Thesis (M.S.)--University of Wisconsin--Madison. / Title from title screen (viewed July 26, 2007). Includes bibliographical references (leaves 105-110). Online version of the print original.

Thesis (M.S.)--University of Iowa, 2007. / Supervisor: Robert L. Brenner Includes bibliographical references (leaves 129-133).

Thesis (M.Sc.)--Saint Mary's University, 2008. / Includes abstract. Supervisor: Georgia Pe-Piper. Includes bibliographical references (leaves 141-148).

Thesis (Ph.D.)--University of Melbourne, School of Earth Sciences, 2009. / Typescript. Includes bibliographical references (leaves 205-235)

No description available.

The Msikaba Formation is a Late Devonian fluvial and marine succession which outcrops from Hibberdene to Port Edward along the south coast of KwaZulu-Natal Province, South Africa. The Formation is composed of brownish conglomerate at the bottom and white-greyish quartz arenite sequence in the middle and mixed quartz-arenite with feldspathic sandstone in the upper sequence. Previous studies put more emphasis on the correlation of Msikaba Formation with the Natal Group and Cape Supergroup, whereas this study revised the stratigraphy, and also put new insight on the petrography, sedimentary facies, depositional environments and diagenesis of the Formation. The total stratigraphic section attains a thickness of 184 m at Margate area and 186 m at Port Edward area. The stratigraphy of Msikaba Formation is well exposed on the outcrops along the KwaZulu-Natal coastline. The stratigraphy is subdivided into 4 new members along Margate to Shelly beach section; namely Manaba Member, Uvongo Member, Mhlangeni Member and Shelly Beach Member from bottom upward. Twelve sedimentary facies were identified and the sedimentary facies were integrated into 4 facies association: Facies association 1 (Gmm+Sm) represents braided fluvial deposits, Facies association 2 (Gcm+St+Sp+Sl+Shb) represents tidal channel and tidal flat deposit, Facies association 3 (St+Sp+Sr+Sl) is result of shallow marine deposit and Facies association 4 (Sp+Sl+St+Sm) is a mixed marine and fluvial deposit. Each facies association represents a specific stratigraphic unit and were deposited in a specific sedimentary environment. Grain size analysis was conducted on seventeen thin sections and 500 grains were counted from each thin section. The sandstone grain size parameters of mean, sorting, skewness and kurtosis fell under the average of 0.75, 0.78, 0.4 and 1.2φ respectively. The results show that most of the grain size are coarse to medium grained throughout the study areas and sorting of the sandstones are moderate to poorly sorted. The cumulative frequency diagrams and bivariate plots show positive skewness and negative kurtosis, which indicate a high hydrodynamic environment. Modal composition analysis and petrography studies show that detrital components of the Msikaba Formation are dominated by monocrystalline quartz, feldspar (mostly K-feldspar) and lithic fragments of igneous and metamorphic rocks. The sandstones could be classified as quartz arenite, sub-arkosic sandstone and feldspathic litharenite; and the provenance analysis indicates that the sandstones were derived from craton interior, recycled or quartzose recycled sources which may derived from weathering and erosion of igneous and metamorphic rocks. Diagenetic processes of the Msikaba Formation have been passed through early, mid- and late diagenetic stages. Cementation, mineral conversion and compaction affect early diagenetic stage; authigenic minerals, quartz and feldspar overgrowth are presented in mid-diagenetic stage, whereas recrystallization, replacement, deformation and dissolution have been strongly affected late diagenetic stage. Microscopy, XRD and SEM-EDX studies have identified five types of cements including smectite clay, kaolinite, hematite, quartz and feldspar cements. Quartz cement, pore-filling and pore-lining clay are the major type of cements in the Msikaba Formation. Based on the lithology, sedimentary structure and facies variations, the Manaba Member was most probably deposited in a braided fluvial environment, the Uvongo Member was deposited in a tidal channel environment, the Mhlangeni Member was formed in shallow marine storm-influenced environment, whereas the Shelly Beach Member was represented mixed marine and fluvial environment. The sequence stratigraphy of Msikaba Formation constitutes a transgressive sequence from Manaba Member to Uvongo Member, whereas it ended as a regressive sequence from Mhlangeni Member to Shelly beach Member. The Msikaba Formation shows major differences with the Natal Group and Table Mountain Group (Cape Supergroup) in the lithology, stratigraphic sequence, sedimentary structures, facies system, palaeocurrent styles, fossil contents and depositional environments, which demonstrate that they are not the equivalent stratigraphic unit. Therefore, the Msikaba Formation is a separate, younger stratigraphic unit, and cannot correlate with the Natal Group and Table Mountain Group as suggested by previous researchers.

The Ordovician rocks of the Bail Hill area, Sanquhar, South Scotland : volcanism and sedimentation in the lapetus Ocean. by M. J .McMurtry. The Bail Hill area lies in the "Northern Belt" of the Southern Uplands and contains sedimentary and volcanic rocks of Llandeilo/Caradoc age. The sedimentary succession has been divided into four formations - the Glenflosh, Kiln, Spothfore and Guffock Formations. The Glenflosh and Guffock Formations are mainly arenaceous and were largely deposited by turbidity currents flowing to the southwest. They typically consist of Tae units. The fine-grained sandstones and siltstones of the Kiln Formation were also deposited by turbidity currents. Parallel-laminated units in the lower part of the formation represent "overbank" deposits, whilst lenticular- bedded units in the upper part are interpreted as channel- mouth deposits. Bouma sequences are not common in these lithologies. The Spothfore Formation consists of rudites deposited by a variety of sediment and fluid gravity flows close to a feeder system. The petrography of greywackes within the formations shows no significant variation across strike, in contrast to successions studied to the southwest. The provenance of detritus in the sediments is believed to be the north-westerly Laurentian continent with a significant but variable intrabasinal contribution of sedimentary and volcanic debris. A stratigraphic succession for the area is proposed, although graptolite evidence for the relative ages of the formations is equivocal. A new stratigraphic unit, the Bail Hill Volcanic Group, is proposed and the petrography and field relations of the subdivisions within this group are discussed. Field relations suggest that the Bail Hill volcano was a composite, central-type structure. Early basaltic lavas were succeeded by more differentiated lithologies and pyroclastic activity increased with time. The mineral and whole-rock chemistry indicates the Bail Hill Volcanic Group has differentiated along the sodic alkaline series (alkali basalt - hawaiite - mugearite - trachyte). Gabbroic and dioritic xenoliths in the extrusive rocks are believed to be fragments of a large sub-volcanic intrusive mass that underlay the Bail Hill volcano in Ordovician times. The volcanic pile as a whole has undergone metamorphism to zeolite facies grade. Higher grade assemblages in the xenoliths suggest that they were hydrothermally altered prior to incorporation in the extrusive rocks. It is concluded that the Bail Hill Volcanic Group represents the remnants of a seamount within the Iapetus Ocean, whilst the sedimentary rocks record the transition from the abyssal plain into a Lower Palaeozoic trench. Northwesterly subduction of the lapetus Ocean crust resulted in the accretion of the Bail Hill area on to the facing edge of the northwesterly Laurentian continent.

Pollen and microscopic charcoal fragments from seven sites (East Sooke Fen and Pixie, Whyac, Porphyry, Walker, Enos, and Boomerang lakes) were used to reconstruct the post-glacial vegetation, climate, and fire disturbance history on southern Vancouver Island, British Columbia, Canada. A non-arboreal pollen and spore zone occurs in the basal clays at Porphyry Lake and likely represents a tundra or tundra-steppe ecosystem. This zone precedes the Pimis contorta (lodgepole pine) biogeochron that is generally considered to have colonised deglaciated landscapes and may represent a late Wisconsinan glacial refugium. An open Pinus contorta woodland characterised the landscape in the late-glacial interval. Fires were rare or absent and a cool and dry climate influenced by “continental-scale katabatic” easterly winds dominated. Closed lowland forests consisting of Picea (spruce), Abies (fir), Tsuga heterophylla (western hemlock), and Tsuga mertensiana (mountain hemlock) with P. contorta and Alnus (alder) and subalpine forests containing Picea, Abies, and T. mertensiana with P. contorta replaced the P. contorta biogeochron in the late Pleistocene. Fires became more common during this interval even though climate seems to have been cool and moist. Open Pseudotsuga menziesii (Douglas-fir) forests with Pteridium (bracken fern) in the understory and Alnus in moist and disturbed sites expanded westward during the warm dry early Holocene. At this time closed Picea, T. heterophylla, and possibly Alnus forests grew in the wettest part of southern Vancouver Island at Whyac Lake. At high elevations, forests consisting of T. heterophylla and Pseudotsuga coupled with Alnus expanded during the early Holocene. Fires occurred frequently in lowland forested ecosystems during this interval, although East Sooke Fen in a dry, open region experienced less fire. At high elevations, charcoal increased somewhat from the late Pleistocene, indicating slightly more fires and reflecting continued moist conditions at high elevations. The mid and late Holocene was characterized by increasing precipitation and decreasing temperature respectively. Mid Holocene lowland forests were dominated by Pseudotsuga with T. heterophylla and Alnus in southeastern regions, T. heterophylla and Thuja plicata (western red-cedar) in southern regions, and T. heterophylla and Picea in southwestern regions. An overall decrease in charcoal influx suggests a decrease in lowland fires, although locally isolated fire events are evident in most sites. Quercus garryana (Garry oak) stands spread westward during the mid Holocene, attaining maximum extent between East Sooke Fen and Pixie Lake, approximately 50 km beyond their modem limit. Lowland sites record a general decrease in fires at this time. At high elevation, mid Holocene forests were dominated by T. heterophylla, Picea, and Abies with Alnus. An overall increase in charcoal influx at high elevations may reflect an increase in the number of charcoal fragments entering the basins by overland flow as opposed to an increase in fire incidence because climate was moister. In the late Holocene, closed T. heterophylla and T. plicata forests became established in wetter western regions, Pseudotsuga forests occupied drier eastern portions, and T. mertensiana and Cupressaceae, likely Chamaecyparis nootkatensis (Alaska yellow cedar), forests were established in sub-alpine sites. Lowland fires were infrequent in wet western regions but frequent in drier eastern regions. A slight reduction in charcoal influx generally occurs at high elevations, implying fewer fires. A recent increase in charcoal influx at East Sooke Fen and Whyac, Walker, Enos, and Boomerang lakes may reflect anthropogenic burning. Holocene paleoclimates were reconstructed at 1,000 year intervals through a geographic information system (GIS) using contemporary climate data and surface and fossil pollen assemblages by establishing empirical regression equations that calibrated contemporary precipitation and temperatures to present day Douglas-fir-western hemlock (DWHI) and T. heterophylla-T. mertensiana (THMl) pollen ratios. / Graduate

No description available.

Charts in pockets bound with piece.