Earth Sciences Report 2002-03

Earth Sciences Report 2002-03

ESR 2002-03

Quaternary Geological Setting of the Athabasca Oil Sands (In Situ) Area, Northeast Alberta

Author(s) Andriashek, L.D. Date 2003-04-01

This report describes the nature and distribution of thick Late Tertiary and Quaternary geological sediments that overlie the bedrock surface above the oil sands deposits in the region between the Cold Lake area and Fort McMurray.

The surface of the underlying bedrock in the study area represents one of the major unconformable surfaces of the Western Canada Sedimentary Basin - the pre-Quaternary unconformity - which spans the period of erosion from the Late Cretaceous-Early tertiary to the onset of glaciation in the Early Quaternary. The bedrock surface is an erosional landscape consisting of isolated upland remnants and deep, broad relicts of paleoriver channel systems that formed during the Late Tertiary but which were later modified by glacial and present-day fluvial processes. Elements of the bedrock landscape have been grouped into four major physiographic units based on differences of elevation and relief. The geometry and physical attributes of the buried channels are discussed.

A terrain analysis map is included, which we constructed primarily from the interpretation of aerial photographs to show the nature and distribution of landforms and surface geological materials deposited in the period from the last glaciation to the present. Although lacking the rigours of a surficial geology map , particularly with respect to a lack of field ground truthing, the terrain analysis map provides useful information regarding the regional distribution of geological material, which affect land-use planning and construction of infrastructure related to the petroleum industry.

Andriashek, L.D. (2003): Quaternary geological setting of the Athabasca Oil Sands (in situ) area, northeast Alberta; Alberta Energy and Utilities Board, EUB/AGS Earth Sciences Report 2002-03, 295 p.