發(fā)布時間：2018-02-23 16:41

  本文關(guān)鍵詞： 銻鉛鋅銀多金屬礦 流體包裹體 成礦作用 扎西康　出處：《中國地質(zhì)大學(北京)》2015年碩士論文　論文類型：學位論文

【摘要】：藏南扎西康銻鉛鋅銀礦床由于其巨大的礦產(chǎn)資源潛力和復(fù)雜的礦床類型近年來受到諸多學者的關(guān)注。本論文通過扎西康礦床地質(zhì)特征研究及流體包裹體分析,探討了成礦作用及可能的礦床類型。扎西康礦床礦體主要賦存于下侏羅統(tǒng)日當組地層中,礦體主要受近南北向斷裂控制,次為北東 南西向斷裂。根據(jù)礦物的共生組合、交切關(guān)系將扎西康礦床劃分為二大成礦期、六個成礦階段,即早期似噴流-沉積期(I)和晚期巖漿熱液疊加改造期(II)。似噴流-沉積期可細分為2個成礦階段,分別為錳鐵碳酸鹽-閃鋅礦-黃鐵礦-毒砂階段(I-1)、錳鐵碳酸鹽-閃鋅礦-方鉛礦-黃鐵礦±毒砂階段(I-2);晚期巖漿熱液改造期可以劃分4個成礦階段,分別為石英(方解石)-閃鋅礦-方鉛礦-黃鐵礦-黃銅礦階段(II-1)、石英-硫鹽階段(II-2)、石英-輝銻礦-辰砂階段(II-3)、石英±方解石脈階段(II-4)。流體包裹體研究發(fā)現(xiàn),礦床各成礦期次階段的各礦物中包裹體類型比較單一,主要以富液的氣液兩相水溶液包裹體為主,缺少兩相型CO2包裹體和三相型CO2-H2O包裹體。早期成礦流體溫度峰值區(qū)間為220℃~240℃,流體鹽度(wt%Na Clequiv,后同)峰值區(qū)間為12%~15%;晚期成礦流溫度具有遞減趨勢,峰值區(qū)間分別為:230℃~310℃(II-1)、230℃~270℃(II-2)、230℃~270℃(II-3)、230℃~260℃(II-4),鹽度也有弱的遞減趨勢,峰值區(qū)間分別為:6%~10t%(II-1)、6%~9%(II-2)、6%~9%(II-3)、3%~6%(II-4)。早期鉛鋅成礦流體屬低溫、中等鹽度的H2O-Na Cl體系,與SEDEX型、MVT型礦床相似;晚期銻成礦流體屬于中低溫、低鹽度H2O-Na Cl體系,與巖漿熱液脈型礦床相似(淺部輝銻礦化屬于熱泉型礦化)。結(jié)合前人H-O同位素研究認為礦床至少存在兩期成礦流體。綜合認為扎西康銻鉛鋅銀礦床為似噴流沉積-巖漿熱液改造型礦床。
[Abstract]:The Zaxikang antimony, lead, zinc and silver deposit in southern Tibet has attracted many scholars' attention in recent years because of its huge mineral resource potential and complex deposit types. In this paper, the geological characteristics of the Zaxikang deposit and fluid inclusion analysis are studied. The ore bodies of Zaxikang deposit are mainly located in the strata of the Lower Jurassic Ridang formation, and the orebodies are mainly controlled by the NNE faults, the next faults are the NE-NW faults. According to the mineral symbiotic assemblages, the orebodies are mainly controlled by the NNE trending faults, according to the mineral symbiotic assemblages. The Zaxikang deposit can be divided into two major metallogenic periods by cross-shear relationship, six metallogenic stages, I. e., the early similar exhalation depositional stage (I) and the late magmatic hydrothermal superposition reformation period, which can be subdivided into two metallogenic stages, and the similar exhalation sedimentary period can be subdivided into two metallogenic stages. They are manganese ferromanganese carbonate, sphalerite, pyrite and arsenopyrite stage, manganese iron carbonate sphalerite galena and pyrite 鹵arsenopyrite stage, and the late magmatic hydrothermal transformation stage can be divided into 4 metallogenic stages. They are quartz (calcite-sphalerite-galena-pyrite-chalcopyrite stage), quartz-sulfide stage (II-2), quartz-stibnite-cinnabar stage (II-3), quartz 鹵calcite vein stage (II-4). The types of inclusions in each ore forming stage of the deposit are relatively single, and the main inclusions are liquid-rich gas-liquid two-phase aqueous solution inclusions. There is a lack of two-phase CO2 inclusions and three-phase CO2-H2O inclusions. The peak temperature range of early ore-forming fluid is 220 鈩，

本文編號：1526869