 | | 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 |  | CURTIS, C. G., TRUMBULL, R. B., DE BEER, C. H., HARRIS, C., REID, D. L., ROMER, R. L. (2011) GEOCHEMISTRY OF THE EARLY CRETACEOUS KOEGEL FONTEIN ANOROGENIC IGNEOUS COMPLEX, SOUTH AFRICA. South African Journal of Geology, 114 (3) 353-378 doi:10.2113/gssajg.114.3-4.353 | Journal (article/letter/editorial) | | EARLY CRETACEOUS KOEGEL FONTEIN ANOROGENIC IGNEOUS COMPLEX, SOUTH AFRICA C.G. CURTIS Department of Geological...South Africa ABSTRACT The Koegel Fontein Igneous Complex in the Western Cape Province of South Africa is...first geochemical study of the Koegel Fontein Complex. Two groups of mafic units are distinguished based...along the continental margin occur in and near the complex. These regional dolerites are much more homogeneous...magmas makes up the bulk of the Koegel Fontein complex, with the large Rietpoort granite pluton and quartz-porphyry |  | | 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 (article/letter/editorial) | | lamprophyre dyke from the Okenyenya igneous complex, northwestern Namibia. Mica separates were heat-treated...lamprophyre dike from the Okenyenya igneous complex, northwestern Namibia (Lanyon and le Roex 1995)....and very rare alkali feldspar and zeolite. The Okenyenya ultramafic lamprophyres are interpreted to represent...synthetic basalt for Na, Ca, Mg, Al, Fe, and Si, orthoclase for K; NBS synthetic glass for Ti; diopside for...1 except TABLE 1. Chemical Analysis (wt%) of Okenyenya (OKJ) and OLA 9037 phlogopites SiO2 TiO2 Al2O3 |  | | 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...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... The circumstances behind this transition are complex. The field evidence may be summarized as follows: |
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