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dc.contributor.advisorKim, Wonsucken
dc.creatorPowell, Erica Janetteen
dc.date.accessioned2011-07-15T15:42:55Zen
dc.date.available2011-07-15T15:42:55Zen
dc.date.issued2011-05en
dc.date.submittedMay 2011en
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2011-05-3010en
dc.descriptiontexten
dc.description.abstractChanges in external forcing having traditionally been the main area of interest in trying to understand paleo-depositional environments in sedimentary systems; however, autogenic variability has been rising in importance, while autogenic behavior has been thought of as a “noise” generator. Recently, autogenic variability has been rising in attention because decoupling allogenic signatures (externally driven) from the stratigraphic record requires robust understanding of autogenic variations (internally generated). This study aims to quantitatively measure autogenic processes under a range of flux conditions and to show that autogenic processes generate distinct signatures rather than random noise. We present data from a matrix of nine different tank experiments in order to systematically evaluate the effects of sediment flux and water discharge variations on the autogenic timescale of fluvial sediment storage and release processes and the implications of this data to the stratigraphic record. The sediment flux tow ater discharge ratio and the absolute values of these two discharges control the autogenic timescale. Variations in sediment supply yield two competing effects on the autogenic timescale. The primary sediment flux control causes a reduction in the autogenic timescale as an increase in sediment supply yields an increased rate of filling the “fluvial envelope” (the space between the maximum and minimum fluvial slopes obtained during storage and release events). In contrast, the secondary sediment flux control increases the size of the fluvial envelope and works against the primary sediment flux control. Increasing the water discharge increases the autogenic timescale by widening the fluvial envelope during the organization of the fluvial system and more importantly, diminishes the functionality of the secondary sediment control. A competition exists between these factors, causing a non-linear range of autogenic timescales for a given sediment flux to water discharge ratio. In the nine experiments here, as the ratio decreases, the secondary effects of variations in sediment supply are suppressed by the relatively high water discharge, and the timescale is more predictable using the primary sediment control. As the ratio increases, the secondary effects from sediment supply are enhanced by a poorly organized fluvial system, and the timescale converges to a narrow range. This suggests significant implications for autogenic sediment delivery and stratigraphic development in a wide range of discharge conditions in field cases.en
dc.format.mimetypeapplication/pdfen
dc.language.isoengen
dc.subjectAutogenicen
dc.subjectFluvial-deltaicen
dc.subjectSediment fluxen
dc.subjectWater dischargeen
dc.subjectFluvial envelopeen
dc.subjectTank experimenten
dc.subjectTimescaleen
dc.titleVarying flux controls on timescales of autogenic storage and release processes in fluvio-deltaic environments : tank experimentsen
dc.date.updated2011-07-15T15:43:06Zen
dc.identifier.slug2152/ETD-UT-2011-05-3010en
dc.contributor.committeeMemberSteel, Ronalden
dc.contributor.committeeMemberMohrig, Daviden
dc.description.departmentGeological Sciencesen
dc.type.genrethesisen
thesis.degree.departmentGeological Sciencesen
thesis.degree.disciplineGeological Sciencesen
thesis.degree.grantorUniversity of Texas at Austinen
thesis.degree.levelMastersen
thesis.degree.nameMaster of Science in Geological Sciencesen


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