沁水盆地中生代晚期构造热事件

TECTONIC THERMAL EVENTS OF LATE MESOZOIC IN QINSHUI BASIN

任战利 赵重远 陈刚 王世成

Ren Zhanli Zhao Zhongyuan Chen Gang Wang Shicheng

在沁水盆地中,通过镜质体反射率、包裹体测温和裂变径迹等方法恢复得到的古地温和古地温梯度有较好的一致性。沁参1井的古地温梯度达每百米4.73～6.10℃,古大地热流在82～106mW/m之间。这样高的古地温梯度肯定与构造热事件有关。经分析,沁水盆地Ro值在纵向剖面不存在错断现象,在平面分布上与中生代晚期的盆地形态相一致,并且高值分布区与岩浆活动有关;盆地内岩体同位素年龄大都在95.34～166.45Ma之间,周边地区岩浆活动带中的500多个同位素年龄的最大丰度值也介于124～153Ma之间。这些都说明这次构造热事件发生在晚侏罗世至早白垩世,是燕山中期运动的反映。

Through the analysis of vitrinite reflectance,inclusion and apatite fission track,paleogeotemperature and paleogeothermal gradient obtained in Late Mesozoic of Qinshui Basin show well coincidence with each other.The paleogeothermal gradient of Qincan-1 well is between 4.73℃/100 m～6.10℃/100 m,its paleoheat flow is 82 mW/m～106 mW/m.This is evidently related to tectonic thermal event.In horizental,the distribution of value coincides with the configuration of the basin in Late Mesozoic,and the high value distribution region was related to magmatic activity.The isotopic age of the rock bodies is between 95.34 Ma～166.45 Ma, and the highest abundent of that in the peripheral magmatic active zones is 124 Ma～153 Ma.It suggests that the tectonic thermal event happened in Late Jurassic-Early Cretaceous,and that the event was the reflection of mid Yenshan movement.

10.11743/ogg19990110