张八岭变质地体细碧石英角斑岩系岩石学和岩石化学

本文在1／5万张八岭幅、珠龙幅区调工作基础上．结合邻区有关资料．从张八岭变质地体的细碧－石英角斑岩系的岩石学、岩石化学及地球化学特征．讨论了细碧－石英角斑岩系的变质作用、岩石化学、原岩建造特点及其原始构造环境。

PETROLOGICAL AND PETROCHEMICAL FEATURES OF SPILITE-QUARTZ-KERATOPHYRE,ZHANGBALING METANORPHIC TERRANE

Zhangbaling metamorphic terrane is located in the east of Qinling-Dabie orogenic zone,which developed between North China Block and Yangtze Block. Based on reginal geologicalsurvey on the scale of 1: 50000, authors paid great attention to the study of petrological andpetrochemical features of spilite-quartz-keratophyre in Zhangbaling metamorphic terrane, inorder to obtain some information on metamorphism, primitive rock formation and tectonie environment from the spilite-quartz-keratophyre.Main conclusions are as follow:1.Spilite-quartz-keratophyte system in Zhangbaling metamorphic terrane is a suite of basic-acid metamorphic volcanic rocks which erupted from sea floor. Eruption activity is characteristic with the intermittence features. The forming tectonic environment belongs to istand arcand active continental margin.2.The spilite-quartz-keratophyre spotem in Zhangbaling metamorphic terrane was aproduct of Jinning movement. Isotopic age is 927Ma, which indicates that the collision between North China Block and Yangtze Block took place in late-Proterozoic era. The spilitequartz-keratophyre system may extend southwards to Taihe-Suosung region.