本文選題：滇東南　切入點(diǎn)：南秧田　出處：《中國地質(zhì)大學(xué)(北京)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：南秧田礦床位于“越北地塊”北部,是我國滇東南地區(qū)最大的以鎢為主的金屬礦床。礦區(qū)電氣石石英巖(脈)大量發(fā)育并具廣泛的白鎢礦礦化,對(duì)礦區(qū)主礦體的疊加富集作用明顯。本文以電氣石著手,以南秧田白鎢礦床中的條帶狀電氣石石英巖和電氣石石英脈為研究對(duì)象,通過詳細(xì)的野外調(diào)查研究、巖相學(xué)研究、地球化學(xué)及B等同位素研究,結(jié)合電氣石石英巖(脈)流體包裹體的資料,對(duì)電氣石石英巖(脈)的流體性質(zhì)、流體來源及礦床成因展開了深入研究。取得的主要成如下:1、針對(duì)電氣石的成因礦物學(xué)、B同位素研究和其在礦床研究中的應(yīng)用等三個(gè)方面,系統(tǒng)梳理和論述了電氣石的研究進(jìn)展。2、通過對(duì)南秧田礦區(qū)電氣石的主量、微量和B同位素等地球化學(xué)研究,查明了礦區(qū)電氣石的物質(zhì)來源、B來源和成因。礦床電氣石均屬于堿性電氣石中鎂電氣石,沒有明顯的光學(xué)分帶和組成分帶,以富Mg及Y位中無Al或低Al為特征,具有相對(duì)高的Fe O/(Fe O+Mg O)比值(0.46-0.65,平均0.53);稀土元素配分曲線與研究區(qū)內(nèi)晚白堊紀(jì)老君山花崗巖稀土元素配分曲線接近;B同位素δ11B值與平均地殼的δ11B值非常接近(-10±3‰),集中在-14‰。這些特征與巖漿期后熱液成因的電氣石特征一致,為與老君山花崗巖有關(guān)的熱液電氣石,其B來源于貧Ca的變質(zhì)泥巖、砂巖。3、厘定了礦區(qū)含礦電氣石石英巖的流體性質(zhì)。流體包裹體特征表明,其均一溫度集中在250~340℃,鹽度3~10 wt%Na Cleq;顯示為中-高溫、低鹽度的成礦流體,推測(cè)其主要是演化的中-低鹽度巖漿來源流體與低鹽度大氣降水混合的產(chǎn)物。4、肯定了晚白堊紀(jì)巖漿期后熱液對(duì)礦區(qū)主礦體的疊加富集作用,認(rèn)為晚白堊世(80-96Ma)華南西部與巖石圈伸展作用有關(guān)的成巖-成礦事件對(duì)本區(qū)鎢礦形成具有重要影響。5、提出了距晚白堊紀(jì)花崗巖體中部距離為有利礦化區(qū),電氣石石英巖(脈)為尋找富礦體的重要標(biāo)志,為礦區(qū)外圍及深部勘查評(píng)價(jià)指明了找礦方向。
[Abstract]:The Nanyangtian deposit is located in the northern part of the "Yubei block", and is the largest tungsten deposit in southeast Yunnan of China. The tourmaline quartzite (vein) in the mining area is extensively developed and widely mineralized in scheelite. The superposition and enrichment of the main orebody in the mining area is obvious. In this paper, the tourmaline quartzite and tourmaline quartz veins in the southern Yangtian scheelite deposit are taken as the objects of study, and the detailed field investigation and petrographic study are carried out. Geochemistry and B isotopic studies, combined with the data of fluid inclusions in tourmaline quartzite (vein), are used to study the fluid properties of tourmaline quartzite (vein). The origin of fluids and the genesis of the deposit have been studied in depth. The main results are as follows: 1. Aiming at the mineralogical B isotope study of tourmaline and its application in ore deposit research, The research progress of tourmaline is systematically reviewed and discussed. 2. The main quantity, trace and B isotopes of tourmaline are studied in Nanyangtian mining area. The material source and origin of tourmaline in mining area have been found out. The tourmaline of ore deposit belongs to magnesium tourmaline in alkaline tourmaline. There is no obvious optical zonation and compositional zone, which is characterized by the absence of Al or low Al in rich mg and Y sites. The REE partition curve of Laojunshan granites in late Cretaceous is close to B isotope 未 11B and the average crustal 未 11B is very close to that of the average crustal 未 -10 鹵3 鈥，

本文編號(hào)：1617976