Petrogenesis of anomalous K-enriched MORB from the Southwest Indian Ridge: 11 degrees 53 minutes E to 14 degrees 38 minutes E
Article Abstract:
Alkaline, moderately nepheline normative and potassium-enriched basalt samples were dredged from the Southwest Indian Ridge. The basalt came from fairly primitive lavas but contained incompatible elements at high concentrations. A model describing the petrogenesis of the samples was constructed by mutual correlation of incompatible elements and analysis of the strontium, neodymium and lead isotopic ratios. Another model accounting for the variation in composition of the samples was constructed with the assumption that partial melts were mixed during rock formation.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1992
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Rb-Sr age determinations of rocks from the okenyenya igneous complex, northwestern Namibia
Article Abstract:
Radiogenic isotopic dating studies have been applied to the Okenyenya igneous complex in Damaraland, Namibia, to find the Rb-Sr age of the intrusive phases, and to determine whether there is any difference in ages between different phases. The isochronic ages range from 128 to 123 Ma for the major phases. The outer rings consist of theoleitic gabbros and the central hills consist of alkali gabbros, showing that alkali gabbros are younger. This cannot be assessed in terms of Rb-Sr ages.
Publication Name: Geological Magazine
Subject: Earth sciences
ISSN: 0016-7568
Year: 1993
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Phyllosilicates in hydrothermally altered basalts from DSDP Hole 504B, Leg 83- a TEM and AEM study
Article Abstract:
A study was conducted to examine phyllosilicates in hydrothermally altered basalts from DSDP Hole 504B Leg 83. The study applies transmission and analytical electron microscopy to evaluate these silicattes as replacements of olivine, clinopyroxene and interstitial materials and as veins for basalts. Results show that silicate parageneses varysystematically with depth and with alteration level.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1992
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