本文選題：遼寧青城子 + 姚家溝鉬礦�。� 參考：《中國(guó)地質(zhì)大學(xué)(北京)》2015年碩士論文

【摘要】：姚家溝鉬礦是遼寧青城子礦田中近年來(lái)新發(fā)現(xiàn)的礦床,位于華北克拉通北緣,遼東裂谷帶,鉬礦床的發(fā)現(xiàn)為青城子礦田的地質(zhì)勘探提供了新的方向。礦床蝕變分帶特征明顯,主要有石英核、鉀化花崗巖帶、綠簾石化花崗巖帶以及矽卡巖化帶,鉬礦化主要在鉀化帶及矽卡巖化帶中。姚家溝巖體具有多期侵入的特征,其中UST石英脈和石英眼是姚家溝巖體出溶熱液的證據(jù)。觀測(cè)到6期流體活動(dòng),石英眼(早期)→鉬礦化石英脈(成礦期)→無(wú)鉬礦化石英脈(后期)→方解石脈(晚期)→硬石膏脈,UST石英脈可能與鉬成礦關(guān)系不大。存在5種類型流體包裹體:除純CO2包裹體外,早期均一溫度211.4~515.4℃,鹽度0.8~19.2wt%Na Cleqv;成礦期均一溫度179.5~424.5℃,鹽度2.4~21.5wt%Na Cleqv;后期均一溫度范圍167.8~353.3℃,鹽度3.4~15.8wt%Na Cleqv;晚期均一溫度132.5~234.1℃,鹽度為0.9~11.2wt%Na Cleqv;UST脈均一溫度158.6~381.7℃,鹽度1.6~21.5wt%Na Cleqv。激光拉曼測(cè)試結(jié)果表明流體包裹體中主要含有H2O,還發(fā)現(xiàn)有CO2、CO32-、HCO3-、CH4,固相成分有黃銅礦、針鐵礦、石英等,早期流體為中高溫中低鹽度富揮發(fā)份(CO2)體系,具弱堿性,在成礦期,流體溫度、壓力、鹽度降低,CO2逸失,體系還原性增強(qiáng),金屬元素大量沉淀下來(lái);到后、晚期,流體溫度、鹽度、CO2含量進(jìn)一步降低,氧化性逐漸增強(qiáng),在方解石脈中已沒(méi)有CO2包裹體,最后表現(xiàn)出強(qiáng)氧化性,產(chǎn)生硬石膏。流體不混溶、圍巖蝕變和流體混合作用是金屬元素沉淀的主要機(jī)理。用等容線相交法估算捕獲壓力,早期為220~145MPa;成礦期180~124 MPa;后期115~60MPa;UST脈148~78MPa。成礦期成礦深度估算為7~4.6km。氫氧同位素研究表明,成礦期流體為巖漿水與大氣降水或變質(zhì)水混和形成,對(duì)比燕遼成礦帶其他鉬礦床,其成礦流體來(lái)源上具有相似性。
[Abstract]:Yaojiagou molybdenum deposit is a newly discovered deposit in Qingchengzi ore field of Liaoning Province in recent years. It is located in the northern margin of North China Craton and in the Liaodong rift zone. The discovery of molybdenum deposit provides a new direction for geological exploration of Qingchengzi Orefield. The characteristics of alteration zones are obvious, including quartz core, potash granite zone, green curtain granite belt and skarn zone, and molybdenum mineralization mainly in kalitization zone and skarn zone. The Yaojiagou rock body is characterized by multiple intrusions, among which the UST quartz vein and quartz eye are the evidence of the exsolution hydrothermal solution of the Yaojiagou rock body. It is observed that fluid activity in stage 6, quartz eye (early) molybdenum fossil vein (ore-forming period) and molybdenum fossilized quartz vein (late stage) calcite vein (late) anhydrite vein and UST quartz vein may not be related to molybdenum mineralization. There are five types of fluid inclusions: except for pure CO2, the early homogenization temperature is 211.4% 515.4 鈩，

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