Refining the chronostratigraphy of the Lower Nanaimo Group, Vancouver Island, Canada, using detrital zircon geochronology

Author: 
Date created: 
2018-12-17
Identifier: 
etd20067
Keywords: 
Detrital zircon geochronology
Forearc basin
Insular Belt
Wrangellia
Abstract: 

Convergent-margin basins (CMBs) are rich in broadly coeval detrital zircon (DZ) owing to the proximity of active magmatic belts. Consequently, DZ geochronology can be employed to assess the utility of stratigraphic frameworks developed for these basins. This study uses DZ data to assess the utility of lithostratigraphy developed for the Cretaceous-aged lower Nanaimo Group in the Georgia Basin, Canada. Results show that the basal lithostratigraphic unit of the Nanaimo Group, the Comox Formation, comprises strata that are neither time correlative nor genetically related. The three lithostratigraphic units directly overlying the Comox Formation (Haslam, Extension, and Protection formations) comprise strata with similar genetic affinities, indicating that deposition of these units was not entirely sequential, and contemporaneous in some locales. Further, sediment provenance evolved through time, which the existing lithostratigraphic framework does not reflect. This work demonstrates that DZ geochronology can effectively test the utility of stratigraphic frameworks in CMBs.

Document type: 
Thesis
Rights: 
This thesis may be printed or downloaded for non-commercial research and scholarly purposes. Copyright remains with the author.
Senior supervisor: 
Shahin E. Dashtgard
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.
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