内蒙古银额盆地希热哈达地区中生代构造活动的磷灰石裂变径迹约束
发布时间：2018-11-06 18:14
【摘要】：银额盆地位于内蒙古西部,自古生代形成之后经历了多期次构造改造。燕山期构造运动使盆地经历了陆内盆山构造演化,并在白垩纪孕育了查干凹陷、居延海凹陷等一系列的生油凹陷,这些生油凹陷的构造演化过程还有待进一步研究。本文通过对银额盆地西北部希热哈达地区(居延海凹陷)的5口钻井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。8个样品的中心年龄为111±8~140±8Ma,径迹长度在12.1±1.9~12.8±2.2μm之间,各样品径迹长度分布具有单峰、负偏的特征。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。该时期是研究区主要抬升期,根据研究区部分钻井样品的镜质体反射率恢复中下侏罗统剥蚀厚度在1069.06~2503.73m之间,证明该时期抬升强烈,油气系统遭受破坏。同时,利用Hefty软件对8个样品开展的热史模拟较为一致地反应研究区在晚侏罗世之前达到最大埋深,之后在140~111Ma之间经历了短暂的快速抬升,进入磷灰石退火带温度范围(120℃左右)。此后较长时间内温度保持极为缓慢的降低,直至60~40Ma退出退火温度上限即生油门限温度,并持续至今,期间并无强烈的构造抬升。结合与银额盆地中部雅干地区和东部尚丹凹陷所开展工作(磷灰石裂变径迹记录年龄为90~113Ma,129~159Ma),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。
[Abstract]:The Yinzao basin is located in the west of Inner Mongolia and has undergone multiple structural transformations since the Paleozoic formation. During the Yanshanian tectonic movement, the basin underwent the evolution of intracontinental basin-orogenic structure, and a series of oil-generating sag, such as Chagan sag and Juyanhai sag, were conceived in the Cretaceous. The structural evolution process of these oil-generating sag needs to be further studied. Based on the study of apatite fission track in 5 wells in Xije-hada area (Juyanhai Sag) in northwestern Yinye Basin, the authors reveal the Mesozoic tectonic evolution history of the studied area. The central age of 8 samples is 111 卤8140 卤8 Ma. The length of track is between 12.1 卤1.9 渭 m and 12.8 卤2.2 渭 m, and the length distribution of each sample has the characteristics of single peak and negative deviation. It reflects the tectonic events of uplift and denudation in the study area during the late Jurassic-early Cretaceous period affected by the Yanshanian III act tectonic movement. This period is the main uplift period in the study area. According to the vitrinite reflectance of some drilling samples in the study area, the denudation thickness of the Middle and Lower Jurassic is between 1069.06 and 2503.73 m, which proves that the uplift is strong and the oil and gas system is destroyed in this period. At the same time, the thermal history of eight samples was simulated by Hefty software. The study area reached the maximum burial depth before the late Jurassic, and then experienced a short period of rapid uplift between 140~111Ma. Enter the apatite annealing zone temperature range (about 120 鈩，
本文编号：2315083
[Abstract]:The Yinzao basin is located in the west of Inner Mongolia and has undergone multiple structural transformations since the Paleozoic formation. During the Yanshanian tectonic movement, the basin underwent the evolution of intracontinental basin-orogenic structure, and a series of oil-generating sag, such as Chagan sag and Juyanhai sag, were conceived in the Cretaceous. The structural evolution process of these oil-generating sag needs to be further studied. Based on the study of apatite fission track in 5 wells in Xije-hada area (Juyanhai Sag) in northwestern Yinye Basin, the authors reveal the Mesozoic tectonic evolution history of the studied area. The central age of 8 samples is 111 卤8140 卤8 Ma. The length of track is between 12.1 卤1.9 渭 m and 12.8 卤2.2 渭 m, and the length distribution of each sample has the characteristics of single peak and negative deviation. It reflects the tectonic events of uplift and denudation in the study area during the late Jurassic-early Cretaceous period affected by the Yanshanian III act tectonic movement. This period is the main uplift period in the study area. According to the vitrinite reflectance of some drilling samples in the study area, the denudation thickness of the Middle and Lower Jurassic is between 1069.06 and 2503.73 m, which proves that the uplift is strong and the oil and gas system is destroyed in this period. At the same time, the thermal history of eight samples was simulated by Hefty software. The study area reached the maximum burial depth before the late Jurassic, and then experienced a short period of rapid uplift between 140~111Ma. Enter the apatite annealing zone temperature range (about 120 鈩，
本文编号：2315083
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