CONTACT NYSE MKT: NGD 5.99 -0.02 TSX: NGD 6.59 -0.06 GOLD: US $ 1,236.78 +4.00 HOME COMPANY PROPERTIES INVESTORS CORPORATE RESPONSIBILITY CAREERS home/properties/operations/peak mines/geology and mineralization .... Properties Operations Cerro San Pedro Mesquite New Afton Peak Mines Project Summary Location Sustainability and Environment Health and Safety Geology and Mineralization Processing Exploration Looking Forward Projects Exploration Geology & Mineralization The Cobar Gold Field is located on the eastern margin of the Early Devonian Cobar Basin, which lies within the northern part of the Lachlan Orogen. Regional crustal extension of the Lachlan Orogen during the late Silurian period (417-423 Ma) created a series of north-south trending deepwater troughs and basins in the region. These include the Cobar Basin with the Raast and Mt Hope Troughs further to the south. The basin contains a two-stage sedimentary fill, regarded as two sequences representing syn-rift and post-rift stages. The lower unit, the Nurri Group, is a fining upwards sequence comprising initial shallow-water sediments that pass rapidly up into more extensive siliciclastic turbidites. The upper unit, the Amphitheatre Group, comprises much more extensive lower energy turbidites. Volcanics form only a small proportion of the syn-rift stratigraphic sequence in the Cobar Basin. Small bodies of felsic porphyry are exposed to the south of the Cobar Gold Field and bodies of intrusive flow-banded rhyolite are exposed in the underground workings at the Peak mine. During the Early Devonian period (395-400 Ma) the Cobar Basin was inverted in response to northeast-southwest compression. This compression was partitioned into a high strain zone along the eastern margin of the basin and a low strain zone in the central and western parts of the basin. Deformation of the basin sediments was controlled by the re-activation of early basin-forming extensional faults and by the formation of new faults. Inversion of the western margin of the basin, at a considerably lesser intensity than that experienced by the eastern margin, subsequently occurred in the Carboniferous period (290-354 Ma). Cobar Basin sediments are generally metamorphosed to chlorite grade. The age of metamorphism has been constrained to have occurred from 395-400 Ma, on the basis of 40Ar/39Ar dating of white micas formed during cleavage development in the higher strain zone along the eastern margin of the Cobar Basin. At the local scale, the structurally controlled Cobar Gold Field is located on the western limb of the Chesney-Narri Anticline, a moderate to tight south-plunging anticline covered by sandstones of the Chesney Formation. Gold mineralization is associated with two principal shear zones, the Peak Shear and Great Chesney Fault Zone, both of which juxtapose the Chesney Formation with the Great Cobar Slate. The deposits usually consist of multiple, steep-dipping dilational lenses with short strike lengths, narrow widths and strong vertical extents. A strong sub-vertical regional white-mica S2 cleavage and a steep north-plunging mineral and extension lineation L2 are present throughout the Gold Field. This cleavage is sub-parallel to the major faults in the Gold Field area. 40Ar/39Ar dating of alteration assemblages at Peak Mines indicates the main stage of mineralization occurred at 401.5 ± 1.0 Ma. legal notice | © 2012 New Gold Inc. Powered By Q4 Web Systems 4.0.6.245