Gold mineralisation at Westralia was first discovered in 1896 and quickly led to the gazetting of the Mt Morgans township. By 1903, 200,000 ounces of gold had been mined from 191,000 tonnes at Westralia confirming very high production grades averaging over 1 ounce of gold per tonne.
The gold at Westralia occurs within a well-defined banded iron formation (BIF) unit from which approximately 900,000 ounces at 4.5 g/t gold was produced up to 1998; with the majority being sourced from the Westralia open pit and historic underground workings. When added to the current 2016 Resource estimate, the pre-mined resource at Westralia is over 2.5 million ounces at a grade of 5.0 g/t Au.
Much of the 2.5 million ounce pre-mined resource occurs over a horizontal strike distance of 2.8km and lies within 700m of the surface. Globally, the deposit has an endowment level of around 3,400 ounces per vertical metre, making it a highly mineralised gold deposit of significance in the West Australian gold fields. Previous mining and on-site treatment of the deposit has demonstrated that the gold is free milling with recoveries of 91%-93% achieved historically from conventional site-based CIP/CIL processing.
Dacian’s initial focus on exploration at Westralia involved the delineation of a discovery at the south end of the Westralia deposit, now referred to as Beresford Underground. By the end of 2013, the Westralia resource had grown to 610,000oz.
In 2014, Dacian commenced an ambitious 14 hole 9,000m diamond drilling program testing the mineralisation potential in an area previously reported as “unprospective for gold mineralisation” and therefore never drill-tested. Follow up drilling of mineralised intersections led to the discovery of a high grade footwall lode called the Allanson Underground and was estimated to contain 1.2Mt @ 9.1 g/t gold for 344,000 ounces (above a 2 g/t lower cut off grade).
During the period from late 2015 to May 2016, Dacian Gold completed a 46,000m diamond drilling program aimed at in-filling the existing Mineral Resources at Beresford Underground and Allanson Underground to Indicated Mineral Resource status.
In July 2016, Dacian Gold’s updated Mineral Resource for Westralia was increased to:
8.6Mt @ 5.8 g/t Au for 1,620,000 ounces (above a 2 g/t Au lower cut off)