本文選題：火山成因塊狀硫化物礦床 + 形成時(shí)代�。� 參考：《地質(zhì)學(xué)報(bào)》2017年08期

【摘要】：火山成因塊狀硫化物礦床越來越受到重視,喀臘達(dá)坂鉛鋅礦位于北東向阿爾金走滑斷裂與東西向阿爾金北緣斷裂夾持的喀臘大灣地區(qū),是阿爾金北緣紅柳溝—拉配泉金、銅、鐵及多金屬成礦帶中唯一大型鉛鋅礦床。礦區(qū)主要出露奧陶系下統(tǒng)卓阿布拉克組火山沉積巖系,呈近東西走向,以向北中等角度傾斜的單斜層為特點(diǎn),傾角30°~58°;礦化嚴(yán)格受火山沉積巖特定層位和巖性控制,即礦體均產(chǎn)于卓阿布拉克組第四亞組的中酸性火山巖(流紋巖、英安熔巖、英安質(zhì)晶屑凝灰?guī)r)中,礦體具有層狀、似層狀特點(diǎn),產(chǎn)狀穩(wěn)定延伸大;最大礦體走向延伸超過2400m,傾向延深大于900m。主要有用組分Pb、Zn,伴生有用組分Cu、Au、Ag、S等。主要蝕變類型有黃鐵礦化、硅化、絹云母化,地表氧化帶形成黃鉀鐵釩化和褐鐵礦化。礦石平均鉛同位素組成為~(208)Pb/~(204)Pb=38.1169、~(207)Pb/~(204)Pb=15.6278、~(206)Pb/~(204)Pb=18.4684,顯示礦石的鉛具有上地殼鉛和造山帶鉛的混合來源;礦石硫同位素組成平均+8.28‰,代表了海相沉積巖來源的硫與巖漿巖來源硫的混合;礦石稀土元素配分曲線與礦區(qū)及喀臘大灣地區(qū)中酸性火山巖的稀土元素配分曲線具有一致性或者相似,說明礦石與含礦中酸性火山巖具有一致的成因與來源;礦石微量元素特征顯示Nb、Ta負(fù)異常與Ba的正異常,反映出存在海相沉積巖物質(zhì)的混入,并具有島弧成礦構(gòu)造環(huán)境。含礦火山巖鋯石SHRIMP U-Pb年齡482~485Ma,代表了礦床的形成時(shí)代為早古生代早奧陶世。綜合喀臘達(dá)坂鉛鋅礦地質(zhì)地球化學(xué)特征的研究,確認(rèn)其屬于火山成因塊狀硫化物礦床(VMS型)。所以,喀臘達(dá)坂鉛鋅礦成礦過程可以概括為:在早古生代奧陶紀(jì)早期北阿爾金洋發(fā)生向南的板塊俯沖,板塊俯沖作用導(dǎo)致俯沖帶下盤的洋殼及其上的海相沉積物和俯沖帶上盤的陸殼發(fā)生部分熔融,形成了中酸性島弧型巖漿;在巖漿噴發(fā)的晚期,逐漸形成富含鉛鋅成礦物質(zhì)的殘余巖漿;當(dāng)這些富含鉛鋅的殘余巖漿發(fā)生噴發(fā),最終形成了火山成因巖塊狀硫化物型鉛鋅礦床�；鹕綆r型鉛鋅多金屬礦床是阿爾金北緣喀臘大灣地區(qū)南帶最重要勘查和預(yù)測(cè)類型,該火山巖型礦化帶的西延區(qū)段是有利的找礦靶區(qū)。
[Abstract]:More and more attention has been paid to the massive sulfide deposits of volcanic origin. The Kaladaban lead-zinc deposit is located in the Kaladawan area, which is located in the north margin of Altun strike slip fault and the north margin fault of east-west direction Altun. It is Hongliugou-Lapaiquan gold, copper, and copper in the northern edge of Altun. The only large-scale lead-zinc deposit in the iron and polymetallic metallogenic belt. The volcanic sedimentary rocks of the Lower Ordovician Zhuobulak formation of the Lower Ordovician in the mining area are nearly east-west, characterized by a monocline inclined to the north, with a dip angle of 30 擄or 58 擄, and the mineralization is strictly controlled by the specific horizon and lithology of the volcanic sedimentary rocks. The orebodies are all occurring in the intermediate acid volcanic rocks (rhyolite, Yingan lava, Anichite tuff) of the fourth sub-formation of the Zhuobulak formation. The orebodies are stratiform, layered and stable and extensible. The largest orebody extends more than 2400m in strike and tends to extend deeper than 900m. There are mainly useful components, such as Pb ~ (2 +) Zn, associated useful components, such as Cu ~ (2 +) ~ (2 +) -Au-Ag-S, and so on. The main alteration types are pyrite silicification sericite surface oxidation zone forming yellow potassium iron vanadium and limonite. The average lead isotopic composition of the ore is as follows: (1) the average lead isotopic composition of the ore is (38.11669) ~ (38.1169) Pb ~ (-1) ~ (20) ~ (204) Pb ~ (- / -) 206B ~ (-1) ~ (15.6278) ~ (th), indicating that the lead of the ore has a mixed source of lead from the upper crust and orogenic belt, and the average sulfur isotope composition of the ore is 8.28 鈥，

本文編號(hào)：1917311