Earth and Planetary Sciences ETDs
Publication Date
Summer 7-12-2024
Abstract
Sedimentation in perennially ice-covered lakes (PICLs) is proposed to be bi-modal, with mud deposited by stream inflow and sand deposited on the ice cover by aeolian processes and then melting through by absorption of solar radiation. Here, we consider Lake Fryxell, a PICL in the McMurdo Dry Valleys, and several lake bed cores about 30 cm in length, to better understand PICL facies through time, using micro X-ray CT (XCT). Using XCT images along with sieve and laser granulometry data, we constrained the grain-size of PICL deposits to dominantly medium / fine sand with a coarse component. The presence of coarse sand offers a key separation between glacio-lacustrine and sea ice facies. This will provide important constraints on facies that develop from PICL environments, and offer further tools to identity them and their valuable paleoclimatic records. Additionally, our methods for imaging frozen samples will extend the range of use for XCT.
Degree Name
Earth and Planetary Sciences
Level of Degree
Masters
Department Name
Department of Earth and Planetary Sciences
First Committee Member (Chair)
Tyler Mackey
Second Committee Member
Peter Fawcett
Third Committee Member
Laura Crossey
Language
English
Keywords
Micro X-Ray CT, McMurdo Dry Valleys, Lake Fryxell, Sedimentology, Facies Models, Perennially Ice-Covered Lakes
Document Type
Thesis
Recommended Citation
Levett, Holly M.. "Sand, Ice, and X-rays: Developing XCT Methods for Frozen Samples and Refining Siliciclastic Facies Models for Perennially Ice-Covered Lakes, Utilizing Cores From Lake Fryxell, McMurdo Dry Valleys, Antarctica." (2024). https://digitalrepository.unm.edu/eps_etds/409
