苏打湖型的湖相碳酸盐岩特征及沉积模式  

The Feature and Deposit Model of Lacustrine Carbonate Rocks Formed in the Course of Soda Lake Evolution

作　　者：黄杏珍[1] 闫存凤 王随继[3] 邵宏舜[1] 妥进才[1] 王寿庆 何祖荣 

机构地区：[1]中国科学院兰州地质研究所,兰州730000 [2]西北石油地质研究所,兰州730020 [3]北京大学城市与环境学系,北京100871 [4]河南石油局勘探开发研究院,河南南阳473132

出　　处：《沉积学报》1999年第A12期728-733,共6页Acta Sedimentologica Sinica

基　　金：国家自然科学基金!49872048

摘　　要：淡水湖泊在咸化为盐湖或碱湖过程中必然经历湖相碳酸盐岩沉积阶段，但至今在国内、外湖相碳酸盐岩研究仍处于湖泊沉积学研究的极薄弱领域。我国第三系古湖泊具有不同的演化方向，大多数问盐湖演化（沉积盐岩）[1]，泌阳凹陷则不同，它向苏打湖演化（沉积碱岩），因而将泌阳凹陷作为向苏打湖演化的典型代表加以剖析，对于对比研究不同类型湖泊中湖相碳酸盐（岩）发育特征和建立沉积模式不仅具有重要的理论意义，而且对评价油气潜能和指导油气勘探也十分有意义。Being one of the most important oil source rock in Biyang depression,the Iacustrine carbonate rock is,here,mainly composed of dolomite, representing the characteristics of lacustrine carbonate rocks formed ln the course of soda lake evolution Under the hot and semi-arid paleoclimate, the upper and lower part of the lower Tertiary are coarse clastic rocks which formed fluvial and Lacustrine facies in interval. The middle part Hetaoyuan Formation consists mainly of lacustrine muddy shale,carbonate and alkaline rocks except fan delta and delta deposits.The depositional model of lacustrine carhonate rocks evoluted to the soda lake: (1)The fan delta facies and delta facies are distributed along the south and north margin of the depression respectively,for the abundant supplement of clastics and low salinity (3‰- 6‰,)are generally not favorable for the formation of carbonate deposition, only forming lots of authigenic calcite and little authigenic dolomite minerals dispersing in mudstone and sandstone or the cements of sandstones. Particularly,in delta facies during flood-interval period or in interchannel deposits,the authigenic ferrodolomite and lime mudstone sheet increases with some lime mud shell oolites, intraclast sandstone and cryptoalgal laminated rocks intercalation deposited; (2)The salinity of lake water ln Lake-shore and lakeubay facies,especially in the latter is high, the authigenic calcites and lime mudstone, ferrodolostone are widespread, in these facies, meanwhile, true ooid-and superficial ooid-bearing grain carbonate rock increases as well; (3)Carbonate rocks in shallow Lake facies are well doveloped,and the total thickness of carbonate rocks is about 300-600 m. The lithology are mainly grey -black, brown -grey dolomite mudstone, ferrodolostone and ooid - intraclast -bearing dololnite mudstone exceljt alkalinebearing lumps and lime mudstone deposition in the near-shore shollow lake facies; (4)Deeper lake facies, excluding turbidite deposition,are short of supplement of fresh water and clastics i

关 键 词：苏打湖型 碳酸盐岩 沉积模式 湖相沉积 

分 类 号：P588.245[天文地球—岩石学] P512.3[天文地球—地质学]