Map of potential Critical and Strategic Mineral (CSM) concentrations in Greece: Mineral systems, deposit types, and exploitation prospects

The map below depicts the potential concentrations of Critical and Strategic Minerals (CSM) in mines, deposits, and mineral occurrences (mineralisations) in Greece. It constitutes a synthetic representation of available public geoscientific data, with emphasis on the geographical distribution and genetic classification of occurrences.

The map is organized around two main mineral systems, as defined in international economic geology:

1. Chemical weathering mineral system
Includes deposit types resulting from epigenetic erosion and concentration processes under tropical or subtropical climatic conditions:Nickel laterites (Ni, Co)

• • Aluminum bauxites (Al, Ga, Sc, REE)
  • Supergene manganese (Mn)
  • Phosphorites (P, REE)
  • Nickel laterites (Ni, Co)
  • Placer monazite (REE)

2. Magmatic/Hydrothermal mineral system
Includes types associated with igneous and hydrothermal activity:

• Porphyry copper-gold (Cu, Pd)
• Skarn (Cu, W, Mo, Bi)
• Polymetallic carbonate replacement Zn-Pb-Ag-Au (As, Sb)
• Volcanogenic massive sulfide (VMS) Zn-Pb-Ag (Cu, Ge)
• Epithermal gold (Cu, Bi)
• Alkaline magmatism (REE, Li, Be, B)
• Intrusion-related veins (Sb)

In the upper left quadrant, all deposit types found in Greece are listed, regardless of whether they belong to the two systems above, along with associated SCM (e.g., germanium in VMS, gallium and scandium in bauxites, REE in monazite).

The central table (25 entries) provides:

• Location name / Regional Unit
• Mineral system and deposit type
• Metal symbol (e.g., Ag, Al, Co, REE, Sb, W, Zn)
• Metal name

The locations are generalized and the sites indicative, to facilitate an overview of CSM potential at a national scale.

Considering geoscientific terminology:

1. In some cases, the term "Metallogenetic System" is chosen over the broader "Mineral System" in maps, which refers exclusively to metallic minerals (from which metals are produced).
2. Internationally, however, "Mineral System" is more accurately rendered because it also includes industrial minerals (gypsum, halite, etc.).
3. Coastal placer monazite (REE) appears, although genetically it might be related to the chemical weathering system, it typically belongs to the "Placer Deposit Mineral System," associated with long-term erosion and sedimentation.

A critical element of the map is the distinction based on deposit "maturity":

• Active Mines (first line of potential SCM exploitation)
• Inactive/Dormant Mines
• Mineral Reserves
• Mineral Resource
• Mineral Occurrences/Mineralisations (indications without documented economic viability)

The presence of CSM in active mines makes them candidates for immediate evaluation as by-product minerals.

More relevant data in the table below, where a proposed categorization with symbols is made based on existing mining activity.

Besides aluminium, nickel, and copper (which are primary and strategic for the EU), the CSM shown in parentheses are usually by-product constituents. Their utilization as by-products can:

• Increase a deposit's viability
• Maximize the developmental contribution of mining activity

For CSM to become actual "national by-products," an integrated mining industry (from ore mineral to metal compound) is required: from extraction to metallurgical production within the country.

Example: Gallium production from bauxites in Greece is feasible because there is an integrated full-scale alumina and aluminium industry. Conversely, without this integration, the added value (know-how, employment, taxes, commercial benefit) is transferred abroad.

The above demonstrates that Greece already has an integrated line (a resource-efficient value chain operation) only for bauxite/aluminium, a fact that allows it to produce gallium. For the remaining CSM, "mature" deposit research is not enough; industrial policy for vertical integration is needed.

Conclusion: A country truly possesses CSM (and mineral wealth in general) only when it can produce them in metallic form within its territory, operating the entire value chain in an integrated, circular, and domestic manner.

The map below illustrates the distribution of strategic and critical mineral occurrences across Greece, organized by mineral system type and deposit style. It highlights a wide range of resources, including volcanogenic massive sulfides (Zn-Pb-Ag with Ge), bauxite (Al-Ga-Sc-REE), laterites (Ni-Co), magnesite (Mg), sedimentary phosphorites (P), magmatic chromite (Cr with Pt-Pd), porphyry Cu-Au-Pd deposits, intrusion-related veins (Sb), supergene Mn, replacement polymetallic ores, placer monazite (REE), graphite, skarn (Cu-W-Mo-Bi), epithermal Au, and magmatic alkaline occurrences (REE-Li-Be-B).

The map categorizes these into two broad mineral systems:

• Chemical weathering mineral system (laterites, bauxite, supergene Mn, phosphorites)
• Magmatic/Hydrothermal mineral system (porphyry, skarn, carbonate replacement, VMS, epithermal, magmatic alkaline, intrusion-related veins)

A table lists 25 indicative sites by name, regional unit, mineral system, and critical metal symbols (e.g., Ag, Al, Au, Co, REE, Sb, W, Zn). The map also differentiates occurrences by level of geological confidence (active mines, dormant mines, confirmed reserves, probable reserves, mineral occurrences).

Importantly, while Al, Ni, and Cu are primary (and EU-strategic) commodities, most SCM shown in parentheses occur as by-products. Their economic viability depends on vertical integration of the extractive metallurgy chain. Greece produces gallium from bauxite because it possesses an integrated alumina/aluminium industry; otherwise, the added value of most SCM would be captured abroad. Therefore, a country truly owns its SCM only when it can produce them in metallic form domestically, through a fully integrated, circular, and local value chain.

Hofstra, A.H., and Kreiner, D.C., 2020, Systems-Deposits-Commodities-Critical Minerals Table for the Earth Mapping Resources Initiative (ver. 1.1, May 2021), U.S. Geological Survey Open-File Report 2020-1042, 26 p., https://doi.org/10.3133/ofr20201042.