Geology & Drilling

Geology

The Ixtaca zone occurs in deformed carbonate rocks about two kilometres southwest of the Tuligtic’s porphyry copper zone (drilled in 2009-2010). Surface manifestation of the Ixtaca zone is very obscure because the region is almost completely covered with volcanic ash. Reports of historic clay mines brought Almaden’s attention to the area.

The epithermal gold-silver target area is characterised by extensively clay altered and silicified volcanic rocks. The alteration is indicative of the upper parts of an epithermal system and includes replacement silicification and sinter, the precipitate or sediment that was deposited from a hot spring. Quartz-calcite veins with textural evidence of boiling have been identified outcropping in limestone roughly 100 meters beneath the exposed sinter.

Initial sampling of these veins and from float boulders of breccia containing quartz vein fragments returned anomalous values in gold and silver as high as 600 g/t silver and 6.1 g/t gold. The sinter and the overlying altered volcanic rocks are highly anomalous in mercury and arsenic. The Ixtaca’s kaolinite and replacement silica alteration zones are typical of the surface manifestation of an ancient hotspring environment. Within the feeder faults which channel hot mineral solutions from depth to surface hotsprings, quartz, carbonate, gold and silver can deposit.

This was the model employed by Almaden in testing the Ixtaca Zone where, in an arroyo beneath the kaolinite and silica alteration, some very narrow (0.1 to 3 centimetre) veins with epithermal textures occur in a small (about 2 metres by 5 metres) outcrop. These veins assayed up to 1 g/t gold and 110 g/t silver. Small cobbles of float in the creek returned assays of up to 600 g/t silver and another such cobble assayed 6.0 g/t gold. Work prior to drilling included a single Induced Polarization geophysical line across this area which detected a resistivity anomaly and several short geochemical soil sample lines showed coincident anomalous gold and silver values.

Drilling

The Ixtaca Zone is largely covered with altered volcanic ash. However, some narrow veins with epithermal textures come to surface in a small outcrop. Preliminary soil sampling of the area returned up to 1.0 g/t gold and 110 g/t silver.

In 2010, a drill program was designed to test a small outcrop. Due to the limited surface exposure of the Ixtaca vein system, three holes were fanned out in a small area, each in a different direction. In August , Almaden reported assay results from first hole ever drilled in the Ixtaca zone: TU-10-01 intersected 302.42 metres of 1.01g/t gold and 48g/t silver and multiple high grade intervals including 1.67 metres of 60.7g/t gold and 2122g/t silver.

Following Discovery Hole TU-10-01, drilling has traced mineralization over one kilometer in a northeasterly orientation and has shown the Main Ixtaca Zone to be a broad and robust vein system intersected by multiple high grade veinlets in a variety of orientations. Drilling has also identified two additional zones: the Ixtaca North Zone and the Northeast Extension.