Evaluation of the uranium--thorium--helium method for dating young basalts

Journal Article · Sat May 10 04:00:00 EDT 1975 · J. Geophys. Res., v. 80, no. 14, pp. 1911-1914

DOI:https://doi.org/10.1029/JB080i014p01911· OSTI ID:4126800

Leventhal, J S

Comparison of K-Ar and ages based on U-Th-He on young basalts from the San Francisco Volcanic Field near Flagstaff, Arizona, shows that approximately one fifth of the He is retained and thus U-Th-He ages are too young. Leaching with weak acid produces large losses of U in only a few minutes, which suggests that He is lost from surficial positions on minerals from radiation damage sites and from interconnecting crystal defects. One sample of large plagioclase phenocrysts showed excess He. It seems unlikely that the U-Th-He method can be used to obtain reliable ages on young basalts. (auth)

• Research Organization: Univ. of Arizona, Tucson
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-017201
• OSTI ID: 4126800
• Journal Information: J. Geophys. Res., v. 80, no. 14, pp. 1911-1914, Journal Name: J. Geophys. Res., v. 80, no. 14, pp. 1911-1914; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

*BASALT-- ISOTOPE DATING
510101* --Environmental Sciences
Terrestrial--Basic Studies- -Radiometric Techniques
AGE ESTIMATION
ARGON
HELIUM ISOTOPES
LEACHING
N44420* --Environmental & Earth Sciences--Radiometric Techniques--Soil
POTASSIUM
THORIUM ISOTOPES
URANIUM ISOTOPES