Study On Vertical Zoning Rule For Shuiyindong Carlin-type Gold Deposit In The Southwestern Guizhou, China

Shuiyindong Carlin-type gold deposit locating at Zhenfeng county of Guizhouprovince, and forming in HuiJiabao anticline axis of ore concentration area’sCarlin-type gold deposit in Southwestern Guizhou province, The ShuiyindongCarlin-type gold deposit is the outsize stratabound concealed gold deposit found inthis area in recent years. Since the deposit was found, there were many scholars whohave researched it succissively, and they all acquired the expectant ac hivements.However, they haven’t probed whether there is ore in the deep area of the deposit.Choosing this deposit as the subject of study, this paper mainly researches the verticalzoning of the elements in it, and tries to reveal the forming factors of the deposit byvertical zoning research of elements, which provides references for prospectingdeposit predictively in deep area.In this research, the author experienced the field geology investigation twice,collecting the samples of ore body and surrounding rock, having the identification ofthe indoor polished thin section under the microscope, testing and analyzing the traceelements of the samples by ICP-MS.Generally, this paper mainly researches: the regional geological background ofthis deposit, geological characteristics of this deposit, geochemical characteristics inthis deposit, vertical zoning law and metallogenic prognosis etc. Through the abovereseach, this paper gets the achievements below:（1） The surrounding rocks of this deposit primarily are clay rock, siltstone andimpure carbonatite in Longtan formation. The overoll characteristics are that thecontent of CaO、MgO、Al₂O₃、TFe₂O₃、TiO₂and K₂O is comparatively higher, thecontent of SiO₂is comparatively lower, the total quantity of rare earth is the lowest,Ce reveals weak negative anomaly,and Eu reveals the positive anomaly.（2） The types of wall rock alteration in this deposit mainly are pyritization,dolomitization, silicification, arsenopyritization, realgar-orpimentization, calcilization,antimonitization, fluoritization, calcination, and cinnabaration etc. The products of thewall rock alteration obviously show the vertical zoning. At the upper part of thedeposit, there mainly are silicification and pyritization; at the middle part, mainlystrong silicification, pyritization and fluoritization etc.；at the underpart, mainly silicification, pyritization, calcilization, fluoritization, realgar-orpimentization and soon.（3） In general, the ore body occurrence is in accordence with the wall rock. Thehost rock of the deposit mainly is bioclastic limestone, and the primary gold bearingminerals are pyrite and arsenopyrite.（4） From the analysis of the relative cofficient matrix, the author gets that theclosest elements with Au are As, Cu, Pb, Zn, Sb, Tl, which states that As, Cu, Pb, Zn,Sb can be regarded as the indicator elements to search for gold.（5） In this deposit, the elments show the obvious zonation on the verticalzonation: the combination of Ag-Pb-Sb-As at the upper part, Sb-As-Tl at the middlepart and Cu-As-Au at the underpart. This combination is coincident with the resultfrom the analysis of the combined factor elements.（6） Except the μ value in the IIfore body that is near to the upper limi（t9.58）andbelongs to the low μ value, each ratio of lead isotope is comparatively stable.All ofthat explains that the lead in pyrite of Shuiyindong mainly origins from lower crustand upper mantle, the lead is mixing origin, its formation is related with magmatism,and the lead comes from the deep part in the form of ore fluid.（7） Besides some influences from the structure and surrounding rock, the mostimportant and influential factor causing the formation of the deposit’s vertical zoningis from the gas-liquid seperation of the ore-bearing hydrothermal solution. That is tosay, in the process of the ore-bearing hydrothermal solution entering into the structurepassage and migrating to the favorable mineralizing condition, the gas and the liquidare seperated because the system containing hydrotherm appears the preesure-reliefboiling. The volatile elements spread to the upper part and gather, while the elementsmigrating in the fluid aggregate at the lower part, which forms the vertical zo ning inthe deposit.（8） The paper gets that people can prospect deep ore predictively, by theanalyzing the vertical zoning of the hydrothermal alteration, the combination ofmineral paragenesis, trace elements, and rear-earth elements in the deposit.