High Grade Drilling Results at Portia
- High grade drilling results confirm and extend Portia pit floor gold mineralisation.
- Includes 10 m @ 8.62 g/t in PTAC 492, partially confirmed by washing results.
Portia Gold Mine Area
All gold assay results have now been received for an intensive drilling program completed in September in and around the Portia Gold Mine. The purpose was to provide better definition of remaining oxidised gold resources that may be recoverable from the open pit with mine design modifications, which are currently being assessed. A total of 66, mostly aircore (AC) holes, were completed for 3,166 metres. Drilling was conducted in two areas as shown in Figure 2 (see link below).
Pit Floor -20RL - A series of nominally 10 m spaced, mostly vertical holes were drilled on the -20RL pit floor to provide better grade definition of ore mining blocks and to test interpreted high grade structures. Typical patchy high-grade gold mineralisation within a lower grade halo was intersected in oxidised and unoxidized (pyritic) strongly weathered basement (saprolite), with some of the higher grade results summarised in the following table (see link below).
Some of these intervals have been reassessed using Havilah's sample washing process which involves producing a panned concentrate from the remaining bulk drill samples (generally 5-20 kg). The concentrate is then observed (the size and quantity of gold grains are recorded) and assayed and a bulk grade can be calculated to compare with the initial assay generated from the 1-3 kg sub sample collected during drilling (i.e. conventional lab assay).
Northern Pit - A drill pad was constructed on the northern slump to allow further drill testing of the northern pit area (see Figure 2 in link below). Drilling from the new drill pad intersected generally weakly mineralised LGC and low grade basement saprolite gold mineralisation which is currently being evaluated for mining viability.
Other Local Prospects
Assay results from earlier PACE drilling of other prospects in the Portia region have now been compiled and evaluated and are presented below (locations are shown in Figure 1 in link below).
Croziers South Prospect - Two additional reverse circulation drillholes (CRRC018 and CRRC019) were completed for 216 metres to infill earlier anomalous results within the copper (gold - bismuth - tungsten) bearing magnetite skarn. Drilling intersected the skarn altered sequence in the weathered and oxidised zone with low copper results but elevated local bismuth (best result 6 m @ 0.16% Bi) and tungsten (best result 6 m @ 0.13% W).
Shylock Prospect - A total of 18 AC drillholes (SHAC020-037) were completed for 1,950 metres on four drill traverses, covering 500 metres of strike, targeting Portia style gold mineralisation at the base of the cover sequence and in basement. Drilling intersected the expected cover sequence with local occurrences of "Portia style" Light Grey Clay (LGC), with best results summarised in the following table (see link below).
A number of intervals have been highlighted for sample washing. At this stage no further drilling is planned.
East Portia Prospect - A total of 6 AC drillholes for 722 metres were completed to test a basement gold-bismuth anomaly for a possible hanging wall repetition of the Portia gold mineralisation (see Figure 1 in link below). Locally anomalous copper intersections were found near the base of oxidation associated with pyrite and local chalcocite and chalcopyrite (copper sulphide minerals). No further drilling is planned at this stage.
Lorenzo/South Portia Prospect - 12 AC drillholes for 1,360 metres were completed as a partial test of the extensive Lorenzo basement multi-element anomaly. Several holes intersected "Portia style" LGC and visible gold was panned from some intervals. Sample washing of most LGC intervals was completed with results confirming the generally low gold values as summarised in the following table (see link below).
Some intervals of weakly anomalous gold are also associated with elevated bismuth and arsenic, which may be useful locally as pathfinder elements for gold. Further drilling is warranted to define the Light Grey Clay (LGC) occurrences and to continue testing other anomalous gold and base metal targets defined from previous drilling in this large and promising mineralised zone.
Commenting on the drilling results, Havilah Managing Director, Dr Chris Giles said: "The pit floor drilling campaign returned some spectacular gold intersections in the saprolite bedrock material as is typical of Portia.
"We are currently updating and refining our internal resource models with the objective of mining and processing as much of this high grade material as possible over coming months.
"The regional drilling did not produce immediate results, but the potential still remains for significant discoveries in this highly mineralised terrain if we are clever enough to decipher the new clues we have gained.
"One of our problems is having so much mineralisation "noise" in this region, and identifying what are the key ore grade mineralisation indicators from all of the anomalous results" he said.
To view tables and figures, please visit:
About Havilah Resources Ltd
Havilah Resources Ltd (ASX:HAV) is a debt free South Australian gold producer having recently financed and developed its first gold mine at Portia in north-eastern South Australia. It plans to follow on with three copper-gold-cobalt mining developments at North Portia, Kalkaroo and Mutooroo, which are underpinned by a JORC resources mineral inventory of over 1.4 million tonnes of copper, 3.6 million ounces of gold, and 18,000 tonnes of cobalt.
Havilah Resources Ltd