摘要
在沉积学和构型要素分析法的指导下,对准噶尔盆地南缘建功煤矿剖面上侏罗统齐古组曲流河砂体进行了构型分析,统计了构型要素和河道砂体的规模和形态,划分了叠置类型。建功煤矿剖面主要发育7种岩石相类型,通过砂体构型分析,识别出6级层级界面,划分出4种构型要素。当可容纳空间增大量(A)与沉积物供给增加量(S)的比值(A/S)大于1时,发育孤立型砂体;随着A/S值减小至1附近时,发育桥接型和叠合型砂体;当A/S值小于1时,发育切叠型砂体。齐古组沉积期,气候炎热干旱,头屯河组沉积期宽阔的湖面下降,建功煤矿剖面发育水深约33.3 m、宽约139.2m的砂质曲流河,河流满岸宽度约805.2m,单一曲流带宽度约6405.2m.齐古组沉积期A/S值先减小后增大,早期发育孤立型砂体和泛滥湖泊砂体;中期发育桥接型砂体、叠合型砂体和切叠型砂体;后期再次以发育孤立型砂体为主。
Guided by the theories of sedimentary and architecture element analysis, the paper analyzed the architecture elements of the meandering river sand body in Upper Jurassic Qigu formation in the southern margin of Junggar basin, counted the scale and shapes of the architecture elements and sand bodies and classified the superimposition types. In this field outcrop, 7 lithofacies are found, boundaries with 6 levels are classified and 4 key architectural elements are identified. When the A/S is bigger than 1, the isolated channel sand bodies are developed. As the A/S decreases and approaches to 1, the bridging channel sand bodies and superimposed channel sand bodies are developed. When the A/S is smaller than 1, the truncated channel sand bodies are developed. During the deposition of Qigu formation, the climate was arid and hot. During the deposition of Toutunhe formation, the broad lake level dropped, a sandy meandering river formed with the depth of about 33.3 m, width of 139.2 m, bankfull width of 805.2 m and single meander belt width of 6405.2 m. In the early stage of the deposition of Qigu formation, the A/S was smaller than 1, corresponding to the development of isolated channel and flood lake sand bodies, in the middle stage, the bridging channel sand bodies, superimposed channel sand bodies and the truncated channel sand bodies were developed. In the late stage, the A/S increased again corresponding to the development of the isolated channel sand bodies.
作者
关旭同
吴鉴
魏凌云
赵进雍
冯庚
李严
GUAN Xutong;WU Jian;WEI Lingyun;ZHAO Jinyong;FENG Geng;LI Yan(MOE Key Laboratory of Orogenic Belts and Crustal Evolution,Peking University,Beijing 100871,China;Institute of Geophysics,Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Urumqi,Xinjiang 830011,China)
出处
《新疆石油地质》
CAS
CSCD
北大核心
2019年第3期290-297,共8页
Xinjiang Petroleum Geology
基金
国家科技重大专项(2016ZX05003-005)
关键词
准噶尔盆地
南缘
建功煤矿剖面
上侏罗统
齐古组
河流沉积
构型要素
叠置类型
Junggarbasin
southernmargin
Jiangongcoalminesection
UpperJurassic
Qiguformation
fluvialdeposit
architecturalelement
superimposition type
