【摘要】：二里溝金礦床位于大渡河金成礦帶上,在大地構造位置上,處于揚子古大陸板塊的西部,揚子陸塊的北西緣,南北向康滇斷塊北部的康定雜巖北側,北西緊鄰松潘—甘孜構造帶之金湯弧形構造帶,南接康滇斷塊中部的石棉巖塊和冕寧巖塊。礦體賦存層位為泥盆系下統(tǒng)危關群第一巖組(Dwg1),巖性為黑色至深灰色炭質板巖、硅質板巖。二里溝礦床成礦類型以硫化物石英脈型為主,蝕變巖型次之。含金硫化物石英脈主要產于黑色至深灰色炭質板巖及絹云母千枚巖中,呈近南北向產出,傾向為263°~310°,傾角52°~73°。礦區(qū)內控礦條件簡單,控礦地質因素主要為節(jié)理裂隙,主要構造為F1壓性破碎帶及“X”共軛節(jié)理。石英脈型金礦石礦物成份:脈石礦物占95%以上,其中石英80%,云母5~10%,方解石、綠泥石、簾石、榍石等微-少量。礦石中金屬礦物含量約占1~5%,原生礦物以黃鐵礦為主,次為方鉛礦、閃鋅礦、黃銅礦、磁鐵礦、菱鐵礦等,自然金、銀金礦,碲化物少量;次生礦物有褐鐵礦、針鐵礦,纖鐵礦等。黃鐵礦粒徑0.03~10mm,以自形立方體、五角十二面體黃鐵礦居多,呈粒狀、浸染狀、細脈狀分布于礦石中。礦石中的金礦物主要為自然金。金的賦存狀態(tài)主要為顯微金、次為明金及超顯微金。自然金以形態(tài)不規(guī)則的粒狀為主,與黃鐵礦關系密切,常鑲嵌于其裂縫之中。礦石以它形、自形晶粒狀、壓碎、交代殘余結構為主,假晶、充填、鑲嵌、交代溶蝕、嵌晶包含結構次之。礦石以塊狀構造為主,網狀、角礫狀、浸染狀構造為輔,局部具星點狀、斑點狀、團塊狀、充填狀、晶洞構造等。圍巖蝕變主要為黃鐵礦化、硅化,次為絹云母化、綠泥石化、碳酸鹽化。對二里溝礦區(qū)的黃鐵礦單礦物進行S同位素分析結果表明:整個二里溝礦區(qū)硫同位素組成均一,變化范圍小,δ34S值為-5‰—4.6‰,平均值為2.36‰,分布較集中。除個別產于炭質板巖中的黃鐵礦出現(xiàn)負值外,其余均為正值,且變化范圍很小,在3.3-4.6‰之間,極差為1.3‰,表明該礦床的硫具有很均一的來源,具幔源硫特征。賦存于黑色碳質板巖中的黃鐵礦,相對虧損重硫同位素34S。其余樣品均為與石英伴生的黃鐵礦,與隕硫鐵標準相比,相對富重硫同位素34S。該礦床主要含硫礦物為黃鐵礦,因此硫化物的硫同位素組成變化范圍及平均值基本上能夠代表成礦流體的硫同位素組成。二里溝礦區(qū)與金礦體密切相伴的脈巖巖石化學分析結果表明,礦區(qū)內出露的巖漿巖有兩類,一類為超基性巖,一類為基性巖。其中超基性巖脈測試樣品根據結合鏡下特征定名為輝石橄欖巖,根據Rittmann A該樣品δ=0.38,屬典型的鈣性巖系�；詭r化學分析成果表明,ω(SiO2)=48.27%~48.41%,平均48.34%屬基性巖,低于我國輝綠巖對照值49.88%,二里溝輝綠巖的K2O+Na2O均值為2.68%,全堿含量不高,在TAS圖中基性輝綠巖投影點落在玄武巖里。全堿(K2O+Na2O)介于1.587%~3.78%,CaO含量8.69%~9.41%,平均值9.05%,將SiO2和堿含量(K2O+Na2O)計算Rittmann指數σ=0.47~2.65,平均值為1.56,屬于典型的鈣堿性巖性。南北向構造是礦區(qū)的基本構造格架,后期又疊加了走向北西的弧形構造。南北向構造按其力學性質,除了走向南北的主構造之外,還有與其配套的橫斷裂及北東、北西向的扭裂面。礦區(qū)脈體的分布以南北向為主,次為北西及北東向。就礦體而言,以北西向分布為主,次為北東向,南北向只有個別礦體而且礦化偏貧。北西向礦體礦化最好,次為北東向礦體。這表明構造對礦床的形成具有首要的控制作用,南北向的主構造面為導礦構造,次級的北西、北東向構造為儲礦構造,特別是北西向構造又受后期弧形構造的疊加,因此是最有利的成礦構造空間。巖漿活動、區(qū)域變質及構造運動為金礦的形成提供了熱源及成礦物質來源。特別是巖漿活動,為金礦的形成起了重要的作用。礦區(qū)的基性巖脈十分發(fā)育,在區(qū)域上基性巖與金礦化有密切的關系,就礦區(qū)而言金礦體有的就直接產出在基性巖脈邊部及其脈體的裂隙中,這表明金與基性脈巖在空間上具有密切的空間關系。根據鋯石測年結果,礦區(qū)內的基性巖脈有兩期,一期輝長巖形成年代為425.2±2.6Ma,另外一期測年結果為221±16Ma,而由ESR石英測年結果可知金成礦期約為13.2Ma,金成礦期明顯晚于基性脈巖。礦區(qū)內如此強烈的基性巖漿活動指示了礦區(qū)內存在深達深部地殼或地幔的基性巖漿上升侵位通道,這些通道不僅有利于深部巖漿侵位,同時也為巖漿活動之后的含金熱液流體活動提供了運移通道。
[Abstract]:Located in the Dadu River gold metallogenic belt, the second Li gully gold deposit is located in the west of the Yangtze paleo continental plate and the northern margin of the Yangtze block, North and south of the Kangding complex in the northern part of the Kang Dian fault block, and the North West of the Jin Tang arc tectonic belt near the Songpan Ganzi tectonic belt, and the asbestos rock block and Mian Ningyan in the middle of the central Kang Dian fault block. The deposit of the ore body is the first rock group (Dwg1) of the Lower Devonian group, the lithology is black to deep gray carbonaceous slate and siliceous slate. The ore-forming type is mainly sulfide quartz vein and altered rock type. The gold sulfide quartz vein is mainly produced in black to dark gray carbonaceous and sericite phyllite, and is near South. The northward output, with a tendency of 263 ~310 degrees, and a dip angle of 52 ~73 degrees. The ore controlling conditions are simple and the ore controlling geological factors are mainly joint fractures. The main structure is the F1 compressional fracture zone and the "X" conjugate joints. The mineral composition of quartz vein type gold ore is more than 95%, including stone 80%, mica 5~10%, calcite, chlorite, epidote, spite, etc. The mineral content of the ore is about 1~5%, the primary mineral is pyrite, the second is galena, sphalerite, chalcopyrite, magnetite, siderite, natural gold, silver gold and telluride, and the secondary minerals are limonite, goethite, and fibrite. The size of pyrite is 0.03~10mm, with the self shaped cube and five horns twelve hedral pyrite. The gold minerals in the ore are mainly natural gold. The gold deposits in the ore are mainly natural gold. The main state of gold is Microgold, the second is the Ming gold and the ultramicro gold. The natural gold is mainly in the irregular form, closely related to the pyrite, and is inlaid in the crack. The ore is shaped, self shaped grain, crushed and metasomatism. The residual structure is mainly pseudocrystalline, filling, inlay, metasomatism and dissolution, and the inlay contains structure. The ore is mainly lump structure, reticulate, breccia, and disseminated structure as auxiliary, local with star point, spot, lump, filling, cavity structure and so on. The alteration of surrounding rock mainly is sericite, silicification, second sericite, green mud petrifaction, carbonation. Two The S isotopic analysis of the pyrite minerals in the Li Gou mining area shows that the sulfur isotope composition of the mine is uniform, the range of variation is small, the value of delta 34S is -5% to 4.6 per thousand, the average value is 2.36 per thousand, and the distribution is more concentrated. The difference between.6 per thousand and 1.3 per thousand indicates that the sulphur of the deposit has a very homogeneous source, with the characteristics of the mantle derived sulfur. The pyrite in the black carbonaceous slate, the relative loss of the sulfur isotope 34S., is the pyrite associated with the quartz. Compared with the standard of the meteorite iron, the main sulfur bearing mineral of the rich sulfur isotope 34S. is yellow. Therefore, the sulfur isotope composition of the sulphide can basically represent the sulfur isotope composition of the ore-forming fluid. The chemical analysis of the vein rocks closely associated with the gold ore body in the two Li gully mining area shows that there are two types of magmatic rocks exposed in the mining area, one is ultrabasic rock and the other is basic rock. The pulse test samples are named pyroxene peridotite based on the characteristics under the combined mirror. According to the Rittmann A, the sample is a typical calcite rock. The results of chemical analysis of the basic rock indicate that omega (SiO2) =48.27%~48.41%, with an average of 48.34% genera rock, is lower than the control value of the diabase in our country, 49.88%, and the K2O+Na2O mean of the Dili diabase is 2.68%, and the total alkali content is 2.68%. Not high, the basic diabase projection point in the TAS map falls in the basalt. All alkali (K2O+Na2O) is between 1.587%~3.78%, CaO content is 8.69%~9.41%, the average value is 9.05%. The Rittmann index Sigma =0.47~2.65 is calculated by SiO2 and alkali content (K2O+Na2O), the average value is 1.56, which belongs to the typical calcic lithology. The north and South structure is the basic tectonic framework of the mining area, and later later The North-South structure is superimposed on the north-west structure. In addition to its mechanical properties, in addition to the main tectonics of the north and south, there are also the cross split and north-east and north-west torsional surface. The distribution of the vein in the mining area is mainly North and south, and the second is north-west and northward. In the case of the ore body, the distribution is mainly North West, and the second is north to North and North and south. There are only individual orebodies and poor mineralization. The mineralization of North West to ore body is the best, which indicates that the structure has the primary control effect on the formation of the deposit, the main tectonic surface of the north and the north is the ore guide structure, the secondary North West and the NE trending structure is the reservoir structure, especially the North West structure is superimposed by the late arc structure. This is the most favorable metallogenic space. Magmatic activity, regional metamorphism and tectonic movement provide the source of heat source and metallogenic material for the formation of gold deposits. Especially magmatic activity, it has played an important role in the formation of gold deposits. The basic rock veins of the mining area are very well developed, and the basic rock is closely related to gold mineralization in the area, and gold is concerned with gold mine. Some of the ore bodies are directly produced in the cracks in the edge of the basic rock veins and their veins, which indicates that the gold and the basic vein rocks have a close spatial relationship in space. According to the results of zircon dating, there are two phases of the basic rock veins in the mining area, the formation age of the first phase of the gabbro is 425.2 + 2.6Ma, the other phase is 221 + 16Ma, and the ESR quartz is measured by quartz. The result shows that the gold mineralization period is about 13.2Ma, and the gold mineralization period is obviously later than the basic vein rock. The strong basic magmatic activity in the mining area indicates the basic magma emplacement channel in the deep crust or mantle, which is not only beneficial to the deep magma emplacement, but also the gold bearing fluid after the magmatic activity. Body activity provides a transport channel.
【學位授予單位】：成都理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P618.51

【參考文獻】

相關期刊論文 前5條

1 劉連登,陳國華,吳國學,張克堯,石建基,張進高;我國淺成熱液金礦的分類探討[J];長春科技大學學報;1999年03期

2 涂光熾;;礦床的多成因問題[J];地質與勘探;1979年06期

3 盧煥章;;流體包裹體巖相學的一些問題探討[J];高校地質學報;2014年02期

4 胡朋,赫英,張義,江思宏,劉妍;淺成低溫熱液金礦床研究進展[J];黃金地質;2004年01期

5 許譜林;呂古賢;張迅與;張迎春;;膠東地區(qū)蝕變巖型和石英脈型金礦床對比[J];礦物學報;2011年S1期

相關碩士學位論文 前1條

1 侯林;丹巴燕子溝金礦礦床地質地球化學初步研究[D];成都理工大學;2010年

，

本文編號：2148356