| The Shuiyindong gold deposit was found in the census of China’s gold in1981,when only found in the Xionghuangyan segment gold of points initially. With theimprovement in the level of productivity and exploration, and gradually found a hugeresource potential of deposit so far has become southwestern Guizhou region of Chinahas proven one of the few super-large gold deposits.Retrospective of Carlin-type gold exploration and research the history ofCarlin-type gold in China are mainly distributed in mainly two GoldenTriangleregions of “Ganshanchuan”and “Dianqiangui”.”Dianqiangui” Golden Triangle areahas been found that the gold （points） over60, Carlin-type gold deposits of the areacan be divided into the two categories of “Fault-control type”and “Stratum-controltype”. Such as The “Fault-control type” of the Lannigou super-large gold deposit, theore bodies are freguently controled by high-angle pressure-shear fracture, produced intwo part near the fault, the Lower Triassic stratum and the Middle Triassicstratum.The host rocks, which are clastic rocks including the muddy siltstone,fine-grained sandstone and silty mudstone.“Stratum-control type”, such as theShuiyindong super-large gold deposit, the ore bodies, which regularly controlled bythe anticline, layered, stratoid and lenticular distribution in the anticline wings of theupper Permian stratum and the interlaminar fracture zone of upper-lower Permianstratum. The host rocks, which primarily silicification and pyritization of carbonaterocks, bioclastic limestone and bioclastic calcarenite.Research on the “Fault-control type” gold deposit is relatively mature, due topoor study conditions and data acquisition is more difficult,“Stratum-control type”gold deposit can not be a comprehensive study of the system.“Geological andgeochemical characteristics of the Shuiyindong gold deposit of Guizhou province”, asthe guide of ore-forming geological theory, by studing the formation of the geological conditions of the deposit, construction type and evolution of mineral assemblages,analyse the typical characteristics of “Stratum-control type” of Shuiyindong golddeposit mineralization geological and geochemical characteristics, in order to providea theoretical basis for further exploration of this type gold deposits and deepconcealed deposits. Afer the study achieved the following understanding:（1） The Shuiyindong gold deposit developed in the special structure of theenvironment, which is the binding site of the Yangtze block, Youjiang rift zones andthe South China geosynclines. The rexion’s long-term complex phasedeposition-tectonic evolution for the deposit provides a mineralizationdeposition-construction, that is, conglomerate, sandstone, siltstone and mudstoneclastic combination'a combination of carbonate rocks and argillaceous rocks. Inaddition, the development of the shallow crust to east-west fracture （east-west reversefaults） and folds （especially the superimposed fold） structure in the form of depositsformation to create a better structural conditions.（2） Gold ore bodies are mainly distributed in the Longtan Formation （P2l）,Changxing Formation （P2c） and construction of altered body （Sbt）, the main orebodies （Ⅱf、Ⅲa、Ⅲb、Ⅲc） produced in the60m range,which is from the top of thefirst member of the Longtan Formation （P2l1） to the bottom of the third member ofLongtan Formation （P2l3）. All ore is primary, in which carbonate rocks minerals asthe main host rocks, seamthickness of2m, with an average grade of14.74×10-6,2.8million tons of ore amounted to57.51%of the total ore, metalthe total amount of upto41.2t, accounting for76.08%of the total resources of the Shuiyindong gold deposit.（3） A variety of wall-rock alteration, silicification, carbonatization, pyritizationand in very close relationship, where gold output parts of all three alteration features.“Three-combination” is a prerequisite for mineralization. Pyrite is the most importantgold-bearing mineral, can be divided into the hydrothermal pyrite and deposition ofpyrite, includ hydrothermal pyrite was disseminated output, small mineral particles（ususlly1～10μm）; Deposition of pyrite banded or lenticular output, large mineralgrains （0.2mm）, mostly since the cube-shaped, the strawberry-shaped, or pentagonaldodecahedron crystal. Gold occurrence at the edge of the pyrite core growth along thesedimentary origin of arsenic pyrite band, the strength of the gold mineralization andgold content in the high or low, depending on the hyrothermal pyritization （arsenicpyrite ring）. Mineral assemblages: quarts-fine-grained pyrite-arsenopytire,quartz-dolomite, quartz-calcite-orpiment-realgra-cinnabar-stibnite and so on.（4） Seam relative surrounding rock with high contents of CaO, MgO, Al2O3, TFe2O3, TiO2and K2O, SiO2content is relatively low. The chemical composition ofthe rocks and minerals of the Shuiyindong gold deposit reflect the interaction betweenthe limestone and the ore-forming hydrothermal, that pyritization, silicification,dolomitization, and clayization, resulting in enrichment of gold precipitation in the orebodise. The level of gold content in the three types of ore as follows: carbonate type(17.23×10-6)＞breccia type (9.04×10-6)＞sandstone type (6.63×10-6), which mayreflects the relationship between gold mineralizazion and wall rock alteration,silicification is too strong and not suitable for the precioitation of gold enrichmen.（5） The concentration of trace elements As, and limestone in the highest contentof As conteng was no significant difference in the claystone and siltstone. Cu, Sb andZn in the carious types of rock, a relatively high concentration of Cu in the limestoneis relatively enriched for claystone and siltstone; Sb concentration was no significantdifference in several rocks; the relative enrichment of Zn in the claystone and siltstone,for limestone. Changes in the content of several active trace elements in the threerocks show that the limestone in the gold grade is very high, this may be the intensityof mineralization due to limestone, gold enrichment may be the main fissure filling,with the continuous inflow of hydrothermal fluids, the salinity gradually increased,gold pretitation in the limestone fissures. In addition, trace factor analysis showed thatthe Shuiyindong gold deposit in the genesis of the at least two, one phase isaccompanied of Ni, Zn, Pb, Cu, Cr, Co, V and Ag with the formation of ore-related tohydrothermal activity, mainly associated minerals are chalcopyrite, galena, nativesilver and dolomite. Another phase is based on the gold-oriented and with a smallamount of sulfide hydrothermal activity, the main associated minerals for arsenicpyrite and arsenopyrite. The close relation of Au and As, Cu, Pb, Sb, which shows thatof As, Cu, Pb, of Sb can be as prospecting gold indicator elements.（6） The∑REE, LREE, HREE and LREE/HREE of limestone of theShuiyindong gold deposit is relatively low. This maybe due to the weak limestoneresist change, prone to a more thorough process of hydrothermal alterationsilicification. Claystone and siltstone because of its strong resist change capacity ofrare earth elements in the process of mineralization and silicification activity is lessobvious. In addition, the claystone and siltstone REE composition similar to theEmeishan basalt, indicates that the source may come from the Emeishan basalt. |
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