Genetic Types of Ultrahigh-Pressure Minerals in Meteorites

摘要

Minerals formed in natural processes at a very high pressure serve as indicators for the genetic interpretation of both terrestrial rocks and meteorites. They contain, at least, three types of ultrahigh-pressure (UHP) minerals with principally different modes of occurrence and paragenetic relations: (1) minute diamond grains (up to 10 nm in size) that are overfilled with fluid hydrogen inclusions in association with moissanite (SiC) and incorporated into a kamacite matrix of chon-drites of all chemical groups; (2) larger (10-10000 nm) diamond grains enriched in fluid inclusions in association with daubreelite, troilite, and moissanite within kamacite injections into ureilites; and (3) ringwoodite, wadsleyite, majorite, and others in glassy veinlets within brecciated chondrites. The main stages of the evolution of the iron-stony meteoritic material of the solar system are recorded in the UHP minerals listed above.