| Longnan area is important gold mineral area in China. There are a lot of largegold deposits in this area. Therefore, the area is the focus of geology survey work.Research gold deposits of western Qinling Yinjiaping area to learning theCarlin-type gold deposits have important practical and theory significance.Base on the Carlin-type gold deposits in Yinjiaping area, from its sourcematerial, formation, sedimentary, structure, study on it through field geologicalinvestigation and laboratory test, analyses its metallogenic condition, using thepetrology and mineral deposit geology and geochemistry, to investigate themechanism of gold mineralization and its causes, draw several conclusions:(1) Through the analysis of correlation and R-cluster of eight elements (gold,silver, mercury, arsenic, antimony, lead, zinc, bismuth and mercury which areanalyzed in geochemical exploration soil survey) in Yinjiaping area, it can be seenthat Hg and Sb are the most relevant, Au and As are closely related, and they arebelonged to the same indicators.And that also shows Au, As, Hg, Sb have a certaindegree of relativity, while Pb, Zn and other elements with almost no relevance whichis independent. Therefore, the elements of Au, Hg, As and Sb may be available as arepresentation indicators for comprehensive analysis and metallogenic prediction.(2) From the regional geological background of the metallogenic analysis andstudy area of geochemical measurement, found the anomalies area in Yinjiaping area,and circle the eight pieces of gold halo anomalies; By field geological survey andlaboratory rock analysis, delineated the Yinjiaping (D-3) gold halo anomalies forprospecting target area, and then found the Yinjiaping gold deposits.(3) Research the gold mineralization geological characteristics in Yinjiapingarea. Mine discovered Au, Sb mineralized body1, about600m, width0.3-5m. Oreminerals to limonite mainly dominated by quartz gangue minerals, precious mineralsare native gold. Structure of the ore has since shaped-hypidiomorphic-he shapedgranular structure, tuffaceous structure, fake like structure, containing structure, gelstructure. Ore brecciated structure constructed with sparse disseminated-Star bulkstructure, star-shaped structure, stockwork structure. Yinjiaping highest grade goldore deposit was25.77g/t, with an average grade of4.56g/t, the lowest grade of 1.00g/t.(4) Mine samples for spectral analysis, we concluded that gold may be amineral mainly from diorite body. The change range of sulfur isotopic is between-2.4‰and3.01‰, sulfur characteristics in the ore close to magmatic sulfurcharacteristics. Through the research to hydrogen and oxygen isotope of water inmineral inclusions, it shows that ore-forming fluid is mainly magmatic hydrothermalmeanwhile, some metamorphic hydrothermal participates in it.(5) Yinjiaping gold deposits of gold granularity mostly submicroscopic-microscopic level, the general development of epithermal mineral assemblages andtrace element combination Au, As, Hg and other closely related carbonate rocks.Metallogenic’s Late Permian-Early Triassic early and mineralization in middle-lowtemperature, is a shallow deposit. In summary, Yinjiaping deposit is a Carlin-typegold deposits in the shallow epithermal activity formation. |
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