川西白玉—中甸地区花岗岩类的形成时代探讨

THE FORMATION AGE OF GRANITOIDS IN THE BAIIYUZHONGDIAN AREA, WESTERN SICHUAN

1985年以来,笔者根据所采样品年龄测定资料,确定白玉—中甸地区化岗岩类形成时代为加里东—喜马拉雅早期。而以印支早、晚期,燕山晚期—喜马拉雅早期为成岩的高峰期。

Since 1985, the author and his colleagues have collected eight samples for whole-rock Rb-Sr isochron age determination, four samples for zircon U-Pb Wrych concordia age determination and Six samples for ^(40)Ar/^(39)Ar fast neutron dating. The ages of granitoids exposed widely in the area can be determined and checked by several methods. The granitoids in the area were determined to be Caledonian—Himalayan in age, and the peak periods for the rock formation are middle and late Indosinian and late Yanshanian-early Himalayan.