青藏高原中北部热—应力演化及隆升作用机制

本文以青藏简原地质、地球物理资料为基础，模拟了印度河－雅鲁藏布江缝合线至昆中断裂间高原自６０Ｍａ以来热异常形成、演化及珠动应力场分布格局。研究表明，青藏高原中北部（安多以北）在中新世以前以浅部地壳逆冲、叠覆、隆升为特征；而在中新世以后，中下地壳及岩石田底部高热异常的形成与演化及差异应力场格局的调整与变异导致高原整体快速隆升，并相应控制浅部构造样式、Ｍｏｈｏ面的错断、叠覆及岩浆岩时空分布；目前该地区基本维持２０Ｍａ时的应力场和热异常格局，但非稳态岩石田上的地壳正潜伏着发生后造山伸展作用的动力学机因，而安多以南现阶段的高热流特征则可能主要受制于断裂摩擦生热。

Thermomechnical Evolution of the Central Northern Qinghai Xizang (Tibet) Plateau and Its Uplift

Based on geological and geophysical data from the Qinghai Xizang(Tibet) Plaieau,the paper shows a drimitive modelling result of the formation and evolution of anomalous tem perature and distribution of the creeping stress field from the Yarlung Zangbo River to Central Kunlun fault since 60 Ma after collision. Before Miocene, the area seenied to be characterizedby reverse thrusting and overriding within the shallow crust in the Chntral Northern Qinghai Xizang(Tibet) Plateau. However, after Miocene the rapid uplifting of the plateau was priballyresuhed from the formation and evolution of anonialous teniperature, adjustment and differenti ation of stress field, which conirolled over the shallow tectonic forins, overlapping and faulting of Moho plane and distribution of magniatic rocks. At present, the framework of anomaloustemperature and stress formed at 20 Ma might still niaintained, but post orogeny extension waspossibly induced in the crust over the unstable lithospheric mantle. In addition, the present day high heatflow in the area souih of Anduo is probably derived from the scratching of faults.