305 Stratigraphy (Posters)
Influence of Rivers, Waves and Tides on Shelf-Edge Delta Architecture and Sand by-Pass to Deep-Water
Paper number: 305-2
Program: Technical Sessions
Time: 8:00 AM – 6:00 PM
Authors
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Ronald SteelUniversity of Texas at Austin, Austin, TX
Abstract
Clinothem 10 shows one large deep-water sand lobe (sandstone volume ~ 53 km3)that correlates to river channel deposits in shelf-edge deltas. These deltas lack a thick wave-dominated sandstone belt at the shelf edge; instead their mouth bar is relatively thin and dominated by flat laminated sandstones (hyperpycnal flows?) that transition to heterolithic, tidally-influenced facies. Fluvial erosion is prominent forming a several 10's kms container, filled by thick fluvial deposits and estuarine strata, which indicate incised valley development and a relative sea level fall. Such incised coastal physiography probably segmented littoral drifts diminishing wave influence, while providing confined areas for tidal amplification and for efficient downslope sand delivery.