Projects
Dos Calandrias
Location
Dos Calandrias (formerly Tongoril) is 5,600 Ha in area and is located in eastern Santa Cruz, 20 km away from a paved highway and serviced by the port of Caleta Olivia, 150 km to the NE.
Ownership
100% Mariana
Previous Exploration
New discovery, no prior company exploration reported.
Geological Setting
Two Jurassic rhyolite domes rimmed by pyroclastics. Extensive hydrothermal breccias at Calandria Sur dome. NW and NE trending epithermal veins at Calandria Norte.
Exploration by Mariana
Following up of satellite imagery in 2008 discovered quartz-sulphide vein/breccias over two broad zones about 600m apart. Initial rock chips assayed up to 21.7 g/t Au, 62 g/t Ag.
The property was visited by leading geological consultant and epithermal specialist Dr. Richard Sillitoe in early 2009. He considered the rhyolite dome setting had potential for low sulphidation epithermal mineralization hosted by veins and breccias.
Sillitoe Tongoril Report Febraury 2009 (pdf)
Subsequent follow up of broad lag gold anomalies discovered further veins at Calandria Norte and breccias at Calandria Sur. Rock chips at Calandria Sur assayed up to 0.8 m @ 5.7 g/t Au and 241 g/t Ag and at Calandria Norte, up to 0.7m @ 20.2 g/t Au, 25 g/t Ag. Trench assays included 17.5m @ 1.9 g/t Au and 56.3 g/t Ag (Calandria Sur) and 2.7m @ 5.4 g/t Au incl. 0.7m @ 20.2 g/t Au 25.4 g/t Ag (Calandria Norte).
Calandria Sur - First Pass Drilling
Eight diamond holes were drilled (883m) with wide zones of gold and silver mineralization intersected in holes CSD 9, 12, 13, 15 and 16 along the brecciated dome margin. Results included:
- 91.5m @ 1.6 g/t Au and 17 g/t Ag from 3.5m (21m @ 4.5 g/t Au and 39 g/t Ag from 40m - CSD15.
- 71m @ 1.1 g/t Au and 23 g/t Ag from 23m (27m @ 1.9 g/t Au and 32 g/t Ag from 63m) - CSD16.
- 102m @ 1.2 g/t Au and 17 g/t Ag from 7m, (20m @ 2.6 g/t Au and 39 g/t Ag from 89m) - CSD13.
Review by Dr R Sillitoe
Dr. Richard Sillitoe carried out an appraisal of the drilling results (link to report 2). He concluded that Calandria Sur is a low-sulphidation epithermal discovery, located along the margin of a hydrothermally brecciated rhyolite dome. Mineralization is disseminated in character and appears to possess bulk tonnage potential. Moreover, he considered there is potential for mineralization elsewhere around the 1500m dome perimeter, of which only 400m has been tested to date. Highest gold grade intercepts abut the dome contact, hosted by silicified breccia and overprinted by a marcasite-pyrite stockwork. Gold-silver mineralization remains open below approximately 100m. He recommended a minimum 2,500-3,000m drill programme to undercut current holes and to test lag anomalies around the remaining dome perimeter, plus consideration of an IP survey in view of the association between the highest gold and silver values and marcasite-pyrite stockworks.
Sillitoe Dos Calandrias Report November 2009 (pdf)
Calandria Norte - First Pass Drilling
Eight holes for 800m tested two vein zones with best intersections of 10m @ 0.6 g/t Au from 54m in CND7 and 4.1m @ 0.9 g/t Au from 47m in CND3. Dr Sillitoe concluded that, although the shallow drill testing of the two mapped veins did not intersect high gold and silver values, at least one deeper hole is warranted.
Forward programme
An expansive drilling campaign is planned for Q1 2010 to undercut and infill the wide intersections obtained to date at Calandria Sur and to explore the remaining 1100m of untested dome perimeter. An IP survey will assist in defining targets.
Figure 1: Deseado Massif and location of Dos Calandrias Project. pdf
