摘要
闪锌矿是东升庙多金属硫铁矿床中主要矿石矿物之一,本文从闪锌矿的产状、矿物共生组合、物理性质、化学成分、微量元素含量征、晶胞参数与FeS含量关系等方面探讨了闪锌矿标型特征及其与矿床成因的关系。本区有两类闪锌矿,其中晚期改造作用形成的闪锌矿比原沉积成因的富铁,形成了闪锌矿向铁闪锌矿转化的矿物系列。进一步确定了矿床成因类型为海底喷气热水沉积-弱改造型矿床。进而讨论了不同成矿期闪锌矿的形成条件。
The Dongshengmiao large--sized polymetallic pyrite deposit in Langshanarea of Innei Mongolia is located in the western part of northern North Chinaplatform and occurs within Langshan--Zhaertai faulted trough. The ore--bearingrock series of Middle Proterozoic Langshan Group is a set of fine clastic rocks-carbonate rocks which have undergone epimetamorphism. This ore deposit bearsresemblance to gigantic Proterozoic pyrite type deposits in the world in manyaspects. In this paper, the author has made a special discussion on the majorore mineral in the deposit--sphalerite, looking into the relationship. betweenthe typomorphic characterstics of sphalerite and genesis of the ore deposit. Sphalerite of this deposit was formed in two stages, with the early sphale-rite related to submarine hot--water exhaled deposition whereas the late spha-lerite to late stage regional metamorphism, being the Product of local mobiliza-tion, accumulation and recrystallization. The author bas further investigated theformation conditions of sphalerite. FeS molecules in sphalerite increase obviouslyfrom early stage to late, and the Zn/Fe ratio decreases from 8.64 to 4.06.Theunit cell parameter of sphalerite grows with the increasing FeS content. Cocontent gradually decreases from early to late stage. Temperature for the for-mation of sphalerite tends to rise from early to late. Sphalerite formedin the process of late metamorphic transformation contains more iron than theoriginally sedimentogenicsp halerite, thus constituting a mineral sequence fromsphalerite to marmatite. Typomorphic characteristics of sphalerite indicateundoubtedly that the Dongshengmiao polymetallic pyrite deposit is geneticallyof submarine hot--water exhaled deposition--weak reformation type.
出处
《岩石矿物学杂志》
CAS
CSCD
1992年第4期375-382,共8页
Acta Petrologica et Mineralogica
关键词
多金属矿床
黄铁矿矿床
成因
Sphalerite
typomorphic characteristic
formation condition
