摘要
运用电感耦合等离子体质谱(ICP-MS)、X射线荧光光谱(XRF)、X射线衍射(XRD)、带能谱的扫描电镜(SEM-EDX)等方法对重庆南川晚二叠世凝灰岩的元素地球化学特征进行了研究。研究发现,凝灰岩中富集Al、Ti、Li、Cu、V、Cr、Co、Ni、Nb、Ta、Zr、Hf、Ga、Sc、Th、U和稀土元素(REE),其中Ti、Nb、Ga和REE异常富集,达到了伴生矿产的工业品位,其综合利用价值值得关注。凝灰岩自底部至顶部微量元素含量有明显增加的趋势,稀土元素(REE)在垂向上分异明显,凝灰岩上部富集轻、中稀土,向下逐渐过渡到富集重稀土类型。凝灰岩中元素的组合特征表明其原始物质可能来源于峨眉山玄武岩岩浆,属于基性火山灰成因。
The geochemical features of the Late Permian tuff in Nanchuan District, Chongqing, southwestern China, were studied using the methods of inductively coupled plasma mass spectrometry （ICP-MS）, X-ray fluorescence（XRF）, powder X-ray diffraction （XRD）, A scanning electron microscope equipped with an energy dispersive X-ray spectrometer（SEM-EDX）. The results show that elements including A1, Ti, Li, Cu, V, Cr, Co, Ni, Nb, Ta, Zr, Hf, Ga, Sc, Th, U and REE are enriched, especially the concentrations of Ti, Nb, Ga and REE, which are higher than cut-off grades of national standards of China, respectively. The potential comprehensive utilization of Ti, Nb, Ga and REE should be paid more attention. The concentrations of trace elements increase from the bottom of tuff to the top, and the rare earth elements （REE） in tuff have obviously differentiation, the upper portion of tuff enriched light rare earth elements （LREE） and medium rare earth elements （ MREE ）, while the lower portion enriched heavy rare earth elements （HREE）. The characteristics of elements and its assemblage in the tuff show that the materials of tuff may be originated from Emeishan basalt magma and of the mafic volcanic origin.
出处
《地质论评》
CAS
CSCD
北大核心
2014年第1期169-177,共9页
Geological Review
基金
国家973课题(编号2014CB238902)
国家自然科学基金资助项目(编号40930420和41272182)的成果
关键词
凝灰岩
稀土元素
地球化学
重庆南川
tuff
rare earth element
geochemistry
Nanchuan, Chongqing
