Petratherm Limited (ASX: PTR) has identified a significant new coherent gold anomalous occurrence from its regional geochemical gold exploration programme at the Comet Project, approximately 80 km southwest of Coober Pedy in South Australia.
The Comet Project contains prospective Archean strata of the Northern Gawler Craton which hosts numerous gold occurrences such as the Challenger gold deposit (1.1 Moz @ 5.1g/t) and is located 30 km east from the recent high-grade Aurora Tank Gold discovery.
The new coherent gold anomalous occurrence (DG1) spans an approximate 2,000m by 800m area – warranting immediate follow-up.
Historical surface geochemical sampling exploration techniques in the region have been severely impeded by shallow cover strata which masks most of the prospective basement rock geochemical response.
To overcome this issue, Petratherm applied a new exploration methodology, where regional scale (400m by 400m) shallow grid drilling has been undertaken to directly sample the top of the in-situ “saprolite” zone clays (deeply weathered basement rock which has been chemically decomposed to clay) below younger transported cover strata. In most areas over the tenement the top of saprolite zone occurs between 5 and 15 metres depth and shallow drilling was undertaken using a light weight and cost effective, land cruiser mounted air core drill rig.
The saprolite sampling programme has proved effective, with early findings indicating sampling provides geochemical data with high level of precision (low noise), eliminates superficial anomalies contained in the transported cover sediment, and most critically provides direct geochemical screening of the prospective basement rock.
The new assay results for the DG1 gold anomalous area has yielded gold in saprolite up to 33 ppb (on a 400m grid). For comparison, the gold in saprolite above primary gold mineralisation at the Comet Gold Prospect 5 km to the northwest ranged between seven to 51 ppb (including all detailed in-fill RAB drill sampling down to a 50m grid size ). Bedrock drilling below the saprolite anomaly at Comet Prospect has yielded multiple high gold intercepts of up to 6.97 g/t Au (refer to PTR ASX release 30/10/20 for summary of significant gold intercepts).
The company has engaged McLeod Drilling to undertake infill sampling over the new prospective zone and this work is scheduled to start in approximately three weeks time and will take about one week to complete.
The company was recently awarded S.A Government grant funding to a level of $147,500 on a 1 for 1 basis through the Accelerated Discovery Initiative (ADI) to assist the Company’s Deep Geochemical Gold exploration for the Comet Project Area.
A small portion of this grant will be used to co-fund the upcoming infill sampling work, with the majority to be spent on regional and infill sampling on the adjoining tenement application area (ELA 2020/0194, “Gina Project”). An initial focus area for the Company on the adjoining Gina Project Area includes the historical Target 14 Gold Prospect which occurs about 5km SW of the new gold anomalous area, and which may be along the same structural trend