Petrology, geochronology and provenance of the Laingsburg and Tanqua Karoo submarine fan systems, Ecca Group, South Africa

[摘要] The integration of whole-rock chemistry, heavy mineral chemistry, detrital zirconmorphology and age dating has enabled high-resolution characterization of thePermian Laingsburg and Tanqua submarine fan provenance in the Karoo Basin,upper Ecca Group, South Africa.Geochemically, the Laingsburg and Tanqua sandstones are classified asgreywacke and litharenite. The chemical index of alteration values for thesesandstones suggest low to moderately weathered sources and a relatively coldclimate. Abundant angular clastic grains and lithic fragments as well as thepredominance of pristine zircons indicate a near provenance and a first cyclederivation. The investigated sandstones originated from a continental island arcand an active continental margin. The source is dominantly intermediate to felsicand includes tonalites, granodiorites, and adamellites or their volcanicequivalents.

[发布机构] Stellenbosch University