No description available.

Thesis (M. Sc.)--University of Sydney, 2009. / Includes graphs and tables. Submitted in fulfilment of the requirements for the degree of Master of Science to the School of Geosciences in the Faculty of Sciences. Title from title screen (viewed May 5, 2009) Degree awarded 2009; thesis submitted 2008. Includes bibliographical references. Also available in print form.

Thesis (Ph. D.)--Université de Nantes, 1970. / On cover: "Travaux du Laboratoire de geologie marine, Faculté des sciences de Nantes, 1970." At head of title: N ̊C.N.R.S.A.O. 48-52. Includes bibliographical references (p. 107-122).

Thesis (Doctoral)--University de Nante, 1986. / Abstract also in English. Includes bibliographical references (leaves 183-189).

Thesis (Ph. D.)--North Carolina State University, 1985. / Vita. Includes bibliographical references (p. 66-67).

Bibliography: pages 131-139. / The construction of bridge embankments and other physical obstacles in estuaries has often resulted in the redistribution of sediments, which ultimately leads to detrimental impacts in these environments. The aim of this study is to investigate how the sediment distribution and dynamics within a specific estuary, the Uilkraals estuary, have been affected by human disturbance; focusing on the impacts arising from construction of two temporary embankments and a permanent bridge and embankment. The Uilkraals estuary is situated in the south-western Cape, approximately 60 kilometres north-west of Cape Agulhas. Human impact has been extensive and engineering projects of various sizes and permanence have marked the recent history of this estuary. A bridge and embankment which cross the estuary 800 m from the mouth were built in 1973. In 1978 an embankment was built between the bridge and the estuary mouth. A second embankment which replaced the first in 1980, was removed before the end of that year. Extensive dune reclamation occurred on the left bank between 1938 and 1973. The techniques used in the study include: (i) a quantitative analysis of all available aerial photographs from 1938 to 1987 (ii) a ground survey and (iii) core and surface sediment sampling. The quantitative analysis reveals that the major changes in estuarine characteristics have been in response to human disturbance. The contour map and cross-sections drawn from the ground survey indicate a build-up of sediment downstream of the bridge and scouring of the channel upstream. The latter suggests the dominance of the flood-tidal current in the estuary. The core sediment analyses are unable to distinguish any real difference in the modes of sediment deposition on either side of the bridge embankment. The embankment has, however, affected deposition by acting as a "hydraulic shelter" to sediment accumulated downstream of the bridge during high run-off events and by initiating deposition of sediment upstream of the embankment. The surface sample analyses indicate that there has been an increase in flow velocities in the vicinity of the bridge since its construction and that the major agents which bring marine sediment into the estuary are flood-tidal currents and wind. It is concluded that the sediment distribution and dynamics of the Uilkraals estuary have been affected by human disturbance. Recommendations for future management of the estuary are that no further embankments should be constructed in the estuary and that the construction of a culvert or culverts under the existing bridge embankment would alleviate a number of problems presently experienced in the estuary.

No description available.

No description available.

Thesis (M.S.)--University of California, Santa Cruz, 2001. / Typescript. Includes bibliographical references (leaves 69-72).

This research involved the study of sediment cores from Loch Etive, Loch Long, Loch Goil and Loch Fyne with the aims of investigating the geochemistry of natural, and manmade radionuclides and heavy metals within the sea loch environment. The main aims of the research were to determine accumulation rates and the extent of mixing within these sediments and to assess the fluxes, sources and temporal variations in input of pollutant heavy metals to these environments. In recent years it has been suggested that Pb is mobile in sea loch sediments which questions the validity of applying ²¹⁰Pb dating in this environment. This has important implications with respect to interpreting sediment cores to assess temporal trends of pollutant inputs and investigating the rates of physical and biogeochemical processes that are taking place in the coastal environment. Hence, one of the aims of this research was to determine whether Pb was mobile in these sediments. The ²⁰⁶Pb/²⁰⁷Pb isotope ratio can potentially be used to determine the extent of pollutant Pb input from leaded petrol to the environment and a further objective of the work was to investigate the isotopic signature of pollutant Pb in the sediment. Concentration of ²¹⁰Pb, ²²⁶Ra, ²²⁸Ra, ²²⁸Th, ²³⁸U, ¹³⁷Cs, ¹³⁴Cs and ²⁴¹Am in the sediments were analysed using gamm a spectroscopy and the heavy metals, Pb, Zn and Cu were determined using X-ray Fluorescence. Stable Pb isotope ratios were determined using Inductively coupled plasma Mass spectrometry. The results obtained indicated that Pb is not subject to diagenetic mobility in these sediments and that ²¹⁰Pb profiles can be used to determine sedimentation rates for most of the sediment cores. lt was not possible to determine accumulation rates for the two cores from Loch Fyne by ²¹⁰Pb dating, and in this case the sedimentation rate was assessed by correlating the maximum concentration of ¹³⁷Cs in the sediments with the maximum ¹³⁷Cs discharge from Sellafield, BNFL's reprocessing plant located on the Cumbrian coast. The flux of ²¹⁰Pb to the lochs varied significantly suggesting that there has been sediment focusing of fine and/or organic rich material to the deeper sites, resulting in an enhanced flux of ²¹⁰Pb to these sediments. Sellafield waste radionuclides also provided useful chronologies by relating sediment maximum concentrations to maxima in the discharges. ¹³⁷Cs was observed to be subject to diffusive movement, invalidating the use of its total depth of penetration as a chronological indicator. The temporal trends of pollutant metal input agreed well with known historical trends and the Pb isotope profiles indicated that the onset of deposition from pollutant Pb from petrol occurred in the late 1920's. The maximum input of Pb from petrol peaked in the early 1980's and since then there has been a decrease in this input. The two sea lochs which were closest to the industrial centre of Glasgow exhibited a large anthropogenic pollutant input, confirming that these sediments have been highly perturbed by human activities, either directly as a result of sludge dumping or due to changes in land use (eg. road construction, deforestation, etc.) in the catchment. All the sea lochs reflected a change in the supply of material to the sediments over the last eighty years, indicating that increased anthropogenic activity has had an effect on these environments.