本文關(guān)鍵詞： 撒納龍哇銅礦 礦床地質(zhì)特征 熱水沉積 噴流巖 礦床成因 礦化富集規(guī)律　出處：《吉林大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：撒納龍哇銅礦床位于青海省三江地區(qū)北西段的主體,其大地構(gòu)造位置處于歐亞大陸南緣、揚(yáng)子古陸西緣,東壩-瀾滄江縫合帶北側(cè)的古特提斯構(gòu)造域北特提斯華力西-印支期造山系的唐古拉陸塊內(nèi)。礦區(qū)出露的地層主要有晚三疊世巴塘群火山巖和灰?guī)r組,并有少量沉積巖重晶石巖出露。賦礦地層主要為英安質(zhì)巖屑晶屑凝灰?guī)r、安山質(zhì)巖屑晶屑凝灰?guī)r、玄武質(zhì)凝灰?guī)r等。其中礦區(qū)玄武質(zhì)凝灰?guī)r鋯石U-Pb年齡為237.5±2.9Ma。玄武質(zhì)凝灰?guī)r地球化學(xué)研究表明,Mg#值平均為50.49,大于地幔巖漿的Mg#值;δEu范圍為1.08~1.69,說明源區(qū)沒有斜長石的分離結(jié)晶作用;(Th/Ta)PM值為1.08~6.46、(La/Nb)PM值為3.97~11.66、(Th/Nb)PM平均值為6.67、TDM1值為792-886Ma,表明巖石的原始巖漿應(yīng)起源于虧損地幔,同時(shí)受到了地殼物質(zhì)或者富集地幔組分的混染。巖石具有鈣堿性系列島弧玄武質(zhì)特征,同時(shí)具有一定的洋中脊(MORB)的屬性。位于HS46號異常區(qū)東南側(cè),圈出1個(gè)(ⅠCuPbZn)礦體,礦體控制長度1600m,寬度4.94-13.34m,Cu品位1.55%,Pb品位2.94%,Zn品位4.69%。位于HS37號異常區(qū),圈出1個(gè)銅(ⅡCu)礦體,礦體長大于200m,厚度6.71m,Cu品位0.84%。野外調(diào)究和室內(nèi)分析確定礦床的兩套成礦系統(tǒng):即通道相周圍具有明顯的礦化,圍巖為火山巖;沉積相中發(fā)育各種重晶石巖、鐵硅質(zhì)巖等。兩個(gè)礦體的金屬礦物主要為黃銅礦、黃鐵礦、方鉛礦和閃鋅礦。礦石結(jié)構(gòu)主要為自形結(jié)構(gòu)、半自形-它形晶結(jié)構(gòu)、脈狀穿插結(jié)構(gòu)、交代殘余結(jié)構(gòu)、骸晶結(jié)構(gòu)。礦石構(gòu)造主要為浸染狀構(gòu)造、條紋狀或條帶狀構(gòu)造、脈狀或網(wǎng)脈狀構(gòu)造、薄膜狀構(gòu)造。圍巖蝕變主要為硅化、綠泥(簾)石化、絹云母化、碳酸鹽化等。并確定了該礦床經(jīng)歷了熱水噴流沉積成礦期和表生氧化期兩個(gè)成礦期。流體包裹體研究表明,通道相石英中成礦流體為中低溫(180~220℃)、低鹽度(1~5wt%NaCl)、低密度(0.84~0.92g/cm3)流體;沉積相重晶石巖中成礦流體為低溫(140~160℃)、低鹽度(8.8~9.6wt%NaCl)、低密度(0.92~0.94g/cm3)流體。硫同位素研究表明,黃銅礦中硫同位素δ34S的均值為-1.9,黃鐵礦中硫同位素δ34S變化范圍為-0.6~-0.3之間,表明深部巖漿硫或幔源硫的特點(diǎn)。重晶石樣品硫同位素(δ34S)分析結(jié)果為15.5和15.8,代表了晚三疊世海相蒸發(fā)巖δ34S的特征。厘定了成礦時(shí)代為賦礦圍巖玄武質(zhì)凝灰?guī)r的形成時(shí)代,即晚三疊世。綜合分析認(rèn)為,撒納龍哇銅礦床為熱水噴流沉積礦床。通過地質(zhì)模型、物化探模型等對該礦床礦化富集規(guī)律進(jìn)行分析,認(rèn)為構(gòu)造錯(cuò)斷影響、重晶石巖與礦化的關(guān)系、(Au、Ag、Cu、Pb、Zn)組合異常、地磁異常正負(fù)交替是找礦的重點(diǎn)地區(qū)。
[Abstract]:The Xanalongwa copper deposit is located in the main body of the northern western section of Sanjiang area, Qinghai Province, and its tectonic position is located in the southern margin of Eurasia and the western margin of Yangtze paleocontinent. On the north side of Dongba Lancang River suture belt, the northern Tethys West to Indosinian orogenic system in the Tangguula block. The strata exposed in the mining area are mainly volcanic rock and limestone formation of the late Triassic Batang Group. A small amount of sedimentary barite rocks are exposed. The ore-hosting strata are mainly clastic tuff tuff, andeshanite crystalline tuff tuff. The zircon U-Pb age of Black Tortoise tuff in the mining area is 237.5 鹵2.9 Ma.The geochemistry study of Black Tortoise tuff shows that the average value of tuff is 50.49, which is larger than the Mg# value of mantle magma, and the 未 EU range is 1.08U 1.69, indicating that there is no plagioclase in the source area. The PM value of the isolated crystallization process is 1.08% 6.46% La / NbO PM value 3.97% 11.66% T / NbO PM average value is 6.67% TDM1 value is 792-886 Ma.This indicates that the original magma of the rocks should have originated from the depleted mantle, and the average value is 7.67% TDM1, which indicates that the original magma of the rocks originated from the depleted mantle. The rocks are characterized by a series of calc-alkaline island arc Black Tortoise and a certain attribute of the mid-oceanic ridge MORB.The rocks are located on the southeast side of the HS46 anomaly area and are surrounded by a (鈪，

本文編號：1536066