Surficial geology, Dazo Creek, British Columbia
Authors: Trommelen M , Smith I R 
Published: November 2010

The Dazo Creek map area (NTS 94I/SW) is situated in the generally flat, low-lying Fort Nelson Lowland physiographic region of northeastern British Columbia. The map area is dissected by the Fort Nelson, Sikanni Chief and Fontas rivers. It is blanketed by Boreal
forest (white and black spruce, aspen, lodgepole pine) and underlain by soils with high fine silt and clay contents that result in extensive, poorly drained bogs and fens. The main economic activities in the map area are oil and gas extraction, with lesser amounts of forestry and trapping.

The surficial geology of the Dazo Creek map area was interpreted from 1:60 000 scale black and white airphotos (British Columbia Integrated Land Management Bureau, 1986). Aspects of the regional surficial geology were also interpreted from shuttle radar topography mission (SRTM) imagery (3-arc
second), and to a lesser extent, light ranging and detecting (LiDAR) imagery. Fieldwork was conducted over a four week period in the summers of 2004 and 2005, largely truck-based, but also including a traverse by rail truck along the CN rail line, jet boat along the Fort Nelson and Sikanni Chief
rivers, and helicopter access in remote areas.

Till is the most extensive surficial material in the Dazo Creek map area and is a clayey-silt diamicton with a clast content varying from 5-15%. Clast lithologies consist of locally derived sandstone, ironstone, chert and shale, intermixed with Canadian Shield and Proterozoic to Paleozoic
sedimentary rocks transported from the northeast. Glacial lake sediments are primarily situated in a flat, low-lying region bounded by the Fontas and Sikanni Chief rivers and Niteal Creek. A small, inactive dune field (4 by 2 km) occurs in the eastern part of the map area, near the Fontas River.
Dune orientation is to the southeast, interpreted to reflect katabatic winds which were funneled between the Laurentide and Cordilleran Ice Sheets. The map area is susceptible to slope movement and there are a number of large landslides along the deeply entrenched river valleys, especially where
cutbanks incise thick (&amp;gt;10 m) Quaternary sediment, and poorly-indurated shale.

The map region is dominated by the presence of clast-poor tills and massive clays and silts unsuited for aggregate use beyond road-bed material. A very extensive mantle of organics throughout the study area adds difficulty in identifying granular aggregate resources. Possible sources are limited to
glaciofluvial gravels adjacent to meltwater channels, or occurring as glaciofluvial terraces. No gravel pits occur in the study area, although a significant, large aggregate deposit occurs just to the north at Elleh Creek (NTS 094J/09).

This map represents a product of the Shallow Gas and Diamond Opportunities in Northern Alberta and British Columbia project, conducted under the Northern Resources Development Program of the Geological Survey of Canada (Natural Resources Canada). The project involved the collaboration of the British
Columbia Ministry of Energy, Mines and Petroleum Resources, Oil and Gas Division, Resource Development and Geoscience Branch, and the Alberta Geological Survey (Alberta Energy and Utilities Board). This mapping exercise was also undertaken as part of an M.Sc. research project conducted by Trommelen
at the University of Victoria, British Columbia.