The 9 km thick Lower Old Red Sandstone succession of the northern part of the Midland Valley Basin, Scotland, ranges from Wenlock to Emsian in age and largely comprises conglomerates in the east passing westwards into sandstones and siltstones. Previously, the depositional and tectonic setting of the basin has been poorly constrained, as has the relationship between sediments of the northern Midland Valley and the Grampian outliers at Aberdeen, Rhynie, Cabrach, Tomintoul and New Aberdour. This study focuses on establishing the stratigraphic framework of the areas and outlining the key controls and source of sedimentation during deposition of the Lower Old Red Sandstone, placing the geological history within the larger Caledonian framework. Sedimentological investigation alongside petrographical point count, heavy mineral and detrital zircon analysis allows the reconstruction of a large distributive fluvial system sourced from the NE within the Caledonian foreland, within which the Lower Old Red Sandstone of the northern Midland Valley Basin was deposited. Sedimentation was continuous across the line of the Highland Boundary Fault. Sedimentation within the Grampian outliers was locally influenced, however facies association development is comparable with the base of the laterally time-equivalent northern Midland Valley Basin stratigraphy. Sedimentary provenance analysis indicates a similar source terrane for the sediments of both areas, with detrital zircon age spectra comparable to those of the Dalradian Supergroup and localised contemporaneous volcanism, with conglomerate clast-size indicating a proximal source. Sedimentation of the Lower Old Red Sandstone of the northern Midland Valley Basin and Grampian outliers is thus attributed to Siluro-Devonian basement uplift in the Caledonian foreland driven by thick-skinned tectonics.

Thesis (M.S.)--University of Nevada, Reno, 2005. / "December, 2005." Includes bibliographical references (leaves 103-112). Online version available on the World Wide Web.

Thesis (D. Sc.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1983. / "Funding was provided by the American Gas Association Project no. PR-153-126, the National Science Fundation under grant OCE-8014930, and NOAA-Sea Grant NA-79AA-D-00101 ; NA 79AA-D-00102." Includes bibliographical references (p. 201-205).

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1983. / Supervised by William D. Grant. Includes bibliographical references (leaves 201-205).

When a semi-infinite body of homogeneous fluid initially at rest behind a vertical retaining wall is suddenly released by the removal of the barrier the resulting flow over a horizontal or sloping bed is referred to as a dam-break flow. When resistance to the flow is neglected the exact solution, in the case of a stable horizontal bed with or without `tail water', may be obtained on the basis of shallow-water theory via the method of characteristics and the results are well known. Discrepancies between these shallow-water based solutions and experiments have been partially accounted for by the introduction of flow resistance in the form of basal friction. This added friction significantly modifies the wave speed and flow profile near the head of the wave so that the simple exact solutions no longer apply and various asymptotic or numerical approaches must be implemented to solve these frictionally modified depth-averaged shallow-water equations. When the bed is no longer stable so that solid particles may be exchanged between the bed and the water column the dynamics of the flow becomes highly complex as the buoyancy forces vary in space and time according to the competing rates of erosion and deposition. Furthermore, when the Froude number of the flow is close to unity perturbations in the height and velocity profiles grow into N-waves and the bed below develops ripples which act to sustain the N-waves in the fluid above. It is our intention here to study dam-break flows over erodible sloping beds as agents of sediment transport taking into account basal friction as well as the effects of particle concentrations on flow dynamics including both erosion and deposition. We shall consider shallow flows over initially dry beds and investigate the effects of changes in the depositional and erosional models employed as well as in the nature of the drag acting on the flow and the slope of the bed. These models include effects hitherto neglected in such studies and offer insights into the transport of sediment in the worst case scenario of the complete and instantaneous collapse of a dam. / Mathematics

When a semi-infinite body of homogeneous fluid initially at rest behind a vertical retaining wall is suddenly released by the removal of the barrier the resulting flow over a horizontal or sloping bed is referred to as a dam-break flow. When resistance to the flow is neglected the exact solution, in the case of a stable horizontal bed with or without `tail water', may be obtained on the basis of shallow-water theory via the method of characteristics and the results are well known. Discrepancies between these shallow-water based solutions and experiments have been partially accounted for by the introduction of flow resistance in the form of basal friction. This added friction significantly modifies the wave speed and flow profile near the head of the wave so that the simple exact solutions no longer apply and various asymptotic or numerical approaches must be implemented to solve these frictionally modified depth-averaged shallow-water equations. When the bed is no longer stable so that solid particles may be exchanged between the bed and the water column the dynamics of the flow becomes highly complex as the buoyancy forces vary in space and time according to the competing rates of erosion and deposition. Furthermore, when the Froude number of the flow is close to unity perturbations in the height and velocity profiles grow into N-waves and the bed below develops ripples which act to sustain the N-waves in the fluid above. It is our intention here to study dam-break flows over erodible sloping beds as agents of sediment transport taking into account basal friction as well as the effects of particle concentrations on flow dynamics including both erosion and deposition. We shall consider shallow flows over initially dry beds and investigate the effects of changes in the depositional and erosional models employed as well as in the nature of the drag acting on the flow and the slope of the bed. These models include effects hitherto neglected in such studies and offer insights into the transport of sediment in the worst case scenario of the complete and instantaneous collapse of a dam. / Mathematics

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: James T. Kirby, Dept. of Civil & Environmental Engineering. Includes bibliographical references.

Thesis (M.S.)--University of North Carolina at Wilmington, 2006. / Vita. Includes bibliographical references (leaves: 60-63)

Dams have altered flow distributions in rivers everywhere, causing a host of changes in channel morphology and sediment dynamics. Although major changes in flow regime have occurred along Yegua Creek, Texas, since the closure of Somerville Dam in 1967, the issue of sediment transport has not been studied in detail. The extent to which sediment is moving through the system remains unclear. This study addresses the extent to which sediment is moving through and downstream of the dam. Analysis of sediment samples collected at 23 sites in the Yegua Creek channel system showed that coarse sand to silt-sized materials dominate the creek upstream of the dam, whereas finer silt and clay sediments characterize the downstream portions. Calculation of the trapping efficiency of the dam indicates that approximately 99.8% of materials from the upper watershed are trapped behind Somerville Dam. Investigations of sediment mobility further suggest that present flows are capable of mobilizing sediments downstream of the dam. Although a de-coupling between the upper and lower portions of the Yegua Creek watershed has likely occurred due to the high rate of sediment trapping, new sediment sources that include tributaries and alluvial storage likely play a larger role in providing materials for sediment transport downstream. Despite a reuction in peak flows, the channel morphology of Yegua Creek has apparently adjusted over the four decades since construction of Somerville Dam to achieve a new equilibrium characterized by sediment movement. These results are corroborated by analysis of aerial photographs. These findings augment our understanding of the many facets of the response of fluvial systems to the disturbance posed by dam construction. Because Yegua Creek is a major tributary to the Brazos River draining to the Texas coast, increased understanding of sediment dynamics within Yegua Creek provides critical insights into the efficacy of sediment delivery in a regional context, and ultimately to the Texas coastline. The findings of this study also provide useful information for managing stream ecosystems affected by impoundments.

Thesis (M.C.E.)--University of Delaware, 2009. / Principal faculty advisor: Jack A. Puleo, Dept. of Civil & Environmental Engineer. Includes bibliographical references.