GRV 90027 is a Martian lherzolitic shergottites （L-S） containing poikilitic, non-poikilitic, and melted pocket components. GRV 99027 is mainly composed of olive （55 vol% ） and pyroxene （37.5 vol% ）, with minor m...GRV 90027 is a Martian lherzolitic shergottites （L-S） containing poikilitic, non-poikilitic, and melted pocket components. GRV 99027 is mainly composed of olive （55 vol% ） and pyroxene （37.5 vol% ）, with minor maskelynite （6 vol% ） and chromite （ 1.5 vol% ）, and trace whitelockite and troilite, ect. In this paper, the mineralogy and petrology of GRV 99027 are reported; in addition, the geochemical characteristics of the REEs and H isotopes in the GRV 99027 are also further investigated. The 2REE in GRV 99027 is relatively low; HREEs are enriched in olivine and pyroxene grains; LREEs are enriched in plagioclase with a high positive Eu anomaly. High EREE value is found in rare mineral whitlockite （less than 0. 2 vol% ）, LREE ≈ HREE, and whitlockite has a negative Eu anomaly. The REE distribution patterns of the whole -rock of GRV 99027 is similar to but different from that of other L-S Martian meteorites, indicating that they came from different location of Mars. GRV 99027 has a high 8D value. Different water-bearing minerals give different contribution for 8D value. The 8D of phosphates generally does not correlate with water content, and 8D has a weak negative correlation with water content. GRV 99027 can be classified as an L-S Martian meteorite based on mineralogical assemblage patterns, REE distribution patterns, and hydrogen isotope. The isotope data of Sr, Nd, Pb, Os and REE from other L-S Martian meteorites were collected to discuss the formation history of the GRV 99027. Similar to other L-S Martian meteorites, GRV 99027 originated from part of Mar＇s mantle; during one strong impact event about 4M years ago, the meteorites were ejected from deep mantle into space, and traveled for a different duration in space （indicated by different cosmic exposure time）, and captured by the Earth later in different time, ultimately falling on the Antarctica as L-S Martian meteorites.展开更多
Thirty-two meteorites were collected in Grove Mountains area, Antarctica, by the 15th and 16th Chinese Antarctic Research Expeditions (CHINARE). Petrography and mineral chemistry of these meteorites are reviewed, amon...Thirty-two meteorites were collected in Grove Mountains area, Antarctica, by the 15th and 16th Chinese Antarctic Research Expeditions (CHINARE). Petrography and mineral chemistry of these meteorites are reviewed, among which there are one Martian lherzolite, one eucrite, one ungrouped iron meteorite, and six unequili-brated and twenty-three equilibrated ordinary chondrites. An equilibrated ordinary chondrite GRV 98004 ( H5 ) has an unusually low cosmic-ray exposure age. Meteorite concentrating processes in Grove Mountains area are discussed. In addition, future studies on Grove Mountains (GRV) meteorites are proposed.展开更多
文摘GRV 90027 is a Martian lherzolitic shergottites （L-S） containing poikilitic, non-poikilitic, and melted pocket components. GRV 99027 is mainly composed of olive （55 vol% ） and pyroxene （37.5 vol% ）, with minor maskelynite （6 vol% ） and chromite （ 1.5 vol% ）, and trace whitelockite and troilite, ect. In this paper, the mineralogy and petrology of GRV 99027 are reported; in addition, the geochemical characteristics of the REEs and H isotopes in the GRV 99027 are also further investigated. The 2REE in GRV 99027 is relatively low; HREEs are enriched in olivine and pyroxene grains; LREEs are enriched in plagioclase with a high positive Eu anomaly. High EREE value is found in rare mineral whitlockite （less than 0. 2 vol% ）, LREE ≈ HREE, and whitlockite has a negative Eu anomaly. The REE distribution patterns of the whole -rock of GRV 99027 is similar to but different from that of other L-S Martian meteorites, indicating that they came from different location of Mars. GRV 99027 has a high 8D value. Different water-bearing minerals give different contribution for 8D value. The 8D of phosphates generally does not correlate with water content, and 8D has a weak negative correlation with water content. GRV 99027 can be classified as an L-S Martian meteorite based on mineralogical assemblage patterns, REE distribution patterns, and hydrogen isotope. The isotope data of Sr, Nd, Pb, Os and REE from other L-S Martian meteorites were collected to discuss the formation history of the GRV 99027. Similar to other L-S Martian meteorites, GRV 99027 originated from part of Mar＇s mantle; during one strong impact event about 4M years ago, the meteorites were ejected from deep mantle into space, and traveled for a different duration in space （indicated by different cosmic exposure time）, and captured by the Earth later in different time, ultimately falling on the Antarctica as L-S Martian meteorites.
基金supported by the Pilot Project of the Knowledge Innovation Program(KIP)of Chinese Academy of Sciences(No.KZCX3-SW-123)
文摘Thirty-two meteorites were collected in Grove Mountains area, Antarctica, by the 15th and 16th Chinese Antarctic Research Expeditions (CHINARE). Petrography and mineral chemistry of these meteorites are reviewed, among which there are one Martian lherzolite, one eucrite, one ungrouped iron meteorite, and six unequili-brated and twenty-three equilibrated ordinary chondrites. An equilibrated ordinary chondrite GRV 98004 ( H5 ) has an unusually low cosmic-ray exposure age. Meteorite concentrating processes in Grove Mountains area are discussed. In addition, future studies on Grove Mountains (GRV) meteorites are proposed.
