發(fā)布時(shí)間：2018-04-23 09:54

  本文選題：一六鎢礦 + 矽卡巖礦床��； 參考：《地質(zhì)學(xué)報(bào)》2017年10期

【摘要】：一六鎢礦大地構(gòu)造位置位于南嶺成礦帶中段南緣,粵北曲仁盆地西南緣,是粵北地區(qū)近年來重要的找礦勘查成果之一。礦床為典型的矽卡巖礦床,礦體賦存于上泥盆統(tǒng)帽子峰組矽卡巖以及NWW向鉀長石-石英-白鎢礦脈和云母石英脈中。通過野外觀察和鏡下研究,本文將成礦過程分為矽卡巖期(A)和熱液期(B),矽卡巖期可以分為早期矽卡巖階段(A1)、晚期矽卡巖階段(A2)、鉀長石英白鎢礦階段(A3),熱液期可以分為云母石英脈階段(B1)和石英碳酸鹽階段(B2)。礦區(qū)包含4種類型的包裹體:含子礦物三相包裹體(Ⅰ型)、氣液兩相水溶液包裹體(Ⅱ型)、CO_2水溶液三相包裹體(Ⅲ型)、純CO_2包裹體(Ⅳ型),Ⅰ型包裹體僅見于A3階段;Ⅱ型、Ⅲ型以及Ⅳ型包裹體在A3和B1階段石英中均有發(fā)育,在A3和B1階段白鎢礦中還發(fā)育Ⅱ型包裹體。A3階段Ⅰ型包裹體完全均一溫度為162~381℃,鹽度為30.1%~45.4%(wt%NaClequiv,下同省略),Ⅱ型包裹體完全均一溫度為154~363℃,鹽度為1.49%~11.0%,Ⅲ型包裹體完全均一溫度為290~390℃,鹽度為2.20%~6.88%;B1階段Ⅱ型包裹體完全均一溫度為152~381℃,鹽度為1.65%~9.32%,Ⅲ型包裹體完全均一溫度為281~378℃,鹽度為2.00%~8.82%。激光拉曼探針分析表明,A3階段和B1階段流體中存在H_2O、CO_2、CH_4和少量CO_3~(2-),指示流體處于還原的環(huán)境。包裹體完全均一溫度—鹽度關(guān)系圖表明,數(shù)據(jù)點(diǎn)主要集中于三個(gè)區(qū)域:a區(qū)對(duì)應(yīng)早期出溶成因的高鹽度流體,b區(qū)反映流體發(fā)生了不混溶作用,c區(qū)反映早期高鹽度流體與低鹽度地下水混合特征。各區(qū)包裹體代表了巖漿期后殘余原始流體不同階段的演化產(chǎn)物。通過Ⅰ型包裹體計(jì)算得出的成礦壓力范圍為86.0~415.8MPa,用Ⅱ、Ⅳ型包裹體對(duì)成礦壓力進(jìn)行校正得出,A3階段成礦壓力范圍為86~115MPa,成礦溫度為176~279℃;B1階段成礦壓力范圍為55~93 MPa,成礦溫度為160~228℃,估算成礦深度范圍為3.62~4.26km。研究認(rèn)為,流體在演化早期存在局部高壓,流體不混溶作用要比外來流體混入更早發(fā)生,而流體混入促進(jìn)了流體的不混溶作用。流體物理化學(xué)條件的改變、外來流體混入以及流體不混溶作用是引起鎢礦沉淀的主要原因。
[Abstract]:The tectonic location of the No. 16 tungsten deposit is located in the southern margin of the middle section of the Nanling metallogenic belt and the southwestern margin of the Quren basin in northern Guangdong Province, which is one of the important prospecting results in the northern part of Guangdong Province in recent years. The deposit is a typical skarn deposit, which occurs in the skarn of the upper Devonian, the NWW feldspar quartz scheelite vein and mica quartz vein. Through field observation and microscopic research, In this paper, the metallogenic process can be divided into skarn stage and hydrothermal stage, skarn stage can be divided into early skarn stage, late skarn stage, late skarn stage, potassium feldspar scheelite stage, hydrothermal stage can be divided into mica quartz vein stage and quartz carbonate stage. The mining area contains four types of inclusions: three phase inclusions containing sub-minerals (type 鈪，

本文編號(hào)：1791458