西藏林周地区红层的天然剩余磁性和印度洋板块的北向移动

举世嘱目的喜马拉雅山系,屹立在我国西藏高原的南部,有关它的形成、演化历史和地质构造特征,很早就引起了人们极大地注意。近十余年来,板块构造学说盛行,不少人也试图用此观点来研究喜马拉雅山系的许多地质问题,认识和解释一些现存的地质现象。1974-1975年,作者参加了西藏高原的科学考察,对林周地区的下第三系--上白垩系林周群红层进行了古地磁学研究。

REMANENCE OF RED BEDS FROM LINZHOU, XIZANG AND THE NORTHWARD MOVEMENT OF THE INDIAN PLATE

The remanence measured from the red beds of Linzhou, Xizang indicates a gradual eastward deviation in magnetic declinations of samples collected from the bottom upward. It is deduced from this fact that during the formation of red beds the basin was subjected to an anticlockwise tectonic movement. Moreover, a method is proposed here, by which the changes in latitudinal distance between two plates can be calculated. And the 3000 km northward movement of the Indian Subcontinent since Late Cretaceous as determined by this method gives an average rate of relative movement between the Indian and the Eurasian Plates should be 5 cm/yr.