No description available.

Thesis (Ph.D.) - University of Glasgow, 2008. / Ph.D. thesis submitted to the Department of Geographical and Earth Sciences, Faculty of Physical Sciences, University of Glasgow, 2008. Includes bibliographical references. Print version also available.

No description available.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1971. / Vita. / Includes bibliograpies. / Ph.D.

The Gorda Escarpment (40.4° N and from 126° W to 124.7° W) is a topographic high which is the eastern portion of the Mendocino Transform Fault. The Vizcaino Block is the anomalously shallow portion of the Pacific plate immediately south of the Gorda Escarpment. Sediments of the Vizcaino Block record a history of uplift and subsidence for itself and the Gorda Escarpment. Previous work on the Mendocino Ridge (the bathymetric expression of the Mendocino Transform Fault west of 126° W, where there is little sediment overlying basement) indicated that the ridge had been above sea level at some time in the past (Krause et al., 1964; Fisk et al., 1993). Assuming that the two bathymetric features have undergone the same response to tectonic forces, this study aims to constrain the timing of uplift and subsidence for the Gorda Escarpment, Vizcaino Block, and Mendocino Ridge by using the geological record of sediments of the Vizcaino Block. ODP Site 1022 drilling penetrated 379 meters into the Vizcaino Block's sediments. Age and lithologic constraints from the recovered cores, along with in-situ sampling by ROV and gravity cores, were integrated with a network of 25 seismic reflection lines. From these it is evident that uplift of the Gorda Escarpment and Mendocino Ridge began before 6 Ma, and was at a maximum at 2.7 Ma. Ocean circulation was likely altered by the uplift of the Gorda Escarpment and Mendocino Ridge. In turn, the altered ocean circulation regime may have had an impact on the regional climate in the Pliocene. From 2.7 Ma until the present the Gorda Escarpment, the Vizcaino Block and the Mendocino Ridge have been subsiding. / Graduation date: 2003

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Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences. / Microfiche copy available in Archives and Science. / Bibliography : leaves 281-295. / by William John Olszewski, Jr. / Ph.D.

It is now accepted that the last British-Irish Ice Sheet (BIIS) was highly dynamic and drained by numerous fast flowing ice streams. This dynamic nature combined with its maritime location made the BIIS sensitive to the rapid climate change that characterised the Last Glacial Interglacial Transition. Gaining an understanding of the behaviour of the BIIS at this time is important to explore the nature of forcing between ice sheets and climate. This thesis presents new chronological data relating to the deglaciation of the northwest sector of the BIIS (NW-BIIS) from onshore dating of moraines using cosmogenic exposure dating. This improved chronological framework is supported by offshore data in the form of a newly constructed Ice Rafted Detritus (IRD) record from the offshore sediment core MD95-2007. These data suggest that deglaciation commenced sometime after 18 ka and that the NW-BIIS was located close to the present day shoreline by 16 ka. Further provenance analysis of the IRD using U-Pb dating of detrital minerals demonstrates that during the Last Glacial-Interglacial Transition MD95-2007 was being supplied distal IRD from a source(s) to the west. The absence of diagnostic Scottish material suggests that after retreat to the coastline at 16 ka calving margins were not re-established during Greenland Interstadial 1. By combining these results with existing data relating to the deglaciation of the NW-BIIS it is possible to summarise the deglaciation history of the NW-BIIS from the continental shelf to mountainous source regions and compare this to numerical models of BIIS behaviour during this time. With a better understanding of the chronology of NW-BIIS retreat it is possible to relate the timing of initial deglaciation to possible forcing factors and gain a better understanding of the response of a marine based sector of an ice sheet to rapid climate change.