内蒙古银额盆地尚丹凹陷中生代构造活动的磷灰石裂变径迹约束  

Apatite Fission Track Constraints on the Mesozoic Tectonic Activities in Shangdan Depression,Yin'e Basin,Inner Mongolia

作　　者：韩伟[1,2] 卢进才[1] 魏建设[1] 张云鹏[1] 李玉宏[1] 李岩[1] 

机构地区：[1]中国地质调查局西安地质调查中心,西安710054 [2]西北大学大陆动力学国家重点实验室/地质学系,西安710069

出　　处：《地质学报》2015年第12期2277-2285,共9页Acta Geologica Sinica

基　　金：国家自然科学基金(41202104)资助;中国地质调查局国土资源大调查项目(1212010733506)资助

摘　　要：本文通过对银额盆地东南缘尚丹凹陷的三条剖面开展磷灰石裂变径迹研究,揭示了研究区中生代构造演化史。5个样品的中心年龄为129±10-159±11 Ma,径迹长度在12.5±2.0-13.3±1.7μm之间,各样品径迹长度分布具有范围较宽、单峰的特征。反映了在晚侏罗世—早白垩世时期,受燕山Ⅲ幕构造运动影响,研究区遭受抬升、剥蚀的构造事件。该时期抬升速率约为40-55m/Ma,且由北向南逐渐降低,是研究区主要抬升期,油气系统遭受破坏。此后至白垩纪末,研究区阿木山组始终处于生烃门限温度内,且构造背景稳定,有利于油气生成。结合与北部凹陷带所开展工作（磷灰石裂变径迹记录年龄为90-113Ma）,证明银额盆地中生代时期存在差异隆升,不同构造位置受不同期次构造运动的影响也存在差异,为银额盆地构造演化研究提供了依据。Using to the apatite fission track of the three sections in the Shangdan depression,the southeastern margin of the Yin＇e basin,the Mesozoic tectonic evolution history in the study area has been studied.The fission track ages of 5samples range from 129±10 Ma to 159±11 Ma,and the track length range from12.5±2.0μm to 13.3±1.7μm.The track length in these samples is characterized by a wide range,and a unimodal pattern.The results show that the study area has undergone uplift-erosion events in the Late Jurassic-Early Cretaceous,which have been affected greatly by curtain Ⅲ of the Yanshan movement.Specifically,the depression has experienced a uplifting process at a uplift rate of 40~55m/Ma with decreasing from north to south.It was the major uplifting period of the study area,and the petroleum system was eventually damaged.Since then,to late Cretaceous the Amushan Formation in the study area came into hydrocarbon threshold,which made great contributions to hydrocarbon generation.Combined with the work undertaken in the northern depression belt（Apatite fission track age is 90-113Ma）,it is recognized that there are some different uplifts in the Yin＇e basin during the Mesozoic era,and different tectonic sites have been affected significantly by different tectonic movements in varied periods.The results provide a solid basis for tectonic evolution of the Yin＇e basin.

关 键 词：内蒙古银额盆地 中生代 磷灰石裂变径迹 构造演化 油气生成 

分 类 号：P618.13[天文地球—矿床学]