Provenance and geochronology of Lomonosov Ridge: A contribution to the geology and tectonic history of the Arctic Ocean from dredged rock samples

This thesis analyzes the OD2016-D2 dredge rock samples collected from a flank of Lomonosov Ridge, a major topographic feature in the Arctic Ocean. U-Pb- and Hf-isotopes were analyzed for 719 detrital zircon grains from ten sandstone samples using the Sensitive High-Resolution Ion Microprobe. The dre...

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Bibliographic Details
Main Author: Robertson, Logan Sidney
Format: Text
Language:English
Published: 2022
Subjects:
Online Access:http://library2.smu.ca/xmlui/handle/01/30935
Description
Summary:This thesis analyzes the OD2016-D2 dredge rock samples collected from a flank of Lomonosov Ridge, a major topographic feature in the Arctic Ocean. U-Pb- and Hf-isotopes were analyzed for 719 detrital zircon grains from ten sandstone samples using the Sensitive High-Resolution Ion Microprobe. The dredge rocks have similar detrital zircon U-Pb age distributions, a Neoproterozoic maximum depositional age, and Scandinavian provenance. Ten lithologies were defined from 176 samples and ten lithofacies from a selection of 96 samples to categorize the rocks and use as a basis for comparison. Two lithofacies associations are present: one indicates a tidal influenced delta setting with fluvial input and the other indicates a tidal flat setting. The lithologies have similar heavy mineral assemblages, whole-rock geochemistry, and have a largely granitic component to their provenance. Overall, the results suggest that there are two Neoproterozoic units unconformably overlain by a possible Lower Paleozoic unit.