ALLUVIAL FACIES DISTRIBUTIONS IN CONTINENTAL SEDIMENTARY BASINS—DISTRIBUTIVE FLUVIAL SYSTEMS

Gary Weissmann, Adrian Hartley, Gary Nichols

Research output: Chapter in Book/Report/Conference proceedingChapter (peer-reviewed)

Abstract

Fluvial depositional patterns in modern continental sedimentary basins from different tectonic settings are dominated by distributive fluvial
systems (DFSs). A review of satellite imagery from over 700 modern continental sedimentary basins from different tectonic and climatic settings shows
that rivers on DFSs are generally not confined to valleys and have a clear apex from which active and abandoned channelbelts radiate outward to form a
positive topographic feature centered on this apex. Channels have no tributaries on the DFSs and commonly decrease in size downstream on the DFSs
due to bifurcation, infiltration, and evaporation. In contrast, fluvial systems in sedimentary basins that are confined within a valley, such as those held
between adjacent or opposing DFSs, incised into a DFSs, or that lie in an axial position in a basin, typically have less area for floodplain development and
display coarse-grained-dominated facies. These confined rivers appear to be more similar to tributary rivers that are commonly described for present
fluvial facies models. Because sediments deposited in continental sedimentary basins are those that constitute the rock record, this work suggests that
many of the fluvial rocks observed may have formed on DFSs. This strongly suggests the need to develop new facies models that account for processes
on DFSs
Original languageEnglish
Title of host publicationRiver To Rock Record: The Preservation Of Fluvial Sediments And Their Subsequent Interpretation
EditorsStephanie Davidson, Sophie Leleu, Colin North
PublisherSEPM (Society for Sedimentary Geology)
Pages327–355
Volume79
ISBN (Print)978-1-56576-305-0
Publication statusPublished - 2011

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