Commencement of Field Exploration at Perrinvale
- Step change in exploration approach driven by geological understanding;
- Potential for increased areas of intermediate to felsic volcanic rocks identified; and
- Banded Iron Formation association with conductors and massive sulphide mineralisation to be targeted.
Since completing field activities at Perrinvale in late 2020, and while the Company focused on finalising the acquisition of a controlling interest in Kalahari Metals Limited (KML) and the recent capital raise, work continued concurrently on the Perrinvale Project with the completion of an Optimisation Study at the Schwabe Prospect and planning for this next phase of field activities.
The Optimisation Study, which has been prepared for internal purposes to assist the management team to develop a strategy at Schwabe which will deliver the best returns for shareholders, indicates positive potential, with a key assumption being the treatment of ore from Schwabe by a third-party. With this assumption in mind, there is clear value in aiming to expand the resource potential within the prospect area.
A programme of review and planning related to the broader exploration potential of the Perrinvale Project has also been undertaken. This includes the:
- detailed review of geophysics (airborne electromagnetic, magnetic & gravity data);
- study of known VHMS deposit areas within the Yilgran in particular and globally in general;
- consideration of observations and results achieved through 2019 and 2020;
- sourcing historic hyperspectral survey outputs; and
- preliminary definition of priority areas of interest for field investigation.
These tasks form the basis for the next phase of field exploration at Perrinvale and represent a step change from primarily drilling previously identified bullseye targets, to systematic application of the technical knowledge gained with the aim of defining a significant VHMS resource base on the project.
Such a resource base may consist of multiple high grade massive sulphide pod like deposits, similar to Schwabe, and/or a larger single deposit area.
Key outcomes of the desktop work have been understanding the setting for the mineralisation drilled to date and how that fits with the broader geology of the project area. With the recognition that there are likely more intermediate to felsic volcanic rocks within the project area than shown on GSWA maps, and that the extensive areas of Banded Iron Formation (BIF) rocks mapped across the project, could be intimately associated with base metal sulphide mineralisation.
A line-by-line review of the 2019 Airborne Electromagnetic (AEM) survey has been completed (refer Figure 1*), which shows a mix of (86) purely conductive conductors (such as Schwabe), as well as (143) conductors that are proximal to / associated with a magnetic response. These conductors proximal to magnetic responses represent areas to be assessed for massive sulphide mineralisation associated with BIF.
In addition to the base metal potential, rock chip samples collected late in 2020 have returned some very high-grade gold assays, suggesting value in the exploration programme remaining open to the gold potential noted in the Company's Prospectus. A total of 24 samples were collected (see Table 1 & figure 2*), with two stand out samples collected around the Fey's Find workings returning 46.76 g/t & 56.55 g/t gold. Multielement assays support hydrothermal fluid movement along a WSW-ENE trend.
The field programme, scheduled to be completed with a five-person crew through the coming six months, will also step beyond the area of the 2019 AEM survey, with guidance from the airborne magnetics and, where present, the 2012 HyMap survey and also provide guidance in determining what areas, if any, of the Company's tenement portfolio with near term expiration dates should be retained or relinquished.
Commenting on the commencement of this new field exploration programme, Martin Holland, Cobre's Executive Chairman and Managing Director, said:
"The Perrinvale Project has delivered high grade VHMS intercepts at the Schwabe Prospect, confirming the potential for valuable copper rich resources. The 2020 drilling, local scale geophysics and mapping has generated a great deal of knowledge for the Company. With that knowledge our technical team is taking the next step in the plan to add to Schwabe and unlock project making VHMS resources."
Background on the Perrinvale Project
As a private company in June 2019, Cobre undertook an initial reverse circulation drilling program within the Perrinvale tenements to investigate targets identified by earlier exploration. At that time, the drilling program intersected very high-grade VHMS base metal & gold mineralisation at shallow depth. The best assayed intercept was at the Schwabe Prospect to date: 5m at 9.75% copper, 3.2g/t gold, 34g/t silver and 3.1% zinc from 50m depth2. Subsequently in August 2019, Cobre completed an airborne electromagnetic survey within the Perrinvale project area and identified a total of 10 potential VHMS prospects. Cobre was listed on ASX in January 2020. Since that time, Cobre has completed diamond core and reverse circulation drilling, an optimisation study on Schwabe Prospect, and continues an exploration programme to unlock the VHMS potential of the Perrinvale area.
*To view tables and figures, please visit:
About Cobre Limited
Cobre Limited (ASX:CBE) is a copper and base-metals explorer with projects in Western Australia and Botswana. The Company recently discovered a new high-grade VMS deposit enriched in Copper, Gold, Zinc and Silver in Western Australia, and is currently exploring approximately 8,100 km2 of tenements within the Kalahari Copper Belt (KCB) in Botswana.