Thesis (M.Sc.)--Memorial University of Newfoundland, 2003. / Error in pagination: Appendix p. [241] is numbered 235. Bibliography: leaves 234-240. Also available online.

Master of Science / Department of Geology / Allen W. Archer / Abstract This study compares the tidally influenced facies found within the Tonganoxie Sandstone Member (Stranger Formation, Douglas Group) (Upper Pennsylvanian) of northeastern Kansas with similar facies directly observed in the upper intertidal mudflats of Turnagain Arm of Cook Inlet (Alaska, USA). The two settings contain strikingly similar facies that are characteristic of upper macrotidal estuaries with a strong influence of tidal activities. Identical aspects and features found within both settings include rhythmic vertical variation in stratum thicknesses (cyclic tidal rhythmites), high estimated sedimentation and aggradation rates, and biogenic and physical sedimentary structures (e.g., drag marks, raindrop impressions, arthropod traces and tetrapod trackways, zigzag burrows, runoff washouts, and upright trees, among others). Tidal rhythmites are the most important evidence that is indicative of the tidal influence on the depositional processes of these two study areas. Such cyclic tidal rhythmites have been reported and described from several Carboniferous settings in the eastern USA. Modern analogs to these Carboniferous rhythmites are usually found within upper macrotidal estuarine depositional environments, especially within fluvio-estuarine transitional zones. These environments are distributed over a wide range of modern latitudes. Using cyclic tidal rhythmites as modern analogs for interpreting similar ancient facies is a powerful tool for paleogeographic and paleoenvironmental reconstructions, although it is somewhat a new approach.

Hydrocarbon producing, deep-water Cisco sands along the Eastern Shelf were studied in the vicinity of Flowers "Canyon Sand" Field to develop a depositonal model explaining their origin, geometry, and style of deposition. Regional correlations and subsurface mapping indicate that producing sands were deposited within the Swastika lithogenetic unit, which contains a network of shelf-margin fluvial/deltaic, slope, and basin depositional systems deposited between transgressive Gunsight and Ivan Limestones. The sands are not "Canyon", but Virgilian in age. During Swastika time a wedge of sediments up to 1100 feet thick was deposited in the study area in response to westward progradation of shelf-margin deltas. Standard mapping techniques and detailed correlations using nearly 700 well logs and the examination of 3 cores indicate that this wedge can be divided into three principal systems: (1) a sand-dominated turbidite, basin and lower slope system, which constitutes the reservoir facies, (2) a shale-rich prodelta/slope system punctuated by slope channel filled gullies, and (3) a sand-dominated shelf-margin fluvial/deltaic system. Ten deltaic lobes, averaging 2 miles in diameter, were recognized. These lobes may have been deposited during a lowstand of sea level. Elongate/lobate geometry and rapid shifting of lobes indicate high depositional rates. Shelf-margin instabilities associated with deltas led to prodelta/slope slumping, gully formation, and generation of turbidity currents. Turbidity currents generated by the earliest deltas to breach the shelf break were of sufficient magnitude to erode a broad, shallow inner-fan valley at the base of the slope. This valley initially focused turbidity currrents onto a base-of-slope terrace, which was mapped on top of the Gunsight Limestone, and formed by differential compaction over a subjacent Canyon delta or carbonate buildup. Low gradients associated with this terrace gave rise to a sediment trap. Nearly all existing production in Flowers Field is established above this terrace. Turbidites deposited within this phase of Swastika evolution display characteristics of an elongate/radial type fan deposit. Continued deltaic progradation filled the inner-fan valley. Once this valley was breached, a network of small channels originating as gullies along slopes in front of the advancing Swastika delta system transported sediment down the slope to form an aggrading/prograding wedge of turbidite and volumetrically less significant grain flow deposits. This change in depositional style led to superposition of what is best classified as an elongate/debris apron type system over the earlier elongate/radial deposits. A critical conclusion is that no single channel developed into a large canyon feeder system, which resulted in facies relationships that differ from commonly accepted models calling on a prolonged point source. Given the importance of turbidite sands in many petroliferous basins, application of the delta-fed model to appropriate turbidite systems can improve exploration strategies. / text

Annually and subannually laminated lacustrine sediments potentially contain a wide range of information that can be interpreted for paleoenvironmental reconstructions. These laminae are produced by the physical and biological processes that operate in the lake and in the surrounding terrestrial environment. However, identification of the influences that control laminae production may not be straightforward, and other processes may subtly influence the overall depositional sequence. This thesis examines two different depositional environments on Colin Archer Peninsula, Devon Island, Canada, with the objective of identifying the factors that influence subannual sediment deposition and how the resultant sedimentary structures can be used as indicators of paleoenvironmental conditions. In proglacial Lake R, clastic sediment deposition is controlled primarily by subannual meteorological conditions. Periods of positive air temperature or large rainfall events produce discernable laminae that, when combined, form a varve sequence. However, overarching geomorphic controls influence the delivery of sediment to the lake and may reduce or enhance the hydrometeorological signal contained in the varves. An additional influence for calibration of the varve record to meteorological observations is the role that melt season thermal inversions have on temperature extrapolation in the High Arctic. Meteorological stations at sea level may not be representative of the surrounding region, thereby reducing the accuracy of vertical temperature estimation. Investigation of the inversions in the central Canadian High Arctic demonstrated that melt season inversions are common and increased inversion frequency may potentially have influenced enhanced glacial melt since the late 1980s, with implications for proglacial lake sediment transport and deposition. In coastal Lake J, late Holocene sediments record a relatively unusual accumulation of microbially induced sedimentary structures (MISS). Such a record has not been previously described in the circum-Arctic, although they are known to exist elsewhere. These sediments are produced by the interaction between clastic sedimentation and cyanobacterial growth and production. Although chronological constraint could not be assigned with certainty to the record, statistical study of the laminated sequence suggested a dominant pattern that is plausibly annual. A heuristic model of annual sediment accumulation was developed in order to explore the potential for quasi-annual paleoenvironmental interpretations. / Thesis (Ph.D, Geography) -- Queen's University, 2008-05-22 09:55:12.184

In north-central Arizona, the Moenkopi Formation of Triassic age consists of generally unfossiliferous red mudstones, siltstones, gypsum, and sandstones that contain abundant sedimentary structures, such as ripple marks, cross-stratification, ripple laminae, salt crystal casts, mud cracks, sole marks, parting lineation, and core-and-shell structures. Three informal members were established for this study: the lower member, the lower massive sandstone, and the upper member. Flaser, wavy, and lenticular bedding, bimodal distribution of ripple laminae dips, parallel ripple marks dominant over cuspate ripple marks, gypsum beds and veins, salt crystal casts, and lack of channel deposits are the suite of sedimentary features that are interpreted to indicate a tidal-flat environment during deposition of the lower member. The very fine grained lower massive sandstone can be divided into four subunits, which were formed by a transgression-regression of the sea. Wavy and ripple laminated beds in subunit one were probably deposited in very shallow water. Medium-scale wedge-planar and trough sets of cross strata with mean dip directions to the southeast make up subunit 2 and indicate megaripples formed by longshore drift. Subunit 3 consists of lenticular, wavy, pod-shaped beds that were created in water shallower than that for subunit 2. Continuous, large-scale, low-angle cross strata of uniform thickness and medium-scale wedge-planar and trough sets of cross strata characterize subunit 4 and are typical of beach deposits. The significant sedimentary features in the upper member are unimodal distribution of ripple laminae dips, cuspate ripple marks dominant over parallel ripple marks, channel deposits with shallow trough cross strata, an increase in the number and thickness of sandstone and siltstone beds compared with the lower member, plus vertebrate bones, tracks, and plant impressions. This suite of features indicates a flood-plain environment. Early in Moenkopi time, north-central Arizona was a tidal flat and sabkha. The sea to the west fluctuated east and west and finally transgressed over the entire area. As the sea regressed, a beach formed, and rivers flowing from the east deposited sediment on a westward-prograding flood plain. In the northern, southern, and central portions of the region, sabkhas existed for a time during regression. At the end of Moenkopi time, the entire area was a flood plain. Considering the association of red beds and evaporites, the absence of fossils in the lower member and the lower massive sandstone, the paleowind directions, and the theory of continental drift, the climate during early and middle Moenkopi time was probably hot and arid. The influx of sandstones, the presence of Calamites (?) impressions, and trackways and bones of amphibians in the upper member suggest that the climate became more humid at the end of Moenkopi time.

Increased human habitation brings associated pressures with it, such as the introduction of contaminants to coastal waters. The major sources of these occur along the KwaZulu-Natal coast via Sappi Saiccor discharge points, Tioxide, AECI, the Mlaas canal, Central Works Outfall and Southern Works Outfall. This study investigated the effects of sediment structure on benthic amphipod communities exposed to sewage and industrial waste from the Central Works and Southern Works Outfalls along the Durban coastline, and used a 4-year dataset of sediment grain size analysis, metal concentrations, Total Kjeldahl Nitrogen (TKN) and Chemical Oxygen Demand (COD) at impacted and reference sites. Results exhibited that the levels of effluent being discharged onto the Durban coast from the Southern Works and Central Works Outfalls do not accumulate in the fine grained sediments in sites where it would be expected. The Mdloti reference site which was dominated by coarse sediment showed the highest concentrations of metals. In addition, the outfalls do not have significant effects on the amphipod communities in the vicinity. Community structure between sites with similar grain sizes tends to be very similar thereby highlighting the possible influence of grain sizes on determining community patterns. Overall, there seemed to be no effect of pollutants on the biology or accumulation in the receiving environment. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2010.

Copies of author's previously published works inserted. / Bibliography: p. 157-165. / ix, 165 p. : ill. (chiefly col.), maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Sonic velocities from the Danian Chalk, Upper Cretaceous Chalk, Lower Cretaceous Greensand/Gault Clay, Lower Cretaceous Wealden, Upper Jurassic mudstones, Triassic Mercia Mudstone, and Triassic Sherwood Sandstone have been used to quantify apparent exhumation in the Celtic Sea/South Western Approaches. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology and Geophysics, 1998

Bibliography: leaves 147-157. / xiii, 157, [70] leaves, [16] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, National Centre for Petroleum Geology and Geophysics, 1999

Thesis (M. Sc.)--University of Adelaide, Dept. of Geology and Geophysics, 1993. / Includes bibliographical references.

Thesis (Ph. D.)--University of Adelaide, National Centre for Petroleum Geology & Geophysics (NCPGG) /Dept. of Geology & Geophysics, 1993. / At head of title: "NERDDC/SENRAC Research Project." Three folded maps in pocket. Two microfiches in pocket. Includes bibliographical references (leaves 155-187).