吐哈盆地台北凹陷中部地区喀拉扎组一段震积岩的发现及其地质意义  

Discovery of seismites in the first member of the Kelaza Formation in central Taibei Sag of Tuha Basin and its geological significance

作　　者：唐文斌[1,2] 徐胜林[2] 陈洪德[2] 陈安清[2] 梁杰[3] 肖冬生[3] 

机构地区：[1]北京大学地球与空间科学学院石油与天然气研究中心,北京100871 [2]成都理工大学沉积地质研究院,四川成都610059 [3]中国石油吐哈油田公司勘探开发研究院,新疆哈密839009

出　　处：《石油与天然气地质》2017年第2期345-354,共10页Oil & Gas Geology

基　　金：国家自然科学基金青年科学基金项目(41602107);成都理工大学中青年骨干教师培养计划项目(JXGG201537;JXGG201538)

摘　　要：吐哈盆地是具有双重基底与前陆结构的多旋回复合盆地。晚侏罗世的燕山运动控制和影响着喀拉扎组的沉积作用。通过20余口钻井的岩心观察,首次在胜北-红连地区上侏罗统喀拉扎组一段中识别出多种地震成因的软沉积物变形构造,包括液化作用成因的砂岩脉(墙)、液化角砾岩、液化卷曲变形、球-枕构造、液化均一层和负载构造;水塑性变形成因的纹层卷曲变形、丘-槽构造、环形层和振动滑塌;脆性变形成因的震积角砾岩、阶梯状微断层和"V"字型地裂缝。依据仅在喀拉扎组一段中识别的震积岩变形特征,建立了震积岩垂向序列,表明研究区在喀拉扎组一段沉积期,受频繁而强烈地震事件的影响。详细对比了震积岩在各口钻井中的时空分布规律,地震强度从北部山前带的胜北地区到南缘的红连地区有减弱的趋势,表明古地震的震源来自博格达造山带。Dickinson三角投点图也显示喀拉扎组一段砂岩的物源主要来自北部的博格达山造山带。震积岩的大量发育表明,燕山运动Ⅱ幕导致博格达山于晚侏罗世喀拉扎组一段沉积期发生了剧烈的构造隆升,该地区的发现的大量震积岩是盆-山关系的特殊沉积响应。Tuha Basin is a polycyclic composite basin with dual base and foreland structures. The Yanshan movement during the Late Jurassic controlled and affected the sedimentation of the Kelaza Formation in the basin. Based on observations of cores from more than 20 wells drilled in the Formation, we recognized for the first time some deformed structures of soft sediments originated from seismieity, including sandstone veins （dikes） , liquefied breccias, liquefied crinkling deformation, ball-pillow shaped structures, liquefied homogeneous layers and load structures of liquefaction origin;lamellar crinkling deformation, mound-trough structures, annular layers and vibration collapse structures of hydroplastie deformation origin ; and seismite breceias, echelonment micro-faults and V-shaped ground fractures of brittle deformation origin. A vertical succession of seismites was established based on the deformation features of seismites recognized in the first member of the Formation. It indicates frequent and intensive seismic activities during the formation of the member. By comparing the spatial and temporal distributions of seismites, we found that the intensity of seismic activities weakened along the Shengbei area at the northern foreland to the Honglian area at the southern margin of the basin,indicating the Bogeda oro- genic belt being the earthquake source. A Dickinson triangle chart also revealed that the belt was the provenance of the sandstone in the first member. The widely-distributed seismites （a special sedimentary response between basins and mountains） in the member also indicated that the Bogeda Mountain was strongly uplifted during the sedimentation of the first member in the Later Jurassic due to the second phase of the Yanshan movement.

关 键 词：震积岩 燕山运动 喀拉扎组 晚侏罗纪 博格达山 台北凹陷 吐哈盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探]