Identification of excess 40Ar by the 40Ar 39Ar, age spectrum technique
January 1, 1976
40Ar/39Ar incremental heating experiments on igneous plagioclase, biotite, and pyroxene that contain known amounts of excess40Ar indicate that saddle-shaped age spectra are diagnostic of excess40Ar 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 the40Ar/36Ar versus39Ar/36Ar isochron diagram reliably reveal the crystallization age in such samples.
Citation Information
| Publication Year | 1976 |
|---|---|
| Title | Identification of excess 40Ar by the 40Ar 39Ar, age spectrum technique |
| DOI | 10.1016/0012-821X(76)90052-2 |
| Authors | M. A. Lanphere, G. Brent Dalrymple |
| Publication Type | Article |
| Publication Subtype | Journal Article |
| Series Title | Earth and Planetary Science Letters |
| Index ID | 70011168 |
| Record Source | USGS Publications Warehouse |