Carbonatites and related rocks at Saltpetre Kop, Sutherland, Cape Province

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Authors:De Wet, J. J.
Volume Title:Annale - Universiteit van Stellenbosch, Serie A1, Geologie
Source:Annale - Universiteit van Stellenbosch, Serie A1, Geologie, Vol.1, p.193-232. Publisher: Universiteit van Stellenbosch, Bibliotekaris, Stellenbosch, South Africa. ISSN: 1013-218X
Publication Date:1975
Note:In English. 55 refs. Geol. map; illus. incl. tables
Summary:A group of extrusive and intrusive South African rocks post-dating Karoo dolerite is described. They include pyroclastic rocks, K-trachyte, carbonatite, biotite-metacarbonatite, and olivine melilitite. Their relative ages and possible relationship are discussed. All these rocks correspond in their content of Ba, Sr, Nb, RE, and Ti. The initial stage in the evolution of the Saltpetre Kop volcano is considered to have been the updoming of the country rocks as the result of gas P. The release of P occurred explosively through perforations in the deformed strata. The breccias were subsequently invaded by carbonatite and K-trachyte. The carbonatite is considered to have resulted from slow differentiation of an alkali peridotite magma, olivine melilitite being generated by equilibration and fractional crystallization under crustal conditions, and K-trachyte probably by mobilization of feldspathic breccia or fenite. A complete analysis (with norms) of an uncontaminated trachyte is presented. [P.Br.]
Subjects:Carbonatites; Cenozoic; Extrusive rocks; Geochemistry; Geologic maps; Igneous rocks; Intrusions; Maps; Mesozoic; Mineralogy; Petrology; Trace elements; Volcanic rocks; Africa; Cape Province region; South Africa; Southern Africa; Sutherland South Africa; Cape Province South Africa; Evolution; Saltpetre Kop; Geologic map
Coordinates:S323800 S321000 E0210500 E0204000
Abstract Numbers:82M/4787
Record ID:1978004650
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
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