng/g Trace element compositional data on achondrite EET84302 which is between Acapulcoite and lodranite. Mittlefehldt 2004 Weigel et al. 1999
Enriched-Depleted MORB Mantle 73 Ta 0.0159           ppm Trace element composition of EDMM (Enriched Depleted MORB Mantle) in ppm. Workman & Hart 2005
Estherville Mesosiderite 73 Ta 69           ng/g Trace element compositional data on Estherville Mesosiderite. Mittlefehldt 2004 Mittlefehldt in press
Simpson & Ahrens 1977
Felsic Archean Granulites 73 Ta 0.58 0.35       34 ppm Median values are used instead of average values in the model calculations to avoid outlyers of small sample populations. Rudnick & Fountain 1995
Felsic Granulites 73 Ta 0.4         137 ppm Average of 116 subsamples and 21 composites. Gao et al. 1998
Felsic Post-Archean Granulites 73 Ta 0.8 0.5       1 ppm Median values are used instead of average values in the model calculations to avoid outlyers of small sample populations. Calculated assuming Nb/Ta = 16. Rudnick & Fountain 1995
Felsic Volcanics 73 Ta 0.8           ppm Condie 1993
Felsic Volcanics 73 Ta 1           ppm Condie 1993
Felsic Volcanics 73 Ta 0.88         972 ppm Average of 895 subsamples and 77 composites. Gao et al. 1998
Felsic Volcanics 73 Ta 1.3           ppm Condie 1993
Felsic Volcanics 73 Ta 1.6           ppm Condie 1993
Felsic Volcanics 73 Ta 1.7           ppm Condie 1993
Felsic Volcanics 73 Ta 1.2           ppm Condie 1993
Felsic Volcanics 73 Ta 1.4           ppm Condie 1993
Frankfort Howardites 73 Ta 40           ng/g Trace element compositional data on Frankfort Howardite. Mittlefehldt 2004 McCarthy et al. 1972
Palme et al. 1978
Fresh Mid-Ocean Ridge Basalts   Nb/Ta 14.73             Constant' ratios in MORB as taken from the 'All MORB' data set according to Salters and Stracke 2003.  The 'All MORB' data set is a compilation of 639 sample ratios to represent the MORB composition.  In using these values and applying a simple mathematical process order to remove the outliers, which are found by calculating the upper and lower quartile range, then applying the outlier criterion (explained in Salters and Stracke 2003 pg.7).  In addition to this method all the samples with La > 5 ppm were rejected.  This, much like with the tests and criteria of the D-MORB values, is a method of removing low degree melts from the MORB data in order to come closer to a value for Depleted Mantle.  Salters & Stracke 2004
Fresh Mid-Ocean Ridge Basalts 73 Ta 0.31         28 ppm Average major and trace element values for Primitive MORB given in weight percent and parts per million respectively. Kelemen et al. 2004
Ganges River Particulates 73 Ta 1.25           µg/g Elemental particulates in major Asian rivers. Averages for major elements are weighted according to the suspended load prior to the construction of dams, for trace elements the average contents are mean values. Martin & Meybeck 1979
Gibson Lodranite 73 Ta 14           ng/g Trace element compositional data on Gibson Lodranite. Mittlefehldt 2004 Weigel et al. 1999
Granites 73 Ta 0.45         8 ppm Analysis of Glenelg River Complex Leucogranite represented in major and minor element abundances as well as slected trace element ratios given by Martin 1995 but plotted in Figure 5 of Kemp & Hawkesworth 2004. Kemp & Hawkesworth 2004 Kemp 2001
Granites 73 Ta 0.7         402 ppm Average of 369 subsamples and 33 composites. Gao et al. 1998
Granites 73 Ta 1.8         1226 ppm Average of 1140 subsamples and 86 composites. Gao et al. 1998
Granites 73 Ta 0.93           ppm Analysis of Archean Calc-Alkaline Type 1 & 2 Granite represented in major and minor element abundances as well as slected trace element ratios given by Martin 1995 but plotted in Figure 5 of Kemp & Hawkesworth 2004. Kemp & Hawkesworth 2004 Sylvester 1995
Granites 73 Ta 1.7           ppm Condie 1993
Granites 73 Ta 1.5           ppm Condie 1993
Granites 73 Ta 1           ppm Condie 1993
Granulites 73 Ta 0.52 0.25       50 ppm Average of granulite facies terrains. Rudnick & Presper 1990
Granulites 73 Ta 1.55         16 ppm Average of granulite facies terrains. Rudnick & Presper 1990
Granulitic Xenolites 73 Ta 0.6         14 ppm Average of granulite facies xenoliths. Rudnick & Presper 1990
Graywackes 73 Ta 0.9           ppm Condie 1993
Graywackes 73 Ta 0.7           ppm Condie 1993
Graywackes 73 Ta 0.85           ppm Condie 1993
Graywackes 73 Ta 0.8           ppm Condie 1993
Graywackes 73 Ta 0.8           ppm Condie 1993
Graywackes 73 Ta 0.76           ppm Condie 1993
Green Clay 73 Ta 0.634         3 ppm Silty clay (37.5%), clay (50%) and nannofossil ooze (12.5%) make up this section. Two analyses have been made for silty clay and the clay lithologies, whereas the ooze is assumed to contain 56% CaO, 44% CO2 and 1000 ppm Sr. Plank & Langmuir 1998
Hydrothermal Sediment 73 Ta 0.155         4 ppm Average of 4 hydrothermal sediments or clays using DCP analyses. Estimated value. Plank & Langmuir 1998
Ibitira Eucrite 73 Ta 153           ng/g Trace element compositional data on Ibitira Eucrite. Mittlefehldt 2004 Jarosewich 1990
Barrat et al. 2000
Interior North China Craton 73 Ta 0.42           ppm Compostional estimate of the interior of the North China craton. Average compostion of granulite terrains. Gao et al. 1998
Interior North China Craton 73 Ta 0.49           ppm Compostional estimate of the interior of the North China craton. Gao et al. 1998
Interior North China Craton 73 Ta 0.56           ppm Compostional estimate of the interior of the North China craton. Average compostion of granulite terrains and calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
Interior North China Craton 73 Ta 0.68           ppm Compostional estimate of the interior of the North China craton. Calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
Interior North China Craton 73 Ta 0.61           ppm Compostional estimate of the interior of the North China craton. Includes sedimentary carbonates. Gao et al. 1998
Interlayerd Clay & Chert 73 Ta 0.07         2 ppm Bottom 65 m of a total section that is 335 m thick (Site 581) dominated by interlayered clay and chert. Plank & Langmuir 1998
Interlayered Chert & Limestone 73 Ta 0.187         5 ppm Average of 5 chert and limestone analyses. Due to the poor recovery of these notoriously hard chert beds, this chert section may be overdiluted by silica causing an underestimation of the geochemical abundances. The dilution factors have therefore been based on the down-core logging for SiO2 contents. The logging data was also used to determine the average CaO as calcium carbonate to dilute all elements (except Sr) accordingly. Plank & Langmuir 1998
Interlayered Clay & Chert 73 Ta 0.483         12 ppm This interval is estimated to be 25% chert based on core descriptions. Average clay from 30-58 m depth is diluted with 25% chert at 100% Si. Average of 12 cherts and clays using DCP analyses. Ta was calculated from Nb/Ta = 15.3 based on unpublished ICP-MS data. Plank & Langmuir 1998
Intermediate Granulites 73 Ta 0.4         136 ppm Average of 115 subsamples and 21 composites. Gao et al. 1998
Intermediate Mafic Archean Granulites 73 Ta 0.62 0.63       5 ppm Median values are used instead of average values in the model calculations to avoid outlyers of small sample populations. Rudnick & Fountain 1995
Intermediate Mafic Granulitic Xenolites 73 Ta 0.6         1 ppm Median values are used instead of average values in the model calculations to avoid outlyers of small sample populations. Calculated assuming Nb/Ta = 16. Rudnick & Fountain 1995
Intermediate Mafic Post-Archean Granulites 73 Ta 1.4 1.4       4 ppm Median values are used instead of average values in the model calculations to avoid outlyers of small sample populations. Rudnick & Fountain 1995
Intermediate Precambrian Granulites 73 Ta 1.6         26 ppm Shaw et al. 1986
Island Arc Andesite 73 Ta 0.08         4 ppm Average major and trace element values from Primitive Oceanic Arc Andesites given by Kelemen et al. 2004. All major element oxide values are given in wt. % and trace elements in ppm. Kelemen et al. 2004
Island Arc Andesite 73 Ta 0.24         64 ppm Average major and trace element values for Average Oceanic Arc Basalt given in weight percent and parts per million respectively. Kelemen et al. 2004
Izu-Bonin Trench 73 Ta 0.239           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 4 or low. Plank & Langmuir 1998
Japan Trench 73 Ta 0.319           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 2 or high. Plank & Langmuir 1998
Java Trench 73 Ta 0.848           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 1 or highest. Plank & Langmuir 1998
Kamchatka Basalt 73 Ta 0.13         22 ppm Average major and trace element values for Kamchatka Arc Basalts given in weight percent and parts per million respectively. Kelemen et al. 2004
Kamchatka Trench 73 Ta 0.133           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 3 or moderate. Plank & Langmuir 1998
Kapoeta Howardites 73 Ta 100           ng/g Trace element compositional data on Kapoeta Howardite. Mittlefehldt 2004 Wanke et al. 1972
Kerm Trench 73 Ta 651           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 4 or low. Plank & Langmuir 1998
Kermadec Basalts 73 Ta 0.26         10 ppm Average major and trace element values for Kermadec Arc Basalts given in weight percent and parts per million respectively. Kelemen et al. 2004
Kimberlite 73 Ta 15.72         22 ppm Average major and trace element composition and selected isotopic ratio data for Koidu Kimberlites from Sierra Leone. Farmer 2004 Taylor et al. 1994
Komatiites 73 Ta 0.05           ppm Condie 1993
Kuriles Trench 73 Ta 0.319           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 2 or high. Plank & Langmuir 1998
Late Archean Upper Crust   La/Ta 43             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Late Archean Upper Crust   La/Ta 42             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Late Archean Upper Crust   Nb/Ta 12             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Late Archean Upper Crust   Nb/Ta 12             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Late Archean Upper Crust 73 Ta 0.69           ppm Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Late Archean Upper Crust 73 Ta 0.69           ppm Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Late Proterozoic Upper Crust   La/Ta 32             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Late Proterozoic Upper Crust   La/Ta 32             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Late Proterozoic Upper Crust   Nb/Ta 13             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Late Proterozoic Upper Crust   Nb/Ta 13             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Late Proterozoic Upper Crust 73 Ta 0.97           ppm Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Late Proterozoic Upper Crust 73 Ta 0.9           ppm Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Lesser Antilles Basalt 73 Ta 0.26         11 ppm Average major and trace element values for Lesser Antilles Arc Basalts given in weight percent and parts per million respectively. Kelemen et al. 2004
Lower Continental Crust 73 Ta 0.84           ppm Wedepohl 1995
Lower Continental Crust 73 Ta 2           ppm Based on the mean values of estimates of the regional abundances of high metamorphic grade Precambrian rock types ad divided by SiO2 contents into ultrabasis, basic, intermediate and silica-rich (see Table 3). Shaw et al. 1986
Lower Continental Crust 73 Ta 0.6           ppm Major and minor element composition of the Lower Crust of the Earth with selected trace element ratios as given by Rudnick and Gao 2004. Kemp & Hawkesworth 2004 Rudnick & Gao 2004
Lower Continental Crust 73 Ta 0.3           µg/g Major and trace element compositional estimates of the lower continental crust as given by Liu et al. 2001 using lower crustal xenoliths from Hannuoba, North China Craton. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Liu et al. 2001
Lower Continental Crust 73 Ta 0.5           µg/g Major and trace element compositional estimates of the lower continental crust as given by Rudnick and Presper 1990 using median worldwide lower crustal xenoliths. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Rudnick & Presper 1990
Lower Continental Crust 73 Ta 1.3           µg/g Major and trace element compositional estimates of the lower continental crust as given by Shaw et al. 1994 using Kapuskasing Structural Zone granulites. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Shaw et al. 1994
Lower Continental Crust 73 Ta 0.5           µg/g Major and trace element compositional estimates of the lower continental crust as given by Condie and Selverstone 1999 using lower crustal xenoliths from the four corners region, Colorado Plateu, USA. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Condie & Selverstone 1999
Lower Continental Crust 73 Ta 2.1           µg/g Major and trace element compositional estimates of the lower continental crust as given by Villaseca et al. 1999 using lithologic proportions of lover crustal xenoliths from Central Spain. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Villaseca et al. 1999
Lower Continental Crust 73 Ta 0.7           µg/g Major and trace element compositional estimates of the lower continental crust as given by Taylor and McLennan 1985, 1995 using average lower crustal abundances. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Taylor & McLennan 1985
Taylor & McLennan 1995
Lower Continental Crust 73 Ta 0.6           µg/g Major and trace element compositional estimates of the lower continental crust as given by Rudnick and Fountain 1995 using global average seismic velocities and granulites. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Rudnick & Fountain 1995
Lower Continental Crust 73 Ta 0.6           µg/g Recommended composition of the Lower Continental crust as given by various sources. Major element oxides are given in wt.% and trace element concentrations are given in either ng/g or ¿g/g. Rudnick & Gao 2004 Rudnick & Fountain 1995
Lower Continental Crust 73 Ta 0.8           µg/g Major and trace element compositional estimates of the lower continental crust as given by Wedepohl 1995 using lower crust in Western Europe derived from siesmic data and granulite xenolith composition. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Wedepohl 1995
Lower Continental Crust 73 Ta 0.6           µg/g Major and trace element compositional estimates of the lower continental crust as given by Gao et al. 1998a using seismic velocities and granulite data from the North China craton. Major element oxides are given in wt.% and trace elements in either ng/g or ¿g/g. Rudnick & Gao 2004 Gao et al. 1998a
Lower Continental Crust 73 Ta 0.6           ppm Rudnick & Fountain 1995
Lower Continental Crust 73 Ta 0.6           ppm Taylor & McLennan 1995
Luzon Basalt 73 Ta 0.16         5 ppm Average major and trace element values for Luzon Arc Basalts given in weight percent and parts per million respectively. Kelemen et al. 2004
MAC 88177 Lodranite 73 Ta 14           ng/g Trace element compositional data on Lodranite MAC 88177. Mittlefehldt 2004 Weigel et al. 1999
Macibini Eucrites 73 Ta 180           ng/g Trace element compositional data on Macibini Eucrite. Mittlefehldt 2004 McCarthy et al. 1973
Buchanan et al. 2000b
Mafic Archean Granulites 73 Ta 0.3 0.2       8 ppm Median values are used instead of average values in the model calculations to avoid outlyers of small sample populations. Rudnick & Fountain 1995
Mafic Granulites 73 Ta 0.65         128 ppm Average of 93 subsamples and 35 composites. Gao et al. 1998
Mafic Granulitic Xenolites 73 Ta 0.55 0.5       18 ppm Median values are used instead of average values in the model calculations to avoid outlyers of small sample populations. Rudnick & Fountain 1995
Mafic Intrusions 73 Ta 0.72         308 ppm Average of 276 subsamples and 32 composites. Gao et al. 1998
Mafic Post-Archean Granulites 73 Ta 0.6 0.2       12 ppm Median values are used instead of average values in the model calculations to avoid outlyers of small sample populations. Rudnick & Fountain 1995
Makran Trench 73 Ta 0.925           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 3 or moderate. Plank & Langmuir 1998
Malvern Howardites 73 Ta 110           ng/g Trace element compositional data on Malvern Howardite. Mittlefehldt 2004 Palme et al. 1978
Manganese Nodules 73 Ta 10           ppm Average concentrations of various elements found in deep sea Manganese nodules.  Sea salt components are subtracted assuming all chloride is of seawater origin. Li 1991 Baturin 1988
Marianas Basalt 73 Ta 0.14         12 ppm Average major and trace element values for Marianas Arc Basalts given in weight percent and parts per million respectively. Kelemen et al. 2004
Marianas Trench 73 Ta 0.758           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 1 or highest. Plank & Langmuir 1998
Marine Pelagic Clay 73 Ta 1           ppm Average concentrations for various elements enriched in Oceanic Pelagic Clays.  Compared to the element values of Shales, the Pelagic Clays are relatively similar with few exceptions.   All sea salt components are subtracted from the sample analysis assuming all chloride is of seawater origin. Li 1991 Turekian & Wedepohl 1961
Marine Pelagic Clay 73 Ta 1           ppm Average concentrations of elements in oceanic pelagic clays.  The elemental values found in the Pelagic clays give good indications on river input of elements to the oceans.  From river sources to mid oceanic ridge sinks this is also a good indicator of atmospheric conditions for varying periods of world history.   Li 1982 Turekian & Wedepohl 1961
Brewer 1975

Marine Shales 73 Ta 0.8           ppm Average concentrations of various elements in shales, note that the values are within a factor of two or better as compared to Oceanic Pelagic Clays with a few exceptions.  The exceptions, as far as this reference is concerned, are not critical and any conclusions drawn are applicable to both Oceanic Pelagic Clays and Shales.  Li 1991 Turekian & Wedepohl 1961
Mavic Volcanics 73 Ta 1.04         632 ppm Average of 538 subsamples and 49 composites. Gao et al. 1998
Mekong River Particulates 73 Ta 1.35           µg/g Elemental particulates in major Asian rivers. Averages for major elements are weighted according to the suspended load prior to the construction of dams, for trace elements the average contents are mean values. Martin & Meybeck 1979
Mesozoic & Cenozoic Extensions 73 Ta 1.2           ppm Rudnick & Fountain 1995
Mesozoic & Cenozoic Extensions 73 Ta 0.8           ppm Lower crustal rocks are combined in proportions as indicated in Figure 2. Average compositions were calculated using mafic granulitic xenoliths since these xenoliths are believed to represent the lowermost continental crust. Rudnick & Fountain 1995
Mesozoic & Cenozoic Orogens 73 Ta 1.2           ppm Rudnick & Fountain 1995
Mesozoic & Cenozoic Orogens 73 Ta 0.8           ppm Lower crustal rocks are combined in proportions as indicated in Figure 2. Average compositions were calculated using mafic granulitic xenoliths since these xenoliths are believed to represent the lowermost continental crust. Rudnick & Fountain 1995
Mesozoic & Cenozoic Upper Crust   La/Ta 28             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Mesozoic & Cenozoic Upper Crust   La/Ta 28             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Mesozoic & Cenozoic Upper Crust   Nb/Ta 13             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Mesozoic & Cenozoic Upper Crust   Nb/Ta 13             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Mesozoic & Cenozoic Upper Crust 73 Ta 0.96           ppm Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Mesozoic & Cenozoic Upper Crust 73 Ta 0.9           ppm Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Metafelsic Volcanics 73 Ta 0.56         41 ppm Average of 38 subsamples and 3 composites. Gao et al. 1998
Metalliferous Clay 73 Ta 0.867         12 ppm Average of 12 metalliferous clays between 10-30 m depth using DCP analyses. Plank & Langmuir 1998
Metapelitic Granulitic Xenolites 73 Ta 1.3 1       15 ppm Median values are used instead of average values in the model calculations to avoid outlyers of small sample populations. Rudnick & Fountain 1995
Mexico Trench 73 Ta 0.675           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 2 or high. Plank & Langmuir 1998
Middle Continental Crust 73 Ta 0.55           µg/g Major and Minor element compositional estimates of the Middle Continental crust as given by Gao et al. 1998a. Major element oxides are given in wt.% and trace elements abundances are given in ¿g/g or ng/g. Rudnick & Gao 2004 Gao et al. 1998
Middle Continental Crust 73 Ta 0.6           µg/g Major and Minor element compositional estimates of the Middle Continental crust as given by Rudnick and Fountain 1995. Major element oxides are given in wt.% and trace elements abundances are given in ¿g/g or ng/g. Rudnick & Gao 2004 Rudnick & Fountain 1995
Middle Continental Crust 73 Ta 1.8           µg/g Major and Minor element compositional estimates of the Middle Continental crust as given by Shaw et al. 1994. Major element oxides are given in wt.% and trace elements abundances are given in ¿g/g or ng/g. Rudnick & Gao 2004 Shaw et al. 1994
Middle Continental Crust 73 Ta 0.6   0.04       µg/g Major and Minor element compositional estimates of the Middle Continental crust as given by This Study (Rudnick and Gao 2004). Major element oxides are given in wt.% and trace elements abundances are given in ¿g/g or ng/g. Rudnick & Gao 2004
Middle Continental Crust 73 Ta 0.6           ppm Major and minor element composition of the Middle Crust of the Earth with selected trace element ratios as given by Rudnick and Gao 2004. Kemp & Hawkesworth 2004 Rudnick & Gao 2004
Middle Continental Crust 73 Ta 0.6           ppm Rudnick & Fountain 1995
Middle Proterozoic Upper Crust   La/Ta 32             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Middle Proterozoic Upper Crust   La/Ta 33             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Middle Proterozoic Upper Crust   Nb/Ta 13             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Middle Proterozoic Upper Crust   Nb/Ta 13             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Middle Proterozoic Upper Crust 73 Ta 0.86           ppm Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Middle Proterozoic Upper Crust 73 Ta 0.94           ppm Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Moore County Eucrite 73 Ta 30           ng/g Trace element compositional data on Moore County Eucrite. Mittlefehldt 2004 Barrat et al. 2000
McCarthy et al. 1973
N-MORB 73 Ta 0.309           ppm Analyses on N-MORB from the Mid-Cayman Rise. Glass compositions reported in ReidgePetDB for sample KNO0054-027-005 then augmented with BA, V and Y data on a similar sample reported by Thompson et al. 1980 and the sole isotopic analysis of a Mid-Cayman rise basalt from RidgePetDB. Klein 2004 Thompson et al. 1980
N-MORB 73 Ta 0.203           ppm Analyses on N-MORB from the Northern section of the East Pacific Rise as reported by Niu et al. 1999. Klein 2004 Niu et al. 1999
N-MORB 73 Ta 0.13           ppm Compositie analyses on N-MORB glasses from the Mid-Atlantic Ridge as reported in the RidgePetDB database. Major and most trace elements for this N-type MORB are taken from the sample EW19309-012-00. Klein 2004 Lehnert 2000
N-MORB 73 Ta 0.192   0.106     26 ppm Trace element average abundances for N-MORB as taken from analysis of 26 fresh MORB glasses defined N-type by the light-REE depletion.  These values were originally measured by Jochum et al. 1988. All standard deviations were calculated from percent values given in Hofmann 1988 (Table 1). Hofmann 1988 Jochum et al. 1988
Nakhla Meteorite 73 Ta 90           ppb Mars elemental abundances as given by Nakhla meteorite (nakhlite) as given in Lodders 1988. McSween, Jr. 2004 Lodders 1998
Nankai Trench 73 Ta 1.008           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 1 or highest. Plank & Langmuir 1998
Nanno Ooze 73 Ta 0.05         2 ppm Based on the nanno ooze of the nearby Site 320 (Hole et al., 1984) since no geochemical data exists for Site 321. Plank & Langmuir 1998
Nano Ooze 73 Ta 0.135         4 ppm Average of 4 nanno oozes after Peate et al. (1997) that have been diluted by the percentages of pure CaCO3 in the drill cores. The biogenic diluent is 28% CaCO3 in this 114 m deep unit. The average was calculated after renormalizing the analyses on a CaCO3-free basis followed by the dilution appropriate for these drill cores. Core estimates have been weigthed by the height of the drilled intervals. Plank & Langmuir 1998
New Hebrides Islands 73 Ta 0.16         6 ppm Average major and trace element values for New Hebrides Arc Basalts given in weight percent and parts per million respectively. Kelemen et al. 2004
North American Shale Composite (NASC) 73 Ta 1.1           ppm Major oxide and minor element compositions for North American Shale Composite. No source reference found in text.  Condie 1993
North Antilles Trench 73 Ta 1.118           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 2 or high. Plank & Langmuir 1998
North Qinling Belt in China 73 Ta 1.15           ppm Compostional estimate of the North Qinling orogenic belt. Average composition of granulite terrains. Gao et al. 1998
North Qinling Belt in China 73 Ta 1           ppm Compostional estimate of the Northern Qinling orogenic belt. Average compostion of granulite terrains and calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
North Qinling Belt in China 73 Ta 1.31           ppm Compostional estimate of the North Qinling orogenic belt. Calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
North Qinling Belt in China 73 Ta 1.2           ppm Compostional estimate of the North Qinling orogenic belt. Includes sedimentary carbonates. Gao et al. 1998
North Qinling Belt in China 73 Ta 0.66           ppm Compostional estimate of the North Qinling orogenic belt. The middle crust of the North Qinling belt is assumed to consist of the underthrusted South Qinling middle crust (see text for explanation). Gao et al. 1998
Nuevo Laredo Eucrite 73 Ta 178           ng/g Trace element compositional data on Nuevo Laredo Eucrites. Mittlefehldt 2004 Warren & Jerde 1987
Oceanic Plateaus 73 Ta 22.86           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Curacao locality, sample CUR14. Values taken from Kerr et al. 1996b. Kerr 2004 Kerr et al. 1996
Oceanic Plateaus 73 Ta 21.96           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Gorgona locality, sample GOR94-35. Values taken from unpublished information. Kerr 2004
Oceanic Plateaus 73 Ta 0.54           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Kerguelen Plateau ODP site 738, sample 34-1 and 88-92. Values taken from Mahoney et al. 1995. Kerr 2004 Mahoney et al. 1995
Oceanic Plateaus 73 Ta 0.58           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Ecuador locality, sample EQ1. Values taken from Reynaud et al. 1999. Kerr 2004 Reynaud et al. 1999
Oceanic Plateaus 73 Ta 5.51           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Kerguelen Plateau ODP site 738, sample 34-1 and 88-92. Values taken from Mahoney et al. 1995. Kerr 2004 Mahoney et al. 1995
Oceanic Plateaus 73 Ta 7.43           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Ontong-Java Plateau ODP site 807, sample 88-3 and 76-79. Values taken from Mahoney et al. 1993a. Kerr 2004 Mahoney et al. 1993
Oceanic Plateaus 73 Ta 6.77           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Colombia locality, sample SDB18. Values taken from Kerr et al. 1997 and Hauff et al. 2000b. Kerr 2004 Kerr et al. 1997
Hauff et al. 2000
Oceanic Plateaus 73 Ta 0.34           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Ontong-Java Plateau ODP site 807, sample 75-4 and 46-48. Values taken from Mahoney et al. 1993a. Kerr 2004 Mahoney et al. 1993
Oceanic Plateaus 73 Ta 0.3           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Colombia locality, sample SDB18. Values taken from Kerr et al. 1997 and Hauff et al. 2000b. Kerr 2004 Kerr et al. 1997
Hauff et al. 2000
Oceanic Plateaus 73 Ta 0.2           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Ontong-Java Plateau ODP site 807, sample 88-3 and 76-79. Values taken from Mahoney et al. 1993a. Kerr 2004 Mahoney et al. 1993
Oceanic Plateaus 73 Ta 8.03           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Ontong-Java Plateau Santa Isabel locality, sample I96. Values taken from Tejada et al. 1996. Kerr 2004 Tejada et al. 1996
Oceanic Plateaus 73 Ta 5.78           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Colombia locality, sample VIJ1. Values taken from Kerr et al. 1997 and Hauff et al. 2000b. Kerr 2004 Kerr et al. 1997
Hauff et al. 2000
Oceanic Plateaus 73 Ta 0.48           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Colombia locality, sample VIJ1. Values taken from Kerr et al. 1997 and Hauff et al. 2000b. Kerr 2004 Kerr et al. 1997
Hauff et al. 2000
Oceanic Plateaus 73 Ta 7.3           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Ontong-Java Plateau Maliata locality, sample SG1. Values taken from Tejada et al. 2002. Kerr 2004 Tejada et al. 2002
Oceanic Plateaus 73 Ta 11.55           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Colombia locality, sample COL472. Values taken from Kerr et al. 2002. Kerr 2004 Kerr et al. 2002
Oceanic Plateaus 73 Ta 7.47           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Kerguelen Plateau ODP site 747, sample 16-5 and 103-6.  Information taken from Salters et al. 1992. Kerr 2004 Salters et al. 1992
Oceanic Plateaus 73 Ta 0.35           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Ontong-Java Plateau Maliata locality, sample SG1. Values taken from Tejada et al. 2002. Kerr 2004 Tejada et al. 2002
Oceanic Plateaus 73 Ta 7.45           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Ontong-Java Plateau Maliata locality, sample ML407. Values taken from Tejada et al. 2002. Kerr 2004 Tejada et al. 2002
Oceanic Plateaus 73 Ta 6.74           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Ontong-Java Plateau ODP site 807, sample 75-4 and 46-48. Values taken from Mahoney et al. 1993a. Kerr 2004 Mahoney et al. 1993
Oceanic Plateaus 73 Ta 0.46           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Kerguelen Plateau ODP site 747, sample 16-5 and 103-6.  Information taken from Salters et al. 1992. Kerr 2004 Salters et al. 1992
Oceanic Plateaus 73 Ta 7.54           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Kerguelen Plateau ODP site 748, sample 79-6 and 90-4.  Information taken from Salters et al. 1992. Kerr 2004 Salters et al. 1992
Oceanic Plateaus 73 Ta 8.6           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Curacaolocality, sample CUR20. Values taken from Kerr et al. 1996b. Kerr 2004 Kerr et al. 1996
Oceanic Plateaus 73 Ta 9.08           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Kerguelen Plateau ODP site 748, sample 79-6 and 90-4.  Information taken from Salters et al. 1992. Kerr 2004 Salters et al. 1992
Oceanic Plateaus 73 Ta 7.22           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Kerguelen Plateau ODP site 749, sample 15-5 and 125-7.  Information taken from Salters et al. 1992. Kerr 2004 Salters et al. 1992
Oceanic Plateaus 73 Ta 0.25           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Ontong-Java Plateau Maliata locality, sample ML407. Values taken from Tejada et al. 2002. Kerr 2004 Tejada et al. 2002
Oceanic Plateaus 73 Ta 18.25           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Gorgona locality, sample GOR160. Values taken from Aitken & Echeverria, Dupre & Echeverria and Jochum et al. 1991. Kerr 2004 Aitken & Echeverria 1984
Dupre & Echeverria 1984
Jochum et al. 1991
Oceanic Plateaus 73 Ta 8.58           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau DSDP site 150, sample 11-2 and 63-67. Values taken from Hauff et al. 2000b. Kerr 2004 Hauff et al. 2000
Oceanic Plateaus 73 Ta 0.4           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Kerguelen Plateau ODP site 749, sample 15-5 and 125-7.  Information taken from Salters et al. 1992. Kerr 2004 Salters et al. 1992
Oceanic Plateaus 73 Ta 8.36           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Kerguelen Plateau ODP site 750, sample 17-3 and 23-26.  Information taken from Salters et al. 1992. Kerr 2004 Salters et al. 1992
Oceanic Plateaus 73 Ta 8.65           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Gorgona locality, sample GOR117. Values taken from Aitken & Echeverria, Dupre & Echeverria and Jochum et al. 1991. Kerr 2004 Aitken & Echeverria 1984
Dupre & Echeverria 1984
Jochum et al. 1991
Oceanic Plateaus 73 Ta 0.23           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau DSDP site 150, sample 11-2 and 63-67. Values taken from Hauff et al. 2000b. Kerr 2004 Hauff et al. 2000
Oceanic Plateaus 73 Ta 8.96           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Carribean-Colombian Oceanic Plateau Ecuador locality, sample EQ1. Values taken from Reynaud et al. 1999. Kerr 2004 Reynaud et al. 1999
Oceanic Plateaus 73 Ta 0.19           ppm Representative analyses of Cretaceous oceanic plateau lavas from the Kerguelen Plateau ODP site 750, sample 17-3 and 23-26.  Information taken from Salters et al. 1992. Kerr 2004 Salters et al. 1992
Oceans Surface water 73 Ta         2.5   ng/kg Surface or near-surface concentratio. Where possible data is from the Pacific ocean that shows the greates variations; otherwhise data is from the Atlantic ocean. Quinby-Hunt & Turekian 1983 Schutz & Turekian 1965
ODP/DSDP Site 417/418 73 Ta 0.097           ppm This analysis represents a super-composite for DSDP Sites 417 and 418 combined. The recipe for this composite can be found in Appendix 1. Staudigel et al. 1996
Orangeite 73 Ta 8.5         114 ppm Average major and trace element composition and selected isotopic data for Orangeites from Swartuggens, Finisch, Bellsbank and Sover kimberlite localities in South Africa. Farmer 2004 Mitchell 1995
Orgueil Chondrite 73 Ta 17         1 ppb Solar system abundances of major and minor elements as based on studies from the Orgueil Meteorite. Abundances in the Orgueil meteorite are adequately close to the C1 chondrite mean except for REE, in which case other studies will yield more preferable results Anders & Ebihara 1982
Orgueil Chondrite 73 Ta 14         1 ppb Orgueil meteorite measurements. Anders & Grevesse 1989
Paleozoic Orogens 73 Ta 0.7           ppm Lower crustal rocks are combined in proportions as indicated in Figure 2. Average compositions were calculated using mafic granulitic xenoliths since these xenoliths are believed to represent the lowermost continental crust. Rudnick & Fountain 1995
Paleozoic Orogens 73 Ta 0.9           ppm Rudnick & Fountain 1995
Paleozoic Upper Crust   La/Ta 28             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Paleozoic Upper Crust   La/Ta 28             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Paleozoic Upper Crust   Nb/Ta 13             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Paleozoic Upper Crust   Nb/Ta 13             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Paleozoic Upper Crust 73 Ta 0.97           ppm Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Paleozoic Upper Crust 73 Ta 0.9           ppm Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. Condie 1993
Parana River Particulates 73 Ta 1.1           µg/g Elemental particulates in major South American rivers. Averages for major elements are weighted according to the suspended load prior to the construction of dams, for trace elements the average contents are mean values. Martin & Meybeck 1979
Pelagic Clay   Nb/Ta 12.6   1.6     7   Plank & Langmuir 1998
Pelagic Clay   Nb/Ta 21.8   4.3     9   Plank & Langmuir 1998
Pelagic Clay 73 Ta 0.053         3 ppm Middle 30 m of a total section that is 335 m thick (Site 581) dominated by pelagic clay. Plank & Langmuir 1998
Pelagic Clay 73 Ta 1.008         55 ppm ODP Site through the toe of the accretionary prism into the basement. Only 350 m of sediments underneath the decollement are considered and used in a simple mean for this homogeneous sedimentary section that was sampled 55 times for every 3-13 m of section. Ta is calculated from the Nb/Ta = 14.2 ratio. Plank & Langmuir 1998
Pelagic Clay 73 Ta 0.739         56 ppm Average of 56 sediments of Cretaceous age representing a diverse lithology including brown, gray, nanno, radiolarian and streaky clays. This section also includes turbidites and is very similar in composition as Site 765 in the East Sunda trench. This average is therefore based on both Site 261 and 765 data. Ta was calculated from Nb/Ta = 12.6 as in Table 4. Plank & Langmuir 1998
Pelagic Clay 73 Ta 1.056         8 ppm Average of 8 sediments that are all younger than Campanian-Maastrichtian and are typically Fe-rich clays. The basal sediments may be of hydrothermal origin. Ta was calculated from Nb/Ta = 12.6 as in Table 4. Plank & Langmuir 1998
Pelagic Clay 73 Ta 0.739         56 ppm Average of 56 sediments of Cretaceous age representing a diverse lithology including brown, gray, nanno, radiolarian and streaky clays. This section also includes turbidites and is very similar in composition as Site 765 in the East Sunda trench. This average is therefore based on both Site 261 and 765 data. Ta was calculated from Nb/Ta = 12.6 as in Table 4. Plank & Langmuir 1998
Pelagic Clay 73 Ta 0.833         6 ppm Average of 6 analyses weighted by depth interval. Plank & Langmuir 1998
Pelagic Clay 73 Ta 0.81         6 ppm Average of 6 analyses weighted by depth interval. Plank & Langmuir 1998
Pelagic Clay 73 Ta 0.81           ppm The uppermost layer of the sediment from Hole 801 of ODP Leg 129. Values given are estimates of the composition of this 65m layer based on the methodology of Plank and Ludden 1992. Elliot et al. 1997
Pelites 73 Ta 1.18         1341 ppm Average of 1238 subsamples and 103 composites. Gao et al. 1998
Pelites 73 Ta 0.95         69 ppm Average of 60 subsamples and 9 composites. Gao et al. 1998
Peninsular Range Batholith 73 Ta 0.29           ppm Analysis of Archean Calc-Alkaline Type 1 & 2 Granite represented in major and minor element abundances as well as slected trace element ratios given by Martin 1995 but plotted in Figure 5 of Kemp & Hawkesworth 2004. Kemp & Hawkesworth 2004 Sylvester 1995
Peru Trench 73 Ta 0.261           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 4 or low. Plank & Langmuir 1998
Petersburg Eucrites 73 Ta 144           ng/g Trace element compositional data on Petersburg Eucrite. Mittlefehldt 2004 Mason et al. 1979
Buchanan & Reid 1996
Phanerozoic Flood Basalts 73 Ta 0.5         1 ppm Major and trace element compositions as well as selected isotopic composition for Parana Flood Basalts in Gramado (Low Ti). Farmer 2004 Peate 1997
Phanerozoic Flood Basalts 73 Ta 1.92         1 ppm Major and trace element compositions as well as selected isotopic composition for Parana Flood Basalts in Urubici (High Ti). Farmer 2004 Peate 1997
Phanerozoic Flood Basalts 73 Ta 0.47         7 ppm Major and trace element compositions as well as selected isotopic composition for Siberian Traps Flood Basalt Gudchikhinsky (Low Ti). Farmer 2004 Wooden et al. 1993
Phanerozoic Flood Basalts 73 Ta 0.92         36 ppm Major and trace element compositions as well as selected isotopic composition for Columbia River Flood Basalts NW US (High Ti). Farmer 2004 Hooper & Hawkesworth 1993
Phanerozoic Flood Basalts 73 Ta 0.48         9 ppm Major and trace element compositions as well as selected isotopic composition for Siberian Traps Flood Basalts Nadezhdinsky (High Ti). Farmer 2004 Wooden et al. 1993
Phanerozoic Flood Basalts 73 Ta 0.37         1 ppm Major and trace element compositions as well as selected isotopic composition for Parana Flood Basalts in Esmeralda (High Ti). Farmer 2004 Peate 1997
Phanerozoic Flood Basalts 73 Ta 1.3         18 ppm Major and trace element compositions as well as selected isotopic composition for Deccan Traps Flood Basalts Kolhapur (Low Ti). Farmer 2004 Lightfoot et al. 1990
Phanerozoic Flood Basalts 73 Ta 0.8         6 ppm Major and trace element compositions as well as selected isotopic composition for Deccan Traps Flood Basalts Mahabaleshwar (High Ti). Farmer 2004 Lightfoot et al. 1990
Philip Trench 73 Ta 0.287           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 4 or low. Plank & Langmuir 1998
Precambrian Canadian Shield 73 Ta 5.7           ppm Analyst: K. Speranzini Shaw et al. 1986
Precambrian Granulites 73 Ta 2.3         88 ppm Shaw et al. 1986
Primitive Mantle   Nb/Ta 17.6             Selected ratios for Primitive mantle abundances averaged from various sources in an effort to compare and contrast values obtained by McDonough 1990 for spinel peridotite xenoliths and their relative associations with the composition of the Earth's Mantle. McDonough 1990 McDonough & Frey 1989
Sun & McDonough 1989
Sun 1982
Primitive Mantle   Nb/Ta 17.6             Element ratios from the Primitive Mantle as given by Hofmann 1988. Gao et al. 1998 Hofmann 1988
Primitive Mantle 73 Ta 40   4       ppb Elemental composition of the Primitive Mantle of the Earth as given from this study and other various sources. These elemental values are compared to those of CI Chondrites given by Palme & Jones 2004 Treatise of Geochemistry. Comments given by the authors in reference to these values: RLE Palme & O'Neill 2004
Primitive Mantle 73 Ta 0.03           ppm Minor and trace element concentrations of the Primitive Mantle according to 4 sources (Jagoutz et al. 1979, Hart&Zindler 1986, Morgan 1986, Hofmann 1986) used as balances for calculations. Wedepohl & Hartmann 1994 Jagoutz et al. 1979
Primitive Mantle 73 Ta 0.0351           ppm Trace element abundances in the Earth's Primitive mantle given in ppm as was first found by Hart and Zindler 1986. The major element factor of 2.51 was used to obtain the mantle values of the refractory trace elements from the abundances of C1 Carbonaceous chondrites. Hofmann 1988 Hart & Zindler 1986
Primitive Mantle 73 Ta 40           ppb Elemental abundances of the Primitive Mantle of the Earth as given by various sources. This set of values are given as a comparison to those of the Bulk Continental Crust given by Rudnick & Gao of the Treatise on Geochemistry Chapter 3.1. Palme & O'Neill 2004
Primitive Mantle 73 Ta 0.035           ppm Minor and trace element concentrations of the Primitive Mantle according to 4 sources (Jagoutz et al. 1979, Hart&Zindler 1986, Morgan 1986, Hofmann 1986) used as balances for calculations. Wedepohl & Hartmann 1994 Hofmann 1988
Primitive Mantle 73 Ta 37   5.6       ppb Pyrolite model for the silicate Earth composition based on peridotites, komatiites and basalts. Error estimate is subjective. McDonough & Sun 1995
Protolith Gabbros at ODP Site 735 73 Ta 0.04         8 ppm Average of 8 protolith samples as defined in the footnote of Table 2 and Table 1. Hart et al. 1999
QUE 94201 Meteorite 73 Ta 23           ppb Mars elemental abundances as given by QUE94201 meteorite, which is a basalitc shergottite, as given in Lodders 1988. McSween, Jr. 2004 Lodders 1998
Radiolarian Clay 73 Ta 0.89         8 ppm The bulk composition of the radiolarian clay was calculated by first estimating the composition of the average clay in the region and then diluting it by 15% biogenic SiO2. Plank & Langmuir 1998
Radiolarian Clay 73 Ta 0.89         8 ppm The bulk composition of the radiolarian clay was calculated by first estimating the composition of the average clay in the region and then diluting it by 15% biogenic SiO2. Plank & Langmuir 1998
Radiolarian Clay 73 Ta 0.65         2 ppm The bulk composition of the radiolarian clay was calculated by first estimating the composition of the average clay in the region and then diluting it by 30% biogenic SiO2. Ta is estimated based on Nb/Ta = 11.9 as in Table 4. Plank & Langmuir 1998
Radiolarites   Nb/Ta 15.5   2.9     7   Plank & Langmuir 1998
Radiolarites 73 Ta 0.29           ppm Estimates of the composition of the Radiolarite section of the sediment column from DSDP Hole 801. This section comprises the final layer of the column and all element values were estimated according to methods of Plank and Ludden 1992. Elliot et al. 1997
Radiolarites 73 Ta 0.285         4 ppm Average of 4 radiolarite analyses that have been corrected using dilution factors based on the down-core logging for SiO2 contents. Plank & Langmuir 1998
Radiolarites 73 Ta 0.33         17 ppm Average of 17 combined analyses weighted by interval height. Plank & Langmuir 1998
Red Clay   Nb/Ta 15.3         1   Plank & Langmuir 1998
Rifted Continental Margins 73 Ta 0.6           ppm Lower crustal rocks are combined in proportions as indicated in Figure 2. Average compositions were calculated using mafic granulitic xenoliths since these xenoliths are believed to represent the lowermost continental crust. Rudnick & Fountain 1995
Rifted Continental Margins 73 Ta 1.1           ppm Rudnick & Fountain 1995
River Particulates 73 Ta 1.25           µg/g World averages for suspended matter in major world rivers. This particular array of rivers can lead to slightly biased results for certain trace elements since those elements are usually measured in temperate and/or arctic rivers. All averages for major elements are weighted according to the suspended load prior to the construction of dams, as for trace elements the average contents are mean values. Martin & Meybeck 1979
Ryuku Trench 73 Ta 0.831           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 4 or low. Plank & Langmuir 1998
Sandstones 73 Ta 0.3           ppm Condie 1993
Sandstones 73 Ta 0.24           ppm Condie 1993
Sandstones 73 Ta 0.31           ppm Condie 1993
Scotia Island Basalt 73 Ta 0.5         11 ppm Average major and trace element values for Scotian Arc Basalts given in weight percent and parts per million respectively. Kelemen et al. 2004
Seawater 73 Ta 0.002           ppb Average concentration of elements in unfiltered seawater.  These values are used in conjuction with concentrations taken from the same elements in filtered river water and then used in equations (given in Li 1982) to determine mean oceanic residence time of particular elements.  Problems arise however with the relative pollution found in average river waters, and a lack of adequate data for filtered seawater to make a better comparison to filtered river water (which in this instance is found to be the most ideal comparison, yet the most difficult to perform). Li 1982
Seawater 73 Ta         2.5   ng/kg This mean ocean concentratio has been calculated based on the correlation expressions in Table 1, assuming a salinity of 35¿, a nitrate concentratio of 30 ¿mol/kg, a phosphate concentratio of 2 ¿mol/kg and a silicate concentratio of 110 ¿mol/kg. Where possible data is from the Pacific ocean that shows the greates variations; otherwhise data is from the Atlantic ocean. Quinby-Hunt & Turekian 1983 Schutz & Turekian 1965
Seawater 73 Ta         1.4e-05     Broeker & Peng 1982
Seawater 73 Ta         14     Unknown distribution type. Ta(OH)5[0+] is the probable main species in oxygenated seawater. Range and average concentrations normalized to 35¿ salinity. Accuracy and concentration range are uncertain. Bruland 1983
Seawater 73 Ta         2.5     Elemental average concentrations of the deep Atlantic and deep Pacific waters summarized by Whitfield & Turner 1987.  Li 1991 Whitfield & Turner 1987
Bruland 1983
Serra De Mage Eucrite 73 Ta 31           ng/g Trace element compositional data on Serra de Mage Eucrite. Mittlefehldt 2004 Barrat et al. 2000
McCarthy et al. 1973
Shales 73 Ta 1.4           ppm Condie 1993
Shales 73 Ta 1.4           ppm Condie 1993
Shales 73 Ta 0.84           ppm Condie 1993
Shergotty Meteorite 73 Ta 250   40       ppb Mars elemental abundances as given by Shergotty meteorite (basalitc shergottite) as given in Lodders 1988. Mars elemental abundances as given by Shergotty meteorite, which is a basalitc shergottite, as given in Lodders 1988. McSween, Jr. 2004 Lodders 1998
Silicate Earth 73 Ta 37   5.6       ppb Pyrolite model for the silicate Earth composition based on peridotites, komatiites and basalts. Error estimate is subjective. McDonough & Sun 1995
Silicate Earth 73 Ta 0.037           ppm Composition of the Silicate Earth as given by elemental abundances in ppm (and wt%). McDonough 2004
Silicate Earth 73 Ta 0.04           ppm Abundances of refractory lithophile elements along with K, Rb and Cs for models of the Bulk Silicate Earth. Data taken from various sources that agree Earth experienced some depletion of semi-volatile to volatile elements in relation to refractory lithophile elements during accretion. McDonough et al. 1992 Taylor & McLennan 1985
Silicate Earth 73 Ta 0.0351           ppm Abundances of refractory lithophile elements along with K, Rb and Cs for models of the Bulk Silicate Earth. Data taken from various sources that agree Earth experienced some depletion of semi-volatile to volatile elements in relation to refractory lithophile elements during accretion. McDonough et al. 1992 Hofmann 1988
Silicate Earth 73 Ta 0.038           ppm Abundances of refractory lithophile elements along with K, Rb and Cs for models of the Bulk Silicate Earth. Data taken from various sources that agree Earth experienced some depletion of semi-volatile to volatile elements in relation to refractory lithophile elements during accretion. McDonough et al. 1992 Jagoutz et al. 1979
Wanke et al. 1984
Silicate Earth 73 Ta 0.041           ppm Abundances of refractory lithophile elements along with K, Rb and Cs for models of the Bulk Silicate Earth. Data taken from various sources that agree Earth experienced some depletion of semi-volatile to volatile elements in relation to refractory lithophile elements during accretion. McDonough et al. 1992 Sun 1982
Sun & McDonough 1989
McDonough & Frey 1989
Silicate Earth 73 Ta 0.037           µg/g Compostioinal models for the bulk Earth, core and silicate Earth are modified after McDonough & Sun (1995). McDonough 1998
Silicic Precambrian Granulites 73 Ta 2.9         23 ppm Shaw et al. 1986
Silicified Limestone 73 Ta 0.17           ppm Mixed siliceous and carbonate lithologies including nannofossil and radiolarian oozes, chalk and chert. The average of the Hein et al. (1983) partly silicified chalk has been used after dilution with 50% total CaCO3. Ta is calculated based on the Nb/Ta = 14.2 ratio. Plank & Langmuir 1998
Silty Mud 73 Ta 0.703         16 ppm The hemi-pelagic clay analyses where averaged over 10 m intervals and then averaged down-unit. Ta is calculated from the Nb/Ta = 15.2 ratio. Plank & Langmuir 1998
Sioux County Eucrite 73 Ta 147           ng/g Trace element compositional data on Sioux County Eucrites. Mittlefehldt 2004 Barrat et al. 2000
McCarthy et al. 1973
Solar System 73 Ta 0.0226   0.00226     1   Anders & Ebihara 1982
Solar System 73 Ta 0.02             Anders & Ebihara 1982 Cameron 1982
Solar System 73 Ta 0.0207   0.000373     2   Solar atomic abundances based on an average of C1 chondrites. Values are not normalised to 100% but they are relative to 10E6 Silica atoms. Anders & Grevesse 1989
Solid Earth 73 Ta 0.025           µg/g Compostioinal models for the bulk Earth, core and silicate Earth are modified after McDonough & Sun (1995). McDonough 1998
Solid Earth 73 Ta 0.025           ppm Bulk elemental composition of the Solid Earth with concentrations given in ppm (and wt% where noted). McDonough 2004
South Antilles Trench 73 Ta 1.3           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 3 or low. Plank & Langmuir 1998
South Margin of North China Craton 73 Ta 0.73           ppm Compostional estimate of the south margin of the North China craton. Includes sedimentary carbonates. Gao et al. 1998
South Margin of North China Craton 73 Ta 0.63           ppm Compostional estimate of the south margin of the North China craton. Average compostion of granulite terrains and calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
South Margin of North China Craton 73 Ta 0.57           ppm Compostional estimate of the south margin of the North China craton. Average composition of granulite terrains. Gao et al. 1998
South Margin of North China Craton 73 Ta 0.51           ppm Compostional estimate of the south margin of the North China craton. Gao et al. 1998
South Margin of North China Craton 73 Ta 0.78           ppm Compostional estimate of the south margin of the North China craton. Calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
South Qinling Belt in China 73 Ta 0.78           ppm Compostional estimate of the South Qinling orogenic belt. Includes sedimentary carbonates. Gao et al. 1998
South Qinling Belt in China 73 Ta 0.72           ppm Compostional estimate of the Southern Qinling orogenic belt. Average compostion of granulite terrains and calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
South Qinling Belt in China 73 Ta 0.66           ppm Compostional estimate of the South Qinling orogenic belt. Gao et al. 1998
South Qinling Belt in China 73 Ta 0.84           ppm Compostional estimate of the South Qinling orogenic belt. Calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
South Sandwich Trench 73 Ta 0.321           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 1 or highest. Plank & Langmuir 1998
Spinel Peridotites   Nb/Ta 17 17 3     4   Data exclusively from Jochum et al. (1989). McDonough 1990
Spinel Peridotites 73 Ta 0.4 0.23 0.51     38 ppm McDonough 1990
Stannern Eucrite 73 Ta 368           ng/g Trace element compositional data on Stannern Eucrite. Mittlefehldt 2004 Barrat et al. 2000
McCarthy et al. 1973
Subducted Sediment   Nb/Ta 14.2   1.8     50   Not including Nb/Ta from DSDP Sites 579 and 581. Plank & Langmuir 1998
Subducted Sediment 73 Ta 0.63   0.06       ppm Global subducting sediment (GLOSS) composition estimate based on DSDP and ODP drill cores for 70% of the worldwide trenches. The average is calculated as a mass-flux-weighted global mean taking into account convergence rates, trench lengths and sediment columns. Includes sediment columns from seafloor that is not currently subducting. Plank & Langmuir 1998
Sumatra Trench 73 Ta 0.803           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 3 or moderate. Plank & Langmuir 1998
Talkeetna Arc Plutonic Rocks 73 Ta 0.028   0.001     31 ppm Geochemical data from the Talkeetna Arc Section of the Lower Crust. These particular values are representative of gabbronorites from the Talkeetna section. All values for major element oxides are given in wt.% and for trace elements in ppm. Trace elements were gathered via XRF and ICP-MS analysis. Kelemen et al. 2004
Talkeetna Arc Plutonic Rocks 73 Ta 0.147   0.003     42 ppm Geochemical data from the Talkeetna Arc Section of the Lower Crust. These particular values are representative of Lavas, tuffs and volcaniclastic samples from the Talkeetna section. All values for major element oxides are given in wt.% and for trace elements in ppm. Trace elements were gathered via XRF and ICP-MS analysis. Kelemen et al. 2004
Talkeetna Arc Plutonic Rocks 73 Ta 0.012   0.001     16 ppm Geochemical data from the Talkeetna Arc Section of the Lower Crust. These particular values are representative of pyroxenites from the Tonsina section. All values for major element oxides are given in wt.% and for trace elements in ppm. Trace elements were gathered via XRF and ICP-MS analysis. Kelemen et al. 2004
Talkeetna Arc Plutonic Rocks 73 Ta 0.174   0.009     13 ppm Geochemical data from the Talkeetna Arc Section of the Lower Crust. These particular values are representative of Intermediate to felsic plutons from the Talkeetna section. All values for major element oxides are given in wt.% and for trace elements in ppm. Trace elements were gathered via XRF and ICP-MS analysis. Kelemen et al. 2004
Talkeetna Arc Plutonic Rocks 73 Ta 0.116   0.036     7 ppm Geochemical data from the Talkeetna Arc Section of the Lower Crust. These particular values are representative of garnet diorites and tonalites from the Klanelneechina section. All values for major element oxides are given in wt.% and for trace elements in ppm. Trace elements were gathered via XRF and ICP-MS analysis. Kelemen et al. 2004
Talkeetna Arc Plutonic Rocks 73 Ta 0.05   0.012     6 ppm Geochemical data from the Talkeetna Arc Section of the Lower Crust. These particular values are representative of garnet granulites from the Tonsina section. All values for major element oxides are given in wt.% and for trace elements in ppm. Trace elements were gathered via XRF and ICP-MS analysis. Kelemen et al. 2004
Terrigenous Sediments   Nb/Ta 13.5   2.4     15   Plank & Langmuir 1998
Tonalites 73 Ta 1.1           ppm Total average of group averages from USA, Canada, Sri Lanka, Greenland, Finland, UK and Portugal using an equal statistical weight. Wedepohl 1995
Tonalites-Trondhjemites-Granodiorites 73 Ta 0.8           ppm Condie 1993
Tonalites-Trondhjemites-Granodiorites 73 Ta 0.65           ppm Condie 1993
Tonalites-Trondhjemites-Granodiorites 73 Ta 0.71         355 ppm Analysis of Archean Tonalite-Trondhjemite-Granodiorite (TTG) represented in major and minor element abundances as well as slected trace element ratios given by Martin 1995 but plotted in Figure 5 of Kemp & Hawkesworth 2004. Kemp & Hawkesworth 2004 Martin 1995
Tonalites-Trondhjemites-Granodiorites 73 Ta 0.39         553 ppm Average of 502 subsamples and 51 composites. Gao et al. 1998
Tonalites-Trondhjemites-Granodiorites 73 Ta 0.7           ppm Condie 1993
Tonalites-Trondhjemites-Granodiorites 73 Ta 0.93         641 ppm Average of 596 subsamples and 45 composites. Gao et al. 1998
Tonga Trench 73 Ta 0.552           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 1 or highest. Plank & Langmuir 1998
Tongan Basalts 73 Ta 0.04         5 ppm Average major and trace element values for Tongan Arc Basalts given in weight percent and parts per million respectively. Kelemen et al. 2004
Transitional Mid-Ocean Ridge Basalts 73 Ta 0.38           ppm Compositie analyses on T-MORB glasses from the Mid-Atlantic Ridge as reported in the RidgePetDB database. Major and most trace elements for this T-type MORB are taken from the sample VEM0025-001-022. Klein 2004 Lehnert 2000
Turbidites 73 Ta 0.797         4 ppm Average of 4 Quaternary turbidites from the Ganges cone after McLennan et al. (1990) assuming that equal proportions of fine (clay-silt) and coarse (silt-sand) units. Ta is calculated based on Nb/Ta = 14.2 that is an estimate of the global continental average. Plank & Langmuir 1998
Turbidites 73 Ta 0.5         4 ppm Similar lithologies as for Site 183 but with a greater thickness of the turbidites. Combined 300 m of Site 183 sediments with 480 m of turbidites in Site 178 and two shallow piston cores. Ta is calculated from Nb/Ta = 14.2 in the global average. Plank & Langmuir 1998
Ultrabasic Precambrian Granulites 73 Ta 2.4         14 ppm Shaw et al. 1986
Upper Continental Crust   La/Ta 35             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. In this model 5 and 10 km extra crust is added to the present-day upper-crustal layer for Phanerozoic and Precambrian areas, respectively. The UCC is calculated from data in Tables 4-6 with a weight ratio for Archean:Proterozoic:Phanerozoic = 50:30:20 that can be further divided into 10% Early and 90% Late Archean; 50% Early and 25% Middle and 25% Late Proterozoic; and 50% Paleozoic and 50% Mesozoic-Cenozoic. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Upper Continental Crust   La/Ta 36             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. The UCC is calculated from data in Tables 4-6 with a weight ratio for Archean:Proterozoic:Phanerozoic = 50:30:20 that can be further divided into 10% Early and 90% Late Archean; 50% Early and 25% Middle and 25% Late Proterozoic; and 50% Paleozoic and 50% Mesozoic-Cenozoic. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Upper Continental Crust   Nb/Ta 13             Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. In this model 5 and 10 km extra crust is added to the present-day upper-crustal layer for Phanerozoic and Precambrian areas, respectively. The UCC is calculated from data in Tables 4-6 with a weight ratio for Archean:Proterozoic:Phanerozoic = 50:30:20 that can be further divided into 10% Early and 90% Late Archean; 50% Early and 25% Middle and 25% Late Proterozoic; and 50% Paleozoic and 50% Mesozoic-Cenozoic. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Upper Continental Crust   Nb/Ta 12             Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. The UCC is calculated from data in Tables 4-6 with a weight ratio for Archean:Proterozoic:Phanerozoic = 50:30:20 that can be further divided into 10% Early and 90% Late Archean; 50% Early and 25% Middle and 25% Late Proterozoic; and 50% Paleozoic and 50% Mesozoic-Cenozoic. Ratios calculated from weighted arithmetic means of rock types given in Appendix A-H. Condie 1993
Upper Continental Crust 73 Ta 0.9           ppm Major and minor element composition of the Upper Crust of the Earth with selected trace element ratios as given by Rudnick and Gao 2004. Kemp & Hawkesworth 2004 Rudnick & Gao 2004
Upper Continental Crust 73 Ta 1.5           µg/g Estimates of trace element compositions of the Upper Continental Crust. These values are taken from Wedepohl 1995 and represent a previous estimate. Rudnick & Gao 2004 Wedepohl 1995
Upper Continental Crust 73 Ta 0.9           µg/g Recommended composition of the Upper Continental Crust as given by various sources which are listed in Table 1 and 2 of Rudnick and Gao 2004 as well as in the text. Rudnick & Gao 2004
Upper Continental Crust 73 Ta 5.7           µg/g Estimates of trace element compositions of the Upper Continental Crust. These values are taken from Shaw et al. 1967 & 1976 and represent averages from surface exposures. Rudnick & Gao 2004 Shaw et al. 1967
Shaw et al. 1976
Upper Continental Crust 73 Ta 0.9   0.1       µg/g Recommended composition of the Upper Continental Crust as given by various sources which are listed in Table 1 and 2 of Rudnick and Gao 2004 as well as in the text. Rudnick & Gao 2004 see text









Upper Continental Crust 73 Ta 0.79           µg/g Estimates of trace element composition of the Upper Continental Crust. These values are taken from Condie 1993 and represent averages from surface exposures. Rudnick & Gao 2004 Condie 1993
Upper Continental Crust 73 Ta 0.74           µg/g Estimates of trace element compositions of the Upper Continental Crust. These values are taken from Gao et al. 1998 and represent averages from surface exposures. Rudnick & Gao 2004 Gao et al. 1998
Upper Continental Crust 73 Ta 0.96           µg/g Estimates of trace element compositions of the Upper Continental Crust. These values are taken from Plank and Langmuir 1998 and represent estimates derived from sedimentary and loess data. Rudnick & Gao 2004 Plank & Langmuir 1998
Upper Continental Crust 73 Ta 0.79           ppm Map model. Concentrations are directly calculated from rock proportions scaled from geologic maps and stratigraphic successions as summarized in Table 2. The UCC is calculated from data in Tables 4-6 with a weight ratio for Archean:Proterozoic:Phanerozoic = 50:30:20 that can be further divided into 10% Early and 90% Late Archean; 50% Early and 25% Middle and 25% Late Proterozoic; and 50% Paleozoic and 50% Mesozoic-Cenozoic. Condie 1993
Upper Continental Crust 73 Ta 0.82           ppm Restoration model. Concentrations are calculated after restoration of the amount of crust lost be erosion, in particular, important when estimating the composition of juvenile continental crust. The restoration is performed based on geologic maps and stratigraphic successions as summarized in Table 2. In this model 5 and 10 km extra crust is added to the present-day upper-crustal layer for Phanerozoic and Precambrian areas, respectively. The UCC is calculated from data in Tables 4-6 with a weight ratio for Archean:Proterozoic:Phanerozoic = 50:30:20 that can be further divided into 10% Early and 90% Late Archean; 50% Early and 25% Middle and 25% Late Proterozoic; and 50% Paleozoic and 50% Mesozoic-Cenozoic. Condie 1993
Upper Continental Crust 73 Ta 0.96   0.12       ppm Revised upper continental crust (UCC) value calculated from the ratios as reported in Table 4 using Al2O3 = 15.2% and Rb = 122 ppm from the Taylor & McLennan (1985) estimate. Uncertainties are calculated from the standard deviations of the mean ratios in Table 4. Plank & Langmuir 1998
Upper Continental Crust 73 Ta 1           µg/g Estimates of trace element compositions of the Upper Continental Crust. These values are taken from Taylor and McLennan 1985 & 1995 and represent estimates derived from sedimentary and loess data. Rudnick & Gao 2004 Taylor & McLennan 1985
Taylor & McLennan 1995
Upper Continental Crust 73 Ta 2.2           ppm Taylor & McLennan 1995
Upper Continental Crust 73 Ta 1.5           ppm UCC = calculated from rock averages compiled by Manheim & Ladergren (1978) in the proportions of Figure 2. Wedepohl 1995
Vanuatu Trench 73 Ta 0.136           ppm Bulk composition estimate of sediments approaching the trench based on DSDP and ODP drill sites. Confidence level = 1 or highest. Plank & Langmuir 1998
Volcanoclastic Sediment 73 Ta 0.119         15 ppm Average of 15 volcaniclastic sediments using DCP analyses as weighted by the height of each drilled interval. Plank & Langmuir 1998
Volcanoclastic Turbidites 73 Ta 1.66           ppm Estimates of the composition of the Volcaniclastic Turbidite section of the sediment column from DSDP Hole 801. Elliot et al. 1997
Volcanoclastic Turbidites 73 Ta 1.226         43 ppm Average of 43 combined analyses weighted by interval height. Plank & Langmuir 1998
Volcanoclastic Turbidites 73 Ta 1.663         13 ppm Average of 13 volcaniclastic turbidites corrected for pure silica using down-core logging for SiO2 contents, in a similar fashion as for the chert sections. Plank & Langmuir 1998
Watson IIE Iron 73 Ta 8.9           ng/g Trace element compositional data on Watson IIE Iron. Mittlefehldt 2004 Olsen et al. 1994
Y-74450 Eucrites 73 Ta 300           ng/g Trace element compositional data on Y-74450 eucrite. Mittlefehldt 2004 Wanke et al. 1977
Y-791491 Lodranite 73 Ta 11           ng/g Trace element compositional data on Lodranite Y-791491. Mittlefehldt 2004 Weigel et al. 1999
Yangtze Craton 73 Ta 0.59           ppm Compostional estimate of the Yangtze craton. Average composition of granulite terrains. Gao et al. 1998
Yangtze Craton 73 Ta 0.57           ppm Compostional estimate of the Yangtze craton. Gao et al. 1998
Yangtze Craton 73 Ta 0.73           ppm Compostional estimate of the Yangtze craton. Calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
Yangtze Craton 73 Ta 0.68           ppm Compostional estimate of the Yangtze craton. Includes sedimentary carbonates. Gao et al. 1998
Yangtze Craton 73 Ta 0.64           ppm Compostional estimate of the Yangtze craton. Average compostion of granulite terrains and calculated on a sedimentary carbonate rock-free basis. Gao et al. 1998
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