煤系细粒沉积纹层特点及与陆相湖泊细粒沉积对比  

Characteristics of fine grain sedimentary striae of coal measures and comparison with fine grain deposits of continental lakes

作　　者：刘莹[1] 刘海燕[1] 赵永福 李增学[1] 王东东[1] Liu Ying;Liu Haiyan;Zhao Yongfu;Li Zengxue;Wang Dongdong(Shandong University of Science and Technology,Shandong Qingdao 266590,China;Oil and Gas Exploration and Management Center,SINOPEC Shengli Oilfield Branch,Shandong Dongying 257000,China)

机构地区：[1]山东科技大学,山东青岛266590 [2]中国石油化工股份有限公司胜利油田分公司油气勘探管理中心,山东东营257000

出　　处：《中国煤炭地质》2020年第8期5-11,共7页Coal Geology of China

基　　金：国家自然科学基金项目“不同盆地背景下细粒沉积微细纹层成因机制与演化模式的比较研究(41672096)”;中国石油化工股份有限公司胜利油田分公司油气勘探管理中心项目(30200384-19-ZC0613-0023)资助。

摘　　要：煤系细粒纹层与陆相湖泊细粒纹层类型和成因具有显著的差异性。陆表海盆地煤系细粒沉积主要形成于分流河道间湾、潟湖环境中,主要为灰黑色波状纹层状泥岩、粉砂岩互层岩相,浅灰色微波纹层状含泥粉砂岩相和灰黑色富有机质纹层状泥岩相。纹层多呈束状、波状以及细微平直的水平状。基准面下降时期细粒沉积岩相、纹层比较发育。陆相湖泊细粒沉积主要形成于弱缺氧还原的静水沉积、深水重力流沉积环境,为棕褐色富有机质平直纹层状白云岩相和黑灰色富有机质页状黏土岩相。纹层呈细薄、平直状,且连续性好。基准面下降时细粒沉积岩相中纹层比较发育。煤系细粒沉积与陆相湖泊细粒沉积形成的构造背景是不同的,成煤环境更需要稳定的构造背景,而陆相湖泊则可能相对于成煤环境来说,具有一定的、有规律的弱震荡性和活动性。另外,生物扰动构造发育是煤系细粒中的重要特点,生物活动对纹层的破坏作用是明显的,水动力条件弱且以闭塞滞留环境为主。陆相湖泊细粒沉积中生物扰动构造不发育或很少见到。湖泊尽管是一个独立封闭系统,但是,湖泊的水动力条件的波动性,以及与季节性气候变化相呼应,湖泊水平面可能更具有往复式活动的特点,导致湖泊细粒沉积纹层的多样性、稳定性和连续性。The types and genesis of fine grain laminations in coal measures are significantly different from those in continental lakes.The coal measure fine grain deposition is mainly formed in the interbay and lagoon environment between distributary channels.The interbedded lithofacies are mainly gray-black wavy lamellar mudstone and siltstone,light gray microwave lamellar siltstone facies and gray black organic-rich lamellar mudstone facies.The laminae are mostly fasciculate,undulate and slightly flat.In the period of base-level decline,fine sedimentary facies and striations are relatively developed.Continental lake fine grain deposition is mainly formed in the hydrostatic deposition and deepwater gravity flow sedimentary environment of weak hypoxia reduction.The main lithofacies types are brown organic-rich,flat laminar dolomite facies and black gray organic-rich shale facies.The laminae are thin,straight and continuous.When the base level drops,fine grained sedimentary facies have relatively developed striations.The tectonic setting of coal measure fine grain deposition is different from that of continental lake fine grain deposition,the coal forming environment requires more stable tectonic setting,and the terrestrial lakes may have certain and regular weak oscillation and activity compared with the coal forming environment.In addition,the development of biodisturbed structure is an important feature of coal measure fine particles,and the destruction effect of biological activities on the laminae is significant.The hydrodynamic conditions are weak and the main environment is the blocking environment.Bioturbation structures are not developed or rarely seen in continental lake fine grain deposits.Although the lake is an independent closed system,the fluctuation of the hydrodynamic conditions of the lake and the response to seasonal climate change may make the lake level more reciprocating,leading to the diversity,stability and continuity of the fine grain sedimentary striae of the lake.

关 键 词：煤系细粒沉积 陆相湖泊细粒沉积 纹层多样性 差异性机制 

分 类 号：TE132.2[石油与天然气工程—油气勘探]