Study On Geological Conditions Of Rhenium In Mabian-muchuan Area Of Leshan City,sichuan Province

The Middle Jurassic Shaxi Temple formation is an important source of the oil and gas concentration in the Sichuan basin region.Also,it is a potential area for various sedimentary deposits.A large number of explorations,research works and data have been carried out by the previous works.However,the limitation of the previous works is that the studied area is small and mainly located near the oil and gas fields.The studied area of this paper is located in Mabian County and Muchuan County of Leshan City in the south of Sichuan Province.There are a few literatures reported by previous works in this area.The last report can be traced back to the sixties of the last century before the restarting of research in the early 20th century.This article is based on four regional geological survey projects in Wumeng Mountain area of Sichuan Province including Mabian County,Muchuan County,Dianlan Ba and Xinshi Town with scaling of 1:50 thousand.Materials has been collected at the beginning and then 1:10 thousand comprehensive geochemical survey in Shaximiao section has been carried out including stratigraphic section survey,geological mapping,typical ore deposits(points)and rhenium bearing rock series.Typical deposit(point),sedimentary environment of rhenium bearing rock series,material sources and paleoclimate are studied by means of rock ore identification,main element analysis,lanthanon element analysis and lithologic combination factor research.Finally,we will launch a discussion on genesis of copper molybdenum rhenium polymetallic ore,metallogenic mechanism of sedimentary rhenium deposits,rhenium metallogenic conditions and then the direction of prospecting is determined.In the hypergenic geologic process,Rhenium is dissolved in water by oxygen complex Re O^4-,so the rocks containing rhenium usually move with the river and then flow into sea after weathering.When large number of organic matter,feldspar and quartz particles are deposited in the river and lake,the organic matter in water adsorb mineral elements(copper,molybdenum and rhenium).During the process of deposition,the organic matter has decomposed&released large amount of H2s gas and produce much sulfur containing solution after dissolved in water.The sedimentary environment changed to partial reducting environment from oxidation environment,which promoted the combination of sulfophilic elements including Mo,Cu,Re with S,and gradually formed molybdenite and water bearing colloid sulfur molybdenum ore(Mo S2.NH2O).According to the symbiotic relationship between rhenium and molybdenum,it is indicated that a considerable proportion of rhenium may enter into molybdenite,sulphide molybdenum ore and sulphur molybdenum copper ore in the form of isomorphism.