内蒙白旗地区火山碎斑熔岩矿物红外光谱特征研究

正镶白旗碎斑熔岩和花岗斑岩中钾长石主要为高正长石和低透长石，有序度低，反映了白旗火山岩形成温度较高，钾长石有序度具明显的变化规律，反映了各相带岩石形成环境的差异性。各相带中石英的红外光谱反映了与钾长石相同的温度变化规律；岩石中锆石主要以晶质锆石为主；磁铁矿的红外光谱特征则表明碎斑熔岩形成于高氧化条件的侵出相环境。

INFRARED SPECTRUM FEATURES AND PETROLOGIC SIGNIFICANCE OF MINERALS IN PORPHYROCLASTIC LAVA FROM BAIQI AREA,INNER MONGOLIA

Porphyroclastic lava in the Baiqi area is a special volcanic rock consisting of lavagroundmass cemented with volcanic elastics. It was formed as a result of magma emplacement inthe basin along the fault. Result of infrared spectrometry indicated that K-feldspars in the porphyroclastic lava and granite porphyry are largely low sanidine and high orthoclase. They are lowin ordering degree. This indicates a high rock-forming temperature. In order of marginal faciestransition factes~central factes-root factes, or from the outer part to the inner part, the ordering degree tends to increase, implying different rock--forming conditions for different factes. Thisis to say, from the marginal factes to the root factes, the crystallization conditions become moreand more favourable. This result is in good agreement with the infrared spectrum features ofquartz in those rocks. In addition, the zircons in the rocks are mainly crystalline zircon. And theinfrared spectrum feature of magnetite indicates that the rock forms in condition of high oxidatlon.