A STUDY ON COSMOGENIC NUCLIDES IN JILIN METEORITE AND ITS TWO-STAGE IRRADIATION HISTORY

作     者：欧阳自远,G.霍依兹,M.赫布纳,T.克尔斯顿 

作者机构：Guiyang Institute of Geochemistry Academia Sinica Max-Planck-Institut für Kernphysik Heidelberg Max-Planck-Institut für Kernphysik Heidelberg Max-Planck-Institut für Kernphysik Heidelberg 

出 版 物：《Science China Chemistry》 (中国科学:化学(英文版))

年 卷 期：1984年第3期

页      面：320-332页

主　　题：body A STUDY ON COSMOGENIC NUCLIDES IN JILIN METEORITE AND ITS TWO-STAGE IRRADIATION HISTORY 

摘      要：Forty-four burk samples of the H chondrite Jilin have been analysed for their contents ofspallogenic, trapped and radiogenic noble gases, and thirty-five samples have been determinedfor their radiocosmogenic nuclides. The Jilin meteorite has an extreme complicated history ofcosmic-ray irradiation. In the 1st-stage, the Jilin meteorite might be located between 0.2--2mbelow the surface of the parent body travelling about 8 m. y. in space and under a geometryof 2π subjected to the radiation of cosmic-ray. According to the data of60Co dating the burialdepth of all samples in the 2nd-stage can be determined and the preatmospheric form andsize of the parent body can be restored （under a geometry of 4π）. The result of this recon-struction is that, the 2nd-stage has a nearly spheric form, with a radius of 85±5 cm, weighing9.7±1.7 Ts. The position of the center of the preatmospheric body is: X=55, Y=55 andZ=39. Jilin meteorite No.1 is located at the center of the parent body and is surroundedwith the fragments. The ablation rate is estimated at about 30%. We have proposed a new modelof the two-stage irradiation, and based on the contents of21Ne-60Co in the samples, a classificationscheme can be worked out for the restoration of relative position of the samples within theparent body.