高校地质学报
高校地質學報
고교지질학보
GEOLOGICAL JOURNAL OF CHINA UNIVERSITIES
2014年
2期
198-212
,共15页
周云%段其发%曹亮%李芳%黄惠兰
週雲%段其髮%曹亮%李芳%黃惠蘭
주운%단기발%조량%리방%황혜란
MVT型铅锌矿%成矿流体%低温%湘西-鄂西
MVT型鉛鋅礦%成礦流體%低溫%湘西-鄂西
MVT형연자광%성광류체%저온%상서-악서
MVT-type lead-zinc deposits%ore-forming fluid%low temperature%western Hunan-western Hubei
对湘西-鄂西地区狮子山、李梅、耐子堡、茶田、打狗洞、董家河、唐家寨、冰洞山、凹子岗等典型铅锌矿床中闪锌矿、方解石、白云石及石英等矿物进行了流体包裹体均一温度、盐度、流体包裹体气相成分、流体包裹体群体液相成分测定,结果表明:成矿流体温度主要分布在80~230℃,总盐度一般>15%,密度多>1g/cm3,成矿压力为223×105~777×105 Pa,是以钠和钙氯化物为主的高浓度溶液,属于低温度、高盐度、高密度的地下热卤水性质的含矿热水溶液。成矿流体阳离子成分主要为Cl-, Na+, Ca2+, K+, Mg2+,流体包裹体氢氧同位素组成表明成矿流体来源与建造水有关,后期可能有雨水和少量变质水的渗入。矿物流体包裹体中含有机质,流体包裹体气相成分中CH4普遍存在,表明成矿与有机质相关,处在控矿构造内容矿层中的有机质使矿床中的硫酸盐硫还原为还原硫,促使成矿流体中的铅、锌沉淀形成矿床。相邻的低温成矿域川滇黔地区典型铅锌矿床成矿温度约为90~280℃,湘西-鄂西地区铅锌矿与川滇黔铅锌矿相比,具有相同的低温成矿特征,矿床类型均为MVT型,两者可能受控于相同的动力学背景。
對湘西-鄂西地區獅子山、李梅、耐子堡、茶田、打狗洞、董傢河、唐傢寨、冰洞山、凹子崗等典型鉛鋅礦床中閃鋅礦、方解石、白雲石及石英等礦物進行瞭流體包裹體均一溫度、鹽度、流體包裹體氣相成分、流體包裹體群體液相成分測定,結果錶明:成礦流體溫度主要分佈在80~230℃,總鹽度一般>15%,密度多>1g/cm3,成礦壓力為223×105~777×105 Pa,是以鈉和鈣氯化物為主的高濃度溶液,屬于低溫度、高鹽度、高密度的地下熱滷水性質的含礦熱水溶液。成礦流體暘離子成分主要為Cl-, Na+, Ca2+, K+, Mg2+,流體包裹體氫氧同位素組成錶明成礦流體來源與建造水有關,後期可能有雨水和少量變質水的滲入。礦物流體包裹體中含有機質,流體包裹體氣相成分中CH4普遍存在,錶明成礦與有機質相關,處在控礦構造內容礦層中的有機質使礦床中的硫痠鹽硫還原為還原硫,促使成礦流體中的鉛、鋅沉澱形成礦床。相鄰的低溫成礦域川滇黔地區典型鉛鋅礦床成礦溫度約為90~280℃,湘西-鄂西地區鉛鋅礦與川滇黔鉛鋅礦相比,具有相同的低溫成礦特徵,礦床類型均為MVT型,兩者可能受控于相同的動力學揹景。
대상서-악서지구사자산、리매、내자보、다전、타구동、동가하、당가채、빙동산、요자강등전형연자광상중섬자광、방해석、백운석급석영등광물진행료류체포과체균일온도、염도、류체포과체기상성분、류체포과체군체액상성분측정,결과표명:성광류체온도주요분포재80~230℃,총염도일반>15%,밀도다>1g/cm3,성광압력위223×105~777×105 Pa,시이납화개록화물위주적고농도용액,속우저온도、고염도、고밀도적지하열서수성질적함광열수용액。성광류체양리자성분주요위Cl-, Na+, Ca2+, K+, Mg2+,류체포과체경양동위소조성표명성광류체래원여건조수유관,후기가능유우수화소량변질수적삼입。광물류체포과체중함유궤질,류체포과체기상성분중CH4보편존재,표명성광여유궤질상관,처재공광구조내용광층중적유궤질사광상중적류산염류환원위환원류,촉사성광류체중적연、자침정형성광상。상린적저온성광역천전검지구전형연자광상성광온도약위90~280℃,상서-악서지구연자광여천전검연자광상비,구유상동적저온성광특정,광상류형균위MVT형,량자가능수공우상동적동역학배경。
Studies on fluid inclusions in sphalerite, calcite, dolomite, and quartz from Shizishan lead-zinc deposit, Limei lead-zinc deposit, Naizibao lead-zinc deposit, Chatian lead-zinc deposit, Dagoudong lead-zinc deposit, Dongjiahe lead-zinc deposit, Tangjiazhai lead-zinc deposit in western Hunan, Bingdongshan lead-zinc deposit and Aizigang lead-zinc deposit in western Hubei, through the analysis of homogenization temperatures, salinity, gas compositions, liquid compositions by heating/freezing system, Laser Raman and Ion Chromatography, show that the temperature of ore-forming fluid is 80-230℃, the salinity is always greater than 15%, the density is greater than 1g/cm3, and the mineralization pressure is about 223×105-777×105Pa. The ore-forming fluid is highly concentrated solution containing mainly sodium and calcium chloride. It belongs to the low temperature, high salinity, high density and mineralized underground hot brine. The cations in ore-forming fluid are mainly Cl-, Na+, Ca2+, K+, Mg2+. The composition of hydrogen and oxygen isotopes show that the origin of ore-forming fluid is related to construction water, with possible infiltration of rainwater and little metamorphic water. There is organic matter in the fluid inclusions. CH4 is widespread in the fluid inclusions. Mineralization is probably related to organic matter. The organic matter in the ore-controlling structure leads to the reduction of sulfate and the deposition of lead and zinc ore. The homogenization temperatures of ore-forming fluid from typical lead-zinc deposits in Sichuan, Yunnan, Guizhou district is 90-280℃. The studied lead-zinc deposits in western Hunan and western Hubei show similar low temperatures and MVT. The lead-zinc deposits in both regions may be controlled by the same tectonic dynamics.