- Title
- The geochemistry and evolution of Palaeogene phonolites, central Namibia:
- Creator
- Marsh, Julian S
- Date
- 2010
- Type
- text
- Type
- article
- Identifier
- http://hdl.handle.net/10962/145000
- Identifier
- vital:38399
- Identifier
- https://doi.org/10.1016/j.lithos.2010.02.012
- Description
- Phonolites of Palaeogene age occur at two different localities in central Namibia, occurring as clusters of eroded monogenetic lava domes. Six phonolites at Aris collectively exhibit a narrow compositional range and represent a single magma system of highly evolved phonolite with high concentrations of Na2O, Rb, Th, Zr, Zn, Pb, and REE and very low abundances of MgO, P2O5, Sr and Ba. No mafic rocks are associated with the Aris phonolites and their ultimate petrogenetic origin remains obscure. The more abundant Staalhart phonolites exhibit more variable but scattered compositional variation consistent with fractional crystallization dominated by sanidine (and nepheline) and pyroxene. The behaviour of REE is decoupled from Zr, Nb, and Th in this suite indicating a controlling role for minor phases in their evolution. The least evolved phonolites have initial 87Sr/86Sr 0.7043, which is identical to a small occurrence of associated plagioclase-bearing nephelinite indicating a possible petrogenetic link.
- Format
- 12 pages, pdf
- Language
- English
- Relation
- Lithos, Marsh, J.S., 2010. The geochemistry and evolution of Palaeogene phonolites, central Namibia. Lithos, 117(1-4), pp.149-160., Lithos volume 117 number 1-4 149 160 June 2010 1872-6143
- Rights
- Publisher
- Rights
- Use of this resource is governed by the terms and conditions of the Elsevier Terms and Conditions Statement (https://www.elsevier.com/legal/elsevier-website-terms-and-conditions)
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Marsh, Julian (Goonie)(Prof)
RU Department of Geology
SDG 13. Climate Action
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