本文選題：大王山鎢鉬多金屬礦床　切入點(diǎn)：山心巖體　出處：《東華理工大學(xué)》2017年碩士論文

【摘要】：大王山鉬鎢多金屬礦床位于中國東南部江西省的中部,地處撫州市宜黃、樂安、崇仁三縣交界處,位于大王山-于山多金屬成礦帶北端。礦石類型主要為脈狀型黑鎢礦,礦脈主要產(chǎn)于圍巖花崗巖內(nèi)的接觸帶中。本文在分析大王山礦區(qū)地質(zhì)背景和成礦地質(zhì)特征基礎(chǔ)上,結(jié)合前人對研究區(qū)賦礦山心單元的細(xì)粒二云母二長花崗巖巖石地球化學(xué)特征、鋯石U-Pb年代學(xué)特征的研究,系統(tǒng)開展了石英-輝鉬礦脈中的石英礦物和硫化礦的流體包裹體、穩(wěn)定同位素地球化學(xué)等方面的研究工作。通過系統(tǒng)總結(jié)賦礦巖體形成時代、成因類型及其形成構(gòu)造環(huán)境,并結(jié)合大王山鎢鉬多金屬礦床的成礦流體特征、成礦物質(zhì)來源,初步建立了該礦床的成礦模型,進(jìn)而對研究區(qū)成礦理論的確定及礦產(chǎn)勘探工作起到重要的指示作用。以下是本次研究獲得的主要成果:(1)根據(jù)前人(項(xiàng)目組)對賦礦山心單元花崗巖體的研究資料,可以看出研究區(qū)花崗巖體具有高鉀鈣堿性、準(zhǔn)鋁質(zhì)-過鋁質(zhì)、富硅堿,貧鎂鈣,高鐵鎂指數(shù)等化學(xué)成分特征,具有殼源花崗巖的特征,屬于高熱花崗巖。其源巖可能為變沉積巖,推斷屬于高分異S型花崗質(zhì)巖石。(2)大王山礦區(qū)石英脈的石英流體包裹體均一溫度為180~280℃(峰值為190~210°C),鹽度為7.86%~20.22%NaCleqv(峰值11~17%NaCleqv)。利用硫同位素溫度計(jì)計(jì)算成礦溫度為315~339℃。由此看出,硫化礦要早于石英脈形成,其形成溫度亦高于石英脈,結(jié)合前人對其它石英脈型黑鎢礦床中的黑鎢礦和石英脈的均一溫度特征,可以判斷該礦床應(yīng)屬于中高溫、中高鹽度的礦床。(3)研究區(qū)的氫氧同位素?cái)?shù)據(jù)研究表明:石英包裹體中的δDV-SMOW值介于-72.5‰~-93.1‰,δ18OH_2O值介于-2‰~1.8‰,從石英包裹體的溫度-鹽度關(guān)系圖中,推斷礦區(qū)成礦流體在演化的過程中經(jīng)歷了流體的混合作用和自然冷卻,進(jìn)一步指示了黑鎢礦要早于石英結(jié)晶,該時期成礦流體成分相對單一,以巖漿水為主,而石英結(jié)晶時成礦流體則體現(xiàn)了巖漿水和大氣降水的混和作用。在巖漿液態(tài)不混溶作用過程中,W、Mo等多金屬成礦元素以及揮發(fā)份不斷富集,進(jìn)而形成石英脈型鎢多金屬分異富集成礦。(4)硫化物硫同位素組成δ34S介于-1.3‰~+1.9‰之間,其中以-1‰~0.6‰之間者居多,平均值為-0.22‰,δ34S值主要集中在零值附近,說明硫源與深部巖漿有關(guān)。(5)通過對大王山鎢多金屬礦區(qū)的地質(zhì)特征、成礦物質(zhì)來源、成礦流體性質(zhì)、大地構(gòu)造背景、成礦機(jī)制等進(jìn)行綜合性研究,建立了該礦床的成礦模式。
[Abstract]:The Dawangshan molybdenum and tungsten polymetallic deposit is located in the middle of Jiangxi Province in southeastern China. It is located at the junction of the three counties of Yihuang, Le'an and Chongren in Fuzhou, and is located at the northern end of the Dawangshan-Yushan polymetallic metallogenic belt. The ore type is mainly vein type wolframite. The ore vein mainly occurs in the contact zone of surrounding rock granite. Based on the analysis of geological background and ore-forming geological characteristics of Dawangshan mine area, combined with the petrogeochemical characteristics of fine-grained dimica monzogranite bearing mine core units in the study area, The U-Pb chronological characteristics of zircon have been studied systematically in the aspects of fluid inclusions and stable isotope geochemistry of quartz minerals and sulphide ores in quartz-molybdenum veins. The metallogenic model of the deposit is preliminarily established by the genetic type and its forming tectonic environment, combined with the ore-forming fluid characteristics of the Dawangshan tungsten and molybdenum polymetallic deposit and the source of the ore-forming material. Thus, it plays an important role in the determination of metallogenic theory and mineral exploration work in the study area. The following is the main achievement of this study: 1) according to the research data of granitic bodies in mine core units by predecessors (project teams), It can be seen that the granite body in the study area has the characteristics of high potassium calc-alkalinity, quasi-aluminum-peraluminous, silicon-rich alkali, poor magnesia-calcium, ferric-magnesium index, etc., and has the characteristics of crust-derived granites. The source rocks may be metamorphic rocks. It is inferred that the homogeneous temperature of quartz fluid inclusions in quartz veins of Dawangshan mining area is 180 ~ 280 鈩，

本文編號：1667516