海相细粒沉积成因机制与有机质富集模式研究进展  

Advances and perspectives in the study of the genetic mechanism and organic matter enrichment models of marine fine-grained sediment

作　　者：施振生[1] 周天琪 SHI Zhensheng;ZHOU Tianqi(Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China)

机构地区：[1]中国石油石油勘探开发研究院,北京100083

出　　处：《石油与天然气地质》2024年第4期910-928,共19页Oil & Gas Geology

基　　金：中国石油天然气股份有限公司科技管理部“十四五”科技重大专项(2021DJ1901)。

摘　　要：综合分析了国内外细粒沉积的特征、成因及有机质富集模式研究进展。海相细粒沉积主要由黏土矿物、石英、碳酸盐矿物和有机质组成,受风力、异轻流、重力流和底流4大搬运营力作用,发育泥纹层和粉砂纹层2类纹层,单一型、顺序型和交互型3类纹层组(层系),块状层、递变层和交互层3类层(层组)。海相细粒沉积发育浊流沉积、底流沉积及远洋-半远洋沉积3种主要沉积相类型及其过渡类型。海相细粒沉积有机质存在高生产力和强保存2种富集模式,高生产力富集模式下黑色页岩主要通过“上升洋流”、“氧含量最低值区(OMZ)”和“近岸透光带缺氧(PZE)”模式形成高有机质富集,强保存富集模式下黑色页岩主要通过“受限盆地”、“改进的受限盆地”、“不规则底形”、“水洼扩张”、“海侵化变层”和“近岸海侵(TN)”模式形成高有机质富集。目前海相细粒沉积成因机制与相模式研究存在的主要问题包括名词术语不规范、不同矿物成分成因不明确,以及细粒浊流沉积、等深流沉积和半远洋沉积难以区分,需要今后进一步研究解决。This study provides a comprehensive analysis of global advances in the study of the characteristics,origin,and organic matter enrichment model of marine fine-grained sediments.These sediments,mainly composed of clay minerals,quartz,carbonate minerals,and organic matter,are predominantly transported by four geological agents:wind,hypopycnal plumes,hyperpycnal plumes,and bottom currents.They exhibit clayey and silty laminae;single,sequential,and alternating laminasets;and massive,graded,and alternating beds.Covering three major types of sedimentary facies,namely turbidite,bottom current,and pelagic to semi-pelagic facies,as well as their transition types,the sediment demonstrates two organic matter enrichment models under high productivity and enhanced preservation.In the high productivity-derived model,the organic matter enrichment in black shales typically involves upwelling currents,oxygen-minimum zones(OMZ),and nearshore photic zone euxinia(PZE).In the enhanced preservation-related model,the enrichment principally involves restricted basins,improved restricted basins,irregular bed form,expanding puddles,transgressive chemocline,and transgressive nearshore(TN)zones.Current challenges in the research on the genetic mechanism and facies models of marine fine-grained sediments primarily include nonstandard terminology,undefined origins of different mineral compositions,and the difficulty in distinguishing among three sedimentary facies:fine-grained turbidite,contourite,and semi-pelagic facies.Further research is required to address these issues.

关 键 词：物质组成 搬运营力 层理 相模式 有机质富集 细粒沉积学 

分 类 号：TE121.3[石油与天然气工程—油气勘探]