Electron microprobe evaluation of terrestrial basalts for whole-rock K-Ar dating
January 1, 1972
Four basalt samples for whole-rock K-Ar dating were analyzed with an electron microprobe to locate potassium concentrations. Highest concentrations of potassium were found in those mineral phases which were the last to crystallize. The two reliable samples had potassium concentrated in fine-grained interstitial feldspar and along grain boundaries of earlier formed plagioclase crystals. The two unreliable samples had potassium concentrated in the glassy matrix, demonstrating the ineffectiveness of basaltic glass as a retainer of radiogenic argon. In selecting basalt samples for whole-rock K-Ar dating, particular emphasis should be placed on determining the nature and condition of the fine-grained interstitial phases.
Citation Information
Publication Year | 1972 |
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Title | Electron microprobe evaluation of terrestrial basalts for whole-rock K-Ar dating |
DOI | 10.1016/0012-821X(72)90262-2 |
Authors | E. A. Mankinen, G. Brent Dalrymple |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Earth and Planetary Science Letters |
Index ID | 70010282 |
Record Source | USGS Publications Warehouse |