TY - JOUR
T1 - Chemical characteristics of the lherzolitic shergottite Yamato 000097
T2 - magmatism on Mars inferred from the chemical compositions of shergottites
AU - Shirai, Naoki
AU - Ebihara, Mitsuru
N1 - Funding Information:
We thank the National Institute of Polar Research and the Meteorite Working Group of NASA for providing samples of Y000097 and ALH 77005, respectively. PGA and INAA analyses were made possible by an inter-university cooperative program for the use of JAEA facilities, supported by the University of Tokyo. We thank Tsutomu Ohtsuki and Hideyuki Yuki of the Laboratory for Nuclear Science, Tohoku University for their assistance with IPAA analyses. Yasuji Oura is acknowledged for his help throughout this work. This study was partly supported by a Grant-in-Aid awarded by the Ministry of Education, Science and Technology (MEXT) of Japan (Nos. 15340193 and 19340169 to ME).
PY - 2009/9
Y1 - 2009/9
N2 - As a part of a consortium study, we analyzed the Martian meteorite Yamato (Y) 000097 by prompt gamma-ray analysis, instrumental neutron activation analysis, and instrumental photon activation analysis. For comparison, we also analyzed Allan Hills (ALH) 77005 using the same methods. The data confirm that Y000097 belongs to lherzolitic shergottites in terms of chemical composition. Although there exist slight differences in elemental abundances among lherzolitic shergottites due to differences in the modal abundances of constituent minerals, they have essentially the same chemical compositions, suggesting they are genetically related and experienced similar formation histories. Zr/Hf ratios obtained for Y000097 and ALH 77005 are subchondritic, consistent with values reported for other lherzolitic shergottites and olivine-phyric shergottites. Such fractionation can be explained by invoking clinopyroxene, ilmenite, or majorite in the petrogenesis of the shergottites' source material. CI-normalized Hf/Sm ratios obtained for Y000097 and ALH 77005 are 1.52 and 1.37, respectively, consistent with superchondritic Hf/Sm ratios reported for shergottites. Based on experimentally derived partition coefficients, majorite is the best candidate mineral for the fractionation of Hf and Sm in shergottites.
AB - As a part of a consortium study, we analyzed the Martian meteorite Yamato (Y) 000097 by prompt gamma-ray analysis, instrumental neutron activation analysis, and instrumental photon activation analysis. For comparison, we also analyzed Allan Hills (ALH) 77005 using the same methods. The data confirm that Y000097 belongs to lherzolitic shergottites in terms of chemical composition. Although there exist slight differences in elemental abundances among lherzolitic shergottites due to differences in the modal abundances of constituent minerals, they have essentially the same chemical compositions, suggesting they are genetically related and experienced similar formation histories. Zr/Hf ratios obtained for Y000097 and ALH 77005 are subchondritic, consistent with values reported for other lherzolitic shergottites and olivine-phyric shergottites. Such fractionation can be explained by invoking clinopyroxene, ilmenite, or majorite in the petrogenesis of the shergottites' source material. CI-normalized Hf/Sm ratios obtained for Y000097 and ALH 77005 are 1.52 and 1.37, respectively, consistent with superchondritic Hf/Sm ratios reported for shergottites. Based on experimentally derived partition coefficients, majorite is the best candidate mineral for the fractionation of Hf and Sm in shergottites.
KW - Chemical composition
KW - Lherzolitic shergottites
KW - Magmatism
KW - Y 000097
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U2 - 10.1016/j.polar.2009.07.003
DO - 10.1016/j.polar.2009.07.003
M3 - Article
AN - SCOPUS:69849114172
SN - 1873-9652
VL - 3
SP - 117
EP - 133
JO - Polar Science
JF - Polar Science
IS - 2
ER -