Studies On Geological-geochemical Characteristics Of Tongkuangyu Iron Oxide-Copper-Gold Deposit In Zhongtiao Mountains, Shanxi Province

Tongkuangyu Deposit is an exceptional large ore deposit in the Zhongtiao Mineralization Zone. Because of its geological complexity, the ore genesis has been discussed for many years. According to comprehensively analyses the geochemical characteristic of occurenced volcanic rocks and intrusive granitic rocks and the ore deposit alteration zoning characteristic, discusses the style of its structure and the rule of its spacial distributing, the ore deposit is classified as the Iron-Oxide-Copper-Gold Deposit (IOCG).The main methods are used in this paper as follows:first, regional geological background and main ore-controlling factors are analysed; secondly, the relation between volcanic rocks and mineralization is discussed; thirdly, genesis of ore deposit is discussed, new ore-forming mode is put forward.According to comprehensive analysis, the author obtained the following new understanding to Tongkuangyu ore deposit:(1) Regional tectonic setting and its evolution history are introduced briefly,the author point out that the rift structure is the basic geological background of ore deposit;(2) Occurred volcanic rocks and intrusive granitic rocks in mining area are investigated ,some geologic and geochemistry characteristics of igneous rocks are discussed in detail,in conclusion,trace elements diagrames display volcanic rocks formed in extensional rift tectonic background,and progressively the avalaible ore-bearing rocks is redefined as porphyroclastic lava due to its high permeability compared with common lava. Some granitic rocks are interpreted as A-type non-orogenic granite, and they are corresponding to rift extensional environment.(3) The ore deposit alteration zoning characteristics are described, co-existing ore minerals and ore texture and structure also are studied in detail, these geologic and geochemical features implies that ore deposit type is classified as Iron Oxide-Copper-Gold Deposit(IOCG),and can be compared with the Olympic Dam Cu-Au ore deposit in Australia.(4) On the basis of studies about volcanic rocks and small-scale structure of Heiyadi-Michagou area neighboured to Tongkuangyu ore deposit,the author consider this area is a prospective area because ore-forming condition is similar to known Tongkuangyu ore deposit.