本文選題：岔河銅礦床 + 成礦物質(zhì)來源��； 參考：《成都理工大學(xué)》2015年碩士論文

【摘要】：揚(yáng)子地塊西南緣是我國(guó)重要的銅、鐵多金屬礦集區(qū),產(chǎn)有大紅山、拉拉等大型、特大型銅鐵多金屬礦床,受到國(guó)內(nèi)外學(xué)者的關(guān)注。岔河銅礦床為該區(qū)域內(nèi)一個(gè)典型的銅多金屬礦床,前人對(duì)該礦床的研究較少,研究程度不高,制約了對(duì)該礦床成礦規(guī)律的認(rèn)識(shí),進(jìn)而影響了找礦。為探討岔河銅礦床的地球化學(xué)特征和礦床成因,在中國(guó)地質(zhì)調(diào)查局工作項(xiàng)目(編號(hào):12120113095500)、中國(guó)核工業(yè)地質(zhì)局重點(diǎn)科研項(xiàng)目(編號(hào):201148)的支持下,在收集大量資料、系統(tǒng)的總結(jié)和分析前人研究成果的基礎(chǔ)上,論文結(jié)合野外工作和室內(nèi)分析測(cè)試等工作,以礦床內(nèi)圍巖、礦石以及熱液石英脈、方解石脈等特征礦物為研究對(duì)象,通過微量元素地球化學(xué)、同位素地球化學(xué)、流體地球化學(xué)、巖石學(xué)、礦床學(xué)等方法對(duì)岔河銅礦床進(jìn)行了深入研究,探索了礦床物質(zhì)來源、流體性質(zhì)及來源、礦床成因等問題。具體取得的成果如下:(1)根據(jù)圍巖的常量元素和稀土元素特征,對(duì)變質(zhì)圍巖進(jìn)行了原巖恢復(fù),結(jié)果表明,岔河銅礦床片巖類和石英巖的原巖為沉積巖,圍巖屬于大陸邊緣雜砂巖,形成環(huán)境可能為被動(dòng)大陸邊緣。(2)岔河銅礦床黃銅礦與黃鐵礦硫同位素組成呈較大負(fù)值與沉積硫同位素組成相似,說明礦石硫源與含礦地層有關(guān)。黃銅礦鉛同位素組成變化較大,具有放射性異常鉛(鈾型鉛和釷型鉛)的特征,在構(gòu)造環(huán)境演化圖解上顯示上地殼來源。微量元素及稀土元素研究表明,成礦物質(zhì)來源于圍巖,成礦流體具有不同來源。(3)岔河銅礦床中兩期方解石碳同位素平均值處于巖漿碳(-5‰~-8‰)與海相沉積碳(-1‰~+2‰)之間,說明碳的來源可能是巖漿碳和海相碳酸鹽共同提供的結(jié)果,暗示成礦流體可能由巖漿水和淺部流體組成,流體中的氧同位素受到大氣降水影響而呈負(fù)漂移。(4)岔河銅礦床成礦期石英流體包裹體研究顯示,成礦流體屬中-低溫、中等鹽度、低密度的流體。結(jié)合碳氧同位素、石英流體包裹體成分及拉曼光譜分析認(rèn)為,成礦流體為巖漿水、變質(zhì)水和大氣降水的混合流體。(5)岔河銅礦床成因:早元古代期間,本區(qū)域存在一系列的邊緣裂谷型優(yōu)地槽,并沉積了一套中-淺變質(zhì)程度的賦鈉質(zhì)和金屬礦質(zhì)的火山沉積巖系,中元古代末格林威爾運(yùn)動(dòng),使區(qū)域地層發(fā)生大規(guī)模變質(zhì)、變形,并存在巖體侵入事件,從而提供了大規(guī)模的熱動(dòng)力,地層中以不同形式存在的水活化,匯聚成賦有較高溶解能力的變質(zhì)熱液,與巖漿水和大氣降水混合。混合流體在運(yùn)移過程中,不斷的萃取地層中的成礦元素,使成礦元素活化、運(yùn)移,當(dāng)流體運(yùn)移到適宜的環(huán)境時(shí),由于壓力的降低、物理化學(xué)條件的改變,流體中的成礦元素沉淀并富集成礦。
[Abstract]:The southwestern margin of the Yangtze block is an important copper and iron polymetallic ore concentration area in China, with large and super large copper and iron polymetallic deposits such as Dahongshan, Lala and so on, which have attracted the attention of scholars at home and abroad. The Chahe copper deposit is a typical copper polymetallic deposit in the region. The previous researches on the deposit are less and the degree of study is not high, which restricts the understanding of the metallogenic law of the deposit and further affects the prospecting. In order to study the geochemical characteristics and genesis of the Chahe copper deposit, with the support of the project of China Geological Survey (No. 12120113095500) and the key scientific research project of China Bureau of Nuclear Industry and Geology (No.: 201148), a large amount of data were collected. On the basis of summarizing and analyzing the previous research results systematically, this paper combines the field work and laboratory analysis and test work, taking the characteristic minerals such as the surrounding rock, ore, hydrothermal quartz vein, calcite vein and so on in the deposit as the research object. By means of trace element geochemistry, isotope geochemistry, fluid geochemistry, petrology and mineralogy, the Chahe copper deposit is deeply studied, and the source of material, fluid property and origin of deposit are explored. The results obtained are as follows: (1) according to the characteristics of major elements and rare earth elements of surrounding rock, the original rock of metamorphic rock is restored. The results show that the original rock of schist and quartzite of Chahe copper deposit is sedimentary rock, and the surrounding rock belongs to continental margin complex sandstone. The formation environment may be passive continental margin.) the sulfur isotopic compositions of chalcopyrite and pyrite are negative and similar to those of sedimentary sulfur isotopes, indicating that the ore sulfur source is related to ore-bearing strata. The lead isotopic composition of chalcopyrite varies greatly and has the characteristics of radioactive anomalous lead (uranium-type lead and thorium type lead), showing the origin of the upper crust in the diagram of tectonic environment evolution. The study of trace elements and rare earth elements shows that the ore-forming materials come from surrounding rock. The average carbon isotopic values of calcite in the two periods are between magmatic carbon (5 鈥，

本文編號(hào)：1993181