川西龙门山北段中生代差异构造隆升特征  

Characteristics of Mesozoic Differential Tectonic Uplift of the North Section of Longmen Mountains,Western Sichuan Basin

作　　者：金文正[1,2] 白万奎 叶治续[4] JIN Wen-Zheng;BAI Wan-Kui;YE Zhi-Xu(School of Energy Resources,China University of Geosciences,Beijing 100083,China;National Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing 102249,China;Geophysical Research Institute of Sinopec Shengli Oilfield Branch,Dongying 257000,Shandong,China;Jidong Oilfield Branch Company,PetroChina,Tangshan 063200,Hebei,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]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 [3]中国石化胜利油田分公司物探研究院,山东东营257000 [4]中国石油天然气股份有限公司冀东油田分公司,河北唐山063200

出　　处：《华南地质》2023年第4期589-600,共12页South China Geology

基　　金：国家自然科学基金项目(编号:41002072);油气资源与工程全国重点实验室开放课题基金(编号:PRP/open-1307)。

摘　　要：川西龙门山冲断带内部发育多条大型断裂并经历了多期且复杂的构造演化。为探讨龙门山北段中生代以来主要断裂带之间的差异构造隆升,本文开展了锆石裂变径迹年龄测定工作,并计算了冷却速率等构造隆升参数。结果表明,锆石裂变径迹年龄主要集中在238~122 Ma之间,唐王寨向斜和仰天窝向斜核部冷却速率为1.211~1.438℃/Myr,剥蚀速率为0.038~0.048 mm/yr。向斜西北翼冷却速率和剥蚀速率相对稍高,分别为1.150~1.586℃/Myr和0.038~0.053 mm/yr,总体上,锆石裂变径迹年龄、冷却速率和岩石隆升幅度等参数在平面呈带状,且与主干断裂近于平行。各构造隆升参数在青川断裂、北川断裂和江油断裂所夹持的不同区域具有不同的变化范围,自北西至南东方向,构造变形兼具“前展式”和“后展式”特征。由前展式变形转变为后展式变形的时期为139~122 Ma。Longmen Mountains thrust belt,located in western Sichuan province,has experienced many complex stages of tectonic evolution and developed multiple large faults.In order to discuss the differential tectonic uplift among the main faults in the northern section of Longmen Mountains since Mesozoic,this paper has carried out zircon fission track dating and calculated several uplift parameters such as cooling rate etc.The research results show that the zircon fission track ages are mainly among 238~122 Ma.The cooling rates of the core of Tangwangzhai Syncline and Yangtianwo Syncline are 1.211~1.438℃/myr,and the denudation rate is during 0.038~0.048 mm/yr there.The cooling rates and denudation rates of the northwest wing of the synclines are relatively higher,which are 1.150~1.586℃/myr and 0.038~0.053 mm/yr respectively.In general,the zircon fission track age,cooling rate and rock uplift amplitude are banded in the plane and parallel to the main faults.The uplift parameters vary in different regions sandwiched by the Qingchuan Fault,Beichuan Fault,and Jiangyou Fault,while the structural deformation is characterizeds by both"Piggyback propagation"and"Overstep propagation"from the northwest to the southeast.The deformation transition from the piggyback propagation to the overstep propagation is between 139 Ma and 122 Ma.

关 键 词：锆石 裂变径迹 构造隆升 中生代 北川断裂 江油断裂 龙门山 

分 类 号：P542.1[天文地球—构造地质学] P597[天文地球—地质学]