| Abstract: | Jasper Seamount is a young, mid-sized (690 km3) oceanic intraplate volcano located about 500 km west-southwest of San Diego, California. Reliable 40Ar/39Ar age data were obtained for several milligram-sized samples of 4 to 10 Ma plagioclase by using a defocused laser beam to clean the samples before fusion. Gee and Staudigel suggested that Jasper Seamount consists of a transitional to tholeiitic shield volcano formed by flank transitional series lavas, overlain by flank alkalic series lavas and summit alkalic series lavas. Twenty-nine individual 40Ar/39Ar laser fusion analyses on nine samples confirm the stratigraphy: 10.3-10.0 Ma for the flank transitional series, 8.7-7.5 Ma for the flank alkalic series, and 4.8-4.1 Ma for the summit alkalic series. The alkalinity of the lavas clearly increases with time, and there appear to be 1 to 3 m.y. hiatuses between each series. -from Authors |
| Genre: | Article |
| ProdID: | 70016600 |
| Citation Author: | Pringle, M. S.; Staudigel, H.; Gee, J. |
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| Citation End Page: | 368 |
| Citation Issue: | 4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Geology |
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| Citation Number Of Pages: | 5 |
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| Citation Search Results Text: | Jasper Seamount: seven million years of volcanism; 1991; Article; Journal; Geology; Pringle, M. S.; Staudigel, H.; Gee, J. |
| Citation Start Page: | 364 |
| Citation Volume: | 19 |
| Citation Year: | 1991 |
| Type: | citation/reference |
| Text: | Jasper Seamount: seven million years of volcanism; 1991; Article; Journal; Geology; Pringle, M. S.; Staudigel, H.; Gee, J. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Tue, 1 Jan 1991 00:00 -0600 |
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