BC’s northern Interior Plateau region south of Vanderhoof and west of Quesnel is covered by a thick layer of glacial sediments and young volcanic rocks. This cover hides the complex geology of the area and potentially untapped mineral wealth and geothermal resources hidden within. Surficial sediment geochemical and mineralogical anomalies can be used to locate buried mineralization.
The TREK Surficial Geochemistry project:
- Generated regional-scale, detailed, high-quality earth science data and information for BC’s underexplored Interior Plateau
- Provided a clearer understanding of the surficial geology and mineral potential in central BC
- Directly stimulated on-the-ground activity to explore for hidden mineral deposits in an area where several rich gold, silver, and copper deposits have already been discovered
Indigenous groups, communities, the mineral exploration sector and land managers need access to reliable earth science information to make informed decisions in the TREK area where mineral potential is high.
Although most of the TREK program area is covered by glacial sediments, geochemistry and mineralogical anomalies can be used to locate buried mineralization. Basal till (a subset of glacial sediment) is ideal for assessing bedrock-hosted mineral potential as it is commonly a first derivative of bedrock, has a relatively simple and predictable transport history and produces a geochemical and mineralogical signature that is more extensive than its original source. The basal till potential maps developed through this project provide information on the potential to find basal till throughout the project area, and the associated geochemical and mineralogical data provides a regional dataset which can be used to assess the mineral potential of the project area.
The TREK program covered a 24,000 km2 area in BC’s central Interior Plateau from Anahim Lake in the west, Vanderhoof in the north and Williams Lake in the east. The Blackwater Gold Project is located in the centre of the program area, about 160 kilometres southwest of Prince George.
How was the data collected?
Basal till potential maps were created using digital aerial photos. Outlines of existing surficial geology contacts were superimposed on the photos, and modified/updated based on observations. Emphasis was placed on differentiating basal till from ablation till, as the latter is not suitable for geochemical sampling. A classification scheme was then applied to the mapping to highlight areas where basal till is most likely to occur.
The basal till potential maps were then used to guide a geochemical sampling program. Samples were collected from natural or anthropogenic exposures such as roadcuts, borrow pits, hand and machine dug soil pits and river and lake cuts. Samples typically were 2-3 kg in size.
What was found?
Geoscience BC Reports 2014-06 and 2017-02 (BCGS Open Files 2014-06 to -15, and 2017-02 to-07) contain 16 basal till potential maps for the TREK program area. By identifying areas where basal till is most likely to occur, the maps are intended to help design mineral exploration projects and guide surficial sediment geochemistry and mineralogy sampling programs.
Geoscience BC Reports 2014-10 and 2015-12 present the geochemical and mineralogical results obtained from analysis of samples collected throughout the project. Basal till is the primary sample medium of the geochemistry survey and is targeted using basal till potential maps discussed above. Lake sediment samples were collected to fill in coverage gaps throughout the project area.
Geoscience BC Report 2015-09 presents the geochemical data for 1,456 archived (previously collected) till samples from the project area.