本文選題：伊春-延壽成礦帶　切入點：鐵力鹿鳴　出處：《吉林大學》2015年碩士論文

【摘要】：鹿鳴鉬礦床地處伊春-延壽成礦帶中南部，該成礦帶位于松嫩地塊的東部，處于松嫩地塊與佳木斯地塊的拼合帶上，本礦床作為成礦帶內(nèi)近年發(fā)現(xiàn)的特大型斑巖型鉬礦床，備受關注。本文通過系統(tǒng)研究礦床地質 地球特征、成巖成礦年齡、成礦物理化學條件，探討成礦物質來源和成礦動力學背景，揭示礦床成因。 礦體發(fā)育在花崗巖體內(nèi)，賦礦巖體是蝕變二長花崗巖、花崗斑巖，金屬礦物呈細脈浸染狀、浸染狀分布于其中，圍巖蝕變具有典型斑巖礦床的分帶特征。巖石地球化學特征表明，二長花崗巖和花崗斑巖屬于高鉀鈣堿性I型花崗巖，巖漿源區(qū)發(fā)生了殼�；烊咀饔茫粠r體具有C型埃達克巖的地球化學屬性，暗示巖漿來源于加厚的下地殼部分熔融。賦礦巖體的Sr同位素初始比值87Sr/86Sr為0.708946~0.711256，介于幔源巖漿和殼源巖漿之間，顯示其巖漿源區(qū)具有殼�；烊镜奶攸c；金屬礦物輝鉬礦S同位素的δ34S值介于5.37‰~6.71‰之間，接近地幔巖漿值，表明金屬礦物的來源可能是幔源巖漿。 與成礦有關的石英脈中流體包裹體多為氣液兩相包裹體，均一溫度范圍主要集中在280~320℃之間；計算出的鹽度范圍介于2.06~22.45wt%NaCl之間，壓力在（123.34~418.52）×105Pa范圍內(nèi)，成礦深度大約在0.41~1.4km，說明鹿鳴鉬礦床形成于淺部環(huán)境的中高溫熱液型鉬礦床。采用LA-ICP-MS技術測得二長花崗巖的兩組鋯石206Pb/238U年齡分別為194.8±0.7Ma和176.2±2.1Ma，表明巖體形成于早侏羅世。結合區(qū)域地質背景，認為在燕山早期，由于受到蒙古-鄂霍茨克構造體系和環(huán)太平洋構造體系兩者雙向俯沖的影響，，佳木斯地塊與松嫩地塊發(fā)生拼合，深部幔源玄武質巖漿發(fā)生底侵，形成了區(qū)內(nèi)新生的加厚下地殼。新生的加厚下地殼部分熔融形成了埃達克質巖漿，完成了成礦元素鉬的初次富集。由于太平洋板塊的持續(xù)俯沖，埃達克質巖漿沿著構造裂隙上侵，后期的熱液活動最終形成了鹿鳴斑巖型鉬礦床。
[Abstract]:The Luming molybdenum deposit is located in the central and southern part of the Yichun-Yanshou metallogenic belt, which is located in the eastern part of the Songnen block and the joint zone between the Songnen block and the Jiamusi block. The deposit is regarded as an extra large porphyry type molybdenum deposit discovered in the metallogenic belt in recent years. In this paper, the geological characteristics of ore deposits, the age of diagenetic mineralization, the physicochemical conditions of mineralization, the source of ore-forming materials and the background of metallogenic dynamics are studied systematically, and the genesis of the deposits is revealed. The orebody is developed in the granite body, the ore-bearing rock body is altered monzomorphic granite, granitic porphyry, and the metal minerals are vein-impregnated and disseminated in them. The rock alteration has the zonation characteristics of typical porphyry deposits. The petrogeochemical characteristics indicate that the monzonitic granite and granitic porphyry belong to high-potassium calc-alkaline I-type granite, and the crust and mantle are mixed in the magma source area. The geochemical properties of the C type adakite indicate that the magma originated from the thickening partial melting of the lower crust. The initial Sr isotope ratio 87Sr/86Sr of the ore-hosting body is 0.708946 / 0.711256, which is between mantle magma and crust-derived magma. The 未 34S value of S isotope of molybdenum is between 5.37 鈥

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