热年代学约束下的松辽盆地石炭-二叠系构造热演化史恢复

Research of basin structure-thermal history is one of the frontier and difficult problem in research of basin analsis and petroleum geology.Songliao basin is located in the central part of Northeast China, Middle shallow oil and gas exploration has reached a high level, the oil and gas in deep position has become a new field of oil and gas exploration currently.The area of Paleozoic marine strata in Songliao Basin is large, Especially the thickness of the Carboniferous Permian source rocks is great and good preservation with great potential for oil and gas exploration. But so far the structure-thermal historyof Carboniferous Permian in Songliao basin has not been yet studied in detail,seriously restricted the process of the deep oil and gas exploration breakthrough.The project takes the results of apatite fission track,zircon fission track and（U-Th）/He dating as constraints and uses a variety of palaeotemperature indicators and thermal dynamic models to quantitative recover the structure-thermal history of Carboniferous Permian in Songliao basin,and determines the time and period of occurrence of tectonic thermal events. On the basis of the above research recovery the late Mesozoic thermal lithosphere thickness, discuss the deep dynamic evolution of Songliao basin.The results of research can provide the ideas and research methods for multiphase tectonic movement area.The project research work has important theoretical significance to the thermodynamics evolution of sedimentary basin under the close basin-mountain coupling relationship and important practical significance to oil and gas exploration in the Carboniferous Permian in Songliao basin.

构造热演化史研究是盆地分析及石油地质领域研究的前沿及难点问题之一。松辽盆地位于东北地区中部，中浅层油气勘探已达到较高程度，深层油气成为目前油气勘探的新领域。松辽盆地古生代海相地层分布面积大，尤其是石炭-二叠系烃源岩厚度大、保存好，具有巨大的油气勘探前景，但迄今为止对石炭-二叠系构造热演化史缺乏深入、系统的研究，严重制约深层油气勘探突破。本项目将以锆石U-Pb定年、磷灰石、锆石裂变径迹及（U-Th）/He定年技术分析结果为约束，应用多种古温标及热动力学模型法来定量恢复松辽盆地石炭-二叠系构造热演化历史，确定构造热事件发生的时间及期次。在此基础上恢复中生代晚期热岩石圈厚度，探讨松辽盆地深部动力学演化过程。本项目研究成果将为多期次构造运动地区构造热演化史的恢复提供思路及研究方法，对盆山紧密耦合关系的沉积盆地热动力学演化研究有重要理论意义，对松辽盆地石炭-二叠系油气勘探有重要现实意义。

构造热演化史研究是盆地分析及石油地质领域研究的前沿及难点问题之一。松辽盆地石炭-二叠系构造热演化史研究程度整体很低，严重制约了该区油气勘探工作。本项目应用多种古温标结合岩石地球化学元素分析方法恢复松辽盆地石炭-二叠系构造-热演化史，建立盆地不同区块石炭-二叠系热演化史模型，确定烃源岩生烃史和热史，预测有利勘探区带，对探讨松辽盆地深部动力学演化具有重要的理论意义，对盆地地热资源开发及利用和上古生界石炭-二叠系油气生成、成藏具有重要的现实意义。.取得以下重要成果：.（1）利用地球化学方法确定了松辽盆地石炭-二叠系构造背景和古气候环境。.（2）明确了盆地现今地温场特征及变化规律，确定了现今地温梯度和大地热流值。.（3）恢复了盆地不同构造单元埋藏史，以叠合盆地热演化史理论为指导，应用多种方法恢复了松辽盆地热演化历史。确定了两期构造-热事件。.（4）明确了松辽盆地石炭-二叠系古地温有两种不同的演化过程，分析了松辽盆地岩石圈经历了先减薄后增生的过程，古地温经历了先升高后逐渐降低的过程。.（5）恢复了盆地不同构造单元石炭-二叠系烃源岩生烃史，预测了有利区。