Gralheira, Portugal - Gold Mining Exploration

Application:Targeting deep extensions in vein systems

The Gralheira deposit lies some 700m (2,300 feet) north of the Jales mine in Northern Portugal and is contained within an extensive mineralized shear zone that extends for some 3,000m (9,800 feet). Romans mined both the Jales and Gralheira deposits; at Gralheira, the Romans mined along a strike length of 2,000m (6,500 feet). The main gold mineralization at Jales is hosted within a system of sub parallel veinlets and veins ranging from 0.5m to 1.5m in width. The Jales was mined to a depth of around 620m (2,000 feet) and is known to be a mesothermal system. Geological theory tells us that mesothermal veins can have great depth extension. The vein system at Gralheira is also mesothermal. Previous drilling has tested the depth extent of the surface veins in the range of 150 to 300 metres. St Elias Mines was intent on proving the system continued to depth and required a means for drill targeting.

St. Elias Mines Ltd.
Jales Property, Portugal

Hercynian Granites
Guilhado Granite - two mica
Muscovite Granite
Jales Granite - two mica
Fonte Verde Granite - two mica

Unnamed Formation (Silurian)
Carbonaceous Schists & Pelites
Phylites & Siliceous Schists

Armorican Formation (Lower Ordovician)

Douro Supergroup (Pre-Ordovician)
Mica Schists, Greywacke, Rare Marble, or Skam

Purpose: The intent of the Titan 24 survey was to provide deep information that would directly enhance the exploration efforts in the vicinity of the mine, particularly providing drill targets that could be related to satellite ore bodies. By mapping the resistivity and chargeability of the subsurface to assist the geologic understanding away from previously drilled environments, a focused program could reduce overall drilling costs by eliminating low potential ground from exploration drilling.

Challenges: Old mine workings, cultural noise, small targets, and deep complex environment.

Survey: The Titan survey was executed on 5 lines, each line was 2.4 km in length and line spacing was roughly 200 metres. The survey was carried out in December and results were made available early in the new year.

Results: The Titan 24 survey identified over fifteen major chargeability high and resistivity low anomalies that are consistent with vein-gold mineralized zones and lie buried between depths of 100-750m. Anomalies are oriented along 5 linear trends (A-E) that extend across the property. Zone A corresponds to the main Gralheira vein system. It is mapped from surface to depths between 500-750m as an IP high feature. It shows potential deep extensions along L100W in particular, L700W and possibly 250E. Deeper ore shoots are implied between 400E and 300W along the baseline. Additional secondary veins are indicated north of the main Gralheira system. Typical Titan 24 data sections for chargeability, resistivity and deep MT resistivity are shown below for one of the lines.

Shallow Chargeability Targets (less than 500m)
Deep Chargeability Targets (greater than 500m)
Low Resistivity Zone Extending To Depth
Deep Low Resistivity MT Targets (greater than 500m)

Titan applications for gold exploration:

Deep structural mapping, shears, faults etc.
Disseminated sulphide distribution (surface to depths of 500m and more)

Follow-up Drill Results:

NEWS RELEASE JALES/GRALHEIRA GOLD PROPERTY , PORTUGAL
DRILLING CONFIRMS GRALHEIRA SYSTEM CONTINUES TO DEPTH

News Release 2005-20, September 6, 2005

Lori McClenahan, President of St. Elias Mines Ltd., and Mr. Alan Matthews, C.Eng., President of Kernow Resources & Developments Ltd., (collectively the “Companies”) are pleased to provide the following results from the recently completed drilling program on the Jales/Gralheira Gold Property (the “Property”) in Portugal . The program consisted of 11 drill holes that totaled 3,978.23 meters (13,048 feet or nearly 2.5 linear miles) of drill core.

The drill program has intersected high-grade gold and silver mineralisation. The drill program successfully achieved its primary objectives of significantly expanding the depth dimensions of the mineralised structures at Gralheira and confirming the TITAN 24 geophysical results.

The drill program successfully intersected mineralisation up to 511m below surface with most drill holes intersecting mineralisation between 380m and 480m below surface. Prior to this drill program, the majority of holes previously drilled along the 2,000m strike length of the Gralheira tested for mineralization only between the surface and a depth of 200m. The single deepest previous intercept was 300m below surface.

Targeting of the current set of drill holes completed on the property was guided by the results of the TITAN 24 geophysical survey completed in late 2004 and by known geology. The TITAN 24 survey showed that the depth extent of the mineralised system could be in excess of 1,250m. (See news release dated March 9, 2005). This drill program has greatly increased the known dimensions of the deposit. All drill holes that tested the Gralheira system intersected the main structure(s). Significant intersections are as follows: click here for the full pdf