Abstract:
The integration of whole-rock chemistry, heavy mineral chemistry, detrital zircon
morphology and age dating has enabled high-resolution characterization of the
Permian Laingsburg and Tanqua submarine fan provenance in the Karoo Basin,
upper Ecca Group, South Africa.
Geochemically, the Laingsburg and Tanqua sandstones are classified as
greywacke and litharenite. The chemical index of alteration values for these
sandstones suggest low to moderately weathered sources and a relatively cold
climate. Abundant angular clastic grains and lithic fragments as well as the
predominance of pristine zircons indicate a near provenance and a first cycle
derivation. The investigated sandstones originated from a continental island arc
and an active continental margin. The source is dominantly intermediate to felsic
and includes tonalites, granodiorites, and adamellites or their volcanic
equivalents.
