岩石圈中热压系数的计算

Calculations of thermal pressure coefficients in the lithosphere.

如同温度，压力也是决定岩石圈中许多地质作用的主要因素。热压是岩石圈中压力的重要组成部分，热压计算的关键在于热压系数。文中计算岩石圈中主要物质和相态的热压系数，分析影响热压系数的因素及热压存在的条件，并指出岩石圈中热压研究的潜在意义，初步结论如下：（1）岩石圈中的热压系数平均值为3MPa／K左右，其变化范围主要为o．33～9．22MPa／K，主要集中于1．08～4．88MPa／K；（2）岩石圈中的热压系数在物质的相变点处剧增；（3）热压存在的前提是等容体系；（4）岩石圈中热压的存在可造成岩石图中地压梯度明显增加，相变点处的热压剧增可能导致火山、地震、成矿作用及变质作用等，具有极为重要的地质意义。

In the lithosphere, the pressure, like the temperature, is one of the key factors in controlling various geological processes. The thermal pressure is an important part of the pressure in the lithosphere and its calculation mainly depends on the thermal pressure coefficient. The paper calculates the thermal pressure coefficients of major substances and phases, discusses the factors influencing thermal pressure coefficient and the conditions of creating thermal pressure in the lithosphere, and indicates the significance of studying the geothermal pressure. The conclusions are as follows： （1） The average value of the geothermal pressure coefficients is about 3 MPa/K, and the varying range is from 0. 33 to 9. 22 MPa/K, mainly between 1.08 and 4.88 MPa/ K. （2） The geothermal pressure coefficients grow sharply at phase transition temperatures. （3） The condition of creating thermal pressure is the existence of an iso-volume system. （4） Because of the thermal pressure in the lithosphere, the geo-pressure gradients grow obviously. At phase transition temperatures, the sharp growths of thermal pressure may cause volcano, earthquake, mineralization, metamorphism, etc. and are of great significance to the understanding of the geological processes in the lithosphere.