080121-08MN006-Sabina Hackett River Project Proposal ... - NIRB

Project Description2.4 Mine Plan2.4.1 Geology and Mineralogy2.4.1.1 GeologyThe following descriptions are based on the work of Squires (1997), Castleman andMioduszewsk (1982), and Hall (2007).The Hackett River occurrences include a number of volcanogenic massive sulphide lenses hostedby metavolcanics and metasediments of the Archean Yellowknife Supergroup within the easternpart of the Archean to Proterozoic age Slave Province (Figure 2.4-1).The Slave Structural Province, comprising approximately 192 square kilometres of thenorthwestern part of the Canadian Shield consists of highly deformed, metamorphosed ArcheanSupracrustal rocks and associated granitoid complexes of varied composition and age.Yellowknife Supergroup metavolcanic rocks, which comprise five to ten percent of the SlaveProvince, occur in 20 discrete north to northwest trending belts. Slave Province Greenstone Beltsare elongate in plan, basin-shaped in cross section, and occur as homoclinal assemblages facingaway from adjacent granitic rocks. Early Proterozoic (Aphebian) clastic sedimentary andcarbonate sequences of the Goulburn Group unconformably overlie the Archean rocks locally.Intrusive rocks of Hudsonian age and younger diabase dykes crosscut the older lithologies.The Yellowknife Supergroup is divided informally into three major sequences. The Back Groupis the lowest sequence and is comprised of felsic to intermediate flows, tuffs and breccias.The Hackett River Group overlies the Back Group and consists of volcanic flows that range fromfelsic to mafic, as well as tuffs and chemical sediments. The uppermost sequence is the BeecheyLake Group, comprising turbidite sediments, greywacke, mudstone and iron formation. TheProject area is underlain by the Hackett River Group which is comprised of three formations fromoldest to youngest, the Siorak, Nauna and Ignerit Formations. The Ignerit Formation isgradational into the overlying Beechy Lake Group.The Siorak Formation is comprised of gneissic and schistose metavolcanic and metasedimentaryrocks that are in contact with the underlying Hanimor Gneiss Complex.The overlying Nauna Formation is comprised of metamorphosed mafic and felsic flows andpyroclastic rocks. This unit is apparently not present in the immediate Project area where theIgnerit Formation overlies the Siorak Formation.The Ignerit Formation hosts the known sulphide-bearing stratigraphy within the Project area.The Ignerit Formation is comprised of basal rhyolitic pyroclastics that are overlain by andesiticand dacitic pyroclastics that are in turn are overlain by rhyolitic tuffs and sediments; these arecapped by clastic sediments. The Lower Rhyolitic Pyroclastic section is at least 450 m thick andis comprised of fragmental agglomerate to tuff with internal gradations to finer argillaceoustuffite and chert. The overlying Andesitic Pyroclastic section is from 60 to 180 m thick and isoverlain by the Dacitic Pyroclastic section that ranges from 180 to 240 m in thickness.January 2008 Hackett River Project – Project Proposal Sabina Silver CorporationReport Version B.1 2–7 Rescan Environmental Services Ltd. (Proj. #833-2)