新疆塔斯特花岗岩的碱交代及其地质意义的探讨

通过对新疆塔斯特花岗岩体岩石结构和地球化学的研究,提出该岩体曾遭受范围较广,强度不大的碱交代作用和碱质深源的新认识,并认为碱作用及其强度是该区金富集规模的控制因素之一。该区地槽褶皱晚期局部松弛的拉张对塔斯特岩体的成岩、分布和碱作用起着控制作用。

INVESTIGATION OF THE ALKALI-METASOMATIS AND ITS GEOLOGICAL SIGNIFICANCE IN THE TASIT GRANITIC BODY, XINJIANG

Besides the granite texture in Tasit granite, the metasomatic textures, such as metasomatic orrosion texture, reaction rim texture, rimmed texture and metasomatic graphic texture etc. developed well, and the main metasom is K-feldspar. The particular geochemistry characteristics and well developing metasomatic textures in Tasit rock body show that the alkali-metasomatism have occurred in this area. The ~(18)O of different generation quartzes in the rock is low and the ~(87)Sr/ ~(86)Sr is equal to 0.7063. These illustrate that the magma and alkaline material are from deep source, but arc hybridized by the crust, The alkali-metasomatis Occurs in late geosynclinal fold period and is relate to the extension occurring the region. The alkali-metasomatism acts to accelerate the formation of the gold deposits and control their scale.