| The Duolanasayi gold deposit, in 180km SW of Altay city in Xinjiang, is a middle-largescale telluride-type gold deposit controlled by the the brittle-ductile shear, albite-granite dykes,and post-stage magma solution of the rift valley dragging of the continental margin in earlyPalaeozoic Era. After Caledonian folding, this area developed open fissure and grew into rift inboth side of south and north in early stage of late Palaeozoic Era. Developing orogen formed inmiddle-late Variscian. The ore bodies, which are situated in the opposite "S" shape in the SNstrike, are present as the albitite veins (mylonitic albitite and mineralized albite-granite) andmineralized phyllite. There are lots of tellurides such as calaverite, petzite, sylvanite.It was developed that the slight metamorphous terrignous clastic rock, shallow sea faciescarbonatite formation of the Jiangjuleke group and the Tuokesalei group of the early-middleDevonian system in Duolanasayi gold deposit district, which consists of grey and green schistosesiltstone, carbonaceous siltstone, phyllitization siltstone and sandy limestone, flag limestone.Being dragged and pressed, the gold deposit district evolved from the rife valley dragging of thecontinental margin to compression and mountain making to local dragging taken place and fit inwith magmatism and mineralization in Variscian. With lots of clastation, mylonitic, schistositycleavage, the rock of gold deposit district are great deformation. The basic structure pattern of thegold deposit district consists of three interformational sliding fault-pulled and fractured-brittle-ductile shear zones, which opposite "S" shape in the SN strike, are present as the ore veinsor dyke, two predominantly isoclinal plunging folds of the Duolanasayi-Akesayi syncline andButuobieshan anticline in middle-later Variscian, and the NNE strike cleavages in late Variscian.There are two stages granite with origin and genesis. One is albite-granite dykes, the other isgranodiorite.The albite-granite dykes, which was the remeiting of the mantle and underthrust ocean crust,is the mantle-type granite in the rift valley dragging of the continental margin. It is bound up withgold mineralization with gold content of 97.1×10-9, and is major ore-bearing formation inDuolanasayi gold deposit. The rock forming principal mineral are albite, quartz, muscovite. Thepetrochemistry show middle SiO2(54-73%), high Al2O3(15.32-17.17%), rich Na2O(3.42-7.97%)and poor K2O(0.83-3.42%). The characteristics of rare elements show thatΣREE are 50.69×10-6-111.39×10-6, LREE/FIREE are 4.82-16.58, (La/Yb)N are 5.70-37.34;δEu are 0.89-1.42,δCe are 0.81-1.0; The primitive rate of(87Sr/86Sr)i is 0.7043.The granodiorite derived from the syntactic magma of the upper-mantle basic magma andlower-crust materials of the plate subduction's island arc in orogenic zone. The rock formingprincipal mineral are anorthose, quartz, diastatite. The petrochemistry show that features of Al2O3,rich Na2O and poor K2O.ΣREE are 134.74×10-6-183.19×10-6, LREE/HREE are 2.52-2.87,(La/Yb)N are 3.98-5.68:δEu are 0.73-0.85,δCe are 0.91-0.99;The primitive rate of(87Sr/86Sr)iis 0.7073. The granodiorite, with xenolith of angite diorite, quartz diorite porphyry and alkalicfeldspar granite in granodiorite batholith, consists of a magma evolution series, and providedenormous hot energy and some ore materials.The three ore types in the Duolanasayi gold deposit are pyrite-gold-altered rock,gold-albite-quartz and ferrohydrite-gold-quartz. The ore minerals include pyrite, native gold,calaverite, pyrrhotite, chalcopyrite, galena, sphaterite scheelite, and the minority of chlcocite, covellite, bilbinskite and minium. The gangue minerals include quartz, calcite and carbonaceousminerals. The wall rock alteration associated with gold mineralization comprises of albitization,muscovitization -sericitization, pyritization and silicification, albite granite, mylonitic albititealbite-quartz, pyrite -muscovite-sericite-quartz and quartz-calcite are five main mineralizingphases. The metallogenetic epoch is 269.0Ma-371.2Ma.Gold minerals in the Duolanasayi deposit are dominated by native gold and gold-bearingtellurides. There are three gold-bearing types of native gold: in inclusion, in crack of minerals andin crack of minerals crystal. The percentage of Au in native gold is high (＞950), and there are alittte of Ag, Hg, Bi, Te, Fe etc. The gold minerals of the gold-bearing tellurides are calaverite,petzite, sylvanite, montbrayite and so on, are characteristic in the gold deposit.According to elements correlating analyses, Au in positive relationship with Bi, Li, Ba, As,Zn, Be, Mo and negative Cu, W. There are four trace elements compound of Cr-Ni-Co-Cu,Rb-Ba-Be-Li, As-Pb-Ag-Zn-Sb and Au-Bi in gold ore.Fluid inclusions studies indicate that the homogenization temperatures rang from 160℃to315℃with the peak values of 220℃-300℃. Mineralization pressures is from 21.0×10 Mpa to64.5 Mpa. The ore fluid inclusion contains Ca2+, K+, Na+, Mg2+; HCO3-, SO42-, HS-, F-, Cl- andAu(max is 5.3×10-6). Salinities of fluid rang from 2.75-10.86NaCl%Wt in gas-solution inclusionsand 35.57-37.22NaCl%Wt in halite-bearing multi-phase inclusions, fO2=10-44.3-10-31.8, fS2=10-16.56-10-10.91, fTe2=10-13.39-10-4.49, pH=3.89-5.55; Eh=-0.58--0.72eV. The mineralizing fluid is aH2O-CO2 system. Sulfur, hydrogen, oxygen and strontium isotopic compositions (δ34S=-2.46‰--7.02‰,δ18OH2O=1.65‰-12.4‰,δD=-132.2‰--51.8‰, The primitive rate of (87Sr/86Sr)i=0.7043-0.7073) suggest the ore-forming fluid of the Duolanasayi gold deposit was a kind ofmixed hydrothermal solution mainly composed of magmatic water, metamorphic water, meteroricwater and formation water in rocks. The magmatic water in early mineralization is mantle fluid.HAu (HS)20,Au(HS)2-,Au(HTe)2-,Au(Te2)-,Au2(Te2)0,Au(Te2)23- and [AuCl2]- arelikely be the principal gold complexes in ore-bearing fluid. Four major types of precipitation ofgold are the action of boiling and exhaust, pressing and shearing in mylonitization stage,condensation and solution mixing in mineralization.Based on the above descriptions, the mineralization pattern of this gold deposit as follow:As a result of the tensile stress of rife in Duolanasayi gold deposit district, the albitite-granitemagma, which is the remelting material of lower-crust and upper-mantle, emergenced along faultand emplacement in the SN strike tension crack of the Tuokesalei group sedimentary formation inearly Variscian.In middle Variscian, the gold deposit district was pressed, as a result, the albitite-granite dykeand the rock of strata were folded and mylonitized. Meanwhile, with the brittle-ductile shear andthe granodiorite emergenced, the gold was activated, migrated, concentrated by the mineralizationof the brittle-ductile shear and post-magma hot fluid activation.The alkalic feldspar granite dyke, with the hot energy and ore-bearing hot fluid emergencedalong brittle-ductile shear zone in the NNE and NE strike, the gold was superimposed and enrichin later Variscian.
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