滑塌型深水重力流沉积特征及沉积模式:以渤海湾盆地临南洼陷古近系沙三中亚段为例

发布时间：2019-01-12 16:34

【摘要】：综合运用钻井岩心、测录井等资料,通过岩心观察、薄片鉴定和粒度分析等方法,对渤海湾盆地临南洼陷古近系沙三中亚段深水重力流沉积类型及其沉积特征、沉积模式展开研究。研究表明,临南洼陷沙三中亚段深水重力流沉积主要发育滑塌沉积、碎屑流沉积和浊流沉积3种成因类型。滑塌沉积以包卷层理、液化砂岩脉、阶梯状小断层、变形岩层与未变形岩层叠置为典型特征。碎屑流沉积中砂质碎屑流沉积分布较广,以突变的底部接触面、块状层理、泥岩撕裂屑、土黄色泥砾、突变或不规则的上接触面为典型识别标志。浊流沉积则以正粒序层理、底部冲刷面和槽模、薄层砂泥互层、不完整的鲍马序列为典型识别标志。滑塌沉积主要发育在三角洲前缘斜坡根部,在滑塌沉积前方形成碎屑流沉积,碎屑流向前搬运的过程中,流体被稀释逐渐转化成浊流。滑塌型深水重力流沉积整体分为近源沉积、中部沉积和远源沉积3个部分:近源沉积主要发育具变形构造的滑塌沉积和厚层块状砂质碎屑流沉积;中部沉积主要发育砂质碎屑流沉积及浊流沉积;远源沉积以薄层浊流沉积为主。
[Abstract]:By means of core observation, thin section identification and grain size analysis, the types and sedimentary characteristics of gravity flow in the deep water of the Paleogene S3 Central member of the Linnan depression in Bohai Bay Basin are studied by using drilling core and logging data. The sedimentary model is studied. The results show that there are three genetic types of deep water gravity flow deposition in the third middle member of Linnan sag: sloughing deposition, clastic flow deposition and turbidite deposition. The collapse deposits are characterized by cladding bedding, liquefied sandstone veins, small ladder faults, deformable rocks and undeformed rocks. Sand clastic flow deposits are widely distributed in clastic flow deposition. The typical identification marks are the abrupt bottom contact surface, block bedding, mudstone tear debris, khaki-yellow mudstone, abrupt or irregular upper contact surface. The turbidite deposition is characterized by normal grain sequence stratification, bottom scouring surface and trough mold, thin layer sand and mud interbed, incomplete Baumar sequence as the typical identification mark. The sloughing deposits are mainly developed at the root of the delta front slope. The debris flow deposits are formed in front of the sloughing deposits. During the process of the debris flowing to the front, the fluids are diluted into turbidite flows. The sloughing deep water gravity flow deposits are divided into three parts: near source deposits, middle sediments and distant sediments: the near source sediments mainly develop deformed sloughing deposits and thick layer massive sand debris flow deposits; Sand clastic flow and turbidite flow are mainly developed in the middle part, and thin layer turbidite deposition is the main source deposit.
【作者单位】：中国石油大学(华东)地球科学与技术学院;
【基金】：国家科技重大专项(编号:2011ZX05009-003)资助~~
【分类号】：P512.2

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