AR-40-AR-39 DATING - INVESTIGATION OF SOME TECHNICAL PROBLEMS AND ITSAPPLICATION TO THE DECCAN-TRAP ROCKS AND A UNIQUE METEORITE FROM ANTARCTICA

Authors
KANEOKA I IWATA N TAKIGAMI Y
Citation
I. Kaneoka et al., AR-40-AR-39 DATING - INVESTIGATION OF SOME TECHNICAL PROBLEMS AND ITSAPPLICATION TO THE DECCAN-TRAP ROCKS AND A UNIQUE METEORITE FROM ANTARCTICA, Science Reports of the Research Institutes, Tohoku University, Series A: Physics, Chemistry, and Metallurgy, 45(1), 1997, pp. 47-51
Citations number
13
Categorie Soggetti
Material Science","Metallurgy & Metallurigical Engineering
Journal title
Science Reports of the Research Institutes, Tohoku University, Series A: Physics, Chemistry, and Metallurgy → ACNP
ISSN journal
00408808
Volume
45
Issue
1
Year of publication
1997
Pages
47 - 51
Database
ISI
SICI code
0040-8808(1997)45:1<47:AD-IOS>2.0.ZU;2-V
Abstract
In order to get more reliable ages and extend the application of Ar-40 -Ar-39 dating for terrestrial and exterrestrial samples, some technica l problems such as the examination of the efficiency of Cd-shielding t o reduce the interference thermal neutron flux and the laser heating m ethod were investigated. It has been reconfirmed that Cd-shielding is effective to reduce the interference Ar-40 produced by thermal neutron from potassium. Further the laser heating method has been successfull y developed in our laboratory and give reasonable ages for some age st andard and Deccan Trap samples. Application of Ar-40-Ar-39 dating meth od gives ages for Deccan Trap samples which range from less than 60 Ma to about 70 Ma. The clast in a unique meteorite from Antarctica gives a in Ar-40-Ar-39 age of about 490 Ma which corresponds to a degassing event and concordant with that of the host meteorite.