川东北地区中、新生代热历史的裂变径迹分析

通过对6个砂岩样品磷灰石裂变径迹年龄的分析和时间-温度演化历史的反演，研究了川东北地区中、新生代的热历史。结果表明，川东北地区的构造-热演化过程可划分为三个阶段：距今105～80 Ma的快速抬升冷却阶段、距今80～12 Ma的相对平静阶段、距今12 Ma以来的快速抬升冷却阶段。在此基础上，分析认为：川东北地区在早白垩世末地层达到最大埋深，之后开始抬升剥蚀，总剥蚀量为2240 m；构造变形始于距今105～80 Ma，构造的发育与气烃生成的高峰期具有良好的匹配关系，有利于区内构造-岩性复合气藏的形成；距今12 Ma以来的新构造运动使得川东构造带进一步的隆升并最终定型，导致了油气的晚期成藏并最终定位。

FISSION TRACK ANALYSIS OF MESOZOIC-CENOZOIC THERMAL HISTORY IN NORTHEAST SICHUAN BASIN

The Mesozoic Cenozoic thermal history of the northeastern Sichuan Basin is studied through analysis of the age of apatite fission tract of 6 sandstone samples and inversion of time temperature evolutionary history. The structural thermal evolution of the study area can be divided into 3 stages: rapid uplifting and cooling stage (105-80 Ma), relative quiescence stage (80-12 Ma), and rapid uplifting and cooling stage (12 Ma to present). The formations reached their maximum burial depth at the end of Early Cretaceous and began to be uplifted and eroded afterwards with a total eroded thickness of 2240 m. Tectonic deformation began in 105-80 Ma, and the good timing between tectonic development and peak generation of hydrocarbons provided favorable conditions for the formation of structural lithologic combination gas reservoir. The neotectonic movement since 12 Ma caused further uplifting and finalization of the eastern Sichuan structural belt, resulting in the late accumulation of hydrocarbons and final emplacement.