热对流成岩作用的基本特征与研究意义

BASIC CHARACTERISTICS OF THERMAL CONVECTION DIAGENESIS AND ITS RESEARCH SIGNIFICANCE

介绍了热对流产生的条件与地质背景 ,指出火成侵入体、盐丘和活跃断层周围等温线陡倾斜场所易发生热对流成岩作用。综述了岩浆成因热对流的岩石学记录 ,包括热变质作用、突然升温—逐渐降温的自生矿物组合和相对高温的自生矿物类型 ,分析了自生伊利石的 K/Ar年龄在热对流成岩作用研究中的作用。阐述了热对流成岩作用对盆地动力学、砂岩储层和油气运移研究的意义。

As a new research field of fluids rock interaction, the thermal convection diagenesis is developing under the basis of basin geofluids research. This paper introduces the condition and geological settings for the thermal convection diagenesis taking place, points out that the places around igneous intrusions or around salt domes or active faults are subjected to diagenetic reaction. The authors comprehensively discuss the lithologic records of thermal convection caused by magma activity, including thermal contact metamorphic rock, thermal alterated rock, the authigenic minerals assemblages of temperature suddenly increasing temperature gradually decreasing, relatively higher temperature authigenic minerals, analyses the importance of the K/Ar age of authigenic illite in the research of thermal convection diagenesis. The authors also emphases the significance of thermal convection diagenesis research in the field of basin dynamics, the reservoir of sandstone and migration of petroleum.