Bedrock structural influences on river morphology

Resource type
Thesis type
(Thesis) M.Sc.
Date created
2020-04-16
Authors/Contributors
Abstract
Bedrock rivers largely set the pace for landscape evolution in unglaciated terrain and yet little is known about what controls their morphologies. I examine the role that geologic structure plays in the alignment and morphology of bedrock canyons at different scales. At the watershed scale, I examine the striking alignment of the Fraser River with the Fraser River Fault zone and its largely unmapped secondary fault structures. I explore how large sediment inputs affect bedrock canyons alignment and their morphological characteristics. At the reach scale, I investigate how geological structure influences bedrock canyon width. I find that width constrictions coincide with dominant sub-horizontal joint sets whereas widenings coincide with dominant sub-vertical joint sets. I consider this in the context of sequential constrictions and widenings and propose a conceptual model where sub-vertical jointing makes canyon walls more susceptible to failure due to river undercutting than horizontal jointing.
Document
Identifier
etd20892
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Copyright is held by the author.
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This thesis may be printed or downloaded for non-commercial research and scholarly purposes.
Scholarly level
Supervisor or Senior Supervisor
Thesis advisor: Venditti, Jeremy
Member of collection
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etd20892.pdf 9.57 MB