(1. 中南大學(xué) 有色金屬成礦預(yù)測教育部重點實驗室，長沙 410083；
2. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院，長沙 410083)
摘 要: 辛莊金礦位于山西陸臺五臺隆起西北側(cè)與燕山沉降帶西南緣兩大構(gòu)造單元相互嵌接的中生代構(gòu)造巖漿活動帶上，礦體產(chǎn)狀受NNW和NW向斷裂控制。根據(jù)脈體穿切關(guān)系和礦物交代關(guān)系，可以將辛莊金礦分為早、中、晚3個成礦階段。本區(qū)流體包裹體主要以氣液兩相包裹體為主，成礦溫度有兩個峰值：320~340 ℃和220~260 ℃，分別對應(yīng)石英-黃鐵礦階段和石英-多金屬硫化物階段，屬于中高溫的范圍。包裹體氣相成分以H2O和CO2為主，并含有一定量的CH4以及極少量的H2、C2H2和C2H6；液相成分主要有Ca2+、Mg2+、Na+、K+、SO42-、Cl-和F-。本區(qū)氫氧同位素組成表明成礦流體具有大氣降水與深部巖漿流體混合特點。總體而言，辛莊金礦的初始流體具有中高溫、富CO2、低鹽度的流體特征，晚成礦階段流體演化為低溫、低鹽度水溶液流體，流體的不混溶導(dǎo)致了主成礦期礦質(zhì)的大量沉淀。辛莊金礦為與燕山期巖漿活動有關(guān)的熱液型金礦床。
關(guān)鍵字: 流體包裹體；成礦流體；礦床成因；辛莊金礦床
（1. MOE Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education,
School of Geoscience and Info-Physics, Central South University, Changsha 410083, China;
2. School of Geoscience and Info-Physics, Central South University, Changsha 410083, China）
Abstract:Xinzhuang gold deposit is located in the Mesozoic tectonic-magma activation area which is embedded by the two tectonic units-the northwestern Wutai uplifts of Shanxi platform and the southwestern Yanshanian subsidence belt. The occurrence of the ore body is controlled by NNW and NW faults. The crosscutting relationships and mineral replacement suggest that the ore forming process includes the earlier, middle and later stages. The fluid inclusions of the ore in this deposit are mainly the gas-liquid inclusions. The ore-forming temperatures have two peak values: 320-340 ℃ and 220-260 ℃, corresponding to the quartz-pyrite-chalcopyrite stage and the quartz-polymetallic sulfide stage, respectively, which indicates that the deposit belongs to the hypo-mesothermal gold deposit. The gas compositions in the fluid inclusions mainly include H2O and CO2, with trace CH4 and H2, C2H2 and C2H6. The liquid phase mainly contain Ca2+, Mg2+, Na+, K+, Cl-, SO42-, Cl- and F-. The composition of hydrogen and oxygen means the mixing of meteoric water and deep magmatic fluid. In general, the ore fluids in the early and middle stages are characterized by meso-to hypothermal CO2-rich and low salinity, which are considered as the nature of metamorphic fluids, whereas the late-stage fluids are low temperature, low salinity and CO2-poor. The fluid immiscibility causes gold precipitation in the middle-stage. The Xinzhuang gold deposit belongs to the quartz vein type related to the Yanshanian mediosilicic-acid magma activities.
Key words: fluid inclusion？ ore forming fluid？ ore genesis？ Xinzhuang gold deposit
