APPLYING HIGH-TEMPERATURE CENTRIFUGES FOR STUDYING MECHANISMS OF SEPARATION OF MAGMATIC MELTS FROM CRYSTALS

Experimental study of the process of separating a melt from the crysta lline matrix in a partially melted olivine-pyroxene-plagioclase mix wa s performed in a high-temperature centrifuge at a(c) = 2500g [m/s(2)]. Generally, four layers of various compositions form in the process of separation of a partial (ca. 20-50 vol %) melt: (1) crystalline resid ual that is ca. 10% melt with insignificant differentiation of crystal line grains from bottom tb top in the lower part of the specimen; (2) a layer of crystals and melt with significant differentiation of cryst als up the specimen; (3) a layer; of separated melt; (4) a layer of em ersed plagioclase crystals with some melt in intercrystalline spaces. Separation of silicate systems at lower melting temperatures requires an increase in the centrifugal force. Based on the results of the expe riments, conclusions were made on the conditions of formation of layer ed magmatic intrusions and anorthosites in the process of differentiat ing basic magmas and anorthositic crust of the Moon.