Ultra-high precision 40Ar/39Ar ages for Fish Canyon Tuff and Alder Creek Rhyolite sanidine: New dating standards required?
Abstract
The 40Ar/39Ar dating technique is a high precision (<0.1%) method with wide application to geological samples. However, the method is predicated on the availability of natural mineral standards of known age. Widely used 40Ar/39Ar standards include sanidine from the (ca. 28 Ma) Fish Canyon Tuff (FCT) and the (ca. 1.2 Ma) Alder Creek Rhyolite (ACR). Despite common usage, the ages of FCT and ACR sanidine have proven contentious, with reported values varying by >2%; well outside the ±0.1% aspiration of EARTHTIME (http://www.earth-time.org)
- Publication:
-
Geochimica et Cosmochimica Acta
- Pub Date:
- November 2013
- DOI:
- 10.1016/j.gca.2013.07.003
- Bibcode:
- 2013GeCoA.121..229P