沥青样品铼-锇同位素分析溶解实验研究
Dissolving Experimental Research of Re-Os Isotope System for Bitumen Samples
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摘要: 沥青样品中Re、Os含量较低,且组成复杂,因含有大量有机质,在溶样过程中会释放大量CO2,需要大量氧化剂。控制样品称样量和氧化剂比例、用量对保证Os的回收率以及测量信号的稳定性非常重要。本文根据沥青样品组成特点改进了Re-Os同位素分析技术方法,称样量由原来的0.2 g增加到0.4 g,氧化剂由原来的3 mL HCl、6 mL HNO3改为3 mL HCl、4 mL HNO3、3 mL H2O2,改进的方法所得到Os的信号强度提高了大约2倍。考察了改变溶剂组成对不同称样量沥青的氧化效果,研究了氧化剂中加入H2O2对不同称样量沥青样品溶解效果,以及对Os的回收率和仪器测量信号强度的影响程度。采用2 mL HCl、5 mL HNO3、2 mL H2O2作为氧化剂,Carius管高温密闭溶样,直接蒸馏法或传统蒸馏法分离富集Os,丙酮萃取法分离纯化Re,用电感耦合等离子体质谱法(ICP-MS)对采自云南某铅锌矿床的沥青样品Re-Os同位素进行分析测定。沥青的Re-Os同位素等时线年龄为(60±2) Ma(MSWD=2.5,n=7),初始187Os/188Os值为4.36±0.14,表明该沥青样品中Re-Os同位素体系的封闭性较好,而且物质来源为典型的壳源性质。建立的方法能够用于沥青年龄厘定与来源示踪方面的研究。
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关键词:
- 铼-锇同位素体系 /
- 沥青 /
- 氧化剂 /
- 称样量 /
- 电感耦合等离子体质谱法
Abstract: The content of Re-Os in asphalt samples is relatively low, and CO2 are released in digestion because of large amounts of organic matter. It is important to control the amount of asphalt in the sample and the proportion of oxidant to ensure the Os recovery and stability of the measured signal. The method for the Re-Os isotope was improved because of large amounts of organic matter contained in bitumen samples. The Oxidants was changed to 3 mL HCl, 4 mL HNO3 and 3mL H2O2 from the original 3 mL HCl and 6 mL HNO3, the improved method making the Os measured signal approximately 2 times larger than before. Changes in oxidants composition increase the amount of the bitumen sample weight greatly from th eoriginal 0.2 g to 0.4 g. Influence of H2O2 added with routine reverse aqua regia and direct distillation from a Carius tube on the signal intensity of osmium measured by Inductively Coupled Plasma-Mass Spectrometry(ICP-MS). was studied. Bitumen samples were dissolved and equilibrated with a known amount of 185Re and 190Os tracers in 2 mL HCl, 5 mL HNO3 and 2 mL H2O2 by a Carius tube at 200℃ for 12 h and 240℃ for 12 h, with the Os and Re separated using direct distillation or routine distillation and solvent extraction techniques, respectively. 187Re/185Re, 187Os/190Os and 192Os/190Os were determined by ICP-MS. Bitumen samples in lead-zinc deposits from Yunnan Province were analyzed. The isochron ages was (60±2) Ma (MSWD=2.5, n=7), and the initial 187Os/188Os values was 4.36±0.14. The results show that Re-Os isotope is an effective tool to date bitumen samples and the Os in the bitumen originated from the crust. The established method can be used to date and trace the source of bitumen samples. -
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Selby D, Creaser R A, Dewing K, Fowler M. Evaluation of bitumen as a 187Re-187Os geochronometer for hydrocarbon maturation and migration: A case study from the Polaris MVT deposit[J]. Canada Earth and Planetary Science Letters,2005,235(1-2): 1-15. Selby D, Creaser R A, Dewing K, Fowler M. Evaluation of bitumen as a 187Re-187Os geochronometer for hydrocarbon maturation and migration: A case study from the Polaris MVT deposit[J]. Canada Earth and Planetary Science Letters,2005,235(1-2): 1-15.
Selby D, Creaser R A. Direct radiometric dating of the Devonian-Mississippian time-scale boundary using the Re-Os black shale geochronometer [J]. Geology, 2005,33:545-548. Selby D, Creaser R A. Direct radiometric dating of the Devonian-Mississippian time-scale boundary using the Re-Os black shale geochronometer [J]. Geology, 2005,33:545-548.
Hannah J L, Stein H J, Zimmerman A, Yang G, Markey R J, Melezhik V A. Precise 2004±9 Ma Re-Os age for Pechenga black shale: Comparison of sulfides and organic material [J]. Geochim Cosmochim Acta,2006,70:A228. Hannah J L, Stein H J, Zimmerman A, Yang G, Markey R J, Melezhik V A. Precise 2004±9 Ma Re-Os age for Pechenga black shale: Comparison of sulfides and organic material [J]. Geochim Cosmochim Acta,2006,70:A228.
Yang G, Hannah J L, Zimmerman A, Stein H J, Bekker A. Re-Os depositional age for Archean carbonaceous slates from the Southwestern Superior Province: Challenges and insights [J]. Earth and Planetary Science Letters, 2009,280: 83-92. Yang G, Hannah J L, Zimmerman A, Stein H J, Bekker A. Re-Os depositional age for Archean carbonaceous slates from the Southwestern Superior Province: Challenges and insights [J]. Earth and Planetary Science Letters, 2009,280: 83-92.
Stein H J, Yang G, Hannah J L, Zimmerman A, Egenhoff S. Re-Os fractionation on instantaneous maturation at the Siljan meteorite impact site, Central Sweden [J]. Geochim Cosmochim Acta, 2009:A1268. Stein H J, Yang G, Hannah J L, Zimmerman A, Egenhoff S. Re-Os fractionation on instantaneous maturation at the Siljan meteorite impact site, Central Sweden [J]. Geochim Cosmochim Acta, 2009:A1268.
Jiang S Y, Yang J H, Ling H F, Chen Y Q. Extreme enrichment of polymetallic Ni-Mo-PGE-Au in lower Cambrian black shales of South China: An Os isotope and PGE geochemical investigation[J]. Palaeogeography, Palaeo-climatology, Palaeoecology,2007,254(1-2): 217-228. Jiang S Y, Yang J H, Ling H F, Chen Y Q. Extreme enrichment of polymetallic Ni-Mo-PGE-Au in lower Cambrian black shales of South China: An Os isotope and PGE geochemical investigation[J]. Palaeogeography, Palaeo-climatology, Palaeoecology,2007,254(1-2): 217-228.
陈郑辉,李超,屈文俊,王登红,张家菁,杜安道.石墨Re-Os同位素分析及其在成矿年代学中的初步运用[J].岩石学报, 2010,26(11): 3411-3417. Mao J W, Lehmann B, Du A D, Zhang G D, Ma D S, Wang Y T, Zeng M G, Kerrich R. Re-Os dating of polymetallic Ni-Mo-PGE-Au mineralization in lower Cambrian black shales of South China and its geologic significance[J]. Economic Geology,2002, 97: 1051-1061. Mao J W, Lehmann B, Du A D, Zhang G D, Ma D S, Wang Y T, Zeng M G, Kerrich R. Re-Os dating of polymetallic Ni-Mo-PGE-Au mineralization in lower Cambrian black shales of South China and its geologic significance[J]. Economic Geology,2002, 97: 1051-1061.
Hannah J L, Bekker A, Stein H J, Markey R J, Holland H D. Primitive Os and 2316 Ma age for marine shale: Implications for Paleoproterozoic glacial events and the rise of atmospheric oxygen[J]. Earth and Planetary Science Letters,2004, 225: 43-52. Hannah J L, Bekker A, Stein H J, Markey R J, Holland H D. Primitive Os and 2316 Ma age for marine shale: Implications for Paleoproterozoic glacial events and the rise of atmospheric oxygen[J]. Earth and Planetary Science Letters,2004, 225: 43-52.
Ravizza G, Turekian G G, Hay B J. The geochemistry of rhenium and osmium in recent sediments from the Black Sea[J]. Geochim Cosmochim Acta, 1991,55: 3741-3752. Ravizza G, Turekian G G, Hay B J. The geochemistry of rhenium and osmium in recent sediments from the Black Sea[J]. Geochim Cosmochim Acta, 1991,55: 3741-3752.
Cohen A S, Coe A L, Bartlett J M, Hawkesworth C J. Precise Re-Os ages of organic-rich mudrocks and the Os isotope composition of Jurassic seawater [J]. Earth and Planetary Science Letters,1999,167: 159-173. Cohen A S, Coe A L, Bartlett J M, Hawkesworth C J. Precise Re-Os ages of organic-rich mudrocks and the Os isotope composition of Jurassic seawater [J]. Earth and Planetary Science Letters,1999,167: 159-173.
朱弟成,朱利东,林丽,熊永柱,庞艳春,付修根.西成矿田泥盆系铅锌矿床中的有机成矿作用[J].地球科学——中国地质大学学报,2003,28(2): 201-208. 付修根,林丽,庞艳春,朱利东,王新利.云南金顶铅锌矿床中的有机质特征及成矿作用探讨[J].成都理工大学学报:自然科学版,2006(6): 621-623. 傅家谟,彭平安.沉积矿床有机地球化学[J].矿物岩石地球化学通报,1988(2): 88-90. 侯增谦,曲晓明,王淑贤,高永丰,杜安道,黄卫.西藏高原冈底斯斑岩铜矿带辉钼矿Re-Os年龄成矿作用时限与动力学背景应用[J].中国科学:D辑,2003,33(7): 609-618. 韩春明,肖文交,赵国春,屈文俊,毛启贵,杜安道.新疆喀拉通克铜镍硫化物矿床Re-Os同位素研究及其地质意义[J].岩石学报, 2006,22(1): 163-170. 毛景文,Holly S,杜安道,周涛发,梅燕雄,李永峰,藏文栓,李进文.长江中下游地区铜金(钼)矿Re-Os年龄测定及其对成矿作用的指示[J].地质学报, 2004,78(1):121-131. Yang S H, Qu W J, Tian Y L, Chen J F, Yang G, Du A D. Origin of the inconsistent apparent Re-Os ages of the Jinchuan, Ni-Cu sulfide ore deposit, China: Post-segregation diffusion of Os [J]. Chemical Geology, 2008, 247:401-418. Yang S H, Qu W J, Tian Y L, Chen J F, Yang G, Du A D. Origin of the inconsistent apparent Re-Os ages of the Jinchuan, Ni-Cu sulfide ore deposit, China: Post-segregation diffusion of Os [J]. Chemical Geology, 2008, 247:401-418.
屈文俊,杜安道,任静.H2O2在黄铁矿的溶解过程中对铼-锇信号强度及年龄的影响[J].分析化学,2008,36(2):223-226. 何红蓼,杜安道,邹晓秋,孙亚莉,殷宁万.铼-锇测年法中锇的化学行为研究[J].分析化学,1994,22(2):109-114. 屈文俊,杜安道.高温密闭溶样电感耦合等离子体质谱准确测定辉钼矿铼-锇地质年龄[J].岩矿测试, 2003,22(4):254-262. 李超,屈文俊,周利敏,杜安道. Carius管直接蒸馏快速分离锇方法研究[J].岩矿测试,2010,29(1):14-16. 杜安道,何红蓼,殷宁万,邹晓秋,孙亚莉,孙德忠,陈少珍,屈文俊.辉钼矿的铼-锇同位素地质年龄测定方法研究[J].地质学报,1994, 68(4):339-347. 屈文俊,杜安道.电感耦合等离子体质谱测定辉钼矿中Re、Os含量时的质量分馏效应的校正[J].质谱学报,2004,25(Z1):181-182. 李超,屈文俊,杜安道.铼-锇同位素定年法中丙酮萃取铼的系统研究[J].岩矿测试, 2009,28(3):233-238. 杜安道,屈文俊,李超,杨刚.铼-锇同位素定年方法及分析测试技术的进展[J].岩矿测试,2009,28(3):288-304. Ludwig K. Isoplot/Ex, version 2.0: A geochronogical toolkit for Microsoft Excel[M]. Geochronology Center,1999. Ludwig K. Isoplot/Ex, version 2.0: A geochronogical toolkit for Microsoft Excel[M]. Geochronology Center,1999.
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