低温热年代学和构造模拟约束下逆冲推覆带的构造-热演化及剥露历史恢复  

Tectonothermal evolution and exhumation history of the fold-and-thrust belt constrained by the low-temperature thermochronology and analog models

作　　者：冯乾乾 邱楠生[1,2] 腾格尔 钟宁宁[1] 吴航[1] 龙康杰 FENG Qianqian;QIU Nansheng;BORJIGEN Tenger;ZHONG Ningning;WU Hang;LONG Kangjie(National Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum,Beijing 102249,China;College of Carbon Neutral Energy,China University of Petroleum,Beijing 102249,China;Oil and Gas Survey Center of China Geological Survey,Beijing 100083,China)

机构地区：[1]中国石油大学(北京),油气资源与工程全国重点实验室,北京102249 [2]中国石油大学(北京),碳中和示范性能源学院,北京102249 [3]中国地质调查局油气资源调查中心,北京100083

出　　处：《地质学报》2024年第11期3341-3353,共13页Acta Geologica Sinica

基　　金：国家自然科学基金地质联合基金重点项目(编号U2244208);国家自然科学基金青年基金项目(编号42302138);中国博士后科学基金面上项目(编号2023M733869);中国石油大学(北京)科研基金(编号2462023XKBH003)联合资助的成果。

摘　　要：利用古温标进行热史模拟时,需要设置时间域和温度域的地质约束,其中时间域约束条件的设置限制了热史结果的准确性。逆冲推覆带发生逆冲推覆时,地层抬升和冷却的同时也发生差异水平滑移,使得同一逆冲席的构造抬升过程存在差异,但古温标模拟热史仅揭示样品的冷却过程,无法获得水平位移的信息,因此如何设置合适的时间域约束模拟热史并准确揭示逆冲推覆带的构造-热演化过程是低温热年代学领域探索研究的科学难题。本文以华南地区川东逆冲推覆带为示例,介绍了一种联合构造模拟、平衡剖面解析和低温热年代学、镜质组反射率等多种古温标的热运动学方法,实现“点-面”结合和整体-局部定量耦合,精细剖析逆冲推覆过程抬升剥露的起始时间、方式、速率、期次和幅度,为逆冲推覆带构造-热演化研究提供思路参考。Reconstructing the thermal history using paleothermal indicators requires accurate time-temperature constraints.These constraints limit the accuracy of the reconstructed thermal histories.In fold-and-thrust belts,differential horizontal slip occurs simultaneously with uplift and cooling of strata,leading to variations in the uplift process.However,the thermal history,which revealed the cooling processes of the samples,cannot consider the impact of flexural slip information,which has a significant effect on the structural analysis of a region with a long lateral slip distance.Establishing appropriate time constraints for thermal history reconstruction remains a key challenge in low-temperature thermochronology research,particularly for accurately revealing the tectonothermal evolution of fold-and-thrust belts.This study addresses this challenge by introducing a new thermo-kinematic approach to constrain tectonothermal evolution of the eastern Sichuan fold-and-thrust belt,South China.This approach integrates analog modeling,balanced reconstruction,and various paleothermal indicators,including low-temperature thermochronology and organic matter maturity data.By combining these techniques,we achieve a“pointto-surface”fusion,quantitatively coupling overall and local analyses.This allows for a detailed dissection of the onset,pattern,rate,stage,and magnitude of uplift and exhumation during the thrusting process.These findings provide valuable insights into the restoration of tectonothermal evolution within the foldand-thrust belt.

关 键 词：低温热年代学 逆冲推覆带 构造-热演化 剥蚀量 

分 类 号：P542[天文地球—构造地质学] P597.3[天文地球—地质学]