Natural Occurrence of MgSiO 3 -Ilmenite and Evidence for MgSiO 3 -Perovskite in a Shocked L Chondrite
- 18 July 1997
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 277 (5324), 352-355
- https://doi.org/10.1126/science.277.5324.352
Abstract
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, MgSiO 3 -ilmenite, and ringwoodite. The amorphous grains have compositions that are similar to those of synthetic MgSiO 3 -perovskites from chemically complex systems and are inferred to be MgSiO 3 -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 MgSiO 3 -perovskite–MgSiO 3 -ilmenite–ringwoodite assemblage is not predicted by phase equilibria studies, but appears to result from crystallization of a melt at pressures above 26 gigapascals.This publication has 23 references indexed in Scilit:
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