CGRG Bibliography of Canadian Geomorphology
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Author : Cummings, D.
Date : 2011.
Title : Stop 1-2A: Regimbald Road Pit.
Publication : Deglacial history of the Champlain Sea basin and implications for urbanization; Joint annual meeting GAC-MAC-SEG-SGA, Ottawa, Ontario, May 25–27, 2011; Fieldtrip guidebook. Russell, H.A.J.; Brooks, G.R.; and Cummings, D.I. (Editors). Geological Survey of Canada Open File
Issue : 6947.
Page(s) : 28-29.
Abstract
The pit is excavated into a tributary-like arm of the esker (see field trip stop map at start of guide book). At this location, the esker is partially overlain by Champlain Sea mud. In a nearby cored well, the esker rests directly on carbonate mudstone bedrock. The coarsest (and presumably most proximal) sediment in the esker is exposed in the Regimbald Road pit. In the exposure, the gravel is organized into thick (1.5–2.5 m) high-angle crossstratified beds that are stacked on top of each other. Cross-strata dip at a high-angle (25–30°) towards the south, which is parallel to the esker long-axis. Clasts are well rounded and are typically pebble to cobble size, although boulders up to ~ 1 m in diameter are present. Clast lithology is similar to that of the regional till: carbonate mudstone predominates, with minor percentages of igneous (granite), sandstone and shale. Within the cross-sets, cyclicity is observed on both a centimetre-scale (alternation of sandy cross-strata with gravelly cross-strata and on a metre-scale (several reactivation-surface bound, downflow-fining packages of cross-strata within a single cross-set).
Bibliography of Canadian Geomorphology