【摘要】：通過野外調(diào)研、輝鉬礦Re-Os定年和流體包裹體研究,對內(nèi)蒙古西烏旗東不拉格鉬鉛鋅礦床的成礦時代、成礦背景和成礦流體特征及流體演化進(jìn)行了探討。研究結(jié)果表明,礦區(qū)發(fā)育斑巖型鉬礦化和熱液脈狀鉛鋅礦化,二者為同一構(gòu)造巖漿事件的產(chǎn)物。鉬、鉛鋅成礦均與區(qū)內(nèi)石英二長斑巖有關(guān),輝鉬礦Re-Os定年結(jié)果表明,成礦時代為中侏羅世(165.2±2.8 Ma),是中國東部燕山期大規(guī)模成礦事件的產(chǎn)物。流體包裹體測試結(jié)果表明,成礦流體主要來自巖漿水,早期成礦流體具有高溫、高氧逸度、富Fe和含CO_2的特征。從成礦早階段至晚階段成礦流體從高溫(312~534℃)、高鹽度(高達(dá)63.9%NaCleq)向低溫(158~166℃)低鹽度(低至0.35%NaCleq)演化。隱爆造成的巖漿減壓沸騰是巖漿流體出溶的主要機(jī)制,早期巖漿流體由于減壓和降溫過程造成熱液發(fā)生CO_2與水的不混溶及流體沸騰,這是早期鉬沉淀的主要機(jī)制,而巖漿流體與還原性地層的水巖反應(yīng)引起的氧逸度降低及大氣水的加入則是鉛鋅沉淀的主要機(jī)制。
[Abstract]:Through field investigation, Re-Os dating and fluid inclusion studies of molybdenum deposits, the metallogenic age, metallogenic setting, ore-forming fluid characteristics and fluid evolution of the Dongboulag Molybdenum Pb-Zn deposit in Xiwuqi, Inner Mongolia are discussed. The results show that porphyry molybdenum mineralization and hydrothermal vein lead-zinc mineralization are developed in the ore area, which are the products of the same tectonic magma event. Molybdenum and lead-zinc mineralization are all related to quartz monzonitic porphyry in this area. The Re-Os dating results of molybdenum indicate that the metallogenic age was the product of large-scale metallogenic event of Yanshanian period in eastern China (165.2 鹵2. 8 Ma),). The results of fluid inclusion test show that the ore-forming fluids mainly come from magmatic water and the early ore-forming fluids are characterized by high temperature, high oxygen fugacity, rich Fe and CO_2. The ore-forming fluid evolved from high temperature (312 ~ 534 鈩，

本文編號：2146317