宁强陨石(CV3)稀有气体的研究

THE NOBLE GASES AND COSMIC RAY EXPOSURE AGE FO THE NINGQIANG CHONDRITE

宁强陨石的岩石学、矿物学及化学组成的研究表明,宁强陨石属于异常的CV3碳质球粒陨石,稀有气体和宇宙射线暴露年龄的测定结果与岩石学及化学组成的研究结果是一致的,宁强陨石的宇宙射线暴露年龄为42.2Ma,在CV3球粒陨石中是最高的,U/Th-4He及40K-40Ar气体保存年龄分别为4170±160Ma和4260±70Ma,这与碳质球粒陨石的气体保存年龄为4200Ma是一致的.

On the basis of study on petrology and chemical composition the Ningqiang chondrite is an anomalous CV3 chondrite (oxidized subgroup). It contains a high abundance of ag-gregational chondrules and a very low abundance of refractory inclusions. The isotopic abundances of the noble gases in bulk samples of the Ningqiang chondrite are measured. Ningqiang chondrite shows a cosmic ray exposure age of 42.2 ±4.0 Ma, the highest for CV3 chon-drites. The U/Th-4He age is 4170 ± 160 Ma whereas the 40K-40Ar age is 4260 ± 70 Ma which are similar to other CV3 chondrites such as Leoville.