摘要
依据中国中、新生代11803件岩浆岩常量元素化学全分析资料,采用Sugisaki的由岩石化学成分推算板块运动速度的方法,求得中国各构造时期板内缩短速度与扩张速度。印支、燕山与四川期板内平均缩短速度均在54~56cm/a,华北期稍小,为45cm/a,喜马拉雅期在中国西部平均缩短速度又达52cm/a,新构造期仅为25~28cm/a。在印支期—华北期,中国西南地区一直存在着扩张速度较低(02~16cm/a)的特提斯洋。喜马拉雅期以来中国西南部进一步碰撞,青藏高原隆升,地壳缩短;而东部地区则普遍表现为微弱的扩张(01~06cm/a)。
Depending on 11803 chemical total analysis data of common elements for magmatic rocks of Meso Cenozoic, using the Sugisaki′s method to determine the intraplate deformation velocity from the chemical composition of rocks, the intraplate shortening(closing), and extension velocities of different tectonic stages for China were obtained. The intraplate average shortening velocities are 5 4~5 6cm/a in the Indosinian, Yanshanian and Sichuanian stages, 4 5cm/a in the North Sinian stage., 5 2cm/a at the western China in the Himalayan stage, and 2 5~2 8cm/a in the Neotectonic stage. From the Triassic to Oligocene, there was still the Tethys Ocean with lower extension velocity(0 2~1 6cm/a)in the southwestern area of China. Since the Himalayan stage, the collision further developed in the southwestern China, the Qinghai Xizang Plateau was uplift and the crust was shortening; however, the weak extensions(0 1~0 6cm/a)showed commonly in the eastern China.
出处
《现代地质》
CAS
CSCD
北大核心
1999年第1期83-92,共10页
Geoscience
基金
国家计委国土司资助
国土资源部科技司资助
关键词
板内变形
缩短速度
扩张速度
岩石化学成分
intraplate deformation, shortening velocity, extension velocity, chemical composition of rock