The Creswick project is considered highly prospective for gold mineralisation hosted within the Dimocks Main Shale (the “DMS”), which extends over a 15km trend from the mining centre of Ballarat to the south, approximately 7km of which is covered by MGA’s granted exploration licence and exploration licence applications.
In the project area, the DMS is an approximately 25 m wide shale containing bedding- and cleavage-parallel auriferous quartz veins. The width of the shale and the occurrence of multiple veins in some zones indicates that potential open pit mining targets may present themselves as exploration progresses. Almost 1,500 shallow primary workings have been mapped in the belt from North Ballarat to Spring Hill (Creswick).
The DMS is the source of much alluvial and deep lead gold. Historical alluvial production is estimated at up to 2.5 million ounces in the Creswick/Berry lead system, and up to 11 million ounces in the Ballarat area as a whole, of which the DMS is a significant contributor.
MGA completed 1687m of reverse circulation (RC) drilling at Creswick in February 2019 for 17 holes. On 8 May 2019, ECR announced that the majority of the drill results had been received, with grades in nine holes ranging from 0.6 g/t gold to 44.63 g/t gold.
The mineralisation has been confirmed as nuggety, which can lead to understated or overstated assays; accordingly, a process of whole-of-bag gravity concentration tests on the RC drill samples was completed in 2019. For more information, please see ECR’s 5 November 2019 announcement.