Geology

The Lac à Paul apatite deposits are located in the Lac-Saint-Jean Anorthositic Suite (LSJAS), which belongs to the central part of the Grenville Geological Province. The LSJAS contains several lobes of proterozoic age. The regional metamorphism is generally upper amphibolite to granulite facies.
 

The Lac à Paul property consists mostly of mafic to ultramafic rocks (anorthosite, gabbros, norite, trocotites and also some pyroxenite, dunite and peridotite).

The apatite deposit of Paul Zone is located in the North-West part of the property. It is composed of a nelsonite stratabound lense in the North and a mineralized anorthositic gabbro (also called apatite gabbro) in the South. In the Eastern part of the zone, a third mineralized envelope, composed of a mix between nelsonite and mineralized anorthositic gabbro (mixed zone) is also observed.

From the geological model used for the resource estimate publish on the February 18, 2015.

 

The nelsonite is the rock of the deposit the richest in apatite. Nelsonite rocks form some metric lenses oriented EW with a vertical dip (70 to 85°) to the South.   Its true thickness is between 10 to 300 meters depending on the depth and its lateral position.
The mineralized anorthositic gabbro (or apatite gabbro) is directly in contact with south of the nelsonite on around 2/3 of the deposit.
This rock is more enriched in apatite close to the contact with the nelsonite. Its true thickness varies from 20 to 220 meters and increases in the Western part.
The mixed zone (mineralized anorthositic gabbro + nelsonite) is only present in the Eastern part of the deposit, in contact South of the nelsonite.  Its true thickness is between 10 to 100 m.
With the Western and Eastern Extension, the total length of the deposit is currently 3 700 meters. This envelope is near the surface (3m) and reaches up to 400m or vertical depth. The deposit is still open laterally and in depth.

 

Main exploration zones

Up-to-Date Resources on All Claims

The resources provided in this table were published in press releases from February 18, 2015, July 16, 2014, May 15, 2014 and November 8, 2011.

Resources Drill Results

(1) Cautionary Statements: Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
(2) Cautionary Statements: Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. There is no certainty that further exploration will result in upgrading this inferred resources in indicated and/or measured resources.

Igneous deposit vs sedimentary deposit

Phosphate rocks are classified into two groups based on the geological origins:


• Intrusive rocks of igneous (or magmatic) origin:  consist of mafic to ultramafic rocks (nelsonite of Lac à Paul) or alkaline rocks (phosphorous carbonatites).
• Sedimentary rocks : these deposits are generally sandstone coming from ancient skeletal of millions of marine life deposited on the ocean floors.

  Igneous Deposit Sedimentary Deposit

Rock grade

Between 4-15 % P2O5

Between 10-30 % P2O5

Mining and crushing

More difficult: hard rocks

Easier, because the rocks are unconsolidated

Concentration
(ore processing)

Easy separation and treatment
Recovery >90 %

Process less effective

Recovery between 65 % and 85 %

Concentrate grade

37-41 % P2O5

Average grade of 29 % P2O5

Concentrate quality

Contain very little or no contaminant

Usualy contain some contaminants (Heavy metals, uranium, cadmium)

 

Apatite and Ilmenite in Quebec : A World-Class Potential (presented at Québec Mines 2015) (French Language)

Apatite and Ilmenite in Quebec : A World-Class Potential
Published on October 18, 2016