HAUTE MANA PROJECT
HAUTE MANA PROJECT
At the heart of a prolific historical gold district, the Haute Mana project covers 121 km² within the same greenstone belt as the Dorlin project that hosts the Nivré deposit. Although an earlier stage project when compared to Dorlin, Reunion expects this part of the district to deliver multiple gold targets during the coming year.
In December 2016, Reunion entered into an agreement with Union Minière de Saül (“UMS”), a private company in French Guiana. Under the agreement, Reunion has the right to acquire an 80% interest in the Haute Mana gold project by completing a preliminary economic assessment (“PEA”) on the project within a period of five years (the “Option Period”). Once Reunion has exercised its option, UMS can decide to retain its 20% participating interest, convert to a 5% NPI or sell its 20% interest at a price to be agreed upon at that time.
The Haute Mana gold project consists of eight mining concessions (the “Concessions”) which are up for renewal, covering an area of 121.5 km² in the central-south part of French Guiana. The property is 170 km SW from the capital city of Cayenne and accessible by a forest trail and aircraft. Geologically, the region is underlain by a Proterozoic greenstone belt composed of volcano-sedimentary sequences intruded by granitoids and cut by the prominent Sophie-Saul shear zone striking NW-SE and extending for more than 30 km. The Sophie-Saul shear zone is one of the most prolific gold producing area of French Guiana. At least six gold “camps” are known along this shear zone, mostly from artisanal work both in alluvial and primary sources.
The Haute Mana concessions were initially awarded to the Bureau Minier Guyanais (BMG) between 1909 and 1912 covering placer and vein gold prospects. Artisanal mining was carried out on the concessions from the late 19th century through the middle of the 20th century.
In the 1950’s, BMG identified several systems of gold-bearing quartz veins in the Sophie, Salomon, Dagobert, Felix and Nicole sectors of the property. Around 1974, BGM was replaced by a successor company, Bureau de Recherches Géologiques et Minières (BRGM), which set up joint ventures with several companies including Cyprus Mining Co., Guyane Ressources, KWG Guyane SARL and lastly Franc-Or Guyane SARL.
The region was extensively mapped and explored by BRGM in the eighties, including 4,500 m of auger and 772 m of diamond drilling.
Ressources Franc-Or did further exploration work in the nineties, including 79 line kilometers of soil sampling and 1,224 m of diamond drilling. The concession area has seen little other systematic exploration and is considered to have excellent potential for ‘shear-type” gold mineralization.
Geology and Mineralization
Gold mineralization at Haute Mana occurs mainly in quartz veins, where it is associated pyrite and lesser amounts of chalcopyrite, galena, pyrrhotite and tellurides. The veins also show evidence of hydrothermal alteration consisting of sericite, calcite and chlorite. Gold is present as free gold, in interstitial grains and also as inclusions in pyrite. Veins vary in thickness from 1 cm to 3 metres and are generally around 1 m thick. Veins are commonly hosted in shear zones in granodiorote intrusives but can also occur in Paramarca metavolcanic units near to contacts with intrusives. The Sophie-Saul shear zone strikes NW-SE and extends across the project, being one of the most prolific gold producing areas of French Guiana.
Vein continuity is variable, with some veins traced along strike for hundreds of metres and down dip for at least 100m, but veins can also pinch out after several metres. High gold grades and visible gold are relatively common in the veins. Drilling by BRGM in the Repentir sector, returned 14.8 g/t over 0.9 m and 22g/t over 1.8 m. The down dip extension of the vein was intersected at 75 m and had an apparent dip of 75 degrees NW.
These deposits are best considered as orogenic mesothermal gold deposits, similar to ones found in the Paleoproterozoic and late Archaen shield regions of Canada, Australia and West Africa. At the Omai gold mine in Guyana, quartz veins are hosted in a quartz monzonite which intruded the volcanic rocks of local greenstone belt. This geological and structural setting is not unlike that reported for the gold-bearing veins at Haute Mana. Omai produced almost 3.8 million ounces of gold between 1993-2005, when the mine closed.