Date of Award

Fall 2019

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Ocean/Earth/Atmos Sciences

Program/Concentration

Oceanography

Committee Director

Dennis A. Darby

Committee Director

David J. Burdige

Committee Member

G. Richard Whittecar

Committee Member

Desmond C. Cook

Abstract

To improve understanding of geographic mineral distribution from the circum-Arctic Ocean, samples from the Arctic periphery were collected and analyzed for (semi-) quantitative mineral composition. Most samples were collected from the North American region of the Arctic Ocean, a region which has had limited mineral investigation. In addition, more than 1000 published clay mineral data points were gathered to provide the most comprehensive clay mineral distribution map to date. The identification of a smectite source within the Canadian Arctic may reduce the usefulness of this mineral as a unique provenance signal for the Eurasian region. Smectite speciation may be useful in maintaining the use of this mineral for provenance determinations. Pyrophyllite, tridymite, zeolite and feldspar species were identified as potentially useful mineral provenance indicators. Strongly contrasting feldspar phases between North America and Eurasia provide an empirical signal for discerning sediment inputs to the Central Arctic. Similarities between ratios of potassium feldspar to plagioclase and quartz to total feldspar indicate that basin-wide sedimentation events likely occurred in the past. These basin-wide sedimentation events, if sufficiently constrained, could be useful for correlations between the eastern and western Arctic basins.

An age model for a sub-Arctic core from Yermak Plateau (JPC22) is developed using oxygen-isotope stratigraphy. The model is based on similarities between the global oxygen-isotope model and a unique paleomagnetic signal. This model identified several periods of rapid sedimentation that, if occurred over broad spatial scales, could be used as correlative tie points for the transfer of ages to central Arctic sediment records.

Central Arctic sediments have long been poorly understood due to the lack of age control. Using the newly developed oxygen-isotope stratigraphy from JPC22 (Yermak Plateau) an age model was developed for a central Arctic core from Mendeleev Ridge (JPC9). Based on this model, sediment transport mechanisms were interpreted in the context of glacial and interglacial environmental changes. Periods of rapid sedimentation are identified in the JPC9. Identification of these rapid events is typically hindered in central Arctic sediments due to reduced overall accumulation rates and reduced resolution. The timing of these unique depositional events appears to be coincident with Greenland stadial and interstadial events, therefore their origin may be related to Dansgaard-Oeschger cycles and other similar or related phenomena.

DOI

10.25777/amnr-k167

ISBN

9781392877760

ORCID

0000-0001-9295-8432

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