中国有色金属学报
中國有色金屬學報
중국유색금속학보
THE CHINESE JOURNAL OF NONFERROUS METALS
2013年
9期
2659-2670
,共12页
黄敏%赖健清%马秀兰%曹德云
黃敏%賴健清%馬秀蘭%曹德雲
황민%뢰건청%마수란%조덕운
地球化学%成矿作用%铅同位素%肯德可克%祁漫塔格
地毬化學%成礦作用%鉛同位素%肯德可剋%祁漫塔格
지구화학%성광작용%연동위소%긍덕가극%기만탑격
geochemistry%metallogenesis%lead isotope%Kendekeke%Qimantage
青海省肯德可克多金属矿床位于祁漫塔格成矿带,矿床产出的大地构造背景为柴达木南缘弧后裂陷构造带中的火山盆地。结合矿床地质成矿条件,通过现场调查,对矿区典型的岩浆岩、围岩及矿石进行了化学全分析、稀土和微量元素分析及铅同位素分析,总结了矿床地球化学特征,查明物质来源,探讨矿床成岩、成矿机制。结果表明:矿区岩体富钠,为钙碱性岩,来源于深部,后期发生混染,为壳幔混合来源。围岩稀土元素分析表明:成岩过程有海水参与,矿床具热水喷流沉积特征。各类矿石铅同位素的μ值介于9.45~9.75之间,具有深源铅和壳源铅特征。铅同位素特征参数示踪、铅构造模式示踪和Δβ?Δγ图解示踪的结果表明:铅来源受岩浆作用影响,主要为壳幔混合铅。岩浆岩、围岩及矿体地球化学特征表明:肯德可克多金属矿床形成过程受海水影响,具热水喷流沉积特征,成岩成矿物质来源深部,受多源混染影响;矿床演化史漫长,从早期热水喷流沉积到的晚古生代的构造-岩浆活动,深化及扩大了成矿体系,晚期热液活动又对矿床进行了叠加改造,具多因复成特征。
青海省肯德可剋多金屬礦床位于祁漫塔格成礦帶,礦床產齣的大地構造揹景為柴達木南緣弧後裂陷構造帶中的火山盆地。結閤礦床地質成礦條件,通過現場調查,對礦區典型的巖漿巖、圍巖及礦石進行瞭化學全分析、稀土和微量元素分析及鉛同位素分析,總結瞭礦床地毬化學特徵,查明物質來源,探討礦床成巖、成礦機製。結果錶明:礦區巖體富鈉,為鈣堿性巖,來源于深部,後期髮生混染,為殼幔混閤來源。圍巖稀土元素分析錶明:成巖過程有海水參與,礦床具熱水噴流沉積特徵。各類礦石鉛同位素的μ值介于9.45~9.75之間,具有深源鉛和殼源鉛特徵。鉛同位素特徵參數示蹤、鉛構造模式示蹤和Δβ?Δγ圖解示蹤的結果錶明:鉛來源受巖漿作用影響,主要為殼幔混閤鉛。巖漿巖、圍巖及礦體地毬化學特徵錶明:肯德可剋多金屬礦床形成過程受海水影響,具熱水噴流沉積特徵,成巖成礦物質來源深部,受多源混染影響;礦床縯化史漫長,從早期熱水噴流沉積到的晚古生代的構造-巖漿活動,深化及擴大瞭成礦體繫,晚期熱液活動又對礦床進行瞭疊加改造,具多因複成特徵。
청해성긍덕가극다금속광상위우기만탑격성광대,광상산출적대지구조배경위시체목남연호후렬함구조대중적화산분지。결합광상지질성광조건,통과현장조사,대광구전형적암장암、위암급광석진행료화학전분석、희토화미량원소분석급연동위소분석,총결료광상지구화학특정,사명물질래원,탐토광상성암、성광궤제。결과표명:광구암체부납,위개감성암,래원우심부,후기발생혼염,위각만혼합래원。위암희토원소분석표명:성암과정유해수삼여,광상구열수분류침적특정。각류광석연동위소적μ치개우9.45~9.75지간,구유심원연화각원연특정。연동위소특정삼수시종、연구조모식시종화Δβ?Δγ도해시종적결과표명:연래원수암장작용영향,주요위각만혼합연。암장암、위암급광체지구화학특정표명:긍덕가극다금속광상형성과정수해수영향,구열수분류침적특정,성암성광물질래원심부,수다원혼염영향;광상연화사만장,종조기열수분류침적도적만고생대적구조-암장활동,심화급확대료성광체계,만기열액활동우대광상진행료첩가개조,구다인복성특정。
Kendekeke polymetallic deposit is located in Qimantage ore belt of Qinghai Province and the background of this deposit is a volcanic basin in the back-arc rift tectonic zone of southern margin of Qaidam. Combined with field investigation and ore-forming geological conditions, the geochemical characteristics of deposit were summarized, the origin of the ore-forming materials was ascertained, the rock-forming mechanism and ore-forming mechanism of the deposit were discussed according to the study of lead isotope as well as chemical analysis, including whole-rock analysis,REE analysis and trace elements analysis. Typical magmatic rocks,wall rocks and ores were used as the research objects. The results show that magmatic rocks belong to calc-alkaline series, rich in sodium and derived from the source of crust-mantle mixed deep in the earth. The REE studies of wall rocks indicate the seawater involved in diagenesis and the deposit with characteristics of exhalative sedimentary deposit. The lead isotope research illustrates the μ values of minerals range from 9.45 to 9.75, which are characterized by both deep-sourced and crust-sourced origins. Based on the tracer analysis regarding the characteristic parameters, lead composition model and Δβ-Δγ diagram, the results show that the ore lead mainly is crust-mantle mixed lead and affected by magmatism during the enrichment process. The geochemical properties of magmatic rocks,wall rocks and ore reveal that Kendekeke deposit was affected by seawater in the formation progress and has the properties of exhalative sedimentary deposit. The diagenetic materials and ore-forming material, which were affected by the mixing of multi-source, came from the deep of the earth. The deposit had a long evolution history, begun from the early exhalative sedimentation to Late Paleozoic tectonic-magmatic activities, deepened and expanded the mineralization system, and the late hydrothermal activities superimposed and reformed the deposit, which is a polygenetic compound deposit.