柴达木盆地东部古生代以来构造-热演化
发布时间：2019-03-17 09:25
【摘要】：柴达木盆地是我国西部三大含油气盆地之一,经历了多期叠加与改造。盆地构造-热演化史研究一方面对分析柴达木盆地的构造成因,揭示青藏高原的形成机制和隆升历史有重要的意义,另一方面为盆地进行油气资源评价提供科学依据。采用平衡剖面技术、磷灰石裂变径迹年龄分布特征定性分析与径迹长度分布数据定量模拟相结合的方法,分析了柴达木盆地东部古生代以来的构造演化过程,研究表明:柴达木盆地东部在侏罗纪早期构造活动强烈,导致了石炭系抬升、剥蚀;白垩纪末期构造运动相对较弱,表现为早期的弱伸展与晚期北东-南西向的挤压;喜山运动在该区域多期发育,主要为喜山运动早期(41.1~33.6Ma)、喜山运动晚期(9.6~7.1 Ma,2.9~1.8 Ma),其中晚喜山运动造成了先存断裂的再次活化。在埋藏史重建的基础上,对柴达木盆地东部热历史进行了恢复,结果表明柴达木盆地东部热历史总体变现为缓慢降低的特征,古生代末期柴达木盆地东部古地温梯度为38~41.5℃/km,地温梯度平均值为39℃/km;古近纪早期地温梯度降为29~35.2℃/km,平均值为约33.0℃/km,古近纪末地温梯度有所变大,新近纪末趋于现今的热状态。柴达木盆地东部古生代以来构造-热演化特征主要受控于研究区岩浆热事件发育与构造活动的特征。
[Abstract]:Qaidam basin is one of the three major petroliferous basins in western China, which has undergone multi-stage superposition and transformation. On the one hand, the study of tectonic-thermal evolution history of the basin is of great significance for analyzing the tectonic origin of Qaidam basin and revealing the formation mechanism and uplift history of the Qinghai-Tibet Plateau. On the other hand, it provides a scientific basis for the evaluation of oil and gas resources in the basin. By means of balanced section technique, qualitative analysis of apatite fission track age distribution characteristics and quantitative simulation of track length distribution data, the tectonic evolution process since Paleozoic in eastern Qaidam Basin is analyzed. The results show that the eastern Qaidam basin has strong tectonic activity in the early Jurassic, which led to the Carboniferous uplift and denudation. The tectonic movement in the late Cretaceous is relatively weak, which is characterized by the weak extension in the early stage and the compression in the NE-SW direction in the late stage. The Himalayan movement developed in many stages in this area, mainly in the early Himalayan movement (41.1~33.6Ma) and the late Himalayan movement (9.6 Ma,2.9~1.8 Ma), in which the late Himalayan movement resulted in the re-activation of the pre-existing faults. Based on the reconstruction of burial history, the thermal history in the eastern Qaidam basin is restored. The results show that the thermal history in the eastern Qaidam basin is gradually decreasing. The paleogeothermal gradient of the eastern Qaidam basin in the late Palaeozoic era is 38 ~ 41.5 鈩，
本文编号：2442153
[Abstract]:Qaidam basin is one of the three major petroliferous basins in western China, which has undergone multi-stage superposition and transformation. On the one hand, the study of tectonic-thermal evolution history of the basin is of great significance for analyzing the tectonic origin of Qaidam basin and revealing the formation mechanism and uplift history of the Qinghai-Tibet Plateau. On the other hand, it provides a scientific basis for the evaluation of oil and gas resources in the basin. By means of balanced section technique, qualitative analysis of apatite fission track age distribution characteristics and quantitative simulation of track length distribution data, the tectonic evolution process since Paleozoic in eastern Qaidam Basin is analyzed. The results show that the eastern Qaidam basin has strong tectonic activity in the early Jurassic, which led to the Carboniferous uplift and denudation. The tectonic movement in the late Cretaceous is relatively weak, which is characterized by the weak extension in the early stage and the compression in the NE-SW direction in the late stage. The Himalayan movement developed in many stages in this area, mainly in the early Himalayan movement (41.1~33.6Ma) and the late Himalayan movement (9.6 Ma,2.9~1.8 Ma), in which the late Himalayan movement resulted in the re-activation of the pre-existing faults. Based on the reconstruction of burial history, the thermal history in the eastern Qaidam basin is restored. The results show that the thermal history in the eastern Qaidam basin is gradually decreasing. The paleogeothermal gradient of the eastern Qaidam basin in the late Palaeozoic era is 38 ~ 41.5 鈩，
本文编号：2442153
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