Cosmogenic and radiogenic noble gases in the Dhajala chondrite

Abstract

Whole rock and chondrules of the Dhajala chondrite were analyzed for Ne, Ar, Kr and Xe by total melting as well as by stepwise heating techniques. The cosmic ray exposure ages for the whole rock and the chondrules are 6.2 ± 0.8 and6.3 ± 1.0m.y. as determined by the ²¹Ne method and 4.8 ± 1.5 and4.2 ± 2.0m.y. by the³⁸Ar method, respectively. The K-Ar age of the whole rock is 4.2 ± 0.4b.y. The elemental composition of the trapped gas in this chondrite is of "planetary" type. The radiogenic ¹²⁹Xe contents in the whole rock and chondrules are similar and this component is very retentively sited in the chondrules.