盐酸及乙酸介质中的碳酸盐岩溶蚀表面特征及机理--以南堡凹陷为例  

Characteristics and Erosion Mechanism of Carbonate in Acetic Acid and Hydrochloride Solutions,An Example from the Nanpu Depression

作　　者：朱文慧[1,2] 曲希玉 邱隆伟 陈勇 龚发雄[2] 吴思萱 

机构地区：[1]中国石油大学地球科学与技术学院,山东青岛266555 [2]中国石油塔里木油田分公司,新疆库尔勒841000

出　　处：《矿物岩石地球化学通报》2015年第3期619-625,共7页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金项目(41372133);中石化科技重点攻关项目(P14019);山东省优秀中青年科学家奖励基金项目(BS2012NJ014);山东省自然科学基金项目(ZR2013DM016)

摘　　要：为了研究酸性条件下碳酸盐岩的溶蚀表面特征及机理,以南堡凹陷及周边凸起区10个典型碳酸盐岩样品为研究对象,进行乙酸和盐酸溶液的溶解实验,并通过扫描电镜观察样品的溶蚀特征。结果显示,岩石结构和矿物成分的选择性溶蚀,是碳酸盐岩溶蚀过程中的主要作用形式;方解石和白云石均存在特有的溶蚀现象,即"溶蚀晶锥"方解石和"蜂窝状"白云石,为晶体选择性溶蚀的产物;表生条件下,灰岩中少量白云石的加入能够增加方解石的溶解度,白云石的含量上限为13%,超过该界限,随白云石含量的增加,溶蚀作用减弱。To investigate characteristics and erosion mechanism of carbonate in acid solutions,ten representative carbonate rock samples were collected from the Nanpu Depression and its surrounding outcrops to conduct dissolution experiments using acetic acid and hydrochloride acid solutions,and the characteristics of dissolution were observed under scanning electronic microscope（ SEM）. The results indicated that： （1） Texture and composition-depended selective dissolution is the main mechanism of carbonate dissolution; （2） Both calcite and dolomite have characteristic dissolution patterns,that is,＂corroded cone＂for calcite and＂honeycomb＂for dolomite,both of which are resulted from the selective dissolution; 3）Under the supergene condition,the solubility of calcite increases when small amount of dolomite is found in limestone,and the critical content point of dolomite is 13%,if higher than this content point,the solubility of carbonate rocks will decrease as the dolomite content increases.

关 键 词：碳酸盐岩 选择性溶蚀 “溶蚀晶锥”方解石 “蜂窝状”白云石 溶蚀机理 

分 类 号：P618.13[天文地球—矿床学]