As part of Southern Gold’s strategic aim of “finding and developing high grade gold deposits and turning them into money”, the Company has acquired four tenements approximately 50 km south-east of the Bulong Project collectively known as the Cowarna Project covering approximately 200 km2.
The Cowarna Project is situated within the Archean Mt Belches Formation which contains banded iron formations (BIFs) interpreted to be the equivalent of the Randall’s BIF sequence. Silver Lake Resource's (ASX: SLR) Randall’s operations (Randall’s, Maxwell’s, and Cock-Eyed Bob mines) are located immediately west of the Cowarna Project area and are hosted within and adjacent to the folded BIF units. Two main BIF units, Santa Claus Formation and Eastern BIF, have been identified as being primary targets for exploration. The potential exists for further, less magnetic units in the stratigraphy, but the potential for these to host gold mineralisation is unknown at present.
Interpreted geology and structure image and the location of SAU leases with respect to the prospective BIF horizon (blue striped units). Neighbouring gold mines and mills also shown.
BIFs are important hosts for gold deposits in the Yilgarn due to their chemistry and rheology. Their magnetic properties often allow them to be readily mapped using magnetic based geophysical methods.
Airborne regional magnetic image with respect to the prospective BIF horizon (white sinuous trace). Neighbouring gold mines and mills are also shown.
The Cowarna area was targeted for acquisition after compilation and review of historical data. Several gold anomalies were identified from previous exploration and are in the process of being further evaluated. Previous exploration methods are also being evaluated in light of modern advances in technology and better understanding of the regional geology.
Nightcrawler and Bamf are two historic occurrences which are being re-evaluated with modern exploration techniques. A vacuum drilling program was conducted in the mid 1990’s and stopped at a pre-existing tenement boundary and does not cover the Bamf prospect which was drilled with a limited program of RC drilling. A trial hand auger sample program has been completed to confirm previous soil anomalism. An extensive suite of 60 major and trace elements has been collected to investigate the nature of the mineralisation in the BIFs. Once the orientation survey has been evaluated, it is planned that the soil surveying will be extended to cover the Bamf prospect as well as further prospects across the Cowarna Project. The previous vacuum sampling has already located significantly anomalous horizons parallel with but stratigraphically above the known BIF horizons The Pryde and Logan anomalies occur at the northern end of a very tightly folded antiformal feature in the Cowarna Project. Anomalous soil samples have been followed up with a small amount of RC drilling by previous explorers; unfortunately the majority of holes were drilled parallel to the dip of the BIF units and so it is believed they missed the target. The strongest mineralisation in the region tends to be associated with the stratigraphically lower Eastern BIF Member which is not present in outcrop at this location. It is interpreted that the Eastern BIF Member occurs approximately 100-200m below the surface and represents an important drill target for Southern Gold. Furthermore, the strongest soil anomalism is associated with fold repetition of the BIF units which supports targeting of the Eastern BIF member in this tight fold closure at depth.
Several anomalous zones were discovered by previous explorers on the northern part of Lake Randall. The Strange and Clea anomalies are the most significant with 3m @0.71 g/t being the most significant intersection at the Strange prospect and no follow-up work was undertaken. This is an area of complex folding and interaction with the regional N-S trending faults which are very well exposed on the lake bed in this vicinity. Detailed mapping, rock chip sampling and soils sampling will be undertaken to explore the prospectivity of this region further.
The Company believes that the Cowarna Project provides considerable scope for further structural targeting of these regionally important BIFs. It is anticipated that the project will provide long term growth potential for Southern Gold, complementing the Cannon Resource mine development and Bulong Project targets.
Location Nightcrawler and Bamf prospects; showing the extent of historic soil sampling and planned orientation survey.
Location of Pryde and Logan prospects, showing extent of historic soil sampling and tightly folded antiform within the BIF horizons.
Location of Strange and Clea prospects, showing extent of historic aircore drilling.