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The AAPG/Datapages Combined Publications Database

CSPG Special Publications

Abstract


Shelf Sands and Sandstones — Memoir 11, 1986
Pages 332-332
Symposium Abstracts: Tectonic Control

Dynamic Equilibria in the Deposition and Preservation of Shelf Facies: Abstract

Julian Thorne1, Donald J. P. Swift2

Abstract

The deposition and preservation of facies in sedimentary basins is controlled by four general factors: 1. the form of the basin subsidence due to tectonic and eustatic factors; 2. the rate of sediment supply; 3. the type of input source material; and 4. dispersive factors such as wave and tidal energy. We have quantitatively investigated the interrelationship of these factors with a two-dimensional numerical model of basin formation and sedimentation. In this preliminary work, we describe a simple model for sediment dispersion on a storm-dominated shelf. Waves and bottom currents are treated as random variables, producing a dominantly longshore advective transport and a net offshore diffusive transport dependent on water depth, grain size, substrate type, and wind fetch. We have found that the shelf morphology will stabilize under a wide range of input parameters that, characteristically, group into two modes: shelves dominated by allochthonous sedimentation (fluvial source) and those dominated by autochthonous sedimentation (coastal erosion source). Our model indicates, however, that under certain conditions a series of clinoforms can prograde indefinitely, resulting in an ever-widening shelf.


 

Acknowledgments and Associated Footnotes

1 Lamont-Doherty Geological Universities, Palisades, New York 10964

2 ARCO Oil and Gas Company, Box 2819, Dallas, Texas 75221, U.S.A.; present address: Department of Oceanography, Old Dominion University, 1054 W.47th Street, Norfolk, Virginia 23508, U.S.A.

Copyright © 2008 by the Canadian Society of Petroleum Geologists