大陆地区构造活动、地热及地壳-上地幔结构之间关系的探讨

随着板块构造学说的兴起和发展,对大洋地区构造活动、地热及地壳-上地幔结构之间的关系已有了较为明确的认识。在大陆地区,由于其构造发展历史的复杂性,对这种关系的认识还远没有大洋区那样系统和清晰。但近二十年来,大陆地区各种地球物理资料的大量积累已为进行这种研究提供了较为坚实的基础。

A DISCUSSION ON THE RELATION AMONG TECTONIC ACTIVITY, CRUST AND UPPER MANTLE STRUCTURE, AND GEOTHERMICS IN CONTINENTAL REGIONS

In this paper, a four-component plot relating mean heat flow, active periods of tectonics and the depths of high conducting layers in the crust and upper mantle has been obtained on the basis of analysing the distribution of geotherms and the depths of high conducting layers in different tectonic regions. There could be two empirical relationships between the depths of high conducting layers in the crust and the upper mantle and the age of the last tectonic event: h-0.21t^1/4 for the crust, and H=0.007t^1/2 for the upper mantle. In the light of above results, it is shown that the process of the lithospheric evolution in continental regions seems to consist of active periods with inc-reasing temperature and intensive activization in the lithosphere, and stable periods with cooling of the lithosphere following each active period. The main energy source in the lithospheric evolution is heat energy from deep. In a given tectonic region, heat flow, tectonic activity, depths of high conducting layers in the crust and the upper mantle, thickness of the crust as well as velocity distribution in the uppermost mantle and other features are essentially reflection of the lithospheric evolution from various aspects and at different structural levels.