巴西桑托斯盆地白垩系Barra Velha组湖相碳酸盐岩沉积特征及成因环境研究  

Research on sedimentary characteristics and genetic environment of lacustrine carbonate rocks of Cretaceous Barra Velha Formation in Santos Basin,Brazil

作　　者：杨柳 范国章 王红平 左国平 李林 王朝锋 张勇刚 庞旭 丁梁波 王思文 李伟强 宋叙 黄小洁 孙海涛[2] YANG Liu;FAN Guozhang;WANG Hongping;ZUO Guoping;LI Lin;WANG Chaofeng;ZHANG Yonggang;PANG Xu;DING Liangbo;WANG Siwen;LI Weiqiang;SONG Xu;HUANG Xiaojie;SUN Haitao(Hangzhou Research Institute of Geology,PetroChina,Hangzhou 310023,China;College of Geosciences,China University of Petroleum,Beijing 102249,China)

机构地区：[1]中国石油杭州地质研究院,杭州310023 [2]中国石油大学(北京)地球科学学院,北京102249

出　　处：《世界地质》2023年第4期701-713,共13页World Geology

基　　金：国家自然科学基金项目(41972097)。

摘　　要：利用岩石薄片、稳定同位素等资料分析了巴西桑托斯盆地白垩系Barra Velha组碳酸盐岩的矿物组成及地球化学特征,探讨了此类湖相碳酸盐岩的沉积成因环境。研究表明,Barra Velha组碳酸盐岩具有灰泥、球状、灌木状特殊结构组分和内碎屑颗粒,形成了泥晶灰岩、球粒灰岩、灌木颗粒灰岩和颗粒灰岩4种岩石类型。结合前人对球粒灰岩和灌木颗粒灰岩提出的微生物、碱湖和钙华等不同观点的证据材料,提出了综合古地形、流体特征的成因环境观点,认为球粒灰岩和灌木颗粒灰岩赋存的流体环境具有高温、高盐度特征,颗粒灰岩形成在浪基面以上的高能环境,泥晶灰岩形成于浪基面以下的低能环境。The mineral composition and geochemical characteristics of Cretaceous Barra Velha Formation carbonate rocks in Santos Basin,Brazil have been analyzed by using thin sections and stable isotopes,and the sedimentary genetic environment of this lacustrine carbonate rocks has been discussed.The results show that the Barra Velha Formation carbonate rocks have special structural components such as calcite mud,spherulite,and shrub grain,as well as other internal debris grains,which are classified into four rock types,i.e.mud crystal,spherulite,shrubby granular,and grain limestones.Combing with the evidence of different viewpoints on microbiology,alkali lakes,and travertine proposed by previous scholars,a new genetic environment perspective has been proposed,which integrates paleotopography and fluid characteristics.It is believed that the fluid environment in which spherical and shrub granular deposits occur is characterized by high temperature and high salinity.Grains are formed in high-energy environments above the wave base,while micrite deposits are formed in low-energy environments below the wave base.

关 键 词：湖相碳酸盐岩 沉积环境 球粒 灌木颗粒 下白垩统 桑托斯盆地 

分 类 号：P618.13[天文地球—矿床学]