摘要
塔里木盆地塔东地区米兰低凸起寒武系—奥陶系发育厚层白云岩,然而该区白云化成因机理研究相对薄弱,严重制约了深层油气勘探的进展。针对上述问题,本文以该区典型井米兰1井为例,在岩心和薄片观察基础上,对30件白云岩样品的稀土元素特征进行了分析。结果表明:所有样品稀土元素北美平均页岩(NASC)配分模式可分为δCe负异常型、δEu负异常、δEu强正异常、δEu正异常型和“V”字型五类;大部分样品δCe均为负异常,表明大部分白云岩都曾经受蒸发泵白云化作用的影响,同时许多样品也表现出多样的δEu异常和配分特征,表明许多白云岩后期受到埋藏流体或(和)多期热液流体的改造;晶粒细小的白云岩主要是蒸发泵作用形成的,晶粒较大的白云岩可能形成于埋藏或多期热液环境,硅质白云岩大多受到了热液的再作用。
The origin of dolomite is a key problem in Cambrian-Ordovician exploration in Tadong area of Tarim basin.In view of the above problem,the rare earth element(REE)characteristics of 30 dolomite samples from Well Milan 1 were analyzed based on the observation of cores and thin sections.The results show that the NASC normalized REE distribution patterns of all samples can be classified into five types:the type ofδCe negative anomaly,the type ofδEu negative anomaly,the type ofδEu strong positive anomaly,the type ofδEu positive anomaly,the type of“V”shape.Further study found that theδCe of most samples is negative abnormal,indicating that most dolomites have been affected by evaporation pump dolomitization,and many samples also show diverseδEu anomalies and distribution characteristics,indicating that many dolomites were transformed by buried fluids or(and)multiphase hydrothermal fluids in the late stage.Among them,dolomite with fine grains is mainly formed by an evaporation pump,and dolomite with large grains may be formed in a buried or hydrothermal environment,while siliceous dolomite is mostly subjected to a hydrothermal reaction.
作者
郭春涛
刘亮
倪玲梅
史江涛
田朋飞
荆雪婷
Guo Chuntao;Liu Liang;Ni Lingmei;Shi Jiangtao;Tian Pengfei;Jing Xueting(The Cultivation Base of Shanxi Key Laboratory of Mining Area Ecological Restoration and Solid Wastes Utilization,Yangquan 045097,Shanxi,China;Department of Earth Sciences and Engineering,Shanxi Institute of Technology,Yangquan 045097,Shanxi,China;Faculty of Culture and Tourism,Qujing Normal University,Qujing 655011,Yunnan,China)
出处
《吉林大学学报(地球科学版)》
北大核心
2025年第1期57-69,共13页
Journal of Jilin University:Earth Science Edition
基金
国家自然科学基金项目(41802171)
山西省高等学校科技创新项目(2021L590)
山西省基础研究计划项目(202203021211287)。
