黄金科学技术
黃金科學技術
황금과학기술
GOLD SCIENCE AND TECHNOLOGY
2014年
2期
24-30
,共7页
王斌%张栋%范俊杰%张峰%潘爱军%朱鹏
王斌%張棟%範俊傑%張峰%潘愛軍%硃鵬
왕빈%장동%범준걸%장봉%반애군%주붕
铜(金)矿床%混合稀释剂法%花岗斑岩%Sr-Nd同位素%卡拉麦里成矿带
銅(金)礦床%混閤稀釋劑法%花崗斑巖%Sr-Nd同位素%卡拉麥裏成礦帶
동(금)광상%혼합희석제법%화강반암%Sr-Nd동위소%잡랍맥리성광대
copper-gold deposit%mixing diluent method%granite porphyry%Sr-Nd isotopic%Kalamaili belt
混合稀释剂法是测定地质样品中放射性同位素组成的重要手段,具有样品用量少、测试精度和灵敏度高等优点。应用混合稀释剂法获取了新疆东准噶尔松喀尔苏铜(金)矿区含矿花岗斑岩的Sr-Nd同位素数据,其中,含矿斑岩样品初始87Sr/86Sr值(ISr)较低且比较分散,变化范围为0.70268~0.71004,均低于大陆地壳ISr平均值(0.719);εNd值较高且为正值,变化范围为+3.8~+8.3,并具有非常年轻二阶段Nd模式年龄,t2DM值在0.4~0.8 Ga之间。 Sr、Nd同位素组成与新疆北部富碱侵入岩相似,其源区很有可能是由于幔源岩浆的底侵作用添加到下地壳中,地壳停留时间较短的新生年轻地壳与幔源岩浆发生了源区混合。东准噶尔卡拉麦里成矿带晚石炭世加厚岩石圈的拆沉导致大规模的幔源岩浆底侵作用,碰撞后的伸展环境为成矿物质的向上运移提供了通道,形成了以多金属矿为主的成矿带。
混閤稀釋劑法是測定地質樣品中放射性同位素組成的重要手段,具有樣品用量少、測試精度和靈敏度高等優點。應用混閤稀釋劑法穫取瞭新疆東準噶爾鬆喀爾囌銅(金)礦區含礦花崗斑巖的Sr-Nd同位素數據,其中,含礦斑巖樣品初始87Sr/86Sr值(ISr)較低且比較分散,變化範圍為0.70268~0.71004,均低于大陸地殼ISr平均值(0.719);εNd值較高且為正值,變化範圍為+3.8~+8.3,併具有非常年輕二階段Nd模式年齡,t2DM值在0.4~0.8 Ga之間。 Sr、Nd同位素組成與新疆北部富堿侵入巖相似,其源區很有可能是由于幔源巖漿的底侵作用添加到下地殼中,地殼停留時間較短的新生年輕地殼與幔源巖漿髮生瞭源區混閤。東準噶爾卡拉麥裏成礦帶晚石炭世加厚巖石圈的拆沉導緻大規模的幔源巖漿底侵作用,踫撞後的伸展環境為成礦物質的嚮上運移提供瞭通道,形成瞭以多金屬礦為主的成礦帶。
혼합희석제법시측정지질양품중방사성동위소조성적중요수단,구유양품용량소、측시정도화령민도고등우점。응용혼합희석제법획취료신강동준갈이송객이소동(금)광구함광화강반암적Sr-Nd동위소수거,기중,함광반암양품초시87Sr/86Sr치(ISr)교저차비교분산,변화범위위0.70268~0.71004,균저우대륙지각ISr평균치(0.719);εNd치교고차위정치,변화범위위+3.8~+8.3,병구유비상년경이계단Nd모식년령,t2DM치재0.4~0.8 Ga지간。 Sr、Nd동위소조성여신강북부부감침입암상사,기원구흔유가능시유우만원암장적저침작용첨가도하지각중,지각정류시간교단적신생년경지각여만원암장발생료원구혼합。동준갈이잡랍맥리성광대만석탄세가후암석권적탁침도치대규모적만원암장저침작용,팽당후적신전배경위성광물질적향상운이제공료통도,형성료이다금속광위주적성광대。
Mixing diluents method was an extremely important way in identifying the composition of radioactive isotopes in rock samples,and it had the advantage of less samples,higher test precision and sensitivity.Therefore, mixing diluents method was applied to obtain date about the Sr-Nd isotopic composition of ore-bearing porphyry in the Songkaersu copper (gold) deposit mining area in eastern Junggar.The 87Sr/86Sr (ISr) initial value was relatively low and decentralized with the range of 0.70268 to 0.71004,which was lower than the average ISr value (0.719) in crust.Additionally,theεNd value was high and positive with the range of+3.8~+8.3 as well very young two-stage Nd model ages,and the t2DM value was between 0.4~0.8 Ga.Sr-Nd isotopic composition was similar to the alkali rich intrusive rock in northern Xinjiang.Its source area was likely to be due to the effect of bottom of invasion of the mantle-derived magma adding to the lower crust,and the newborn and young crust with shorter crustal residence time mixed with mantle-derived magma.The delamination of upset the late carboniferous to the lithosphere in east Carboniferous resulted in large bottom of invasion mantle-derived magma.The stretching environment after collision provided the ore-forming materials of upward migration channel,and formed metallogenic belt which was mainly with polymetallic ore.