發(fā)布時(shí)間：2018-01-30 17:38

  本文關(guān)鍵詞： 都龍鋅錫多金屬礦床 老君山花崗巖 層狀矽卡巖 地球化學(xué) 礦床成因　出處：《中國地質(zhì)大學(xué)(北京)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：本次研究選取我國著名的都龍鋅錫多金屬礦床為研究對(duì)象,以詳實(shí)的野外地質(zhì)調(diào)查為基礎(chǔ),巖漿-構(gòu)造-流體-成礦為主線,系統(tǒng)的研究了礦區(qū)巖漿巖的地球化學(xué)特征、礦床的地質(zhì)特征和礦床地球化學(xué)特征,從而對(duì)該礦床的成礦物質(zhì)來源、礦床成因及成礦機(jī)制進(jìn)行探討。通過本次研究工作,獲得了以下主要認(rèn)識(shí):(1)分別對(duì)礦區(qū)內(nèi)出露的老君山花崗巖和南溫河花崗片麻巖體進(jìn)行了LAICP-MS鋯石U-Pb測(cè)年、地球化學(xué)、同位素地球化學(xué)等方面的分析研究。實(shí)驗(yàn)結(jié)果表明,老君山花崗巖形成于晚白堊紀(jì)(88~83Ma),巖石地球化學(xué)特征為高分已S型花崗巖,形成于同碰撞向拉伸轉(zhuǎn)換階段,源區(qū)原巖以變質(zhì)泥巖為主;南溫河花崗片麻巖形成于晚志留紀(jì)(411Ma),巖石地球化學(xué)特征表現(xiàn)為S型花崗巖,形成于后碰撞拉伸背景,源區(qū)原巖以變質(zhì)砂巖為主。(2)礦體形態(tài)不規(guī)則,主要以層狀、似層狀、透鏡狀、脈狀和條帶狀等產(chǎn)出,常見分枝復(fù)合、尖滅再現(xiàn)、膨脹收縮和穿層交叉等現(xiàn)象。圍巖蝕變包括矽卡巖化、綠泥石化、綠簾石化、絹云母化、碳酸鹽化等。礦石類型包括塊狀礦石、浸染狀礦石、條狀帶礦石、斑雜狀礦石和脈狀礦石。成礦期次可劃分為矽卡巖期、熱液成礦期和表生氧化期。(3)矽卡巖礦物的電子探針研究表明,都龍礦床中的矽卡巖主要以鈣矽卡巖為主,成礦環(huán)境具有從弱氧化環(huán)境向還原環(huán)境轉(zhuǎn)變的特點(diǎn)。同時(shí),礦區(qū)中的層狀矽卡巖是巖漿熱液在地層層間滑脫帶或破碎帶流動(dòng)過程中,通過滲透交代作用與碳酸鹽圍巖發(fā)生反應(yīng)所形成。(4)都龍鋅錫多金屬礦床流體包裹體主要包括三種類型:富液相包裹體、富氣相包裹體和含子礦物三相包裹體,包裹體氣相成分以CH_4+CO_2±N_2為主。流體的溫度、鹽度和密度具有從早期到晚期逐漸降低的特點(diǎn)。(5)對(duì)都龍礦床銅街礦段的錫石單礦物樣品進(jìn)行LA-ICP-MS錫石U-Pb成礦年代學(xué)研究,獲得88±5Ma的等時(shí)線年齡和89.4±1.4Ma的諧和年齡,表明都龍鋅錫多金屬礦床的形成與老君山巖漿作用關(guān)系密切。(6)通過對(duì)礦區(qū)不同階段石英、方解石、磁鐵礦的氫、氧同位素研究,都龍鋅錫多金屬礦床的成礦流體早期源于原生巖漿水,晚期變?yōu)橐蕴焖疄橹鞯幕旌狭黧w;碳、氧同位素研究表明含礦熱液的碳來源于巖漿熱液,與圍巖地層并無親緣性;礦區(qū)主要硫化物的硫同位素來源于花崗質(zhì)巖漿,與地層中硫化物的硫同位素相差較大;鉛同位素研究表明,都龍鋅錫多金屬礦床成礦物質(zhì)的鉛同位素組成來源于老君山花崗巖源區(qū)。綜上所述,本次研究的都龍鋅錫多金屬礦床為一巖漿熱液矽卡巖型礦床,其中礦化與老君山二期花崗巖最為密切。
[Abstract]:This study selected China's famous Dulong zinc tin polymetallic deposit as the research object, based on field geological investigation and detailed basis of magmatic tectonic fluid mineralization system as the main line, the study of the geochemical characteristics of mine magmatite, geological features and ore deposit characteristics of the earth, and the source of ore the material of the deposit, discusses the genesis and metallogenic mechanism of ore deposit. Through this research, the main conclusions are as follows: (1) were within the mining area Laojun Mountain Nanwenhe granite and granite gneiss body exposed by LAICP-MS zircon U-Pb dating, geochemistry, isotope geochemistry analysis etc.. The experimental results show that the Laojun Mountain granite formed in the late Cretaceous (88~83Ma), rock geochemistry has high as S type granite, the conversion stage tensile in collision formation, original rocks by metamorphic mudstone The main; Nanwenhe granite gneiss formed in late Silurian (411Ma), rock geochemistry features of S type granite, formed in the post collision stretching background, the original rock source area by metamorphic sandstone. (2) the orebody shape is irregular, mainly layered, stratoid, lenticular, vein and ribbon etc. output, common branching, pinch reproduction, expansion and contraction and wear layer cross phenomenon. The wall rock alteration includes skarn, chloritization and epidotization, sericitization, carbonation etc.. Ore types include massive ore, disseminated ore, ore strip, taxitic ore and ore vein. The metallogenic period can be divided into skarn stage, hydrothermal stage and supergene oxidation stage. (3) electron microprobe study of skarn minerals show that the Dulong ore deposits in skarn mainly calcareous skarn metallogenic environment has mainly from weak oxidation environment to the characteristics of reducing environment change. The same When the layered silicates in the mining area is the skarn magmatic hydrothermal formation in the interlayer gliding belt or belt in the process of flowing, formed by infiltration metasomatism with carbonate rock reaction. (4) are in fluid inclusions of zinc tin dragon polymetallic ore body mainly includes three types: rich liquid inclusion rich. Vapor inclusions and halite bearing three-phase inclusions, gas composition of fluid inclusion in CH_4+CO_2 + N_2. The fluid temperature, salinity and density is decreased gradually from early to late. (5) cassiterite samples of copper ore section of longkuang bed street LA-ICP-MS study on metallogenic chronology of cassiterite U-Pb, obtained 88 + 5Ma isochron age of 89.4 + and 1.4Ma concordant age, indicate the formation of Dulong zinc tin polymetallic deposit and Laojun Mountain magmatism closely. (6) by the mining area in different stages of quartz, calcite, magnetite, hydrogen, oxygen isotope studies, all The early ore-forming fluid source zinc tin dragon polymetallic deposit in primary magmatic water, advanced into mixed fluid in Tianshui mainly; carbon, oxygen isotope studies show that the ore bearing hydrothermal carbon derived from magmatic hydrothermal fluid, and the surrounding strata no affinity; the main source of sulfur isotope sulfide mine in granitic magma, and sulfur the formation of sulfide in different isotope; lead isotope studies indicate that the Dulong zinc tin polymetallic ore deposit mineral composition of lead isotope from Laojun Mountain granite source region. In summary, the study of the Dulong zinc tin polymetallic ore deposit is a magmatic hydrothermal skarn deposit, the mineralization and granite the Laojun Mountain two close.

【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：P618.2
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本文編號(hào)：1476837