地球学报
地毬學報
지구학보
ACTA GEOSCIENTIA SINICA
2010年
1期
73-82
,共10页
王立社%侯俊富%张复新%秦艳%曹红霞%齐亚林%杨鹏飞%金拴联%房波%周燕
王立社%侯俊富%張複新%秦豔%曹紅霞%齊亞林%楊鵬飛%金拴聯%房波%週燕
왕립사%후준부%장복신%진염%조홍하%제아림%양붕비%금전련%방파%주연
庙湾组%黑色岩系%稀土地球化学%干燥缺氧环境%北秦岭
廟灣組%黑色巖繫%稀土地毬化學%榦燥缺氧環境%北秦嶺
묘만조%흑색암계%희토지구화학%간조결양배경%북진령
Miaowan Formation%black rock series%REE geochemistry%dry and anoxic environment%Northern Qinling
笔者采用等离子质谱仪(ICP-MS)方法对北秦岭大荆区奥陶纪-志留纪庙湾组黑色岩系岩石的稀土元素及V、Ni、Cr、U、Th等微量元素含量进行了测定.结果显示岩石轻稀土元素相对重稀土元素富集,Eu异常值δEu为0.63～10.61(绝多数大于1.54)多呈正异常,Ce异常值δCe为0.65～1.02(平均为0.893)异常微弱且有正负差异;U/Th值为0.38～4.07,w(V)/w(V+Ni)值为0.38～0.93以及w(Ce)/w(La)值为1.27～2.17.将这.些特征值与前人研究成果对比,并利用La/Yb-Ce/La和La/Yb-REE判别图解判别后,认为北秦岭区庙湾组黑色岩系形成于活动陆缘一种干燥缺氧较深浅海环境,黑色岩系形成过程中有热液作用参与.
筆者採用等離子質譜儀(ICP-MS)方法對北秦嶺大荊區奧陶紀-誌留紀廟灣組黑色巖繫巖石的稀土元素及V、Ni、Cr、U、Th等微量元素含量進行瞭測定.結果顯示巖石輕稀土元素相對重稀土元素富集,Eu異常值δEu為0.63～10.61(絕多數大于1.54)多呈正異常,Ce異常值δCe為0.65～1.02(平均為0.893)異常微弱且有正負差異;U/Th值為0.38～4.07,w(V)/w(V+Ni)值為0.38～0.93以及w(Ce)/w(La)值為1.27～2.17.將這.些特徵值與前人研究成果對比,併利用La/Yb-Ce/La和La/Yb-REE判彆圖解判彆後,認為北秦嶺區廟灣組黑色巖繫形成于活動陸緣一種榦燥缺氧較深淺海環境,黑色巖繫形成過程中有熱液作用參與.
필자채용등리자질보의(ICP-MS)방법대북진령대형구오도기-지류기묘만조흑색암계암석적희토원소급V、Ni、Cr、U、Th등미량원소함량진행료측정.결과현시암석경희토원소상대중희토원소부집,Eu이상치δEu위0.63～10.61(절다수대우1.54)다정정이상,Ce이상치δCe위0.65～1.02(평균위0.893)이상미약차유정부차이;U/Th치위0.38～4.07,w(V)/w(V+Ni)치위0.38～0.93이급w(Ce)/w(La)치위1.27～2.17.장저.사특정치여전인연구성과대비,병이용La/Yb-Ce/La화La/Yb-REE판별도해판별후,인위북진령구묘만조흑색암계형성우활동륙연일충간조결양교심천해배경,흑색암계형성과정중유열액작용삼여.
The abundances of rare earth elements and some trace elements such as V, Ni, Cr, U and Th of the black rock series from the Miaowan Formation in North Qinling Mountain were measured by using the ICP-MS method.The results show that the black rock series of the Miaowan Formation is usually of the LREE-enriched type, that the samples are characterized by slightly negative or positive Ce anomalies (δCe=0.65～1.02) and distinct positive Eu anomalies (with δEu mostly higher than 1.54), and that the ratios of U/Th display a wide variation range from 0.38 to 4.07, the ratios ofw (V)/w (V +Ni)(=0.38～0.93) are normal, and the ratios ofw (Ce)/w (La) (=1.27～2.17) are relatively high. A study of the parameters of REE and trace elements in comparison with the available data and an analysis of the La/Yb-Ce/La and La/Yb- REE diagrams reveal that the black rock series was formed in a dry, anoxic and shallow sea environment belonging to an active continental margin, with the participation of some hydrothermal fluids.
