Submarine Fan Through Slope to Deltaic Transition Basin-Fill Succession, Tanqua Karoo, South Africa
Grant D. Wach, Theodore C. Lukas, Robert K. Goldhammer, H. Deville Wickens, A. H. Bouma, 2000. "Submarine Fan Through Slope to Deltaic Transition Basin-Fill Succession, Tanqua Karoo, South Africa", Fine-Grained Turbidite Systems, Arnold H. Bouma, Charles G. Stone
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Superb sections of submarine fan deposits within the Late Permian Ecca Group are exposed within the Tanqua Karoo basin. Five discrete fan systems are capped by shales and deltaic deposits of the Kookfontein and equivalent Koedoesberg formations. Progradation of the deltaic deposits across the basin was in response to a decrease in accommodation space created by relatively high rates of sedimentation within the foreland basin setting. Evidence for the transition from submarine fans to deltaic deposition has been enigmatic, with limited evidence of sediments representative of slope deposition.
The sedimentology and sequence stratigraphy of the Hangklip Fan represents a slope fan and channel complex that shallows up into deltaic deposits, coincident with decresing accomodation space. Erosional slump scars, cutting into laminated shale with chaotic infill of sand intraclasts, point toward slope depositional processes that are not in evidence in the underlying submarine fan deposits. Wave ripples and the trace fossil Gyrochorte suggest substantially shallower depositional conditions than either the submarine fan or slope fan deposits, which are devoid of such features.