| Abstract: | 40Ar 39Ar incremental heating experiments on igneous plagioclase, biotite, and pyroxene that contain known amounts of excess 40Ar indicate that saddle-shaped age spectra are diagnostic of excess 40Ar in igneous minerals as well as in igneous rocks. The minima in the age spectra approach but do not reach the crystallization age. Neither the age spectrum diagram nor the 40Ar 36Ar versus 39Ar 36Ar isochron diagram reliably reveal the crystallization age in such samples. ?? 1976. |
| Genre: | Article |
| ProdID: | 70011168 |
| Citation Author: | Lanphere, M. A.; Brent, Dalrymple, G. |
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| Citation End Page: | 148 |
| Citation Issue: | 2 |
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| Citation Language: | English |
| Citation Larger Work Title: | Earth and Planetary Science Letters |
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| Citation Number Of Pages: | 8 |
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| Citation Search Results Text: | Identification of excess 40Ar by the 40Ar 39Ar, age spectrum technique; 1976; Article; Journal; Earth and Planetary Science Letters; Lanphere, M. A.; Brent, Dalrymple, G. |
| Citation Start Page: | 141 |
| Citation Volume: | 32 |
| Citation Year: | 1976 |
| Type: | citation/reference |
| Text: | Identification of excess 40Ar by the 40Ar 39Ar, age spectrum technique; 1976; Article; Journal; Earth and Planetary Science Letters; Lanphere, M. A.; Brent, Dalrymple, G. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Thu, 1 Jan 1976 00:00 -0600 |
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