Geomorphology - Calvert Island

Hakai Geomorphology - Polygon Features: Version 2 generated January 2015 by Jordan Eamer, Coastal Erosion and Dune Dynamics Laboratory at the University of Victoria. Reproduction requires explicit permission from the author: [e-mail] This dataset was created for researchers at Hakai to utilize in instances where data on subsurface material type and relative age would be beneficial. It was created with a goal similar to other surficial geology maps in the region (e.g. http://www.env.gov.bc.ca/van-island/maps/surfical.jpg), with a focus on unconsolidated sediments deposited and reworked since the last glaciation. Data used in the generation of this map was collected through several different means. In areas with the highest resolution (e.g. proximal to the institute), subsurface data was directly observed through soil pits, natural sedimentary exposures, or cores. Where this was not possible, visual interpretation of a bare earth model generated from airborne lidar data assisted in extrapolation of geologic and landform trends that were directly observed. Derivatives of this model were also used, such as principal component analysis of hillshade models (e.g. Devereux et al., 2008) and a ruggedness index (Riley et al., 1999). Map data were created by Jordan Eamer and Dan Shugar. Devereux BJ, Amable GS, Crow P. 2008. Visualisation of LiDAR terrain models for archaeological feature detection. Antiquity 82: 470-479. Riley SJ, DeGloria SD, Elliot R. 1999. A terrain ruggedness index that quantifies topographic hetergeneity. Intermountain Journal of Science 5:23-27. Legend: BEACH: Modern accretionary beach, composed of sediments ranging from coarse silt to block sized clasts. DUNE: Modern (rare) and relict (common) sand dune composed of sediments of coarse silt to coarse sand grain size. Modern dunes are sparsely vegetated and relict dunes may be vegetated along a gradient dependent on age (e.g. grasses colonize a recently stabilized dune, full canopy forest cover on a dune stabilized many hundreds to thousands of years ago). TOMBOLO: Accretionary feature composed of sand sized grains that is formed principally from wave refraction around a headland. May be active or relict on this map (active are easily identified by open exposure to ocean and little to no vegetation). INTERTIDE: Intertidal flats that are generally composed of mud (clay and silt) sized sediments and low energy wave climate. RELBEACH: Relict beach. Typified by sand-sized unconsolidated sediments, dense vegetation cover, and flat topography. FILL: Valley-bottom alluvium, basin (e.g. lacustrine) sediments, marsh organic rich sediments, or any combination. Generally reserved for sites not investigated thoroughly and as such is a "catch-all" for areas hypothesised to conatain said sediments. GLAFLUV: Glaciofluvial sands, gravels, and boulders. Areas that were ice proximal in the pleistocene and are typified by a high-energy depositional environment. SPIT: Coastal spit that consists of sand-sized unconsolidated sediments shaped by wave action and tidal currents. QCOVER: Areas covered by late Quaternary unconsolidated sediments. Differentiated from the rest of the landscape (not covered by the above units) as areas likely to have >2m of uncosolidated sediment covering the underlying bedrock. Boundary between this unit and the area dominated by bedrock or a thin veneer of sediments by, in increasing order of precision, i) the NRCAN Geologic map for the area (Geologic Survey of Canada Rivers Inlet (92M) - Queens Sound (102P), compiled by J.A. Roddick, 1996; ii)a ruggedness index (Riley SJ, DeGloria SD, Elliot R. 1999. A terrain ruggedness index that quantifies topographic heterogeneity. Intermountan Journal of Science 5:23-27) derived from the 2m resolution DEM generated from the airborne LiDAR data; iii) visual interpretation of the DEM; and iv) ground truthing based on fieldwork performed from 2011-2013. Hakai Geomorphology - Linear Features: Version 1 generated December 2014 by Jordan Eamer, Coastal Erosion and Dune Dynamics Laboratory at the University of Victoria. Reproduction requires explicit permission from the author: [e-mail] Legend: MORAINE: Semi-linear ridges composed of clast-dominated angular sediments, with coarse sand matrix and gravel to block (>2m) sized clasts. Ridges typically no more than 5 metres high, and are late Pleistocene in age and as such are typically vegetated. SHORE: Relict (raised) shorelines that represent some portion of the previous coastline. Sedimentology varies from dune-backed (well sorted sands) to weathered cobbles. FIELDVAL: y refers to features that have been validated in the field. Features not containing a y in this attribute field are assumed from analysis of the DEM. Bedrock Geomorphology: Version 1 generated December 2014 by Dan Shugar, Coastal Erosion and Dune Dynamics Laboratory at the University of Victoria. Reproduction requires explicit permission from the author: [e-mail] This shapefile contains oriented linear and areal features identified through analysis of the DEM. These data may be used in a future study of glacial ice character and directionality. Last updated: March 26th, 2015. Map information currently undergoing publication and a citation will be added. Version 2 generated January 2015 by Jordan Eamer, Coastal Erosion and Dune Dynamics Laboratory at the University of Victoria.