Early evolution of a forearc basin: Georgia Basin, Vancouver Island, Canada

Author: 
Date created: 
2018-12-18
Identifier: 
etd20065
Keywords: 
Sequence stratigraphy, transgression
Coal
Forearc basin
Late Cretaceous
Nanaimo Group
Abstract: 

The Late Cretaceous lower Nanaimo Group was deposited in the forearc Georgia Basin of BC, Canada along the western margin of the Canadian Cordillera, and records its initiation and early depositional evolution. Nanaimo Group strata are currently subdivided into 11 lithostratigraphic units, which are identified based on lithology, texture (i.e., dominantly coarse- or fine-grained), and position relative to the basal nonconformity and to one another. Paleotopography on the basal nonconformity, however, ensures that these lithostratigraphic units are not time correlative, and hence, cannot reliably be used to reconstruct basin evolution. Herein, transgressive-regressive sequence stratigraphy is employed to construct a stratigraphic framework for the lower Nanaimo Group. Eight depositional phases are identified in the lower Nanaimo Group. Depositional phases are separated by flooding surfaces, regressive surfaces, or unconformities. The stratigraphy of the lower Nanaimo Group reflects net transgression, manifested as an upwards transition from braided fluvial conglomerates through to marine mudstones.

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 Dashtgard
Department: 
Science: Department of Earth Sciences
Thesis type: 
(Thesis) M.Sc.
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