EarthRef.org Digital Archive (ERDA) -- 40Ar/39Ar Age Determination 14D30789 (IESS10040

Description
This upload contains the 40Ar/39Ar geochronology age determination of sample MV1203-D59-12 from Concordia Seamount in Walvis Ridge and was calculated using the ArArCALC freeware. The preferred age of 42.50 ± 0.03 Ma is the age plateau and is interpreted as the eruption age of the sample. Recoil pattern, but plateau may be acceptable. The age determination was carried out on a sample of trachybasalt (groundmass) in an incremental heating experiment and using the bulk laser heating extraction method. The analyses were run on a ARGUS-VI mass spectrometer and the ages were calculated relative to flux monitor FCT-NM (4B25-14) (sanidine) with an age of 28.201 ± 0.082 Ma. This sample was collected by Anthony Koppers (akoppers@ceoas.oregonstate.edu). Sample Description: Standard. Sample Treatment: Fine-grained, moderately vesicular basalt. Moderately altered GM, moderately ol-phyric, sparsely cpx-phyric..

Instructions
This ERDA upload contains four separate 40Ar/39Ar age calculation files generated with ArArCALC. Both the XLS and PDF files are for easy viewing in Microsoft Excel or Adobe Acrobat Reader, whereas the AGE file is readable by the ArArCALC software only and the XML file is generated for the GEOCHRON online database project. For full age calculation functionality it is recommended that you open the AGE file in the ArArCALC software that is available as freeware online at http://earthref.org/ArArCALC ...

Keywords
40Ar/39Ar, Geochronology, Radiometric Age Dating, K/Ar, Argon, Mass Spectrometry, ArArCALC, Data Reduction, IESS10040 (IGSN), 14D30789 (Experiment), WALVIS RIDGE, MV1203 (13-INT-04) (Project), Dredging (Collection Method), Ship (Platform Type), Individual Sample (Collection Object), Igneous>Volcanic>Mafic (Rock Classification), Groundmass (Mineral Type), 106-212 µm (Grain Size), 8.2 mg (Sample Weight), Seamount (Feature Type)