 | | Journal (article/letter/editorial) | | and Okenyenyaigneous complexes, north-western Namibia Received: 10 August 1993/Accepted: 15 January...units of the Brandberg and Okenyenya igneous complexes, northwestern Namibia, confirm the Early Cretaceous...rocks of Okenyenya, 133.3 _+ 1.4 to 129.2 _+ 0.7 Ma. The mean K - A r age of the Okenyenya complex is essentially...dating of this complex (129.1-123.4Ma). K - A r chronology for the Brandberg complex is in conflict with...layered intrusion yields the oldest age from the complex, 135.2 4- 1.4 Ma. The concordancy of age measurements |  | | Journal (article/letter/editorial) | | extensive crustal contamination in the Okenyenya igneous complex, Namibia I13MA A. MARTINEZ,J CHRIS HARRIS...Energy, Geological Survey, P.O. Box 2168, Windhoek, Namibia (Received August 9, 1995; accepted in revised...rock types from the 130 Ma Okenyenya igneous complex of northwestern Namibia. These rock types include...monzodioritic body was the earliest to crystallize in the complex and this was followed by relatively uncontaminated...contamination so that uncontaminated rock types in the complex can be identified and their strontium, neodymium |  | | Journal (article/letter/editorial) | | Damaraland Lamprophyres and Carbonatites, Northwestern Namibia: Evidence for Plume–Lithosphere Interactions ANTON...igneous complexes in Damaraland, northwestern Namibia. Lamprophyres, emplaced as late-stage dykes, stocks...WORDS: geochemistry; lamprophyre carbonatite; Namibia; Tristan plume ∗Corresponding author. Telephone:+27-21-650-2921...complexes extend through Damaraland in northwestern Namibia (Fig. 1) and provide an example of the contiguous... 1. Simplified geological map of northwestern Namibia, showing the main outcrop regions of the Etendeka |  | | Journal (issue) | | island. The eontribution of Birkenmajer deseribes a region not very familiar in literature. He gives a review...transmission of seismic energy through the tectonically complex overlying section (Fig. 3). 239 100 km Basel...ofIvrea (crossed ruling); CRL = Cremosina line complex, bounding the Ivrea-Ceneri body (narrow horizontal...Helvetic nappes and the External Massifs is similarly complex, yet did not produce a comparable effect, and that...Scientific Party, 1991; Buness, 1992). The border region of the Po plain is problematic. Here, excellent |  | | Book | | simplest way to visualize the chemical composition of complex silicate materials is as a mixture of oxides: silicon...of composition: anorthite bytownite labradorite andesine oligoclase albite An100–An90 (also refers to...NaAlSi3O8). Solid solution in pyroxenes is more complex, so representing the composition of a pyroxene...be ignored. Garnet compositions are still more complex and require six end-members (Box 5.2). Such ‘formula... see Fig. 1.5); the dashed lines delineate the region of overlap between alkali and subalkali basalts |
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