四川冕宁木落寨稀土矿床成岩成矿的^40Ar/^39Ar年代学研究
^40Ar/^39Ar geochronology of rocks and ores from the Muluozhai REE deposit in Mianning County, Sichuan province.
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摘要: 木落寨稀土矿床位于四川省冕宁县境内,雅砻江西侧.矿体产于英碱正长岩与变质辉绿岩和大理岩接触的构造破碎带中.此前,英碱正长岩被认为形成于燕山期,但没有任何同位素年龄资料的报道.本文通过40Ar/39Ar快中子活化分析,得出英碱正长岩微斜长石的40Ar/39Ar坪年龄为31.2±0.56Ma,等时线年龄为30.6±2.6Ma.矿石金云母的Ar/39Ar坪年龄为35.5±0.5Ma,等时线年龄为35±1Ma.微斜长石的年龄比金云母年龄偏小,是因为两者的Ar同位素封闭温度不同,前者约为170℃,而后者为350℃.两者年龄差较大表明在35.5~31.2Ma之间,矿体和岩体均进入了较慢冷却阶段,冷却速率约为41.9℃/Ma.因此,木落寨矿床的矿石与英碱正长岩的形成年龄接近,均属新生代喜马拉雅期.木落寨矿床成岩成矿年龄的确定,对于进一步了解该区域偏碱性火成岩的形成时代及拓宽区域稀土找矿远景,具有很大意义.
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关键词:
- ^40Ar^-39Ar年龄 /
- 英碱正长岩 /
- 木落寨稀土矿床 /
- 四川冕宁
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Key words:
- ^40Ar/^39Ar ages /
- Nordmarkite /
- Muluozhai REE deposit /
- Mianning County
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[1] 杨光明,常诚,左大华,刘学良.1998.四川省德昌县DL稀土矿床成矿条件研究.1~89.
[2] 陈文,郭彦如,崔彬等.2002a.东昆仑西大滩岩系变质和变形事件的同位素年代学研究.地质论评,48(增刊):103-109
[3] 四川省地质局.1966 1:20万冕宁幅区域地质调查报告.85~102.
[4] Chen W,Guo YR,Cui B et al.2002a.Research on the isotopic ages of the deformations and metamorphisms of the Xidatan rock series,East Kunlun Mountains.Geological Review,48 (Supple.):103 -109
[5] 四川省地质局.1974.1:20万金矿幅区域地质调查报告.90~105.
[6] 四川省地质局西昌地质队.1961.冕宁木落稀土矿区地质普查报告.1~81.
[7] Chen W,Liu XY,Zhang Y.2002b.Continuous laser stepwise heating 40 Ar/39 Ar dating technique.Geological Review,48 (Supple.):127-134
[8] 陈文,刘新宇,张思红.2002b.连续激光阶段升温40Ar/39Ar地质年代测定方法研究.地质论评,48(增刊):127-134
[9] Chen W,Sun S,Zhang Y et al.2005.40Ar/39Ar geochronology of the Qiugemingtashi-Huangshan ductile shear zone in East Tianshan,Xinjiang,NW China.Acta Geologica Sinica,79 (6):790 -804
[10] 陈文,孙枢,张彦等.2005.新疆东天山秋格明塔什-黄山韧性剪切带40Ar/39Ar年代学研究.地质学报,79(6):790-804
[11] 骆耀南.1995.中国攀枝花-西昌古裂谷带.见:张云湘主编.中国攀西裂谷文集.北京:地质出版社.1-25
[12] Chen W,Zhang Y,Ji Q et al.2002c.The magmatism and deformation times of the Xidatan rock series,East Kunlun Mountain.Science in China (Series B),45 (Supple.):20 -27
[13] Ludwig KR.2001. Isoplot/Ex,rev.2.49:A Geochronological Toolkit for Microsoft Excel.Berkeley Geochronological Center,Special Publication,1:a
[14] 骆耀南,俞如龙.2001.龙门山-锦屏山陆内造山带喜马拉雅期构造-岩浆作用主要特征及其动力学模式.见:陈毓川,王登红主编.喜马拉雅期内生成矿作用研究.北京:地震出版社.88-95
[15] Luo YN.1985. Panzhihua-Xichang paleo-rift zone,China.In:Zhang YX (Ed.).Contribution to Panzhihua-Xichang rift,China.Beijing:Geological Publishing House.1 -25 (in Chinese with English abstract)
[16] 蒲广平.2001.攀西地区稀土成矿历史演化与喜马拉雅期成矿基本特征.见:陈毓川,王登红主编.喜马拉雅期内生成矿作用研究.北京:地震出版社.104-116
[17] Luo YN and Yu RL.2001. Major features and dynamic model of the Himalayan tectonic-magmatism in the intracontinental orogenic belt in Longmenshan-Jingpingshan,Sichuan Province.In:Chen Yuchuan and Wang Denghong (Eds.).Study on Himalayan Endogenic Minealization.Beijing:Seismological Press.88-96(in Chinese with English abstract)
[18] 施泽民.1993.牦牛坪喜马拉雅期稀土矿床的厘定及其意义.四川地质学报,13(3):247-254
[19] 田世洪.2005.青藏高原东缘喜马拉雅期冕西稀土成矿带地质地球化学特征及其成矿动力学研究.中国地质科学院博士论文,1-131
[20] Pu GP.2001. The evolution history of rare earth elements mineralization and major features of Himalayan REE deposits in the PanzhihuaXichang area,Sichuan.In:Chen Yuchuan and Wang Denghong (Eds.).Study on Himalayan Endogenic Minealization.Beijing:Seismological Press.104 -116 (in Chinese with English abstract)
[21] 田世洪,张桂兰,侯增谦等.2005.四川冕宁木落寨稀土矿床稳定同位素研究及其意义.矿床地质,24(6):647-655
[22] Shi ZM.1993. Age conjecture and meaning of Himalayan REE deposit in Maoniuping.Sichuan Geology Acta,13 (3):247-254 (in Chinese with English abstract)
[23] 田世洪,袁忠信,张桂兰等.2006.四川木落寨稀土矿床与成矿有关的花岗岩问题及其意义.岩石矿物学杂志,25(2):110-118
[24] Steiger RH.and Jager E.1977. Subcommission on geochronology:convention on the use of decay constants in geo-and cosmochronology.Earth Planet.Sci.Lett.,36:359 -362
[25] Tian SH.2005. The Himalayan Mianxi REE belt on the eastern margin of the Tibetan plateau:geology,geochemistry and geodynamics of the Mineralization,unpub.Ph.D dissertation.Institute of Mineral Resource,CAGS,Beijing,1 -131
[26] 王登红,陈毓川,徐珏等.2005.中国新生代成矿作用(上).北京:地质出版社.350-351
[27] Tian SH,Zhang GL,Hou ZQ et al.2005. Stable isotope data from Muluozhai REE deposit in Mianning County,Sichuan Province,and their geological implications.Mineral Deposits,24 (6):647-655(in Chinese with English abstract)
[28] 袁忠信,白鸽,丁孝石等.1993.四川冕宁牦牛坪碱性花岗岩锆石U-Pb同位素年龄及其地质意义.矿床地质,12(2):189-192,147
[29] Tian SH,Yuan ZX,Zhang GL et al.2006. Discussion on ore-formingrelated granite in the Muluozhai REE deposit,Sichuan Province and their significance.Acta Petrologica et Mineralogica,25 (2):110 -118 (in Chinese with English abstract)
[30] 袁忠信,施泽民,白鸽等.1995.四川冕宁牦牛坪轻稀土矿床.北京:地震出版社.19-22,39-41
[31] Wang DH,Chen YC,Xu J et al.2005. Cenozoic mineralization in China.Beijing:Geological Publishing House.350-351(in Chinese with English abstract)
[32] Yuan ZX,Bai G,Ding XS et al.1993. U-Pb isotopic age of zircon from the Maoniuping alkali granite,Sichuan Province and its geological significance.Mineral Deposits,12 (2):189-192,147 (in Chinese with English abstract)
[33] Yuan ZX,Shi ZM,Bai G et al.1995. The Maoniuping rare earth ore deposit,Mianning County,Sichuan Province.Beijing:Seismological Press.19-22,39-41 (in Chinese with English abstract)
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