安徽省金寨县沙坪沟钼矿床稳定同位素地球化学特征
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摘要
安徽省金寨县沙坪沟钼矿床是近年来秦岭—大别成矿带发现的超大型斑岩钼矿床,已探明钼资源储量246×10~4t。通过对沙坪沟钼矿床不同勘探线剖面和不同深度代表性样品的S、H、O稳定同位素地球化学的研究,揭示了沙坪沟钼矿床S、H、O同位素组成特征及其空间分布特征。矿床硫化物硫同位素组成变化范围较窄,δ~(34)S变化于+0.4‰～+6.2‰,平均值为+3.47‰,落在火成岩范围,分布具明显的塔式效应,硫的来源比较均一,主要为深源硫。成矿流体的δ~(18)O_(包裹体水)为0.40‰～7.52‰。流体包裹体中δD变化范围为-90‰～-63‰。主成矿期成矿流体总体为岩浆水。在不同勘探线剖面上矿化中心具高的δ~(34)S、δ~(18)O值,而且显示出从深部钠长石—钾长石—硅化带→黄铁绢英岩化带→浅部的绿泥石—碳酸盐化带δ~(34)S、δ~(18)O值有降低的趋势。上述特征表明沙坪沟钼矿床主成矿期成矿环境由碱性向酸性过渡,且没有发生明显的低δ~(18)O作用,成矿环境相对封闭,外部对流循环的雨水系统参与成矿作用程度相对较小,与东秦岭其他斑岩钼矿床不同。
Shapinggou molybdenum deposit,Jinzhai County,Anhui Province,is a super large porphyry molybdenum deposit discovered in the Qinling-Dabie metallogenic belt in recent years. The proven reserves of molybdenum resources are 246×10~4 t. The S,H,O stable isotopes for representative samples from different prospecting line sections at various depths were analyzed in this paper. The sulfur isotopic composition of sulfides in the ore deposit varies in a narrow range from +0.4‰ to +6.2‰. The average value is +3.47‰ within the range of igneous rocks,showing Gaussian distribution in histogram. The source of sulfur is relatively uniform,mainly deep sourced sulfur. The δ~(18)O value of ore-forming fluid inclusions ranges from 0.40‰ to 7.52‰,and δD value of fluid inclusions ranges from -90‰ to -63‰,which suggest that ore-forming fluid for main mineralization resulted from magma. High δ~(34)S and δ~(18)O values correspond to mineralization central zone at various prospecting line sections. Besides,the δ~(34)S and δ~(18)O values have a decreasing tendency from albite feldspar-potassium feldspar-silicified zone,beresitization zone to chlorite-carbonation zone. The above characteristics indicate that the geochemical environment of ore-forming fluid of Shapinggou molybdenum deposit changed from alkaline into acidity during the main ore-forming period. There is no obvious low δ~(18)O effect,the ore-forming occurred in a quite closed environment,and meteoric water with external convection circulation is relatively less involved in the mineralization. The geochemical environment is different from other porphyry molybdenum deposits in the East Qinling district.
Shapinggou molybdenum deposit,Jinzhai County,Anhui Province,is a super large porphyry molybdenum deposit discovered in the Qinling-Dabie metallogenic belt in recent years. The proven reserves of molybdenum resources are 246×10~4 t. The S,H,O stable isotopes for representative samples from different prospecting line sections at various depths were analyzed in this paper. The sulfur isotopic composition of sulfides in the ore deposit varies in a narrow range from +0.4‰ to +6.2‰. The average value is +3.47‰ within the range of igneous rocks,showing Gaussian distribution in histogram. The source of sulfur is relatively uniform,mainly deep sourced sulfur. The δ~(18)O value of ore-forming fluid inclusions ranges from 0.40‰ to 7.52‰,and δD value of fluid inclusions ranges from -90‰ to -63‰,which suggest that ore-forming fluid for main mineralization resulted from magma. High δ~(34)S and δ~(18)O values correspond to mineralization central zone at various prospecting line sections. Besides,the δ~(34)S and δ~(18)O values have a decreasing tendency from albite feldspar-potassium feldspar-silicified zone,beresitization zone to chlorite-carbonation zone. The above characteristics indicate that the geochemical environment of ore-forming fluid of Shapinggou molybdenum deposit changed from alkaline into acidity during the main ore-forming period. There is no obvious low δ~(18)O effect,the ore-forming occurred in a quite closed environment,and meteoric water with external convection circulation is relatively less involved in the mineralization. The geochemical environment is different from other porphyry molybdenum deposits in the East Qinling district.
引文
[1]陆三明,宋传中.北淮阳地区银山铅锌矿床成矿地质背景和找矿方向[J].安徽地质,2003,13(2):115-118.
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[3]陆三明,徐晓春,彭智.北淮阳构造带东段隐爆角砾岩型多金属矿床的地质特征及成因[J].地质与勘探,2005,41(3):7-11.
[4]彭智.北淮阳东段基础地质评述[J].安徽地质,2004,14(3):172-176.
[5]彭智,陆三明,徐晓春.北淮阳构造带东段金多金属矿床区域成矿规律[J].合肥工业大学学报(自然科学版),2005,28(4):364-368.
[6]彭智,杜建国,陈芳,等.北淮阳东段同兴寺碱性岩体地球化学特征、LA-ICP-MS锆石U-Pb年龄及其地质意义[J].地质学报,2015,89(4):701-714.
[7]刘文灿,王果胜.北淮阳地区中生代逆冲推覆构造[J].现代地质,1999,13(2):143-149.
[8]刘文灿,孙善平,李家振.大别山北麓晚侏罗世金刚台组火山岩地质及岩相构造特征[J].现代地质,1997,11(2):237-243.
[9]王波华,邬宗玲,张怀东,等.安徽省金寨银沙地区中生代岩浆岩地质地球化学特征及其找矿意义[J].安徽地质,2007,17(4):244-248.
[10]徐晓春,楼金伟,陆三明,等.安徽金寨银山钼-铅-锌多金属矿床Re-Os和有关岩浆岩40Ar-39Ar年龄测定[J].矿床地质,2009,28(5):621-632.
[11]黄凡,王登红,陆三明,等.安徽省金寨县沙坪沟钼矿辉钼矿Re-Os年龄——兼论东秦岭-大别山中生代钼成矿作用期次划分[J].矿床地质,2011,30(6):1039-1055.
[12]黄凡,王登红,陈毓川.中国东部中生代典型钼矿研究[M].北京:地质出版社,2013:106-122.
[13]张怀东,王波华,郝越进,等.安徽沙坪沟斑岩型钼矿床地质特征及综合找矿信息[J].矿床地质,2012,31(1):41-51.
[14]陈红瑾,陈衍景,张静,等.安徽省金寨县沙坪沟钼矿含矿岩体锆石U-Pb年龄和Hf同位素特征及其地质意义[J].岩石学报,2013,29(1):131-145.
[15]王萍.安徽金寨沙坪沟钼矿区岩浆岩特征及成因[D].合肥:合肥工业大学,2013:1-87.
[16]刘啟能.安徽金寨沙坪沟斑岩钼矿床及其与岩浆岩的关系[D].合肥:合肥工业大学,2013:19-31.
[17]任志,周涛发,袁峰,等.安徽沙坪沟钼矿区中酸性侵入岩期次研究——年代学及岩石化学约束[J].岩石学报,2014,30(4):1097-1116.
[18]陆三明,阮林森,赵丽丽,等.安徽金寨县沙坪沟钼铅锌矿田两期成岩成矿作用[J].地质学报,2016,90(6):1167-1181.
[19]张怀东,史东方,郝越进,等.安徽省金寨县沙坪沟斑岩型钼矿成矿地质特征[J].安徽地质,2010,20(2):104-108.
[20]赵新福,李建威,马昌前,等.北淮阳古碑花岗闪长岩侵位时代及地球化学特征:对大别山中生代构造体制转换的启示[J].岩石学报,2007,23(6):1392-1402.
[21]张红,孙卫东,杨晓勇,等.大别造山带沙坪沟特大型斑岩钼矿床年代学及成矿机理研究[J].地质学报,2011,85(12):2039-2059.
[22]孟祥金,徐文艺,吕庆田,等.安徽沙坪沟斑岩钼矿锆石U-Pb和辉钼矿Re-Os年龄[J].地质学报,2012,86(3):486-494.
[23]张怀东,王根节,王波华,等.沙坪沟斑岩型钼矿含矿岩体及其蚀变特征[J].安徽地质,2010,20(4):260-266.
[24]郭波,朱赖民,李犇,等.东秦岭金堆城大型斑岩钼矿床同位素及元素地球化学研究[J].矿床地质,2009,28(3):265-281.
[25]魏庆国,原雷,姚军明,等.秦岭钼矿带成矿特征及其与美国克莱马克斯-亨德森钼矿带的对比[J].大地构造与成矿学,2010,33(2):259-269.
[26]CLAYTON R N,O'NEIL J R,TOSHIKO K M.Oxygen isotope exchange between quartz and water[J].Journal of Geophysical Research,1972,77(17):3057-3067.
[27]O'NEIL J R,CLAYTON R N,MAYEDA T K.Oxygen isotope fraction in divalent metal carbonates[J].The Journal of Chemical Physics,1969,51(12):5547-5558.
[28]CHAUSSIDON M,LORAND J P.Sulphur isotope composition of orogenic spinel lherzolite massifs from Ariege(North-Eastern Pyrenees,France):An ion microprobe study[J].Geochimica et Cosmochimica Acta,1990,54:2835-2846.
[29]OHMOTO H,RYE R O.Isotope of sulfur and carbon[M]//BARNES H L.Geochemistry of Hydrothermal Ore Deposits.New York:Wiley,1979:509-567.
[30]尹观,倪师军.同位素地球化学[M].北京:地质出版社,2009:30-31.
[31]张理刚.湖南东坡千里山花岗岩和钨多金属矿床稳定同位素地球化学[J].桂林冶金地质学院学报,1989(3):259-267.
[32]王玉荣,胡受奚.钾质交代蚀变过程中金活化转移实验研究——以华北地台金矿为例[J].中国科学:地球科学,2000,30(5):499-508.
[33]何俊,徐晓春,王萍,等.安徽沙坪沟斑岩钼矿床赋矿岩体钾质交代作用及其微量元素和Sr-Nd同位素响应[J].矿床地质,2018,37(3):611-629.
[34]JOCHEN H.稳定同位素地球化学[M].刘季花,等,译.北京:海洋出版社,1996:116-132.
[35]张理刚.成岩成矿理论与找矿——中国主要类型矿床及花岗岩类岩石的稳定同位素地质学[M].北京:北京工业大学出版社,1989:1-200.
(1)徐晓春,陆三明,彭智.安徽省北淮阳内生金及多金属矿找矿研究.安徽省地质矿产勘查局313地质队(内部研究报告).2006.
[2]陆三明.北淮阳构造带东段银山铅锌矿床形成的构造背景[D].合肥:合肥工业大学,2003:1-87.
[3]陆三明,徐晓春,彭智.北淮阳构造带东段隐爆角砾岩型多金属矿床的地质特征及成因[J].地质与勘探,2005,41(3):7-11.
[4]彭智.北淮阳东段基础地质评述[J].安徽地质,2004,14(3):172-176.
[5]彭智,陆三明,徐晓春.北淮阳构造带东段金多金属矿床区域成矿规律[J].合肥工业大学学报(自然科学版),2005,28(4):364-368.
[6]彭智,杜建国,陈芳,等.北淮阳东段同兴寺碱性岩体地球化学特征、LA-ICP-MS锆石U-Pb年龄及其地质意义[J].地质学报,2015,89(4):701-714.
[7]刘文灿,王果胜.北淮阳地区中生代逆冲推覆构造[J].现代地质,1999,13(2):143-149.
[8]刘文灿,孙善平,李家振.大别山北麓晚侏罗世金刚台组火山岩地质及岩相构造特征[J].现代地质,1997,11(2):237-243.
[9]王波华,邬宗玲,张怀东,等.安徽省金寨银沙地区中生代岩浆岩地质地球化学特征及其找矿意义[J].安徽地质,2007,17(4):244-248.
[10]徐晓春,楼金伟,陆三明,等.安徽金寨银山钼-铅-锌多金属矿床Re-Os和有关岩浆岩40Ar-39Ar年龄测定[J].矿床地质,2009,28(5):621-632.
[11]黄凡,王登红,陆三明,等.安徽省金寨县沙坪沟钼矿辉钼矿Re-Os年龄——兼论东秦岭-大别山中生代钼成矿作用期次划分[J].矿床地质,2011,30(6):1039-1055.
[12]黄凡,王登红,陈毓川.中国东部中生代典型钼矿研究[M].北京:地质出版社,2013:106-122.
[13]张怀东,王波华,郝越进,等.安徽沙坪沟斑岩型钼矿床地质特征及综合找矿信息[J].矿床地质,2012,31(1):41-51.
[14]陈红瑾,陈衍景,张静,等.安徽省金寨县沙坪沟钼矿含矿岩体锆石U-Pb年龄和Hf同位素特征及其地质意义[J].岩石学报,2013,29(1):131-145.
[15]王萍.安徽金寨沙坪沟钼矿区岩浆岩特征及成因[D].合肥:合肥工业大学,2013:1-87.
[16]刘啟能.安徽金寨沙坪沟斑岩钼矿床及其与岩浆岩的关系[D].合肥:合肥工业大学,2013:19-31.
[17]任志,周涛发,袁峰,等.安徽沙坪沟钼矿区中酸性侵入岩期次研究——年代学及岩石化学约束[J].岩石学报,2014,30(4):1097-1116.
[18]陆三明,阮林森,赵丽丽,等.安徽金寨县沙坪沟钼铅锌矿田两期成岩成矿作用[J].地质学报,2016,90(6):1167-1181.
[19]张怀东,史东方,郝越进,等.安徽省金寨县沙坪沟斑岩型钼矿成矿地质特征[J].安徽地质,2010,20(2):104-108.
[20]赵新福,李建威,马昌前,等.北淮阳古碑花岗闪长岩侵位时代及地球化学特征:对大别山中生代构造体制转换的启示[J].岩石学报,2007,23(6):1392-1402.
[21]张红,孙卫东,杨晓勇,等.大别造山带沙坪沟特大型斑岩钼矿床年代学及成矿机理研究[J].地质学报,2011,85(12):2039-2059.
[22]孟祥金,徐文艺,吕庆田,等.安徽沙坪沟斑岩钼矿锆石U-Pb和辉钼矿Re-Os年龄[J].地质学报,2012,86(3):486-494.
[23]张怀东,王根节,王波华,等.沙坪沟斑岩型钼矿含矿岩体及其蚀变特征[J].安徽地质,2010,20(4):260-266.
[24]郭波,朱赖民,李犇,等.东秦岭金堆城大型斑岩钼矿床同位素及元素地球化学研究[J].矿床地质,2009,28(3):265-281.
[25]魏庆国,原雷,姚军明,等.秦岭钼矿带成矿特征及其与美国克莱马克斯-亨德森钼矿带的对比[J].大地构造与成矿学,2010,33(2):259-269.
[26]CLAYTON R N,O'NEIL J R,TOSHIKO K M.Oxygen isotope exchange between quartz and water[J].Journal of Geophysical Research,1972,77(17):3057-3067.
[27]O'NEIL J R,CLAYTON R N,MAYEDA T K.Oxygen isotope fraction in divalent metal carbonates[J].The Journal of Chemical Physics,1969,51(12):5547-5558.
[28]CHAUSSIDON M,LORAND J P.Sulphur isotope composition of orogenic spinel lherzolite massifs from Ariege(North-Eastern Pyrenees,France):An ion microprobe study[J].Geochimica et Cosmochimica Acta,1990,54:2835-2846.
[29]OHMOTO H,RYE R O.Isotope of sulfur and carbon[M]//BARNES H L.Geochemistry of Hydrothermal Ore Deposits.New York:Wiley,1979:509-567.
[30]尹观,倪师军.同位素地球化学[M].北京:地质出版社,2009:30-31.
[31]张理刚.湖南东坡千里山花岗岩和钨多金属矿床稳定同位素地球化学[J].桂林冶金地质学院学报,1989(3):259-267.
[32]王玉荣,胡受奚.钾质交代蚀变过程中金活化转移实验研究——以华北地台金矿为例[J].中国科学:地球科学,2000,30(5):499-508.
[33]何俊,徐晓春,王萍,等.安徽沙坪沟斑岩钼矿床赋矿岩体钾质交代作用及其微量元素和Sr-Nd同位素响应[J].矿床地质,2018,37(3):611-629.
[34]JOCHEN H.稳定同位素地球化学[M].刘季花,等,译.北京:海洋出版社,1996:116-132.
[35]张理刚.成岩成矿理论与找矿——中国主要类型矿床及花岗岩类岩石的稳定同位素地质学[M].北京:北京工业大学出版社,1989:1-200.
(1)徐晓春,陆三明,彭智.安徽省北淮阳内生金及多金属矿找矿研究.安徽省地质矿产勘查局313地质队(内部研究报告).2006.
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