"February 2004" / Includes bibliographical references (leaves 216-227) / Each accompanying profile sheet is named and numbered individually. / xvi, 245 leaves : ill. (some col.), maps (col.), charts ; 30 cm. + 1 location map ( 22 x 30 cm. folded to 22 x 15 cm.) + 4 geologic profiles ( 56 x 100 cm. folded to 20 x 29 cm.) ; in pocket inside back cover. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Earth and Environmental Sciences, Discipline of Geology and Geophysics, 2004

High rates of soil loss and high sediment loads in rivers necessitate efficient monitoring and quantification methodologies so that effective land management strategies can be designed. Constructing a sediment budget is a useful approach to address these issues. Quantifying a sediment budget using classical field-based techniques, however, is labour intensive and expensive for poorly gauged, large drainage basins. The availability of global environmental datasets in combination with GIS techniques provides an opportunity for studying large basins. Following this approach, a framework is presented for constructing sediment budgets for large, data-sparse drainage basins, which is applied to the mountainous upper Indus River basin in northern Pakistan. The methodological framework consists of five steps: (1) analyzing hydro-climatological data for dividing the drainage basin into characteristic regions, and calculating sediment yields; (2) investigation of major controls on sediment yields; (3) identification and mapping of sediment source areas by spatially distributed modelling of erosional processes; (4) spatially distributed modelling of sediment yields; and (5) carrying out the sediment budget balance calculation at the basin outlet. Further analysis carried out on the Indus data has enabled a better understanding of sediment dynamics in the basin.<p> Analysis of the available hydro-climatological data indicates that the basin can be subdivided into three characteristic regions based on whether runoff production and subsequent sediment generation is controlled by temperature (Region 1, upper, glacierized sub-basins), precipitation caused by the monsoon and western disturbances (Region 3, lower sub-basins), or a combination of the two (Region 2, middle reach sub-basins). It is also demonstrated that contrary to the conventional model, the specific sediment yield increases markedly with drainage area along the Indus River. An investigation of major controls on specific sediment yield in the basin indicates that percent snow/ice cover is a major land cover control for specific sediment yield. Spatially distributed erosion modelling predictions indicate that 87% of the annual gross erosion takes place in the three summer months with greatest erosion potential concentrated in sub-basins with high relief and a substantial proportion of glacierized area. Lower erosion rates can be explained by the arid climate and low relief on the Tibetan Plateau, and by the dense vegetation and lower relief in the lower monsoon sub-region. The model predicts an average annual erosion rate of 3.2 mm/a or 868 Mt/a. Spatially distributed sediment yield predictions made with coupled models of erosion and sediment delivery indicate that the Indus sub-basins generally show an increase of sediment delivery ratio with basin area. The predicted annual basin sediment yield is 244 Mt/a and the overall sediment delivery ratio in the basin is calculated as 0.28. The long-term mean annual sediment budget, based on mass balance, is characterized by a gross erosion of 762.9, 96.7 and 8.4 Mt, and a gross storage of 551.4, 66.1, and 6.5 Mt in the upper, middle, and lower regions of the basin, respectively. The sediment budget indicates that the major sources of eroded sediment are located in the Karakoram, in particular in the Hunza basin. Substantial sediment storage occurs on the relatively flat Tibetan Plateau and the Indus River valley reach between Partab Bridge and Shatial. The presented framework for sediment budget construction requires relatively few data, mostly derived from global datasets. It therefore can be utilized for other ungauged or poorly gauged drainage basins of the world.

Two new analytical methodologies were developed for chlorine and bromine stable isotope analyses of inorganic samples by Continuous-Flow Isotope Ratio Mass Spectrometry (CF-IRMS) coupled with gas chromatography (GC). Inorganic chloride and bromide were precipitated as silver halides (AgCl and AgBr) and then converted to methyl halide (CH3Cl and CH3Br) gases and analyzed. These new techniques require small samples sizes (1.4 µmol of Cl- and 1 µmol of Br-). The internal precision using pure CH3Cl gas is better than ∓0.04 ‰ (∓STDV) while the external precision using seawater standard is better than ∓0.07 ‰ (∓STDV). The internal precision using pure CH3Br gas is better than ∓0.03 ‰ (∓STDV) and the external precision using seawater standard is better than ∓0.06 ‰ (∓STDV). Moreover, the sample analysis time is much shorter than previous techniques. The analyses times for chlorine and bromine stable isotopes are 16 minutes which are 3-5 times shorter than all previous techniques. Formation waters from three sedimentary settings (the Paleozoic sequences in southern Ontario and Michigan, the Williston Basin and the Siberian Platform) were analyzed for 37Cl and 81Br isotopes. The δ37Cl and δ81Br values of the formation waters from these basins are characterized by large variations (between -1.31 ‰ and +1.82 ‰ relative to SMOC and between -1.50 ‰ and +3.35 ‰ relative to SMOB, respectively). A positive trend between δ81Br and δ37Cl values was found in all basins, where an enrichment of δ81Br is coupled by an enrichment of δ37Cl. In the Paleozoic sequences in southern Ontario and Michigan, the δ37Cl and δ81Br signatures of formation water collected from northwest of the Algonquin Arch are distinct from those collected from southeast of the Arch. All of the brines from the northwest of the Algonquin Arch are characterized by depleted isotopic values in comparison with the isotopic values from the brines from southeast of the Arch. The δ81Br signatures of the two brines show total separation with no overlaps. The δ37Cl values show some overlap between the two groups. One of the scenarios that can be put forward is that the Arch forms a water divide, where sediments southeast of the Arch are dominated by Appalachian Basin formation waters, and the sediments located northwest of the Arch are dominated by the Michigan Basin formation waters. The δ81Br and δ37Cl signatures of the Williston Basin brines suggest the existence of several different brines that are isotopically distinct and located in different stratigraphic units, even though they are chemically similar. The relatively wide range of δ37Cl and δ81Br of the formation waters suggests that the ocean isotopic signatures were variable over geologic time. A seawater temporal curve for δ81Br and δ37Cl was proposed with a larger variation of δ81Br in comparison with δ37Cl. The isotopic variations of these two elements agree very well with 87Sr/86Sr seawater variation during the same period. In general, the use of chlorine and bromine stable isotopes can be very useful in assessing the origin and the evolutionary processes involved in evolving formation waters and also in distinguishing different brines (end members). Furthermore, they can be employed to investigate the hydrogeological dynamics of sedimentary basins.

Two new analytical methodologies were developed for chlorine and bromine stable isotope analyses of inorganic samples by Continuous-Flow Isotope Ratio Mass Spectrometry (CF-IRMS) coupled with gas chromatography (GC). Inorganic chloride and bromide were precipitated as silver halides (AgCl and AgBr) and then converted to methyl halide (CH3Cl and CH3Br) gases and analyzed. These new techniques require small samples sizes (1.4 µmol of Cl- and 1 µmol of Br-). The internal precision using pure CH3Cl gas is better than ∓0.04 ‰ (∓STDV) while the external precision using seawater standard is better than ∓0.07 ‰ (∓STDV). The internal precision using pure CH3Br gas is better than ∓0.03 ‰ (∓STDV) and the external precision using seawater standard is better than ∓0.06 ‰ (∓STDV). Moreover, the sample analysis time is much shorter than previous techniques. The analyses times for chlorine and bromine stable isotopes are 16 minutes which are 3-5 times shorter than all previous techniques. Formation waters from three sedimentary settings (the Paleozoic sequences in southern Ontario and Michigan, the Williston Basin and the Siberian Platform) were analyzed for 37Cl and 81Br isotopes. The δ37Cl and δ81Br values of the formation waters from these basins are characterized by large variations (between -1.31 ‰ and +1.82 ‰ relative to SMOC and between -1.50 ‰ and +3.35 ‰ relative to SMOB, respectively). A positive trend between δ81Br and δ37Cl values was found in all basins, where an enrichment of δ81Br is coupled by an enrichment of δ37Cl. In the Paleozoic sequences in southern Ontario and Michigan, the δ37Cl and δ81Br signatures of formation water collected from northwest of the Algonquin Arch are distinct from those collected from southeast of the Arch. All of the brines from the northwest of the Algonquin Arch are characterized by depleted isotopic values in comparison with the isotopic values from the brines from southeast of the Arch. The δ81Br signatures of the two brines show total separation with no overlaps. The δ37Cl values show some overlap between the two groups. One of the scenarios that can be put forward is that the Arch forms a water divide, where sediments southeast of the Arch are dominated by Appalachian Basin formation waters, and the sediments located northwest of the Arch are dominated by the Michigan Basin formation waters. The δ81Br and δ37Cl signatures of the Williston Basin brines suggest the existence of several different brines that are isotopically distinct and located in different stratigraphic units, even though they are chemically similar. The relatively wide range of δ37Cl and δ81Br of the formation waters suggests that the ocean isotopic signatures were variable over geologic time. A seawater temporal curve for δ81Br and δ37Cl was proposed with a larger variation of δ81Br in comparison with δ37Cl. The isotopic variations of these two elements agree very well with 87Sr/86Sr seawater variation during the same period. In general, the use of chlorine and bromine stable isotopes can be very useful in assessing the origin and the evolutionary processes involved in evolving formation waters and also in distinguishing different brines (end members). Furthermore, they can be employed to investigate the hydrogeological dynamics of sedimentary basins.

High rates of soil loss and high sediment loads in rivers necessitate efficient monitoring and quantification methodologies so that effective land management strategies can be designed. Constructing a sediment budget is a useful approach to address these issues. Quantifying a sediment budget using classical field-based techniques, however, is labour intensive and expensive for poorly gauged, large drainage basins. The availability of global environmental datasets in combination with GIS techniques provides an opportunity for studying large basins. Following this approach, a framework is presented for constructing sediment budgets for large, data-sparse drainage basins, which is applied to the mountainous upper Indus River basin in northern Pakistan. The methodological framework consists of five steps: (1) analyzing hydro-climatological data for dividing the drainage basin into characteristic regions, and calculating sediment yields; (2) investigation of major controls on sediment yields; (3) identification and mapping of sediment source areas by spatially distributed modelling of erosional processes; (4) spatially distributed modelling of sediment yields; and (5) carrying out the sediment budget balance calculation at the basin outlet. Further analysis carried out on the Indus data has enabled a better understanding of sediment dynamics in the basin.<p> Analysis of the available hydro-climatological data indicates that the basin can be subdivided into three characteristic regions based on whether runoff production and subsequent sediment generation is controlled by temperature (Region 1, upper, glacierized sub-basins), precipitation caused by the monsoon and western disturbances (Region 3, lower sub-basins), or a combination of the two (Region 2, middle reach sub-basins). It is also demonstrated that contrary to the conventional model, the specific sediment yield increases markedly with drainage area along the Indus River. An investigation of major controls on specific sediment yield in the basin indicates that percent snow/ice cover is a major land cover control for specific sediment yield. Spatially distributed erosion modelling predictions indicate that 87% of the annual gross erosion takes place in the three summer months with greatest erosion potential concentrated in sub-basins with high relief and a substantial proportion of glacierized area. Lower erosion rates can be explained by the arid climate and low relief on the Tibetan Plateau, and by the dense vegetation and lower relief in the lower monsoon sub-region. The model predicts an average annual erosion rate of 3.2 mm/a or 868 Mt/a. Spatially distributed sediment yield predictions made with coupled models of erosion and sediment delivery indicate that the Indus sub-basins generally show an increase of sediment delivery ratio with basin area. The predicted annual basin sediment yield is 244 Mt/a and the overall sediment delivery ratio in the basin is calculated as 0.28. The long-term mean annual sediment budget, based on mass balance, is characterized by a gross erosion of 762.9, 96.7 and 8.4 Mt, and a gross storage of 551.4, 66.1, and 6.5 Mt in the upper, middle, and lower regions of the basin, respectively. The sediment budget indicates that the major sources of eroded sediment are located in the Karakoram, in particular in the Hunza basin. Substantial sediment storage occurs on the relatively flat Tibetan Plateau and the Indus River valley reach between Partab Bridge and Shatial. The presented framework for sediment budget construction requires relatively few data, mostly derived from global datasets. It therefore can be utilized for other ungauged or poorly gauged drainage basins of the world.

A flow duration curve (FDC) defines the relation between the flow amount of any time (daily, yearly, or another time) and its frequency. Moreover, FDCs are used in many water resources projects. However, the ungauged basins or limited amount of gauging in a basin is a common problem. Therefore, regional FDCs are needed to be developed in ungauged basins. Oltu basin has been chosen as the study area, which is located in the north-eastern part of Turkey in &Ccedil / oruh Basin. Two parametric approaches and a statistical approach have been applied to develop regional flow duration curves (FDCs) in Oltu Basin. Parametric approaches cover two different models, namely Model Kocatepe, which is a five parameter model depending on the regression analysis between discharge having certain probability of occurrences and geomorphologic and climatic factors / Model Quimpo, which is a two parameter model proposed by Quimpo. Lognormal distribution has been used in the statistical approach. Several performance indices have been evaluated to decide on if the model dependable or not. As a result of these analysis, it is concluded that, Model Quimpo gives good results in small basins, whereas, Model Kocatepe is effective in large areas. Statistical approach is not an appropriate method to use while regionalizing FDCs in Oltu basin.The analysis performed for short-term duration has revealed that 5-years record lengths of discharges are enough to develop a dependable FDC compared to regional FDC. The validation results and the performance indices are presented with the analysis results.

This study focuses on the main depocenter of the Andrew Formation in the Moray Firth Basin, located at the junction of the Central and Viking Grabens, in the central North Sea. The objectives of this report are to (1) define the sequence stratigraphic framework of the Andrew Formation, (2) describe and characterize the depositional systems associated to the Andrew slope to basin system, and (3) interpret the depositional processes that have dominated sediment emplacement. Specific facies association of the Andrew Formation are determined by the nature (point source or linear source) and caliber (volume, grain size, sand:mud) of sediment supply to the slope environment. Genetic interpretation of the Andrew Formation focuses on understanding depositional processes which dominated sediment emplacement. Seven depositional facies have been identified for the Andrew slope and basinal system; turbidite channel-fills, turbidite lobes, mounded turbidite lobes, sheet turbidites, debris flows and slumps, low density turbidites and hemipelagic drapes. Seven depositional processes collectively create the above mentioned Andrew depositional facies; turbidity currents, cohesive mud flows, sandy debris flows, muddy debris flows, slumping, low density turbidity currents and suspension settling. The Andrew Formation consists of upper and lower depositional units identified on seismic by bounding downlap terminations and on well logs by high-gamma marker beds. The lower Andrew displays three distinct sand-rich lobes, delineated by isopach and sand percent maps and log motif characteristics. Proximal, mounded, sand-rich units disperse into unchannelized sheet turbidites in the basin plain areas. The upper Andrew downlaps the lower unit, and a single, linear sediment source was centered in the Witch Ground Graben. The sediment dispersal pattern and internal facies character suggest the upper unit is a proximal slope-apron downlapping and filling inter-lobe bathymetric lows of the underlying unit. The lower Andrew is interpreted to be a structurally focused, sand-rich lobe complex, without associated incised canyons. The Andrew system evolved as the delta platform expanded onto the proximal fan, resulting in a linear sediment source spilling over the slope as a fringing slope-apron. The Andrew depositional system in the slope and basin environment is characterized by a high degree of facies disorganization composed of a wide array of gravity-flow deposits. / text

Deriving accurate streamflow estimates for ungaged watersheds provides a challenging task for water resource engineers. Traditional methods include correlation to the nearest USGS streamflow station or numeric simulation of watershed rainfall-runoff processes. Mean annual flow, ten percent exceedance and other streamflow indices can be normalized and non-dimensionalized by dividing by the watershed drainage area and the mean annual precipitation rate. Obtaining non-dimensional parameters can be especially useful for extrapolation of flows to downstream, ungaged, coastal fringe regions. Florida and other states along the Gulf Coast exhibit strong variability in the magnitude of streamflow fraction of precipitation. The irregular patterns created by the variance in magnitude do not correlate well with traditional statistical methods of parameter estimation. Using spatial and hydrologic factors, this study, through parameter sensitivity analysis, correlates land-use, slope, soil type, precipitation, and watershed area to a non-dimensional fraction that is to be applied to ungaged regions to determine the streamflow scaling. The study domain for the land-use correlation method is West-Central Florida. Strong trends in correlation to land-use were found but underlying geology must also be considered when defining the study domain. Urbanization, depth-to-water-table and grassland were the dominant parameters in the northern study domain yielding an 80 percent correlation to streamflow fraction for the combined factors. While in the southern domain, wetlands and depth-to-water-table combined to be an indicator with a 75 percent correlation.

Not available / text

This research focuses on how sediment supply, sea level and delta processes control the partitioning of the sediment budget across and into the topset, slope and basinfloor compartments of deepwater basins. Addressing this problem provides significant insight to characterize source-to-sink systems, improve tectono-stratigraphic models and predict sand bypass to deepwater areas. The research was carried out in the Lance-Fox Hills-Lewis shelf margin formed during the Maastrichtian in the Washakie-Great Divide basin of southern Wyoming. I use a database with approximately 520 wells integrated with outcrops to develop a high resolution, dynamic stratigraphy approach for shelfmargin characterization. The results emphasize the driving role of sediment supply in rapid shelf-margin building and deepwater sand emplacement. On the study margin, high sediment supply was able to outpace shelf accommodation even at times of relatively high and rising sea level. At these times, shelf margin clinoforms developed a more aggradational architecture with relatively thick and more marine influenced topsets formed in response to basin deepening due to rapid subsidence. The high supply and subsidence are interpreted to have resulted from crustal loading and significant erosion during prominent Laramide thrust-driven source uplift. The high supply caused the formation of highstand shelf-edge deltas with strong wave and river influences. These deltas resulted in extensive coastal sand belts at the shelf margin, and bypass of significant volumes of sand to deepwater areas. In contrast, during times of stable to very low rates of sea level rise, the basin developed more progradational clinoforms with more terrestrial and generally thinner topsets. More of the sediment was funneled to the basin floor and shelfedge deltas were under strong river and tidal influence. Stable or even falling sea level resulted from decreased subsidence or slight basin uplift, interpreted to have resulted from decreasing uplift, tectonic quiescence or possibly slight tectonic rebound in the basin. The Lewis-Fox Hills margin is considered supply-dominated, a term to denote moderately deep shelf margins (< 1000 m) that prograde at high rates (several tens of km/my) and deliver sand to deepwater areas recurrently and in large volumes even at sea level highstand.