On 25 October 2016 Variscan announced that it had been granted the Couflens licence, located in the Pyrenees region, covering an area of 42km2 centred on the Salau tungsten-copper-gold mine. Prior to its closure in 1986, Salau was one of the highest grade tungsten mines in the world, with an average recorded Life of Mine production grade of approximately 1.5% WO3.

Subsequently Apollo Minerals Limited (ASX: AON) acquired Ariege Tungsten SAS, the company in joint venture with Variscan over Couflens where it can maintain an 80% interest in the project by spending €2.5 million within 3 years, with Variscan free-carried until the completion of a successful DFS or the total expenditure of €25 million.

Salau Mine

The Salau skarn tungsten deposit is located approximately 130 km south of Toulouse, within the Pyrenees region near the border with Spain.

The deposit was discovered in 1964 by the BRGM (Bureau de Recherches Géologiques et Minières). Les Mines d’Anglade (LMA) operated the mine from April 1971 to November 1986 which is reported to have produced 0.93 million tonnes of ore at an average grade of 1.5% WO3 (Fonteilles et al., 1989) to yield approximately 11,500 tonnes of WO3 in concentrate. Notwithstanding the existence of remaining resources, the discovery of promising mineralised zones elsewhere (Fonteilles et al., 1989) and the much higher grade production from the last years of production (up to 2.48% WO3), the precipitous fall in the tungsten price caused by Chinese dumping in 1986 led to mine closure.


 Salau mine graph

 Salau mine production



Salau is a tungsten-bearing (primarily scheelite) skarn deposit developed at the contact between Devonian pelites and calcareous sediments (the ‘Barregiennes’) and a Hercynian-aged granodiorite stock (‘Fourque’). The skarn formed within both the carbonate-bearing sediments and, to a much lesser degree, the host granodiorite. Mineralisation is directly related to the Fourque granodiorite which provided hot, tungsten-gold-copper bearing solutions that reacted with the host rocks to form the skarns and deposit metal-bearing minerals.


 Salau geology targets digram

Plan view of the geology and targets with recorded scheelite occurrences at surface
around the Salau tungsten mine

Salau consists of two known mineralised systems, the ‘Bois d’Anglade’ embayment (North Formation, Gulf South Formation, Column and SC ore zones) and ‘Veronique’. Bois d’Anglade was discovered first and provided the bulk of the early production. Veronique, 300 metres to the west, was discovered in 1975 and provided higher grade tungsten production (average 1.9% WO3), including gold-rich material (not recovered in milling) towards the end of the mine life. In limited sampling this material graded around 10g/t gold in the lower section of the Veronique Southeast zone (Fonteilles et al, 1989).

The geometry of the orebodies at Salau is complex and appears controlled mainly by irregularities in the intrusive contact and by faulting. Two principal types of metalliferous skarns are developed:

Prograde skarns – initial metasomatism resulted in the formation of broad zones of prograde skarns containing modest tungsten values (0.2 to 0.5% WO3),

Retrograde skarns - later hydrothermal fluids overprinted the prograde skarns and deposited sulphide-rich material (mainly pyrrhotite) containing substantially higher values of tungsten, gold and copper. It is these sulphide-rich skarns which provided the bulk of the former production from Salau.

In a general sense Salau can be compared to the Mactung and Cantung skarn deposits of the Yukon, USA. These large tonnage, high grade systems, (e.g. Mactung, 44.8 Mt at 0.85% WO3 - Narciso H. et al, 2009) are skarn deposits formed by multistage granodiorite intrusions into calcareous sequences, similar to Salau.


 Salau mineralised zones

Composite long section through the Salau mineralised system showing the key
mineralised zones defined from previous exploration/mining. Approximate recorded
position of LMA underground drilling testing the lower section of Veronique shown in
yellow (red - >1.0% WO3, blue - low grade/barren). Source - Dr. Nick Le Boutilliere.

Exploration Targets and Upside

Previous underground drilling by the former mine owners recorded a number of high grade tungsten-bearing skarn intersections below the 1230 metre level access adit, the down-plunge continuation of the Veronique ore system. This enabled a non-JORC resource to be calculated by LMA with a similar tungsten grade to that derived from mining in the upper levels of Veronique. The system remains open at depth and is believed to contain substantial gold credits as stated in Fonteilles et al, 1989.

Potential also remains around the other previously mined areas (Veronique and Bois d’Anglade systems) where remnant zones of tungsten-bearing material appear present.

In addition, unexplored discoveries documented by LMA occur at “Ouer d’Aigle” and “Christine”, plus a number of other scheelite skarn occurrences at the surface on the flanks of the Fourque granodiorite.

Exploration Plan

The initial exploration work plan for the Couflens Project includes -

  •  Acquisition and digitisation of available mine and exploration data
  •  Mine area and old tailings area risk assessments
  •  Initial access and assessment of existing mine development and stoping areas
  •  Mapping and sampling of mineralisation exposed in previously developed mine areas
  •  Generation of a 3D model of the geology, zones of mineralisation and principal controls on mineralisation
  •  Underground drilling to confirm known zones of mineralisation and test for extensions of these zones
  •  Estimation and reporting of a Mineral Resource in accordance with the JORC Code
  •  Surface exploration programs to further assess identified prospects and generating new targets within the broader project area
  •  A second phase of exploration may include the development of an underground incline to provide access below the existing mine workings and to allow more extensive drill testing of the down plunge continuation of the high grade Veronique system and parallel structural positions

Initial work will focus on defining sufficient high grade tungsten mineralisation to justify commencement of mine feasibility studies, as well as testing the gold potential within and adjacent to the Salau mine area.

The Company will undertake the work program with a strong commitment to all aspects of sustainable development with an integrated approach to economic, social, environmental, health and safety management.