THE EFFECTS OF THE ORIENTED PRESSURE ON ROCK MASSES AND SOME MINERALS THEREIN

Some Syntectonic metamorphic granites are known to have undergone morphological changes under oriented pressures during their formation, which gives rise to special structures. Meanwhile some minerals such as quartz in the rock have also undergone such a change,i.e.the change from granular through lamellar up to banded structures. Zircon displays pressure-solution phenomena and has become that resembling the’ sediment-transported-type zircon. The cell dimension and refractive index N of garnet have also changed.Even plagioclase number may also show regular deviation. Likewise,the original moderate—pressure granulite was reconstituted by the intense oriented pressure into highpressure granulite with a characteristic mineral association, in which exsolved lamellar albite and exsolved k-f eldspar are developed. The former forms exsolved perthite,while the latter antiperthite. In addition, the pressure shadow of garnet is ready to be observed in the rock.