柴达木盆地西部新生界陆相湖盆碳酸盐岩沉积环境与沉积模式

发布时间：2018-01-26 16:36

本文关键词： 柴达木盆地古近纪新近纪湖相碳酸盐岩沉积相沉积模式　出处：《古地理学报》2017年05期 　论文类型：期刊论文

【摘要】：利用野外露头、岩心、测井录井和分析化验资料,对柴达木盆地西部(简称"柴西地区")新生界干柴沟组湖相碳酸盐岩进行了研究,划分了其沉积微相类型,研究了其分布规律,分析其形成环境和控制因素,并建立了相应沉积模式。该区湖相碳酸盐岩在垂向上与碎屑岩频繁互层,湖相碳酸盐岩包括颗粒灰岩、藻灰岩、泥晶灰岩和混积岩4大类11种,划分出了灰泥坪、颗粒滩、藻丘(礁)、浅湖湾以及(半)深湖泥灰岩相等5种沉积微相。通过分析不同碳酸盐岩及其微相时空展布特征,认为其发育主要受控于湖盆构造运动、湖平面变化、陆源碎屑注入、古气候与古水介质条件、古地貌与古水深环境,并在此基础上建立了柴西湖相碳酸盐岩的沉积模式。研究认为柴达木盆地西部干柴沟组沉积时期,湖盆为典型咸化湖盆,构造活动相对稳定,湖平面上升达到峰值。碳酸盐岩主要发育在湖侵期,高频湖平面变化形成了碳酸盐岩与碎屑岩频繁互层。在枯水期,盆地坡折处发育碎屑岩滩坝或三角洲前缘沉积;在湖侵期,盆地坡折处发育了鲕粒滩及藻灰岩,盆地洼陷区发育泥灰岩或灰质泥岩。
[Abstract]:Based on field outcrop, core, logging logging and analysis of laboratory data, the lacustrine carbonate rocks of the Cenozoic Ganchaigou formation in the western Qaidam Basin were studied, and the sedimentary microfacies types were classified. The distribution law is studied, the forming environment and controlling factors are analyzed, and the corresponding sedimentary model is established. The lacustrine carbonate rocks are frequently interbedded vertically with clastic rocks, and the lacustrine carbonate rocks include granular limestone. There are 11 species of algal limestone, mudstone limestone and mixed rocks, which are divided into plaster flat, granular beach and algal dune (reef). There are five sedimentary microfacies in shallow lake bay and (half) deep lake marl limestone. By analyzing the temporal and spatial distribution characteristics of different carbonate rocks and microfacies, it is considered that the development of shallow lake bay and (half) deep lake marl is mainly controlled by the tectonic movement of lake basin and the change of lake plane. Land-based clastic injection paleoclimate and paleo-water medium conditions paleogeomorphology and paleo-water depth environment. On this basis, the sedimentary model of carbonate rocks in Chaixi lacustrine facies has been established. It is considered that during the deposition period of Ganchaigou formation in western Qaidam basin, the lake basin is a typical saline lake basin, and the tectonic activity is relatively stable. The carbonate rocks mainly developed during the transgression period, and the high frequency lake level changes resulted in frequent interbedded carbonate rocks and clastic rocks. The detrital rock beach dam or delta front sediments are developed at the slope break of the basin. During the lacustrine transgression, oolitic beach and algal limestone were developed at the slope break of the basin, and marl or lime-mudstone were developed in the basin depression.
【作者单位】：中国石油大学(北京)地球科学学院;中国石油大学(北京)油气资源与探测国家重点实验室;中国石油青海油田勘探开发研究院;
【基金】：国家自然科学基金面上项目(编号:41672098)资助~~
【分类号】：P618.13
【正文快照】： 3中国石油青海油田勘探开发研究院,甘肃敦煌136202柴达木盆地西部地区(简称“柴西地区”)新生代主要发育碎屑岩地层,前期勘探已证明柴西南干柴沟组(包括古近系下干柴沟组和新近系上干柴沟组)的碎屑岩地层中亦广泛发育湖相碳酸盐岩。目前已在跃进、砂西、花土沟以及南翼山等多

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