流体包裹体在建立四川盆地古地温剖面研究中的应用

APPLICATIONS OF FLUID INCLUSIONS IN THE STUDY OF PALEO GEOTEMPERATURE IN SICHUAN BASIN

根据四川盆地沉积－埋藏史、主要地热事件、井下Ｒｏ剖面及钻井测温资料的综合分析，应用流体包裹体均一温度资料推算了四川盆地中部各地质时期地层的古地温，并建立了古地温梯度表，用此表可计算四川盆地各时期地层古地温．根据包裹体均一温度确定的古地温表明：四川盆地地层地温梯度由古至今逐渐降低，现今地温状况对古地温状况有明显的继承性．东吴运动（地裂运动）峨嵋山玄武岩大规模喷溢时期是盆地地温梯度最高时期，推算其地温梯度可达６．５℃／１００ｍ．盆地内各区块的地温梯度与盆地的构造背景有关．靠近康滇裂谷的川西南古地温梯度最高，随着距康滇裂谷的距离增加，古地温梯度和今地温梯度也逐渐降低．

With the homogenization temperature of fluid inclusions, the paleo-geotemperature gradient of the strata in different geologic times in the middle part of Sichuan Basin can be calculated on the basis of an integrated analysis of the depositional_burial history of the Basin, the main geothermal events, the data of logging temperature and vitrinite reflectance ( R o) from the cores of wells. Furthermore, the paleo_geotemperature gradient chart can also be established. The chart can be used to calculate the paleo_geotemperature of individual stratum in different geologic time in Sichuan Basin. The results show that the paleo_geotemperature gradient decreases with the strata changing new. The present_geotemperature is the inheritance of the ancestor. Dongwu movement period with the large scale basalt eruption is the maximum geotemperature gradient period of Sichuan Basin, measuring 6.5℃/100m. The geotemperature gradient of the Basin is related to the tectonic setting. The maximum value of paleo_geotemperature gradient of Southwest Sichuan, is nearing the Kangtian rift, and the paleo_and present_geotemperature gradient are gradually decreasing as faraway from the Kangtian rift.