The Study Of Sedimentary-Exhalative Characteristics And Genesis Of Luoba Lead-Zinc Deposit In The West Qinling Mountains

The Luoba lead-zinc deposit mineralization rock environment geological andgeochemical characteristics and the analysis of its causes mainly gained someunderstandingLuoba Pb-Zn deposit occurs mainly in the northern margin of the Yangtze platein Late Paleozoic with the rift basin in the north and south respectively, with east-westDangchang Liangdang fracture and Lixian-Mayan River-fracture clamp, along withthe further evolution of basin, at the edge of the Basin wide development ofsyndepositional faults HuangZhuguan and RenTushan-JiangLuo fault, control ofmining area jet mineralization and facies distribution. At the same time,syndepositional faults are not only the migration of ore-forming fluids channel, but alsoits deposition sites.Determine the Luoba lead-zinc deposit is a hot water sedimentary deposit, andsubjected to the final-the Indosinian strong metamorphism and deformationtransformation function.Determine the deposit water jet sedimentary facies and channel two sets ofmineralization system, the channel is mainly composed of two contemporaneous faultand a series of transversion layer sulfide veins body, ore body banded, net veined, orepreserved early jet depositional fabric, pyrite ore has a laminated structure, functionshape of sphalerite, galena; quenching and channel microstructure, siliceous rock,tourmaline exhalative rock on. Exhalative sedimentary facies ore bodies are mainlydistributed in the middle and upper part, often with a layered orebody, stratoid andlenticular in stratum rock occurrence, with basically the same.The ore-bearing rocks (siliceous rocks) and ores rare earth, trace element,isotope geochemical characteristics were studied in detail, the result shows that theore-bearing rocks and ores have similar origin and evolution, and the typical exhalativesedimentary deposits consistent with hot water.The summarization of metallogenic system: tension, depression effect ofsyngenetic fault activity and volcano activity between coupled to form a convectionwater jet deposition system. In the volcano effect heat driven, ore fluid along thecontemporaneous faults into the relatively closed reduction of the nature of the seabedwith depression, and seawater chemical reaction formed the initial source of ore layer or mineralization stratum, finally to carbon argillaceous slate for the hot waterdeposition marked the end of. In the final-Indosinian strong orogeny that strata andorebody synchronous folds, large thermal power so that the ore source layer formingcomponents Pb, Zn, Ba activation and migration, in favorable structural and lithologicparts (such as the North Wing Luoba anticline and turning end portion formed)enrichment, Luoba Pb-Zn deposit.