黑云
2.THE DISCOVERY OF PERCUSSION FIGURE OF BIOTITE FROM THE ARCHAEAN ROCKS AND ITS GEOLOGICAL SIGNIFICANCE IN BENXI AREA,LIAONING PROVINCE,CHINA
3.but that of the upper Anshan Group is 450-500℃, the pressure is less than 5×10~8Pa.
4.The biotite metamorphic temperature of the middle Anshan Group is 556-620℃, the pressure is less than 5×l0~8Pa;
5.(5) The Kd values of Tc on biotite are higher than that on granite and the sorption properties is similar to that of granite;
6.Both the core and the mantle have inclusions of biotite, hornblende, quartz and plagioclase.
8.The Dadongshan pluton in the middle section of Nanling Mountains is co mposed of 4 rock units,of which the earlier units consist of biotite monzonitic granites and the later biotite granites,with a biotite 40Ar/39Ar plateau age o f (162.3±1.2) Ma.
9.Furthermore, ~(40)Ar/~(39)Ar and K-Ar ages of individual mineral indicate that for isotopic age measurement hornblende and biotite are analogously the ideal minerals, while for K-Ar technique hornblend is the best followeed by the biotite, and the feldspar age has to be used with great care.
10.Also studied in this paper is a zoned structure of retrograde mica, which consists of an inner zone of paragonite, an intermediate zone of muscovite_margarite intergrowths and an outer zone of biotite.
