石油与天然气地质 ›› 2011, Vol. 32 ›› Issue (3): 430-439.doi: 10.11743/ogg20110316

• 石油与天然气地质 • 上一篇    下一篇

松辽盆地基底石炭-二叠系热演化史

  

  • 出版日期:2011-06-28 发布日期:2011-09-23

Restoration of thermal history of the PermoCarboniferous basement in the Songliao Basin

  • Online:2011-06-28 Published:2011-09-23

摘要:

摘要:松辽盆地北部石炭-二叠系镜质体反射率值普遍较高,普遍大于3.0%,不同构造单元石炭-二叠系镜质体反射率值差异较大。松辽盆地深层石炭-二叠系基底镜质体反射率-深度关系曲线分为两种类型,表明松辽盆地深层石炭-二叠系基底有不同的热演化过程。一种是两段型,镜质体反射率-深度曲线在石炭-二叠系顶部不整合面上、下镜质体反射率值发生突变,不整合面之下石炭-二叠系镜质体反射率值及古地温明显高于上覆地层,表明石炭-二叠系最大古地温是在早白垩世登娄库组沉积之前达到的,白垩纪以来沉积地层厚度对石炭-二叠系古地温提高及热演化程度没有影响。另一种为似线型,石炭-二叠系顶部不整合面上、下镜质体反射率值及古地温连续变化,表明石炭-二叠系最大古地温是在晚白垩世—渐新世之前达到的, 白垩纪以来沉积的地层厚度对石炭-二叠系古地温及热演化程度的提高有贡献。在综合分析有机质镜质体反射率、包裹体测温、裂变径迹年龄等多种参数的基础上,对松辽盆地基底石炭-二叠系热演化史进行了恢复,并分析了热演化史与油气生成的关系。

关键词: 关键词:裂变径迹, 古地温, 构造-热事件, 热演化史, 石炭-二叠系, 松辽盆地

Abstract:

Abstract: Vitrinite reflectance of the PermoCarboniferous in the north of Songliao Basin is generally high,usually more than 30%,and varies greatly in different tectonic units.The curve of vitrinite reflectance(Ro)depth(H)of the PermoCarboniferous basement in Songliao Basin has two types,which means that they have different thermal history.One is a twosection type.Vitrinite reflectance values change abruptly across the unconformity on top of the PermoCarboniferous.The Ro values and paleotemperature of the PermoCarboniferous strata under the unconformity are obviously higher than that of the overlying strata,indicating that the maximum paleotemperature of PermoCarboniferous strata had been reached before the deposition of the Early Cretaceous Denglouku Formation.The sedimentary strata deposited since the Cretaceous have no influences on the improvement of the PermoCarboniferous paleotemperature and thermal maturity.The other is a pseudolinear type.The Ro values and paleotemperature vary successively across the unconformity on top of the PermoCarboniferous strata,which shows that maximum paleotemperature of the PermoCarboniferous strata had been reached betwen the Late Cretaceous and Oligocene.The sedimentary strata since the Cretaceous contribute to the improvement of PermoCarboniferous paleotemperature and thermal maturity.Based on comprehensive analysis on vitrinite reflectance,fluid inclusion,fissiontrack age and so on,paleotemperature and thermal history of Songliao Basin is restored,and the relation between basin thermal history and hydrocarbon generation is analyzed.