地质学报
地質學報
지질학보
ACTA GEOLOGICA SINICA
2014年
8期
1539-1548
,共10页
王建%谢桂青%陈风河%朱乔乔%李伟%张志远
王建%謝桂青%陳風河%硃喬喬%李偉%張誌遠
왕건%사계청%진풍하%주교교%리위%장지원
辉钼矿%Re-Os同位素定年%硫同位素%鸡笼山金矿%鄂东南
輝鉬礦%Re-Os同位素定年%硫同位素%鷄籠山金礦%鄂東南
휘목광%Re-Os동위소정년%류동위소%계롱산금광%악동남
molybdenite%Re-Os isotopic dating%sulfur isotope%Jilongshan Au deposits%southeastern Hubei
鄂东南地区是我国长江中下游Cu-Au-Fe-Mo成矿带中最重要的组成部分之一,其中鸡笼山金矿是是区内典型的大型矽卡岩金矿床。本文利用Re-Os同位素定年方法对鸡笼山金矿床进行了成矿时代测定,获得了辉钼矿的Re-Os同位素模式年龄范围为147.7±2.4~151.6±4.0Ma,等时线年龄为148.6±1.5Ma,与矿区内花岗闪长斑岩SHRIMP锆石U-Pb年龄151.6±0.7Ma相吻合,也与鄂东南地区其他矿田的成矿时代基本一致。鸡笼山矽卡岩金矿床可能形成于岩石圈伸展构造背景。硫同位素值为-2.5‰~5.5‰,均值为2.84‰,具有明显的塔式效应,反映了成矿物质具有岩浆来源的特征;辉钼矿中 Re 含量为174.3×10-6~871.4×10-6,平均为476.2×10-6,表明成矿物质来源属于壳幔混源型。
鄂東南地區是我國長江中下遊Cu-Au-Fe-Mo成礦帶中最重要的組成部分之一,其中鷄籠山金礦是是區內典型的大型矽卡巖金礦床。本文利用Re-Os同位素定年方法對鷄籠山金礦床進行瞭成礦時代測定,穫得瞭輝鉬礦的Re-Os同位素模式年齡範圍為147.7±2.4~151.6±4.0Ma,等時線年齡為148.6±1.5Ma,與礦區內花崗閃長斑巖SHRIMP鋯石U-Pb年齡151.6±0.7Ma相吻閤,也與鄂東南地區其他礦田的成礦時代基本一緻。鷄籠山矽卡巖金礦床可能形成于巖石圈伸展構造揹景。硫同位素值為-2.5‰~5.5‰,均值為2.84‰,具有明顯的塔式效應,反映瞭成礦物質具有巖漿來源的特徵;輝鉬礦中 Re 含量為174.3×10-6~871.4×10-6,平均為476.2×10-6,錶明成礦物質來源屬于殼幔混源型。
악동남지구시아국장강중하유Cu-Au-Fe-Mo성광대중최중요적조성부분지일,기중계롱산금광시시구내전형적대형석잡암금광상。본문이용Re-Os동위소정년방법대계롱산금광상진행료성광시대측정,획득료휘목광적Re-Os동위소모식년령범위위147.7±2.4~151.6±4.0Ma,등시선년령위148.6±1.5Ma,여광구내화강섬장반암SHRIMP고석U-Pb년령151.6±0.7Ma상문합,야여악동남지구기타광전적성광시대기본일치。계롱산석잡암금광상가능형성우암석권신전구조배경。류동위소치위-2.5‰~5.5‰,균치위2.84‰,구유명현적탑식효응,반영료성광물질구유암장래원적특정;휘목광중 Re 함량위174.3×10-6~871.4×10-6,평균위476.2×10-6,표명성광물질래원속우각만혼원형。
Southeast Hubei Province is one of the most important part of the Cu-Au-Fe-Mo metallogenic belt in the middle-lower Yangtze River in China,the Jilongshan Au deposit is a large skarn gold deposit in this area.This paper use Re-Os isotope dating method for the determination of timing of the Jilongshan gold deposit.The molybdenite Re-Os isotopic model age range from 147. 7 ±2. 4 to 151. 6 ±4. 02Ma with an isochron age of 148. 6±1. 5Ma,which is alomost similar to zircon SHRIMP U-Pb age of 151. 6±0. 7Ma of granodiorite porphyry in the Jilongshan Au skarn deposit.These data are alos consistent with skarn Cu-Fe mineralization age in Southeast Hubei.The Jilongshan skarn Au deposits may be formed in lithosphere extension tectonic setting.Sulfur isotope values are -2. 5‰~5. 5‰ with an mean value of 2. 84‰, eflecting that the characteristics ore-forming material originated from magmatic origin.The content of Re in molybdenite is 174. 3 ×10-6~8714 ×10-6 ,with an average value of 476. 2 ×10-6 ,indicating that the sources of ore-forming are deried from a mixture of crust and mantle material.