A New IAB Lab Iron Meteorite from China

Ponganis, K V ; Lavielle, B ; Spettel, B ; Buchwald,V F ; Nishiizumi, K ; Caffee, M W ; Marti, K

Lawrence Livermore National Laboratory

关键词: Rare Gases;    Shielding;    China;    Iron Meteorites;    58 Geosciences;   

DOI  :  10.2172/15013415
RP-ID  :  UCRL-ID-145419
RP-ID  :  W-7405-ENG-48
RP-ID  :  15013415

美国|英语

来源: UNT Digital Library

【 摘 要 】

Dr. W. Wei, at UCSD, provided our laboratory with chips from a suspected iron meteorite. The mass (>10 kg) was found approximately 8 northwest of Zhongshan in Guangxi province by a farmer in his fields. This mass has now been identified as an IAB iron meteorite (provisional name Zhongshan No.1) based on its composition, N signature, and petrographic analysis. A second chip from a much larger mass (Zhongshan No.2), still in the ground, was recently made available and work is in progress on it, but not reported. Preliminary N isotopic analysis on Zhongshan sample No.1 suggested that the iron mass might be a IAB/IIICD type. Petrographic inspection and INAA analysis has verified that this sample is a typical member of the coarse octahedrites, of the resolved chemical group IAB. Zhongshan No.1 was well-shielded. Its estimated CRE age is {ge}440 Ma. Determination of the radionuclides and noble gases on Zhongshan sample No.2 (in progress) will give useful information on the exposure and shielding history of the meteoroid and its possible atmospheric break-up.