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Trace Element and Nd-Sr Isotopic Composition of Lamprophyres from the Ditrau Alkaline Massif, Romania
- Article from:
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Geolines
- Article date:
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January 1, 2006
- Author:
- Batki, AnikÃ; ³; ; PÃ; ¡; l-MÃ; ³; lnÃ; ¡; r, ElemÃ; ©; r
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Copyright informationCopyright Institute of Geology 2006. Provided by ProQuest LLC. (Hide copyright information)
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Lamprophyres are a group of alkali-rich igneous rocks containing essential amphibole and/or biotite-phlogophite and form subvolcanic dykes, sills, plugs, stocks, vents or margins to larger intrusions (Rock 1991 ). Alkaline lamprophyres (AL) have 'basanitic to nephelinitic'compositions, low-Si (41-43% SiO^sub 2^), high-Na (3-4% Na^sub 2^O) content and usually Na » K. Calc-alkaline lamprophyres (CAL) are 'shoshonitic' in composition and have high-Si (49-52% SiO^sub 2^) and high-K (2-5% K^sub 2^O) among lamprophyres. Both of them are rich in Sr, Rb, Ba, Th, Zr, LREE and volatiles (Rock 1991). This paper presents trace element, rare-earth element and radiogenic isotope data, and discusses ...