【摘要】：黑龍江省先鋒北山金礦床位于完達山地塊西南端，地處環(huán)太平洋成礦帶，屬于錫霍特—阿林超地體增生部分。完達山地塊位于興凱地塊以北，佳木斯地塊以東地區(qū)。該區(qū)域主要經(jīng)歷了印支期-燕山期強烈的構(gòu)造巖漿活動，這兩期構(gòu)造巖漿演化作用為區(qū)內(nèi)成礦作用提供了有利的地質(zhì)條件。本文大量收集、分析整理區(qū)域及礦區(qū)地質(zhì)資料基礎(chǔ)上，對先鋒北山金礦區(qū)進行野外地質(zhì)調(diào)查，對采集樣品進行室內(nèi)綜合分析，以此深入研究礦床地質(zhì)特征、礦床成因類型及成礦構(gòu)造環(huán)境。 先鋒北山金礦床礦體主要賦存在皮克山組上段酸性火山巖中，受EW向弧形斷裂帶控制，在已發(fā)現(xiàn)的三條礦化帶中共探明19條礦體，礦體多呈脈狀、透鏡狀產(chǎn)出，礦石具有脈狀、網(wǎng)脈狀、細脈浸染狀構(gòu)造。根據(jù)礦石礦物生成順序可劃分熱液期和表生氧化物期，其中熱液期可劃分為石英-黃鐵礦，石英-自然金兩個成礦階段。圍巖蝕變主要有硅化、絹云母化、碳酸鹽化及青磐巖化等。 主成礦階段包裹體類型主要為氣液兩相包裹體，屬NaCl-H2O流體體系，均一溫度范圍為105.5～277.8℃，鹽度范圍為0.7～5.4wt％NaCleqv,密度范圍為0.76～0.94g/cm3，成礦壓力在8.92～19.30MPa之間，成礦深度為0.89～1.41km。說明主成礦階段的流體具中低鹽度、低溫、成礦壓力較低的特點，綜合分析認為，先鋒北山金礦床屬于淺成低溫?zé)嵋盒徒鸬V床。 先鋒北山賦礦流紋巖、流紋質(zhì)角礫巖和巖屑晶屑凝灰?guī)r屬于堿性系列巖石，LREE相對富集，HREE相對虧損，輕重稀土元素分異明顯，具有明顯的負銪異常，富集大離子親石元素（LILE），虧損高場強元素（HFSE），Rb和Sr，Ti和Zr、Nb和Ta等比值顯示出殼源特征。礦區(qū)內(nèi)花崗閃長巖屬于過鋁質(zhì)高鉀鈣堿I型花崗巖，LREE相對富集，HREE相對虧損，銪異常不明顯，富集大離子親石元素（LILE）Rb、Th、K，虧損高場強元素（HFSE）Nb、Ta、P、Ti等；石英閃長玢巖LREE相對富集，HREE相對虧損，無銪異常；富集大離子親石元素（LILE）Rb、Th，K等，虧損高場強元素（HFSE）Nb、Ta、P、Ti等地球化學(xué)特征顯示其屬于準(zhǔn)鋁質(zhì)高鉀鈣堿性巖石。 礦區(qū)內(nèi)發(fā)育的花崗閃長巖的鋯石U-Pb年齡為128.3±2.6M，石英閃長玢巖的鋯石U-Pb年齡為108.48±0.99Ma，，賦礦流紋巖及流紋質(zhì)角礫巖鋯石U-Pb年齡分別為為116.98±0.47Ma和116.98±0.42Ma，結(jié)合礦區(qū)侵入接觸關(guān)系，限定先鋒北山金礦形成于早白堊世晚期116.98±0.47Ma和108.48Ma之間。 根據(jù)對礦區(qū)賦礦圍巖及脈巖的巖石地球化學(xué)特征，運用火山巖構(gòu)造判別圖解，確認先鋒北山金礦形成于碰撞后構(gòu)造環(huán)境，結(jié)合成巖成礦時代，認為先鋒北山金礦床的形與太平洋板塊俯沖和完達山地塊與佳木斯地塊的拼合有著密切的關(guān)系，系古太平洋構(gòu)造體制由擠壓變?yōu)樯煺贡尘跋碌漠a(chǎn)物。
[Abstract]:Xianfeng Beishan gold deposit in Heilongjiang Province is located at the southwest end of the Wandashan massif, located in the Pacific Rim metallogenic belt, and belongs to the accretive part of the Sihott-Arin superterrane. The Wandashan block is located north of Xingkai block and east of Jiamusi block. The tectonic magma activity in this area mainly experienced from Indosinian to Yanshanian epoch, and the evolution of tectonic magma in these two periods provided favorable geological conditions for mineralization in the region. On the basis of collecting, analyzing and arranging the geological data of the area and mining area, this paper makes a field geological survey on Xianfeng Beishan Gold Mine area, and carries out an indoor comprehensive analysis of the collected samples in order to further study the geological characteristics of the deposit. Genetic types of ore deposits and metallogenic tectonic environment. The ore bodies of Xianfeng Beishan gold deposit mainly occur in the acid volcanic rocks of the upper Pikeshan formation, controlled by the EW arc fault zone. 19 ore bodies have been discovered in the three discovered mineralization zones. The orebodies are mostly vein-like, lenticular and veinlike. Reticular veins, vein-like structures. According to the ore mineral formation sequence, the hydrothermal stage and the superoxide stage can be divided into two metallogenic stages: quartz pyrite and quartz natural gold. The main alteration of surrounding rock is silicification, sericite, carbonization and Qingwanglianlitization. The main types of inclusions in the main metallogenic stage are gas-liquid two-phase inclusions, which belong to NaCl-H2O fluid system. The homogenization temperature ranges from 105.5 鈩

本文編號：2231643