摘要
采用地层厚度分析、“零点”分析、位移 /距离曲线分析和断层生长指数分析等方法 ,讨论了牙哈负反转断裂带的几何学和运动学特征、主反转期及控油作用 ,结果表明牙哈主断裂主反转期为早白垩世 ,负反转活动结束于中新世康村期—上新世库车期。牙 1号断裂主反转期为中新世苏维依期 ,牙 2号断裂主反转期为晚白垩世—老第三纪 ,二者都于中新世康村期结束反转活动。
The Yaha negative inversion fault belt,which include main Yaha fault,Ya No.1 fault and Ya No.2 fault,is located at the north uplift of Tarim basin. The fault belt is the boundary between the north Tarim uplift and Kuche depression .The main Yaha fault,elongating more than 200 km.is a listric fault that trends NEE and dipps southward,and the dip angle of the fault plane is steep in the shallow strata and become flat in the deep strata.Ya No.1 fault,dipping northward and elongating 35 km,is on the south of main Yaha fault.Ya No.2 fault, dipping northward and elongating about 38 km,is on the south of main Yaba fault and Ya No.1 fault.Ya No.1 and No.2 faults are also negative inversion faults,controlling'graben-type'fault-blocks with main Yaha fault.Yaha fault belt is developed along pre-existing basement faults or weak zones.The evolution of the fault belts has the characteristics of thrustion in the early phase(pre-Cretaceous)and negative inversion in the late stage(Cretaceous-Tertiary). The characteristics of geomety,kinematics,main inversion phase and hydreocarboncontrolling of Yaha negative inversion fault belt,north Tarim uplift,are discussed in this paper according to the analysis of sequence thickness,displacement-distance plot,inflection point,null point and fault growth index.The point of change from thrusting to negative inverstion faulting in the displacement-distance plot is the inflection point which represents the main inversion phase.And the point of transformation from net compression to net extension is the null point.The inflection point of displacement-distance plot of main Yaha fault is at the bottom of Lower Cretaceous,indicating that the negative inversion of main Yaha fault began at the initial Early Cretaceous.The main negative inversion phase is at the Early Cretaceous,henceforth the negative inversion weakens gradually.The secondary inversion phases exist in the late Cretaceous-Paleogene,Suwiyi and Kanchun epoch of Miocene.Fault growth index of main Yaha fault in the main inversion phase of Lower Cretaceous is about 1.44～1.54.And the growth index in the secondary inversion phase is about 1.25～1.28.The negative inversion terminates at the Kanchun epoch of Miocene and Kuche epoch of Pliocene. The inflection point of displacement-distance plot of Ya No.1 fault is at the bottom of Suwiyi Formation of Miocene,indicating that the main inversion phase of the fault is at the Suwiyi epoch of Miocene,and the growth index of the fault at this time is about 1.1～1.69. The inflection point of displacement-distance plot of Ya No.2 fault is at the bottom of Upper Cretaceous-Lower Paleogene,indicating that the main inversion phase of the fault is at the Late Cretaceous-Paleogene,and the growth index of the fault at this time is about 1.1～1.18. A series of local structures.including fault-blocks,fault-anticlines and buried-hill-drapes,are developed along Yaha fault belts.The formation of these structures has a rerationship to negative inversion of the fault belt at the late Yanshan and Himalayan.The Yaha fault belt has the excellent hydrocarbon accumulation conditions because of matched time of main inversion,trap formation,petroleum migration and accumulation.
出处
《沉积学报》
CAS
CSCD
北大核心
2000年第2期302-309,共8页
Acta Sedimentologica Sinica
基金
中国博士后科学基金项目
"八五"国家科技攻关项目! ( 85 1 0 1 )资助
关键词
负反转断裂
油气聚集
塔里木盆地
断裂带
negative inversion fault main inversion phase displacement-distance plot hydrocarbon accumula-tion Tarim basin
