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Glacial Geologic Framework and Drift Prospecting for a Portion of the QUEST Project Area

Lead Researcher(s):  B. Ward

Project ID:  2007-026

Key Research Organization(s):  Simon Fraser University

Project Location:  Central Interior

Strategic Focus Area:  Minerals

Summary



The area of mountain pine beetle infestation in central British Columbia has areas of highly prospective bedrock geology, but exploration has been limited due to thick cover of surficial deposits. Knowledge of the glacial history, specifically the ice flow history and dominant transport direction is vital to interpret geochemical surveys. Significant knowledge gaps exist in the glacial history of the QUEST area and thus pose a significant hindrance on exploration. This project was designed to address these knowledge gaps by providing a Quaternary framework and both regional and detailed till based geochemical surveys. Glacial Geologic Framework and Drift Prospecting in QUEST Project area

The project stimulated exploration in beetle kill affected areas by the release of new surficial geology and geochemical survey data and provided a framework for companies to interpret their own datasets. The project also provided invaluable training for at least two M.Sc. students and numerous undergraduates. This ambitious project occured over three years and provided:

  1. The regional glacial geologic framework for NTS 93 G, H (west half), and J from the central portion of the Quest area.
  2. A map of approximate drift cover for areas within NTS 93 G, H (west half), and J based on existing terrain, soils, and surficial geology mapping as well as forestry-related terrain mapping.
  3. Terrain mapping of six 1:50,000 scale sheets
  4. Till geochemical (trace, minor and major elements by aqua regia-ICP and INAA) and gold grain counts and heavy mineral separates of these new sheets,
  5. Detailed geochemical surveys down ice of two geophysical anomalies from the recently completed geophysical surveys.
Geoscience BC Map 2010-14-1 shows relative drift thickness in north-central BC, covering NTS mapsheets 93G, 93H/w and 93J/s. Constructed from previous mapping and recent field-checking, the map is intended as an aid to mineral exploration, providing information on the distribution and relative thickness of surficial sediments and generalized ice flow history. This will help to determine areas that are more suited for drift prospecting and bedrock prospecting, as well as provide guidance as to the dominant transport direction when interpreting the results of geochemical surveys. The map in PDF format, the ESRI ArcGIS map document and data used to produce the map are included in this release. The datasets include ice flow indicators, drift thickness and outcrop locations, along with base map features providing background context. The report is by D.M. Maynard, B.C. Ward, M. Geertsema, N. Roberts and D. Sacco.

In Geoscience BC Report 2013-08 the maps contained within this report show ice flow patterns for NTS 093G, H (west) and J, and detailed ice flow history for parts of NTS 093J (near Prince George, BC). The report also contains a regional ice flow model for the northern Interior Plateau region. Constructed from previous mapping and recent field studies, the report is intended as an aid to mineral exploration in central BC. The report consists of one PDF sheet, and the ESRI ArcGIS shapefiles of striations, regional ice flow and detailed ice flow data.

Geoscience BC Report 2013-10 comprises six 1:50,000 terrain maps in the McLeod Lake map sheet (NTS 093J), as well as a digital data package. The maps are hybrid surficial geology / terrain maps that were produced using standardized terrain mapping methods. Surficial material, surface expression and geomorphological processes were used to delineate terrain polygons on 1:40,000 black-and-white aerial photographs. The map legend is a closed, surficial geology format based on the dominant surficial material and is used to assign polygon colours. Individual polygon labels can contain more detailed terrain information based on the terrain classification system. Where applicable, additional polygon information such as sediment descriptions and minor surficial materials and surface expressions are recorded in the terrain database.

The maps will be useful to the resource industry by indicating areas that contain till and therefore can be used in drift prospecting. The maps can also be used to identify various types of granular resources, such as aggregate for road building, fine grained (clay) material for lining tailings ponds, and bulk fill.

Geoscience BC Report 2013-15 presents a large dataset and summarizes the results of regional till surveys and Quaternary studies conducted in the heart of the QUEST Project area. Regional-scale till sampling followed by detailed surveys around samples with elevated or anomalous values were carried out to assess the mineral potential, specifically targeting Cu-Au porphyry and volcanogenic massive sulphide (VMS) mineralization. Till is the preferred sampling medium for geochemical and mineralogical surveys in glaciated terrain such as in the QUEST area, because it is considered a first derivative of bedrock and has been shown to aid in identifying potentially mineralized bedrock units covered by thick glacial deposits. Along with the analytical data, this report describes these till sampling surveys and graphically displays the results from detailed aqua-regia ICP-MS and INAA analyses to help vector exploration efforts.

Thick surficial deposits within the QUEST Project area have hindered mineral exploration activity. Regional-scale till sampling followed by detailed surveys around samples with elevated or anomalous values was carried out to assess the mineral potential of this area, specifically targeting Cu-Au porphyry and volcanogenic massive sulphide (VMS) mineralization. Till is the preferred sampling medium for geochemical and mineralogical surveys in glaciated terrain because it is commonly considered a first derivative of bedrock and has been shown to aid in identifying potentially mineralized bedrock units covered by thick glacial deposits.

The results include aqua-regia ICP-MS analysis on the clay fraction, INAA on the silt plus clay fraction, INAA on heavy mineral separates and mineralogical data including counts of gold grains, pyrite grains and cinnabar grains from the heavy mineral fraction. The clay fraction, digested by aqua regia with an ICP-MS finish, provides a more robust data set with lower detection limits than the coarser fraction by INAA.

All raw data is attached in appendices, which give exploration geochemists regional data sets to compare with property-scale geochemical results. The geochemical data are also graphically displayed and some broad interpretations are made in terms of potential mineralization, such as porphyry Cu-Au, VMS, precious and base metal veins and mercury. Many of the geochemical anomalies suggested by the mapped data are not explained by known mineral showings.

Deliverables