Local Geology

The main rock types at Igor are:

• quartzites, arenites and shales of the Chimú Formation.
• arenites, quartzites and carbonaceous shales with syngenetic pyrite in the underlying Chicama Formation.

This sedimentary sequence has been extensively folded, thrusted and dissected by major faults. The structure is dominated by an anticline some 3 kilometers (km) long and 2 km wide.

There are a number of dacitic dykes, stocks and sills. May have phyllic and argillic alteration. Minor Granodiorite is present some of the deep drillholes.

Mineralization at Igor consists of a series of veins, breccias and mantos principally with a north to south orientation, although secondary north-east to south-west and north-west to south-east trends are also important.

Gold and silver are the most important metals. Geochemically, there is abundant arsenic and antimony and weak localised base metal (lead and zinc) mineralization. Copper grades are generally low, but frequently increase with depth. Oxidation, especially along structures, is pervasive and commonly extends to depths of several hundred meters.

The mineralization appears to be Low to Intermediate Sulphidation epithermal in character and there are indications of a deep porphyry copper gold system underlying the Igor District.

There are three main target areas on the project:

Domo - a zone of bedding-parallel mantos and perpendicular veins along the crest of the southeast end of the Igor Anticline. Mineralization is controlled by a series of northeast-southwest trending faults.

Tesoros – a system of veins, breccias and mantos along a major north-northeast striking fault that has localized the emplacement of dacitic porphyries and pebble dykes.

The mineralization at Domo and Tesoros constitutes the NI 43.101 compliant resource that Sienna is scheduling for production in 2013.

Callanquitas - the most recently discovered and potentially the most important target at Igor. Mineralization consists of a series of north-south striking, structures over a zone some 900 meters long and 200 to 300 metres wide. Mineralization is open to the north, south and at depth.