塔里木克拉通南华纪—寒武纪隆坳格局演化

Evolution of uplift and depression framework of Tarim Craton in Nanhua-Cambrian

塔里木克拉通南华纪—寒武纪的隆坳格局控制着寒武系盐下生储盖的时空分布,对塔里木盆地新元古界—寒武系油气勘探选区有着重要的影响。通过野外地质露头、新的三维地震资料和钻孔,综合研究塔里木克拉通南华纪—寒武纪的构造古地理演化。研究结果认为,南华纪,在罗迪尼亚超大陆裂解的拉张背景下,形成主动裂陷与被动隆起,表现为“两隆四坳”构造背景,分别为中央隆起、库车—塔北隆起、满加尔坳陷、麦盖提坳陷、阿瓦提坳陷与和田坳陷。震旦纪,经历库鲁克塔格运动后的挤压—拉张构造背景,塔南隆起强烈隆升,塔西地台形成,南华纪的阿瓦提坳陷与麦盖提坳陷转变为台内凹陷;构造古地理可划分为塔南隆起、塔西地台、满加尔坳陷与和田坳陷,塔西地台可分为塔北凸起、柯坪—古城凸起、阿满古梁、满西古梁、阿瓦提凹陷、满西凹陷、麦盖提凹陷与乌什凹陷。寒武纪,在柯坪运动后转为拉张环境,构造古地理可划分为塔南隆起、温宿—牙哈隆起、塔西地台、罗西地台、和田坳陷、满加尔坳陷与乌什斜坡7个一级构造单元,塔西地台内部根据古地形凹凸特点进一步划分为柯坪—古城凸起、阿满古梁、满西古梁、轮南—古城台缘、麦盖提凹陷、阿瓦提凹陷与满西凹陷7个二级构造单元。

The uplift-depression framework of Tarim Craton in Nanhua-Cambrian controlled the temporal and spatial distribution of source rock,reservoir and cap rock assemblages of the subsalt Cambrian,which had an important influence on the selection of favorable exploration zones of the Neoproterozoic-Cambrian.The tectonic paleogeographic evolution of Tarim Craton in Nanhua-Cambrian is comprehensively studied by using field outcrops,new acquired 3D seismic and wells data.Results show that in Nanhua period,active rifts and passive uplifts were formed in extensional setting caused by the breakup of Rodinia supercontinent,with a structural pattern of“two uplifts and four depressions”,including the Central Uplift,Kuqa-Tabei Uplift,Manjiar Depression,Maigaiti Depression,Awati Depression,and Hotan Depression.In Sinian period,affected by the compressional-extensional tectonic settings after the Kuruktag movement,the southern Tarim Uplift was strongly uplifted,the western Tarim Platform was developed,and the Awati Depression and Maigaiti Depression changed into the intra platform sags;The tectonic paleogeography was divided into four units,i.e.,southern Tarim Uplift,western Tarim Platform,Manjiar Depression and Hotan Depression.Furthermore,the western Tarim Platform was subdivided into Tabei Bulge,Keping-Gucheng Bulge,Aman Paleo Ridge,Manxi Paleo Ridge,Awati Sag,Manxi Sag,Maigaiti Sag and Wushi Sag.In the Cambrian,controlled by the extensional setting after the Keping movement,the tectonic paleogeography was divided into seven first-order structural units,namely the southern Tarim Uplift,Wensu-Yaha Uplift,western Tarim Platform,Luoxi Platform,Hotan Depression,Manjiar Depression and Wushi Slope.According to the characteristics of sag and swell paleotopography,the interior of the western Tarim Platform was further subdivided into seven secondary structural units,i.e.,Keping-Gucheng Bulge,Aman Paleo Ridge,Manxi Paleo Ridge,Lunnan-Gucheng Platform Margin,Maigaiti Sag,Awati Sag and Manxi Sag.