青藏高原构造变形与热应力场

自新生代以来,青藏高原构造变形的特点表现为强烈的SN向挤压、逆冲、推覆构造,在后期出现伸展拉张构造。这些构造的形成除了与印度板块推挤有关外,尚与地壳深部温度变化引起的热应力有关。该文计算了由于地壳温度升高引起的热应力场及位移场,指出热应力场及位移场的基本特点,分析了他们在青藏高原构造变形中的作用。考虑到印度板块的推挤、重力和热应力场的共同作用,可以较好地解释青藏高原构造变形的特点及动力学机制。 

TECTONIC DEFORMATION AND THERMAL STRESS FIELD IN QINGHAI-TIBET PLATEAU

The tectonic deformation in Qinghai-Tibet plateau displays strong compression, shortening and thrust in South-North direction since Cenozoic.During the compression and shortening, extensional structure is developed in Qinghai-Tibet plateau.For the purpose of understanding formation extensional structure in compression environment, thermal stress field and displacement field by temperature rising is calculated in crust.The feature of thermal stress field is described.A rising in temperature in lithosphere may cause very substantial tensile stress in shallow and compression stress in deep crust.Considering stress field caused by combined effect of northward push from Indian plate, gravity and thermal stress, tectonic deformation features in Qinghai-Tibet plateau can be understood better.