Sedimentologic and paleoceanographic implications of terrigenous deposits on the Maurice Ewing Bank, southwest Atlantic Ocean

Simple item page
dc.contributor.advisorAnderson, John B.en_US
dc.contributor.committeeMemberCasey, Richard E.en_US
dc.contributor.committeeMemberDunbar, Robert B.en_US
dc.creatorMacDonald, Scott Edwarden_US
dc.date.accessioned2018-12-18T21:18:51Zen_US
dc.date.available2018-12-18T21:18:51Zen_US
dc.date.issued1984en_US
dc.description.abstractThe Maurice Ewing Bank (MEB) provides a unique environment in which to study deep-sea clastic sedimentation as the observed sedimentary sequences are not readily explained by traditional depositional models. Grain size distributions of sediment samples are utilized to identify styles of sediment transport and current velocities at the benthic boundary layer. These data, along with physical oceanographic information, allow for examination of the relationship between sedimentation on the bank and circumpolar currents. Causal relationships between glacial episodes, current intensification, and bottom current scour were previously postulated. Results indicate that modern sediment distribution is controlled by both bottom and surface currents, and is modified by mass-flow processes. Indirect determinations of current velocities, using a curve relating sediment transport to current velocity, suggest a uniform energy regime of 8-12 cm/sec over the bank. These moderate velocities are supported by geostrophic velocity profiles. The results of this study also demonstrate that misinterpretations regarding current velocities may result when statistical parameters, such as mean grain size and sorting, are used as indicators of fluctuations in bottom current velocities. Similar conclusions can be drawn concerning the use of bottom photographs and nephelometer profiles to infer the relative strength of bottom energy regimes. Current velocities assigned to down-core samples indicate no major fluctuations in circumpolar current intensity since PIio-Pleistocene time. Similar results were obtained from examination of Argentine Basin cores. These results refute the previously inferred causal relationship between current intensification and glacial episodes. The identification of mass-flow deposits provides an alternate explanation for the depositional and erosional history of the MEB.en_US
dc.format.digitalOriginreformatted digitalen_US
dc.format.extent218 ppen_US
dc.identifier.callnoThesis Geol. 1984 MacDonalden_US
dc.identifier.citationMacDonald, Scott Edward. "Sedimentologic and paleoceanographic implications of terrigenous deposits on the Maurice Ewing Bank, southwest Atlantic Ocean." (1984) Master’s Thesis, Rice University. <a href="https://hdl.handle.net/1911/104207">https://hdl.handle.net/1911/104207</a>.en_US
dc.identifier.digitalRICE1835en_US
dc.identifier.urihttps://hdl.handle.net/1911/104207en_US
dc.language.isoengen_US
dc.rightsCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.en_US
dc.titleSedimentologic and paleoceanographic implications of terrigenous deposits on the Maurice Ewing Bank, southwest Atlantic Oceanen_US
dc.typeThesisen_US
dc.type.materialTexten_US
thesis.degree.departmentEarth Scienceen_US
thesis.degree.disciplineNatural Sciencesen_US
thesis.degree.grantorRice Universityen_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Artsen_US
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
RICE1835.pdf
Size:
6.88 MB
Format:
Adobe Portable Document Format
Download
Collections
Rice University Theses and Dissertations