發(fā)布時(shí)間：2018-05-15 15:41

  本文選題：礦床成因 + 控礦因素�。� 參考：《中國(guó)地質(zhì)大學(xué)(北京)》2017年博士論文

【摘要】：大青山金礦床位于塔里木板塊東北緣,北山古生代裂谷系南亞帶西段,處于大青山-紅十井-白山金、銅、鐵、鹽類(lèi)成礦帶上。長(zhǎng)期以來(lái),針對(duì)大青山金礦床的研究多集中于礦床地質(zhì)特征,在成礦年代學(xué)、成礦流體性質(zhì)和來(lái)源以及礦床成因等方面幾乎處于空白,這在一定程度上制約了該礦床及成礦帶中其他類(lèi)似金礦床的找礦進(jìn)程。鑒于此,本文在大量野外地質(zhì)工作的基礎(chǔ)上,綜合運(yùn)用構(gòu)造地質(zhì)學(xué)、巖石學(xué)、礦物學(xué)、礦床學(xué)、礦床地球化學(xué)、流體包裹體地質(zhì)學(xué)、同位素地質(zhì)學(xué)等多學(xué)科理論和方法,在查明大青山金礦床成因和控礦因素的基礎(chǔ)上,總結(jié)了成礦規(guī)律,指明了下一步找礦方向。礦床產(chǎn)于下石炭統(tǒng)紅柳園組變質(zhì)巖中,其原巖為一套雜砂巖、亞雜砂巖和長(zhǎng)石砂巖夾粘土巖。礦區(qū)內(nèi)識(shí)別出3期變質(zhì)變形作用,分別對(duì)應(yīng)3期石英脈,其中第2期為含金石英脈礦體。金礦體受庫(kù)魯克脆韌性-韌性剪切帶及其次級(jí)斷裂控制,總體走向NEE。礦石類(lèi)型分為石英脈型和蝕變巖型。礦石中金屬礦物有自然金、毒砂、黃鐵礦、黃銅礦、方鉛礦、閃鋅礦、磁黃鐵礦、銅藍(lán)及赤鐵礦等;非金屬礦物包括石英、絹云母、方解石、綠泥石、鐵白云石、菱鐵礦及鈉長(zhǎng)石等。圍巖蝕變以硅化、絹云母化、黃鐵礦化、毒砂化、綠泥石化、鈉長(zhǎng)石化和碳酸鹽化為主。流體包裹體及同位素研究表明,成礦期石英脈中主要賦存氣液兩相鹽水包裹體和CO_2-H_2O三相包裹體。成礦流體總體屬于中高溫(205~423℃)、低鹽度(0.22~8.80%NaCl_(eqv))、中等密度(0.55~0.85 g/cm~3)的H_2O-CO_2±CH_4±N_2體系。成礦流體來(lái)源主要為變質(zhì)水,并與圍巖發(fā)生了水-巖反應(yīng)。流體不混溶作用可能是該礦床中金等成礦物質(zhì)大量沉淀的原因。成礦作用發(fā)生于早二疊世(274 Ma),與賦礦地層中的變質(zhì)增生鋯石形成時(shí)代(269.6 Ma)一致。成礦物質(zhì)可能主要來(lái)源于毗鄰的三峰山VMS銅礦床及其賦礦玄武巖。大青山金礦床屬于海西期末區(qū)域變質(zhì)過(guò)程中形成的造山型金礦床。綜合研究表明,大青山金礦床受地層、構(gòu)造、蝕變圍巖等因素控制,在此基礎(chǔ)上,探討了構(gòu)造-成礦作用過(guò)程,建立了礦床的成因模式,認(rèn)為區(qū)內(nèi)4號(hào)、37號(hào)、41號(hào)、68號(hào)、104號(hào)、109號(hào)及115號(hào)石英脈具有較好的找礦前景。
[Abstract]:The Daqingshan gold deposit is located in the northeast margin of Tarim plate and in the western part of the South Asian belt of the Paleozoic rift system of the Beishan Mountains. It is located in the Daqingshan-Hongshijing-Baishan gold, copper, iron and salt metallogenic belt. For a long time, the study of Daqingshan gold deposit is mostly focused on the geological characteristics of the deposit, and is almost blank in the aspects of metallogenic chronology, ore-forming fluid nature and origin, and the genesis of the deposit, etc. To some extent, this restricts the prospecting process of the deposit and other similar gold deposits in the metallogenic belt. In view of this, on the basis of a great deal of field geological work, this paper synthetically applies the theories and methods of structural geology, petrology, mineralogy, deposit geochemistry, fluid inclusion geology, isotope geology and so on. On the basis of finding out the genesis and ore-controlling factors of Daqingshan gold deposit, the metallogenic law is summarized and the next prospecting direction is pointed out. The deposit occurs in the metamorphic rocks of Hongliuyuan formation of Lower Carboniferous. The primary rocks are a set of complex sandstone, sub-complex sandstone and feldspathic sandstone intercalated with clay rock. Three stages of metamorphic deformation have been identified in the mining area, corresponding to three periods of quartz veins respectively, and the second stage is the orebody of gold-bearing quartz veins. The gold orebody is controlled by the Kuluk ductile shear zone and its secondary faults, and the overall strike is NEE. The ore type is divided into quartz vein type and altered rock type. The metallic minerals in the ore are natural gold, arsenopyrite, pyrite, chalcopyrite, galena, sphalerite, pyrrhotite, copper blue and hematite, etc.; Non-metallic minerals include quartz, sericite, calcite, chlorite, iron dolomite, etc. Siderite and albite, etc. The main alteration of surrounding rock is silicification, sericite, pyrite, arsenopyrite, green mud petrification, albite and carbonization. The study of fluid inclusions and isotopes shows that there are mainly gas-liquid two-phase brine inclusions and CO_2-H_2O three-phase inclusions in quartz veins during the metallogenic period. The ore-forming fluid generally belongs to the H_2O-CO_2 鹵CH_4 鹵N2 system of moderate and high temperature of 205 ~ 423 鈩，

本文編號(hào)：1892932