本文選題：黑云母標型特征 + 角巖斑巖成礦　； 參考：《成都理工大學》2015年碩士論文

【摘要】：甲瑪?shù)V床位于西藏岡底斯成礦帶東段,是公益性與商業(yè)性勘查結(jié)合取得的重要成果。目前銅資源量超過700萬噸,共伴生鉬、鉛、鋅、金、銀資源量均達到大型以上規(guī)模。甲瑪?shù)V床是由斑巖鉬銅礦體、矽卡巖銅多金屬礦體、角巖銅鉬礦體以及破碎帶中獨立金礦體構(gòu)成的“四位一體”典型斑巖成礦系統(tǒng)產(chǎn)物。本文在充分收集整理礦區(qū)地質(zhì)資料和前人研究成果的基礎上,立足于礦區(qū)最新的勘查成果,通過詳細的地質(zhì)調(diào)查和鉆孔地質(zhì)編錄等,采用巖、礦石光薄片顯微鑒定、電子探針分析等系統(tǒng)研究礦區(qū)黑云母特征。詳細厘定了甲瑪銅多金屬礦床的黑云母的成因類型,主要由兩類黑云母組成,一類是原生黑云母,屬于成礦前黑云母;另一類是巖漿-熱液形成的熱液黑云母,屬于成礦期黑云母。巖體中的原生黑云母為巖漿黑云母,熱液黑云母為熱液交代黑云母和熱液新生黑云母。角巖中原生黑云母為角巖化熱變質(zhì)過程中形成的黑云母,分為斑點狀黑云母和條帶狀黑云母;熱液黑云母:巖漿在熱液分異過程中形成于角巖內(nèi)部或裂隙中的熱液黑云母,按照典型的共生礦物組合,可分為4類:A類:黑云母細脈;B類:石英+黑云母脈;C類:石英+黑云母+綠泥石脈;D類:石英+黑云母+鈉長石脈。研究了兩類黑云母的地球化學性狀。原生黑云母和熱液黑云母落于黑云母分類圖中富鎂黑云母和金云母區(qū)域,巖體中的黑云母偏向于富鎂黑云母,具有富鎂特征。角巖中,與原生黑云母相比,熱液黑云母中Mg含量的升高,Cu含量升高,Fe含量降低,Fe2+和Fe3+分異程度增大;巖體中,與原生黑云母相比,熱液黑云母具有Ti O23%,Al2O315%,低鈦高鋁的特征,Fe含量降低,Mg含量的升高,Cu含量升高。五類熱液黑云母化學成分沒有明顯的差別,D類熱液黑云母TFe O含量較其他熱液黑云母較低,巖體中的熱液黑云母TFe O含量較其他熱液黑云母偏高。確定了2類黑云母形成的物理化學條件�；◢彴邘r中原生黑云母的結(jié)晶溫度變化在730~750℃,logf O2變化范圍是-11.5~-13.0�；◢彴邘r屬于造山帶鈣堿性巖系,具殼�；煸吹某梢蛱攸c。與原生黑云母相比,角巖中熱液黑云母Fe2+/(Fe2++Mg2+)比值均一程度低,且Fe3+/Fe2+比值相對含量顯著升高,甚至部分熱液黑云母不含F(xiàn)e2+,指示巖漿-熱液流體體系逐漸向氧化態(tài)過渡,有利于斑巖銅礦的形成。探討了兩類黑云母的形成與礦化的關系。相比原生黑云母,Cu更趨于富集于熱液黑云母;而Mo元素在原生黑云母和熱液黑云母中普遍存在,并不具有選擇性賦存的特征。對于熱液黑云母所在的巖礦石樣品,礦化作用的強度與黑云母中Cu含量呈正相關。
[Abstract]:Jiama deposit is located in the eastern section of the Gangdis metallogenic belt in Tibet, which is an important result of the combination of public welfare and commercial exploration. At present, the amount of copper resources is more than 7 million tons, and the associated molybdenum, lead, zinc, gold and silver resources have reached large scale. Jiama deposit is a typical porphyry ore-forming system composed of porphyry molybdenum copper ore body, skarn copper polymetallic body, hornstone copper-molybdenum ore body and independent gold ore body in broken zone. On the basis of fully collecting and arranging geological data of mining area and previous research results, based on the latest exploration results of mining area, through detailed geological investigation and geological cataloguing of boreholes, this paper adopts microscopic identification of light and thin sections of rocks and ores. The characteristics of biotite in mining area were studied by electron probe analysis (EPMA). The genetic types of biotite in Jiama copper polymetallic deposit are determined in detail, which are mainly composed of two types of biotite, one is primary biotite, which belongs to pre-metallogenic biotite, and the other is hydrothermal biotite formed by magmatic hydrothermal solution. It belongs to biotite in metallogenic period. The primary biotite in the rock mass is magmatic biotite, hydrothermal biotite is hydrothermal metasomorphic biotite and hydrothermal neo-biotite. Proto-biotite in hornstone is biotite formed during hornstone thermal metamorphism, which is divided into spotted biotite and striped biotite; hydrothermal biotite: hydrothermal biotite formed in the interior or fissure of hornstone during hydrothermal differentiation. According to the typical symbiotic mineral assemblage, it can be divided into 4 groups: category A: biotite vein type B: quartz biotite vein type C: quartz biotite chlorite vein type D: quartz biotite albite vein. The geochemical properties of two classes of biotite were studied. The primary biotite and hydrothermal biotite fall in the magnesium-rich biotite and phlogopite area in the classification map of biotite. The biotite in the rock mass tends to be rich in magnesium-rich biotite and has the characteristics of magnesium-rich. In hornstone, compared with primary biotite, the increase of mg content in hydrothermal biotite and the increase of Cu content decrease the differentiation degree of Fe _ 2 and Fe _ 3, and in the rock mass, compared with that of primary biotite, the difference of Fe _ 2 and Fe _ 3 increases. Hot liquid biotite has TIO _ (23) and Al _ 2O _ 3 _ (15). The characteristic Fe content of low titanium and high aluminum content decreases the increase of mg content and the increase of Cu content. There is no obvious difference in the chemical composition of the five kinds of hydrothermal biotite. The TFeO content of D type hydrothermal biotite is lower than that of other hydrothermal biotite, and the TFeO content of hydrothermal biotite in rock mass is higher than that of other hydrothermal biotite. The physical and chemical conditions for the formation of two classes of biotite were determined. The crystallization temperature of protobiotite in granitic porphyry varies in the range of -11.5 ~ 13.0 at 750 鈩，

本文編號：2072264