Glen Wills History
The historic Glen Wills and Sunnyside goldfields lie 40km north of Omeo in the alpine region of the East Gippsland. The region can be accessed by road from Omeo or Albury. Synergy Metals has a mining lease over the main historical workings and has also secured the surrounding exploration areas.
Victoria has a rich history of gold production in the 19th century, making it one of the premier mineral producing regions in the world.
The area has had a long history of gold exploration and mining, dating back to the 1850s. Glen Wills was one of the major early goldfields in the North-East of Victoria that included the Mt Elliot, Dart, Harrietville, Bright, Wandiligong, Freeburgh, Beechworth and Bethanga goldfields.
Earlier modern day exploration focused on tin as well as gold. In the neighbouring goldfields of late 1970s-1980s, explorers targeted large stockwork or disseminated gold as well as alluvial gold.
Mining started in the district in the 1860s and became more significant in the 1880s. Like most Victorian gold mining operations, the manpower shortages during and after World War I forced the curtailment of operations and the subsequent low gold price allowed only intermittent mining until the 1960s. Some modern geological exploration work was subsequently carried out and Synergy Metals entered into a farm-in arrangement in January 2004 and took control of the project in 2005.
The Glen Wills goldfield is located in the eastern part of the Lachlan Fold Belt, in the Omeo Structural Zone. The Omeo zone (containing the Omeo Metamorphic Complex) extends north from Cassilis to the Hume Weir and into New South Wales. It is dominated by a basement of deformed Ordovician turbidites intruded by numerous granite plutons. Many of the sedimentary rocks have been metamorphosed to schist, gniess and migmatite.
All these rocks were severely deformed and metamorphosed during the Benambran Orogeny in the Early Silurian Period. The rocks were tightly folded, regionally metamorphosed and S-type granites intruded. Further, though less intense, deformation took place in the Late Silurian (Bindian), Middle Devonian (Tabberabberan) and Early Carboniferous (Kanimblan). The Tabberabberan event is thought to have resulted in crenulation cleavage, kink folds and brittle deformation. It also probably caused reactivation of pre-existing faults.
The historic workings are located on a mineralised fault which runs more than 5 kilometres through the Glen Wills and Sunnyside areas. Historically, access to the mineralised zone was through adits and recent visual inspection has confirmed the continuity of the mineralisation and the good ground conditions. The historic site also includes a stamp battery and a tailings facility.
The mineralised fault dips at 60-80 degrees and historic stopes were generally 1m to 7m wide. Historic workings focused on high grade mineralisation with average recovered grades of 22.9g/t.