Targeted Geoscience Initiative: Increasing Deep Exploration Effectiveness

The Targeted Geoscience Initiative (TGI) is a collaborative federal geoscience program that provides industry with the next generation of geoscience knowledge and innovative techniques, which will result in more effective targeting of buried mineral deposits.

TGI–Areas of Interest

A simplified bedrock geologic map and a shaded relief map are combined to give a textured geologic perspective of Canada

 

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TGI Increasing deep exploration effectiveness

A simplified bedrock geologic map and a shaded relief map are combined to give a textured geologic perspective of Canada. The features are shown in pastel colours as a backdrop to the Targeted Geoscience Initiative areas of interest (2015-2020). These sites are distributed across the country in most of the provinces and territories. There are 8 in Yukon, 2 in Nunavut, 6 in British Columbia, 1in Saskatchewan, 2 in Manitoba, 9 in Ontario, 6 in Quebec, 2 in Newfoundland and Labrador, 2 in New Brunswick, and 2 in Nova Scotia. There are 8 Volcanic and Sedimentary Systems, 6 Nickel, Copper and Platinum Group Elements, 7 Porphyry Systems, 3 Uranium and 14 Gold Systems and 1 specialty metal systems.

 

Current situation

  • Canada’s reserves of metals have been declining for more than 30 years.
  • Deeper exploration for new resources is required to offset the increasing rarity of surface discoveries

Focus of the TGI program

  • Developing more robust methods of determining if geological systems contain deeply buried ore and providing innovative exploration vectors to ore deposits, thus reducing the inherent risk and cost of mineral exploration.
  • Resolving geological processes that liberate ore metals from their source rocks, transport them and control their eventual deposition.
  • Developing new and improved geoscience knowledge and techniques to enhance modelling and detection of Canada’s major mineral systems.
  • Training and mentoring students to increase the number of highly qualified personnel available to the mineral industry.

Program design: Ore System Approach

TGI uses an ore system approach to project definition. This approach will guarantee that the best-suited deposits are used to support the development of next generation of exploration-related geoscience knowledge and methods.

  • TGI is a knowledge-based, thematic program that uses the best examples of ore systems from across Canada.
  • Projects and activities are not centred in a geographic region. Instead, they are thematic and integrate data and knowledge from multiple sites across the country (see map).
  • Scientific hypotheses underpin the program and define the critical knowledge gaps within ore systems.

TGI Projects

I.  Uranium Systems

Canada is the world’s second largest uranium producer and with demand projected to increase, new exploration models are required to meet demand and support existing mining communities. The uranium project will focus on: (1) key unresolved factors controlling mineralization and deposition of high-grade, large tonnage unconformity-related ore bodies; and (2) sources and processes of uranium enrichment in iron oxide-alkali alteration systems that host iron oxide-copper-gold (IOCG) deposits.

The Uranium Fluid Pathways subproject will focus on novel means of identifying the fertile faults that are the main fluid conduits during formation of unconformity-related uranium deposits.  Through application of geochemical, isotopic, mineralogical and geophysical data analysis, the study aims to examine the role of long-lived reactivation of crustal-scale shear zones and quantify ore-related demagnetisation/alteration along structural trends and the intersections of crustal-scale faults.  A component of the subproject will also evaluate the role of marine brines in the formation of ‘giant’ uranium deposits, following on from recent studies that suggest marine brines play a critical role in scavenging metals from source rocks and efficiently transporting ore to form large tonnage uranium deposits (e.g., Athabasca Basin deposits, Olympic Dam IOCG).

The Uranium-Rich Deep Metasomatic Processes subproject will address sources and processes of uranium enrichment in iron oxide-alkali alteration systems that host IOCG and similar deposits by evaluating the spatial and temporal fluid-metal evolution of these metasomatic systems. By integrating the effects of deep, high-temperature alteration through to shallower low-temperature environments, the subproject aims to modernize the genetic model for metal/fluid sources, fluid pathways and ore formation through primary to remobilized ores.

Subprojects & Activities:

I. Uranium Fluid Pathways

U-1.1 - Fingerprinting fertile fluid corridors in the formation of unconformity-related deposits using non-traditional isotopes (Lead: V. Tschirhart)

U-1.2 - Role of marine brines in the formation of giant uranium deposits (Lead:  E. Potter)

2. Uranium-rich Deep Metasomatic Processes

U-2.1 - Metal pathways and traps in polymetallic (U +/- Fe, Cu, Au, REE) metasomatic ore systems (Lead:  E. Potter)

Latest Uranium Project Publications:  Publications

2010-2015 Uranium Synthesis results: Uranium

II.  Porphyry-related mineral systems

For porphyry systems, the two main knowledge gaps in the ore-forming process are: 1) How, when and why do parental magmas gain sufficient metals to produce world-class, supergiant metal deposits; and 2) How, when and where are metals deposited into economic ore concentrations?

The Porphyry-related mineral systems project will study porphyry-related processes at all stages of ore formation to identify controls influencing the fertility of primary magmas, and how metals are transported and concentrated within the mid- to-upper crust.  The Mineral Markers subproject will focus on resolving information stored within the chemistry and mineralogy of silicate and sulphide minerals to study questions pertinent to specific processes operating at discrete points within the source-to-sink evolution of porphyry ore-forming systems. The Arc-related Porphyry and Post-orogenic Porphyry subprojects seek to define the evolution, timing and systemic controls on the occurrences and characteristics of porphyry-related mineralization within accretionary orogenic and post-orogenic settings.

Sub-projects & Activities:

1. Cordilleran Cu±Mo±Au porphyry mineralization in space and time

P-1.1. - Geochronology and subduction controls on the nature and spatial distribution of Cordilleran porphyry-related deposits (Lead:  J. Chapman)

P-1.2. - Deep mineralization processes within porphyry Cu-Au deposits of the Canadian Cordillera (Lead:  J. Chapman)

P-1.3. - Integrated 3D model of magmatic-hydrothermal evolution in the Guichon Creek Batholith (Lead:  E. Schetselaar)

2. Appalachian post-orogenic porphyry systems in space and time

P-2.1 - Linking characteristics of post-orogenic, polymetallic porphyry-style ores to tectonically-driven temporal and spatial controls across an accretionary orogen (Lead: D. Kellett)

3. Mineral markers of porphyry processes

P-3.1 - Deconvolution of complex spatial-temporal records of porphyry fertility recorded in till minerals (Lead:  A. Plouffe)

P-3.2 - Controls on the fertility of porphyry W-Sn-Mo-Zn mineralizing systems recorded in scheelite and tourmaline (Lead:  B. McClenaghan)

Latest Porphyry Project Publications: Publications

2010-2015 Porphyry Synthesis results: Intrusion-Related Systems

III.  Gold Systems

Many of Canada’s largest gold deposits are spatially associated in defined clusters of deposits, or gold districts, which point to common ore-forming processes and/or sources. The precise mechanisms that control the uneven distribution of these exceptional concentrations of gold through space and time represent knowledge gaps that hamper the development of predictive ore forming models, even within some of Canada’s classic gold districts.  These knowledge gaps include source, transport mechanisms, and concentration processes (source-to-ore).

This project will focus at a district to regional scale, to develop innovative ideas on source(s), conduit(s) and depositional mechanisms for gold enrichment through space and time.  The project will focus on measurable markers of ore forming processes, with the intention to develop predictive models that will help target areas with greater potential for gold, even where direct indicators to ore may be subtle or lacking.

Sub-projects & Activities:

1. System controls on gold through space and time

G1.1 - Gold through space and time at the Archean (Lead: P. Mercier-Langevin)

G1.2 - Mantle gold mobility (Lead: C. Lawley)

G1.3 - New approaches to dating hydrothermal gold deposits (Lead: B. Davis)

G1.4 - Fingerprinting ore processes in auriferous systems (Lead: S. Jackson)

2. Tectonic influences on gold

G2.1 - Deep faults, synorogenic clastic sequences, alkaline magmatism and gold deposits: testing and refining the Timmins-Kirkland Lake model in areas with high gold potential (Lead: W. Bleeker)

G2.2 - Proterozoic gold and its tectonic triggers and traps (Lead: C. Lawley)

G2.3 - Phanerozoic orogenic gold and crustal-scale faults: ore-forming mechanisms at different depths (Lead: S. Castonguay)

G2.4 – Lithotectonic controls on Paleoproterozoic gold distribution in the Archean rocks of the Amaruq area, Nunavut (Lead: P. Mercier-Langevin)

G2.5 - Lithotectonic controls on the genesis and distribution of the carbonate replacement-type ("Carlin-style") gold zones of the Rackla gold belt, Selwyn Basin, Yukon (Lead: N. Pinet)

Latest Gold Project Publications: Publications

2010-2015 Gold Synthesis results: Lode Gold

IV.  Nickel-Copper-PGE-Chrome Systems

Magmatic ore deposits of Ni-Cu-PGEs, Cr, and Fe-Ti-V represent an important class of mineral deposits across Canada, forming the backbone of a number of established and emerging mining camps (e.g., Thompson, Raglan, Sudbury, Voisey’s Bay, Mid-Continent Rift (MCR), and Ring of Fire). They are the product of magmatic ore systems, fueled by large volumes of deep-seated magma derived from the Earth’s mantle. Within these larger magmatic systems, the majority of mineral deposits form near the magmatic centre of the system, often in clusters, where magma fluxes are highest and more focused, and the geological conditions are more dynamic (e.g., rifting, upwelling mantle, trans-lithospheric faults, active magma conduits).

The Nickel-Copper-PGE-Chrome project will advance the geoscience knowledge of this class of deposit, and their fundamental ore systems, by integrating data across all scales, from the deposit scale to the full magmatic system scale. Key questions such as. the magma source and its composition (source, and its fertility); melting processes; magmatic conduits; where were the highest fluxes; where and how were metals concentrated (traps); sulphur sources and timing of sulphide saturation; local and regional stratigraphic controls; and which specific magmatic pulses were most productive, and what  were their specific tectonic drivers or triggers will be addressed?

Sub-projects & Activities:

1. System scale and deposit scale controls on Ni-Cu-PGE mineralization in cratonic areas and their margins

NC-1.1 - Extent, origin and deposit controls of the 1883 Ma Circum-Superior large igneous province, northern Manitoba, Ontario, Nunavut, Quebec, and Labrador (Lead: W. Bleeker)

NC-1.2 - Localization of high-value footwall mineralization within the Sudbury Impact Structure (Lead: W. Bleeker)

NC-1.3 - Controls on the localization and timing of mineralized intrusions in the intra-continental rift systems (Lead: W. Bleeker)

2. Magmatic architecture of Cr-bearing ore systems

NC-2.1 Architecture of Magmatic conduits in Cr-PGE/Ni-Cu-PGE ore systems (Lead: M. Houlé)

NC-2.2 - Ni-Cr metallotects: Synthesis, update, and revised models for the Superior Craton (Lead: M. Houlé)

Latest Nickel-Copper-PGE-Chrome Project Publications: Publications

2010-2015 Nickel-Copper-PGE-Chrome Synthesis results: Nickel-Copper-Platinum Group Element-Chrome

V.  Volcanic and Sedimentary Systems

Volcanic- and sedimentary-hosted mineralisation encompasses a diverse array of deposit types (e.g., VMS, SEDEX, MVT), that share common genetic processes, and in some cases, spatial and temporal linkages. Aspects that will be investigated include: metallogenic ties between SEDEX and MVT deposits; the potential role of magmatism in SEDEX formation; ore-fluid properties and metal complexation, transport, and fluid pathways; the role of ambient conditions such as anoxia and euxinia; and the hydrogenous origin of metals in HEBS. The results will advance knowledge of the respective roles of metal sources, fluid migration and ultimately deposition in space and time. The project will provide the basis for enhanced genetic and exploration models, particularly for deeply buried or concealed deposits.

The Seafloor Ore Deposition subproject will determine the sources of metals, ligands and other components in VMS, SEDEX, and HEBS deposits; identify transport pathways; and determine the role of ambient conditions (e.g., anoxia, euxinia) in or near seafloor ore deposit formation.

The Base Metal Sources and Mineralizing Processes subproject will investigate the primary genetic connections between sedimentary deposits and magmatic systems, identify key physico-chemical/isotopic features of ore fluids; and identify the depositional controls by placing mineralising events in temporal and spatial context.

Sub-projects & Activities:

1. Seafloor ore deposition through space and time

V-S 1.1 - Role of anoxia, euxinia and microbes in seafloor hydrothermal sulphide (VMS and SEDEX) deposit formation (Lead: J. Peter)

V-S 1.2 - Development of genetic and exploration models for hyper-enriched black shale (HEBS) deposits of the Ogilvie and Richardson Mountains, Yukon (Lead: J. Peter)

2. Base metal sources and mineralizing processes

V-S 2.1 - Is there a genetic link between SEDEX and MVT deposits of the Canadian Cordillera? (Lead: S. Paradis)

V-S 2.2 - Magmatism and relationships to sediment-hosted Zn-Pb deposits (Lead: S. Paradis)

V-S 2.3 - Elucidating VMS mineralising fluid pathways from the geophysical responses to hydrothermal alteration (Lead: E. Schetselaar)

V-S 2.4 - Fingerprinting fluid source regions and pathways of volcanogenic massive sulfide deposits (Lead: J. Peter)

Latest Volcanic and Sedimentary Project Publications: Publications

2010-2015 Volcanic and Sedimentary Synthesis results: