GENETIC-RELATIONSHIP OF METAMORPHIC REACTION AND DEHYDRATION-MELTING - EXAMPLE FROM AL-RICH GNEISS OF KHONDALITE SERIES ON THE BORDER OF JIN(SHANXI PROVINCE)-INNER MONGOLIA

The high-temperature and pressure experimental data of garnet, sillima ntite and biotite-bearing potash feldspar gneiss (SGBG, natural block rock) has shown that metamorphic reactions between garnet and melt, an d mineral assemblage evolutional features are not only controlled by P -T condition, bur also genetically correlate with dehydration-melting of biotite and partial melting of felsic minerals. Combining experimen tal data with theoretical analyses, the genetic mechanism of metamorph ic reaction and its dynamic significance have been demonstrated in the process of metamorphic evolution of khondalite series on the border o f Jin(Shanxi Province)-Inner Mongolia.