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岩石圈是比较坚硬的地球外层,能承受相当大的偏应力,相反,软流圈和地球深部由于蠕动,应力差是比较小的。Turcotte和Oxburgh(1976)曾对岩石圈中的应力源作过评述。此后,对岩石圈应力的了解,特别是对板块边界的性质及岩石圈最上弹性部分的应力集中的了解有了进展。本文简单评述各种应力源并评价它们在构造活动中的相对意义。通常把作用于岩石圈的应力系分为两大类型:可恢复型和不可恢复型(Bott,1982)。可恢复型的应力系是持续存在的应力,是起始的边界力或体力连续出现或反复作用的结果,即使应变能是逐渐地散失的。两个主要例子是板块边界力和均衡补偿的地表载荷力造成的应力系。不可恢复型的应力系是那种由初始存在的应变能释放而散失的应力。弯曲应力、表层应力和热应力属于此类。岩石圈中任一点的实际应力是,由叠加的应力系组合产生的。这种应力系会受局部力学性质横向变化的影响。
The lithosphere is a relatively hard outer layer of the Earth that can withstand considerable deviatoric stress. On the contrary, the asthenospheric and earth-depths are relatively small due to creep and stress. Turcotte and Oxburgh (1976) have commented on stress sources in the lithosphere. Since then, progress has been made in understanding the lithospheric stress, in particular the nature of plate boundaries and the stress concentration in the uppermost elastic part of the lithosphere. This article briefly reviews various stressors and assesses their relative significance in tectonic activity. The stresses acting on the lithosphere are usually divided into two major types: recoverable and non-recoverable (Bott, 1982). Recoverable stress system is the persistence of stress, is the initial boundary force or physical continuous or repeated results, even if the strain energy is gradually lost. Two main examples are the stress due to plate boundary forces and equilibrium compensated surface loading forces. Unrecoverable stress is the kind of stress that is dissipated by the strain energy that is initially present. Bending stress, surface stress and thermal stress fall into this category. The actual stress at any point in the lithosphere is due to the combination of superimposed stress lines. This stress can be affected by the lateral changes in local mechanical properties.