Natural occurrence of MgSiO3-ilmenite and evidence for MgSiO3-perovskite in a shocked L chondrite

被引：107

作者：

Sharp, TG

Lingemann, CM

Dupas, C

Stoffler, D

机构：

[1] INST PLANETOL,D-48149 MUNSTER,GERMANY

[2] UNIV BAYREUTH,BAYER GEOINST,D-95440 BAYREUTH,GERMANY

[3] MUSEUM NATURKUNDE,D-10115 BERLIN,GERMANY

来源：

SCIENCE | 1997年 / 277卷 / 5324期

关键词：

D O I：

10.1126/science.277.5324.352

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Shock-induced melt veins in the Acfer 040 L5-6 (S6) chondrite contain a previously unknown set of high pressure phases consisting of amorphous grains similar in composition to majorite, MgSiO3-ilmenite, and ringwoodite. The amorphous grains have compositions that are similar to those of synthetic MgSiO3-perovskites from chemically complex systems and are inferred to be MgSiO3-perovskite that crystallized. From the melt at high pressure and temperature and subsequently amorphized after pressure release. The ilmenite represents a natural occurrence of a potentially important mineral in Earth's mantle. The MgSiO3-perovskite-MgSiO3-ilmenite-ringwoodite assemblage is not predicted by phase equilibria studies, but appears to result from crystallization of a melt at pressures above 26 gigapascals.

引用

页码：352 / 355

页数：4

共 43 条

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