کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4683341 1349298 2008 20 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Noble gases of the Yamato 000027 and Yamato 000097 lherzolitic shergottites from Mars
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
Noble gases of the Yamato 000027 and Yamato 000097 lherzolitic shergottites from Mars
چکیده انگلیسی

We used total melting and stepwise heating methods to measure noble gases within bulk samples from Yamato 000027 and Yamato 000097 lherzolites as well as a melt-vein sample from Yamato 000027. He and Ne are dominated by cosmogenic noble gases. The obtained cosmic-ray exposure age of 4.6 ± 1.5 Ma, an average age based on cosmogenic 3He, 21Ne, and 38Ar for these samples, is consistent with the ages of other lherzolitic shergottites, indicating a common impact event for the ejection of lherzolites from Mars. Heavy noble gases released from the bulk samples at low temperatures were elementally fractionated terrestrial atmosphere. Martian noble-gas isotopic signatures, 40Ar/36Ar = 1900 and 129Xe/132Xe = 1.3, were observed at high temperatures (>1000 °C). The melt-vein sample released greater amounts of atmospheric Ar, Kr, and Xe at low temperatures than the bulk samples. Large amounts of Ar and Kr, as well as excess 40Ar and 129Xe, were evolved from the melt-vein sample at 1400 °C, and the gas shows very high 36Ar/132Xe (=3100) and 84Kr/132Xe (=76) values. Maximum 40Ar/36Ar and 129Xe/132Xe values of the melt sample were 1100 and 1.6, respectively, at 1600 °C. Cosmogenic Kr shows an absence of 80Kr and 82Kr produced by neutron capture on Br, which suggests a small pre-atmospheric body. Overall noble gas compositions for Y000027 and Y000097 support pairing for the Yamato 00 shergottites.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polar Science - Volume 2, Issue 3, 25 September 2008, Pages 195–214
نویسندگان
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