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 u-sing acetic acid and hydrochloride acid solutions,and the characteristics of dissolution were observed under scanning elec-tronic 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.