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现代地质 ›› 2020, Vol. 34 ›› Issue (01): 74-87.DOI: 10.19657/j.geoscience.1000-8527.2020.004

• 岩石学 • 上一篇    下一篇

湖北秭归地区震旦系灯影组白云岩地球化学特征及其成因意义

马佳怡1(), 谢淑云1(), 张默海1, 焦存礼2, 韩俊3, 鲍征宇1, 邬铁4, 张海5   

  1. 1.中国地质大学 地球科学学院,湖北 武汉 430074
    2.中国石油化工股份有限公司 石油勘探开发研究院,北京 100083
    3.中国石油化工股份有限公司 西北油田分公司,新疆 乌鲁木齐 830011
    4.广东有色工程勘察设计院,广东 广州 510300
    5.贵州省地质矿产勘查开发局 113地质大队,贵州 六盘水 550001
  • 收稿日期:2018-10-13 修回日期:2019-07-10 出版日期:2020-03-05 发布日期:2020-03-07
  • 通讯作者: 谢淑云
  • 作者简介:谢淑云,女,教授,1976年出生,地球化学专业,主要从事碳酸盐岩储层溶解动力学与覆盖区地球化学找矿及定量地球化学的研究工作。Email: tinaxie@cug.edu.cn
    马佳怡,女,硕士,1996年出生,地球化学专业,主要从事碳酸盐岩储层溶解动力学的研究工作。Email: mjycug@163.com
  • 基金资助:
    国家重大专项“大型油气田及煤层气开发”(2008ZX05005);中国石化科技开发部项目 “塔里木寒武系-中下奥陶统储层发育模式研究”(P16112);中国石化“塔里木盆地深层优质碳酸盐岩储层成因与分布”项目(P14038)

Geochemical Features and Genesis of Dolomite in Sinian Dengying Formation of Zigui Area, Hubei Province

MA Jiayi1(), XIE Shuyun1(), ZHANG Mohai1, JIAO Cunli2, HAN Jun3, BAO Zhengyu1, WU Tie4, ZHANG Hai5   

  1. 1. School of Earth Sciences, China University of Geosciences, Wuhan,Hubei 430074, China
    2. Research Institute of Exploration & Production, SINOPEC, Beijing 100083, China
    3. SINOPEC Northwest Company, Urumqi, Xinjiang 830011, China
    4. Guangdong Nonferrous Metals Engineering Investigation Design Institute, Guangzhou,Guangdong 510300, China
    5. No.113 Geological Team,Guizhou Bureau of Geology & Mineral Resources,Liupanshui,Guizhou 550001, China
  • Received:2018-10-13 Revised:2019-07-10 Online:2020-03-05 Published:2020-03-07
  • Contact: XIE Shuyun

摘要:

白云岩化流体性质与成岩作用是近年来碳酸盐岩成岩作用研究的热点,研究白云岩的成因有利于进一步认识白云岩储层的形成机制并为优质储层的预测提供依据。通过岩石学、矿物学(X射线衍射)、地球化学(微量元素、稀土元素、碳氧同位素)方法,系统研究湖北秭归地区灯影组不同类型白云岩的成因,并分析了可能的白云岩化模式。样品的微量元素特征显示,秭归地区白云岩未受到陆源碎屑物质的影响,形成于气候干旱、海水咸度较大且氧化的沉积环境中;Sr含量特征显示白云岩发生了较为彻底的白云岩化,其成岩环境为温度较高的埋藏环境,成岩过程中未受到淋滤作用的影响;秭归地区白云岩化流体主要来源于海水。结合蒸发白云岩(萨布哈)及埋藏白云岩化模式解释了秭归地区泥微晶白云岩及晶粒白云岩的形成过程。

关键词: 灯影组, 地球化学, 白云岩, 成因模式, 秭归地区

Abstract:

Fluid properties of dolomitization and dolomite diagenesis is a hotspot of carbonate diagenesis research in recent years. It is very important to study the genesis of dolomite and to understand the formation mechanism of dolomite reservoirs, which can be used to predict high-quality reservoirs. In this paper, the genesis of dolomites in Dengying Formation in Zigui County has been studied systematically via petrological, mineralogical (X-ray diffraction), and geochemical (trace elements, REEs and carbon-oxygen isotopes) analyses, and possible dolomitization patterns were inferred. According to the trace element characteristics, the Zigui dolomites had not been affected by terrigenous debris, and were formed in an arid, highly-saline seawater and oxidizing environment. The Sr contents show that the dolomites have been completely dolomitized, and the diagenetic environment was likely a high-temperature burial one with no effect of syn-diagenetic leaching. The dolomitized fluids were mainly derived from seawater. Based on the results above, we proposed the evaporite dolomite (Sabuha) and burial dolomitization models to account for the formation of mud microcrystalline dolomite and crystalline dolomite in Zigui area.

Key words: Dengying Formation, geochemistry, dolomite, diagenetic model, Zigui area

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