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| Detailed Reference Information |
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Cambon, P., Joron, J.L., Bougault, H., Treuil, M., Jackson, E.D., Koizumi, I., Avdeiko, G., Butt, A., Clague, D., Dalrymple, G.B., Greene, H.G., Karpoff, A.M., Kirkpatrick, R.J., Kono, M., Hsin Yi, L., McKenzie, J., Morgan, J. and Takayama, T. (1980). Leg 55, Emperor Seamounts; trace elements in transitional tholeiites, alkali basalts, and hawaiites; mantle homogeneity or heterogeneity and magmatic processes. Initial Reports of the Deep Sea Drilling Project 55: 585-597. |
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According to the classification of the elements which was made previously from the samples recovered in the Atlantic Ocean, with regard to their physicochemical properties and partition coefficients, the following items can be formulated from the study of the Emperor Seamount samples drilled during Leg 55: 1) The chondritic nature of the 'primordial' mantle is confirmed through Y/Tb, Zr/Hf, and Nb/Ta ratios. 2) The value 9 for the La/Ta ratio has been found related to topographic highs or platforms in the Atlantic Ocean (the value is 18 in other cases, corresponding to typically 'depleted' tholeiites). The values close to 9 found for Emperor Seamount samples independently of their petrographic classification (tholeiite, alkali basalts, or hawaiite) tend to confirm the correlation of this ratio to topography. 3) The single Th/Ta ratio observed in tholeiites, alkali basalts, and hawaiites suggests similar mantle sources for these different rock types. 4) The transition elements belonging to the same series, characterized by different partition coefficients, show a fractionation. This fractionation can be interpreted as the result of partial melting. 5) Ti and V are fractionated in hawaiites as a consequence of titanomagnetite crystallization. |
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Keywords
alkalic composition; basalts; Deep Sea Drilling Project; Emperor, Seamounts; fractional crystallization; fractionation;, geochemistry; howaiites; igneous processes; igneous rocks; IPOD;, Leg 55; mantle; North Pacific; Northwest Pacific; Pacific Ocean;, petrology; physicochemical properties; processes; Site 430; Site, 432; Site 433; tholeiites; trace elements; volcanic rocks; West, Pacific, 02, Geochemistry |
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Journal
Initial Reports of the Deep Sea Drilling Project |
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