Cordilleran Project

Summary

Introduction

Southeastern British Columbia contains two of the largest, most profitable (ca. $80B worth of metals extracted), and oldest (ca. 100 years) mining districts in the Cordillera: 1) Sullivan Pb-Zn mine (now closed);  and, 2) Highland Valley porphyry Cu-Mo district (10 years of production left).  The area also contains the most extensive and highest concentration of base metal mineral showing and mineral deposit types in the Canadian Cordillera.  However, mineral exploration has lagged in this area over the past 20 years, partly because of an obsolete (>30 year old) geoscience knowledge base.  Not only has diminished mining and mineral exploration activity affected resource-dependent communities, but the Mountain Pine Beetle infestation throughout much of the area potentially requires a shift in resource base to mining for many of the formerly forestry-based resource dependant communities.

The third Targeted Geoscience Initiative (TGI-3) Program is providing "mapping to help sustain the reserves of base metals in established mining communities” through a  5 year (2005 to 2010) $5M / year geoscience national program.  The activities of the TGI-3 Cordilleran Project in B.C. are linked with those of the Federal Mountain Pine Beetle Project (MPBP) and B.C. Geological Survey and Geoscience B.C.

The multi-agency TGI-3 Cordilleran project is helping to address the geoscience knowledge gap by improving the geoscience knowledge of established mining districts in southern British Columbia during its 5 year lifespan (2005-2010).  In doing so, it helps to reduce the exploration risks associated with extending known ore reserves and finding new ones. Five established, base metal deposit type targets will be investigated: 1) "Broken Hill- type" Pb-Zn-Ag deposits in high-grade metamorphic rocks of Paleoproterozoic age  (e.g.,. Ruddock Creek, Kingfisher, Cottonbelt, Jordan River, Ledge); 2) sedimentary exhalative (SEDEX) deposits in rocks of Mesoproterozoic age (e.g., Sullivan District, North Star) and Paleozoic age (e,g., Locojo, Keystone, Rift); 3)  volcanic-hosted massive sulphide (VHMS) deposits in rocks of Paleozoic age (Eagle Bay VHMS-bearing assemblage; e.g.,  Goldstream, Standard, Spire); 4) carbonate-hosted Pb-Zn deposits in rocks of Lower Cambrian age (e.g.., Reeves MacDonald, Jersey, Duncan, Bluebell, Wigwam); and, 5) porphyry copper deposits in plutonic rocks of Mesozoic age (e.g., Highland Valley (HVD) and Afton districts).

Most TGI-3 activities are focused on the following metallotects:  the Triassic-Jurassic arc (southern Quesnel Trough); high grade metamorphic rocks (of Paleoproterozoic age) of the Monashee Complex; Lower Paleozoic Kootenay Arc; and, Mesoproterozoic Purcell Basin.

Project Objectives

  1. Contribute to the TGI- 3 program goal of supporting Canada's base metal reserves in vulnerable mining communities.
  2. Identify geoscience information gaps critical to base metal exploration
  3. Assist the mining sector in evaluating and targeting exploration initiatives by providing a detailed, seamless, multi-parameter geological map of southern BC.
  4. Advance the 3D geological understanding of the Sullivan Mining Camp, BC.
  5. Establish the areal extent and nature of the Eagle Bay VHMS-bearing assemblage, and identify likely target areas prospective for base metal deposits.
  6. Fingerprint (geologically, geochemically, geophysically) established porphyry copper deposits as a means of targeting new exploration opportunities elsewhere in the Quesnel Trough belt
  7. Spark a renaissance in exploration activity in the Kootenay Arc belt via new maps and ideas
  8. Create partnerships with universities, BC Geological Survey, Geoscience BC, and, when appropriate, the mining and exploration industry.
  9. Contribute to filling the capacity gap in highly qualified personnel for the mining exploration industry by hiring and training (mentoring) undergraduate and graduate students and upgrading the skills of professional explorationists.  This is where there are opportunities for academic researchers and their students to contribute to the TGI-3 program.

The principal outputs will be new syntheses for Pb-Zn and for porphyry base metal deposits in the southern Cordillera.

Highlights

Pb-Zn synthesis

Prospective areas for Zn-Pb deposits in TGI3 project area include environments in the miogeocline, Purcell basin, Kootenay Arc, Monashee Complex and Eagle Bay assemblage.  Exploration risk for the various deposit types in these varied geological environments is reduced by:

  • publication of seamless geological maps in paper and digital form underway
  • completion of two 1:50K scale maps in the miogeocline and associated geochronology of sills (potential heat engines for development of mineralized dolomite diatreme breccia units);
  • publication of series of formerly proprietary maps and detailed data-sets associated with the Sullivan SEDEX district;
  • completion of project identifying and characterizing late Proterozoic and Mesozoic sulphide-bearing veins in Sullivan district;
  • stratigraphic, structural, geochemical and geochronological studies of prospective “rift sag” facies to identify major tectonic disruptions which may be related to SEDEX potential in the Sullivan district;
  • searchable data archive of geology, alteration, drill hole location, mine sections and grade/tonnage information for the Sullivan Mine;
  • evaluation of Sullivan district for (stratabound) Cu and (sill-associated) Ni-Cu-PGE potential and IOCG (Iron Range) potential via mapping, structural, mineralogical, alteration, and geochemical studies on whole rock and mineral samples;
  • reassessment of 25 carbonate-hosted Zn-Pb (±Ag) showings, prospects and former mines in southern Kootenay Arc, interaction with ongoing mineral exploration programs (e.g., Sultan Minerals, ReMac Zinc Corporation, and others) and comparison with classic Irish-type and Mississippi Valley-type deposits;
  • mapping, and geochemical analyses associated with new SEDEX-type barite discovery in black shales of the northern Kootenay Arc completed;
  • completion of detailed mapping, geochemical and geochronological work on the basin architecture of lower and middle Paleozoic rocks in the northern Kootenay Arc to identify structures contemporaneous with base metal mineralization;
  • completion of the GSC-GBC-industry funded multiparameter geophysical survey in southern Kootenay Arc; and
  • compilation and assessment of drill-hole and rock property information from proprietary database completed;
  • contributing to preservation of drill core library on Vine property.

Porphyry Cu-Mo Synthesis

Risks to mineral exploration in prospective areas north of the Highland Valley District (HVD) were reduced by:

  • release of 70 O.F. maps of aeromagnetic and radiometric data from Bonaparte Lake multiparameter geophysics survey, co-funded by GSC, Geoscience B.C. and industry; release of digital files via NRCan, Geoscience B.C. and BCGS MapPlace websites;
  • “ground-truthing” aeromagnetic anomalies by bedrock mapping and geophysical rock property measurements in central and northern part of survey footprint.  Mapping showed multi-phase (multi-episode) nature of northern Thuya Batholith with latest Triassic diorite and syenite phases most prospective for Cu and Au;
  • validating the geophysical data via 280 in-situ gamma ray spectrometry measurements and more than 3500 magnetic susceptibility measurements on outcrops as well as determining multi-parameter geophysical rock properties on 841 samples.  All will aid in ongoing modeling of the observed geophysical anomalies;
  • preparation of 9 surficial geology maps and collection of over 500  large (approx. 30 kg) and over 800 small (approx. 2 kg) bulk till samples for geochemical and mineralogical follow up studies;
  • collection of 500 biogeochemical samples linked to MINFILE and assay localities of known Cu mineralization will complement till geochemical sampling and help test radiometric anomalies;
  • mapping, geochronology (9 samples), geochemical and isotopic studies (67 samples) in the HVD provide “type” examples against which “unknowns” e.g. Thuya Batholith and regional mineralized plutons (20 samples) can be compared; and
  • new stratigraphy, ages, geochemical and paleomagnetic data and 1:20K and 1:250K scale maps of detailed and regional distribution of the Chilcotin Group cover rocks to help identify areas of thinnest cover.

Porphyry Mo exploration (MAX mine area)

Risks to mineral exploration for further porphyry Mo deposits similar to the MAX Mine reduced by:

  • detailed compositional, age, alteration and structural description of the MAX porphyry Mo mine; and
  • biogeochemical sampling over the MAX mine and in unexplored areas adjacent to it to identify new exploration targets.

Cordilleran project contact information:

Dr. Bob Anderson

Dr. Suzanne Paradis