本文關鍵詞： 銅多金屬礦床 VMS 地質特征 礦床成因 礦化富集規(guī)律 尕龍格瑪?shù)V床　出處：《吉林大學》2017年碩士論文　論文類型：學位論文

【摘要】：尕龍格瑪銅多金屬礦床位于青海省玉樹地區(qū),大地構造位置屬青藏高原碰撞造山帶東北部,夾持于金沙江縫合帶與龍木錯雙湖縫合帶之間,北羌塘地體北緣,南側為南羌塘地體,北東側為松潘甘孜地體,屬于三江多金屬成礦帶。尕龍格瑪成礦年齡在晚三疊世,與賦礦地層時代相同。礦區(qū)內出露的地層為三疊系巴塘群第二巖組。組成地層的巖石以英安質和安山質的凝灰?guī)r、火山角礫巖及集塊熔巖為主,局部夾火山碎屑沉積巖。尕龍格瑪?shù)V區(qū)位于治多復向斜之次級緊閉背斜地段,核部地層安山質凝灰?guī)r為礦區(qū)的含礦巖層,該疊加褶皺控制了尕龍格瑪?shù)V床現(xiàn)今的構造形態(tài)。礦區(qū)內未見侵入巖發(fā)育,對安山質凝灰?guī)r進行巖石地球化學研究,表明巖體具有島弧火山巖特征。尕龍格瑪?shù)V床分為東西兩個礦區(qū),其中東礦區(qū)研究勘探程度較高,目前共圈出銅鉛鋅礦體6條,銅礦體4條,鉛鋅(銅)礦體2條。其中2號礦體,為整個區(qū)內最為厚大、且品位較高的礦體。其他礦體均為一些隱伏礦體。相對于西礦區(qū)各礦體,品位均較高。本次工作主要在東礦區(qū)進行。礦體有整合和不整合兩類,整合型礦體呈層狀、似層狀產出于安山質凝灰?guī)r中,不整合型礦體呈脈狀和細脈浸染狀產于整合型礦體下部。尕龍格瑪?shù)V床含礦巖性組合為安山質凝灰?guī)r以及熱水噴流沉積巖,如重晶石巖、碧玉巖及鐵白云巖等,在礦體的頂板還發(fā)育有碳泥質板巖,為熱水噴流沉積成礦作用結束的標志。礦區(qū)的礦石構造類型主要為條帶狀構造、塊狀構造、浸染狀構造,其次為脈狀構造。礦石中礦物種類繁多,其中金屬礦物包括黃銅礦、方鉛礦、閃鋅礦、黃鐵礦、斑銅礦、黝銅礦、輝銅礦、銅藍和孔雀石等,非金屬礦物包括方解石、重晶石、石英和絹云母等。尕龍格瑪銅多金屬礦床后期改造作用較弱,基本保存了原始熱水沉積特征。成礦作用類型主要為熱水噴流沉積成礦作用。對與成礦關系密切的重晶石和石英進行包裹體研究得知,成礦期沉積相成礦溫度范圍為105.2℃-234.2℃;流體鹽度范圍為0.18-7.58%NaCl eqv;流體密度為0.845-0.995g/cm3而通道相成礦溫度范圍為251.3℃-360.8℃;流體鹽度范圍為2.06-7.99%NaCl eqv;流體密度為0.616-0.839g/cm3。氫氧同位素特征顯示成礦流體主要為海水,還可能有少量巖漿水混入。硫同位素特征顯示成礦流體中的硫主要來自細菌還原的海水硫酸鹽或其基底巖石。鉛大地構造模式圖解顯示鉛主要來源于上地殼,很可能是成礦熱液淋濾下部基底地層帶上來。根據(jù)尕龍格瑪銅多金屬礦床大地構造位置、控礦構造、容礦巖石、圍巖特征以及礦體形態(tài)等基礎地質特征及其地球化學特征確定其成因類型為VMS型礦床。
[Abstract]:The Galonggma copper polymetallic deposit is located in the Yushu area of Qinghai Province. The tectonic location is northeast of the collision orogenic belt of the Qinghai-Xizang Plateau, located between the Jinsha River suture zone and the Longmuco Shuanghu suture zone, and the northern margin of the northern Qiangtang terrane. The south Qiangtang terrane is located in the south and the Songpan Ganzi terrane in the north, belonging to the Sanjiang polymetallic metallogenic belt. The strata exposed in the mining area are the second rock formation of the Triassic Batang Group. The rocks that make up the strata are the tuff, volcanic breccia and agglomerate lava, which are mainly composed of lithoclastic and anshanian tuff, volcanic breccia and agglomerate lava. The Galonggma mining area is located in the secondary closed anticline area of Zhiduofuxiao, and the Anshanian tuff is the ore-bearing rock bed of the ore area. The superimposed fold controls the present tectonic form of the Galonggema deposit. No intrusive rocks have developed in the ore area, so the petrogeochemical study of Anshan tuff has been carried out. It shows that the ore body has the characteristics of island arc volcanic rock. The Galonggema deposit is divided into east and west ore areas, and its Middle East ore area has a high degree of research and exploration. At present, there are 6 copper, lead and zinc ore bodies and 4 copper ore bodies in the Middle East. There are 2 lead zinc (copper) orebodies, of which 2 ore bodies are the thickest and higher grade ore bodies in the whole area. The other orebodies are some concealed orebodies. This work is mainly carried out in the east mining area. There are two types of ore bodies: integrated and unconformable. The integrated orebodies are stratiform and bedded in Anshan tuff. The non-integrated orebodies occur in the lower part of the integrated orebodies in the vein and veinlet forms. The ore-bearing rock assemblage of the Galonggema deposit is composed of Anshan tuff and hot water jet sedimentary rocks, such as barite, Jasper and iron dolomite, etc. There are also carbonaceous muddy slate on the roof of the orebody, which is the sign of the end of ore-forming process by hot water jet deposition. The ore structure types of the mining area are mainly banded structure, block structure, disseminated structure, etc. The minerals in the ore include chalcopyrite, galena, sphalerite, pyrite, placerite, tetrahedrite, chalcopyrite, copper blue and malachite, and non-metallic minerals include calcite, barite, etc. Quartz and sericite, etc., the Galonggema copper polymetallic deposit is relatively weak in its late transformation, The primary hot water sedimentary characteristics are basically preserved. The metallogenic types are mainly hydrothermal jet sedimentary mineralization. The study on the inclusions of barite and quartz, which are closely related to the mineralization, shows that the temperature range of metallogenic sedimentary facies is 105.2 鈩，

本文編號：1538949