Spatial and Temporal Evolution of a Permian Submarine Slope Channel-Levee System, Karoo Basin, South Africa

• DOI: 10.2110/jsr.2011.49
• Publication Date: 2011-07-18T20:52:16Z
• Authors: C. N. Di Celma; R. L. Brunt; D. M. Hodgson; S. S. Flint; J. P. Kavanagh
• Keywords: 15. Life on land; 01 natural sciences; 0105 earth and related environmental sciences

Abstract The Laingsburg depocenter of the SW Karoo Basin, South Africa, includes a series sandstone-dominated deepwater clastic deposits (units A and B Formation Unit C to G overlying Fort Brown Formation) separated vertically by regional mudstones records basin-floor upper-slope deposition during Permian icehouse climate. provides nearly continuous exposures over tens kilometers, presence regionally persistent internal mudstone markers (lower upper mudstones) allows distribution sedimentary facies architectural elements slope-turbidite system be documented for more than 30 km downslope 20 across slope. spatial temporal interpreted depositional environments (external levees, channel belts confined combination basal erosion overbank aggradation along margins, distributive frontal splays) reveals distinct changes in sedimentation pattern stratal architecture turbidite through time. evolved stepwise manner from weakly incised, levee-confined belt its downdip splays (C1), entrenched sinuous channel–levee complex set that fed submarine fans farther into basin (C2), backstepping package thin-bedded distal (C3). is as lowstand sequence set, composed three sequences, each which systems tract (C1, C2, C3) mudstone-prone interval taken represent transgressive highstand tracts. combined marked 30-m-thick C–D interposed between D. together form composite sequence. At scale evolutionary trend C1 C3 reflects an overall basinward then landward stepping profile, product waxing waning flow energy (volume efficiency).