苏州阳西脉岩蚀变型高岭土矿床成因探讨  

A PRELIMINARY DISCUSSION ON THE GENESIS OF THE YANGXI DIKE ALTERATION TYPE KAOLIN DEPOSIT IN SUZHOU, JIANGSU PROVINCE

作　　者：易发成[1] 田煦[1] 李虎杰[1] 郑自立[1] 

机构地区：[1]西南工学院非金属矿研究所

出　　处：《矿床地质》1996年第1期87-94,共8页Mineral Deposits

摘　　要：阳西脉岩蚀变型高岭土矿体受阳山逆掩断层的控制。高岭土主要矿物成分为1T高岭石、7A埃洛石及石英,并含少量叶腊石、地开石、绢云母、黄铁矿、方铅矿及闪锌矿等。根据矿床地质特征、矿物组合、成矿物理化学条件等讨论,高岭土矿床形成于中低温、中压、酸性、还原的介质条件。其主要成矿作用为与岩浆活动有关的热液作用。The Yangxi dike alteration type kaolin deposit is controlled by Yangxi overthrust. In the area, wall-rock alterations are well developed and exhibit zonation. Main mineral composition of kaolin includes 1T kaolinite, 7 halloysite and quartz as well as small amounts of pyrophyllite, serieite, dickite, pyrite, galena and sphalerite. The protolith of kaolin is chiefly syenite porphyry. According to inclusion and sulfur stable isotope geothermometer, the ore-forming temperatures are 170～300℃, and the ore-forming depth is 3280m or so. The calculated physical-chemical parameters of the hydrothermal ore-forming stage are as follows: lgf_(S_2)=—10.46; lgf_(O_2)=—31.37; lgf_((CO)_2)=—22.77; lgα_(H_2S)=—7.54; lgα_(HS^-)=—21.58; lgα_(HSO_4^-)=—31.92; lgα_(SO_4^(2-))=—34.01. The ore-forming media are in a reduction environment. The ore-forming hydrothermal solution seems related to postmagmatic activity of intermediate-acid intrusives, being acid hydrothermal solution with rich CO_2Cl^- and poor SO_4^(2-). The channelway for the migration of hydrothermal solution is mainly the faulted zone. It can be inferred from the above discussion that the Yangxi dike alteration type kaolin deposit must have been formed through the hydrothermal alteration of syenite porphyry in acid and reducing media under the action of mesothermal-epithermat solution related to the activity of intermediate-acid magma, with the superimposition and transformation of subsequent weathering-leaching.

关 键 词：高岭土矿床 矿床成因论 脉岩 蚀变型 

分 类 号：P619.232[天文地球—矿床学]