鄂尔多斯盆地早中侏罗世延安组软沉积物变形及成因分析  

SOFT SEDIMENT DEFORMATION AND GENESIS OF THE EARLY-MIDDLE JURASSIC YANAN FORMATION,ORDOS BASIN

作　　者：冷丹凤[1] 田坤 王彩霞[1] 师学耀[1] LENG Dan-feng;TIAN Kun;WANG Cai-xia;SHI Xue-yao(Exploration and Development Technology Research Center,Yanchang Oilfield Co.,Ltd.,Yan’an 716000,Shaanxi Province,China;Shaanxi Yanchang Petroleum(Group)Co.,Ltd.,Xi’an 710069,China)

机构地区：[1]延长油田股份有限公司勘探开发技术研究中心,陕西延安716000 [2]陕西延长石油(集团)有限责任公司研究院,陕西西安710069

出　　处：《地质与资源》2020年第5期454-460,418,共8页Geology and Resources

摘　　要：古地震相关的软沉积物变形构造在盆地演化中具有指示盆地及其周缘构造活动的作用.在鄂尔多斯盆地延安组岩心描述和野外调查过程中,于定边西南部DT3522井、安塞延河剖面中,发现并识别出软沉积物液化变形层,包括液化作用相关的枕状层、液化砂岩脉、液化角砾岩、泥火山,以及负载构造、球枕构造等9种变形构造.通过软沉积物变形层位对比,变形特征研究,结合区域构造背景认为,鄂尔多斯盆地延安组延7油层组沉积末期,发生了3期古地震活动,且呈现地震强度先弱后强的特征.The paleoearthquake-related soft sediment deformation structure plays a role in revealing the tectonic activity of basin and periphery in basin evolution.Based on the core description and field survey of Yanan Formation in Ordos Basin,the soft sediment liquefaction deformation layers are identified in DT3522 well in the southwest of Dingbian and the Yanhe section in Ansai,including the liquefaction-related pillow beds,liquefied sandstone vein,liquefied breccia,mud volcano and 9 deformation structures such as load structure and ball-and-pillow structure.Through study on the correlation between soft sediment deformation layers and deformation characteristics,combined with regional tectonic setting,it is believed that there are 3 stages of paleoseismic activities with the earthquake from weak to intense in the late sedimentary period of Y7 oil layer in Yanan Formation,Ordos Basin.

关 键 词：鄂尔多斯盆地 早中侏罗世 延安组 软沉积物变形 古地震 陕西省 

分 类 号：P583[天文地球—岩石学] P315[天文地球—地质学]