New high-pressure polymorphs of magnetite, ilmenite, olivine, pyroxenes and feldspars

Abstract

The new high-pressure shock-produced minerals discovered in meteorites can be considered as the possible components of the deep-seated geospheres. The structure peculiarities of the recently discovered minerals of this genetic type and of the geophysical interest are discussed in the paper. The special attention is addressed on the structure transformation under high pressure of the (Fe,Ti)-oxides and the new HP-polymorphs of ilmenite, post-spinel phases, magnetite, olivine, pyroxene and feldspars. The high-pressure polymorphs of these minerals are thought to be the constituent of the deep Earth’s interior. The crystal structures and composition of new НР-minerals discovered in meteorites and in the rocks near terrestrial impact craters provide the richer information on the complicate petrology of deep-seated geospheres which cannot be obtained on the base of laboratory experiments. On this basis it is also possible to predict their role as potentially important carriers of large ion lithophile elements in the Earth’s mantle and, hence, important contributors to the Earth’s heat budget.