• Exploration fieldwork coupled with study of historic drilling data is now complete
• 4 new drillholes are proposed, designed to intersect extensions of gold and base metal mineralisation in skarns at Mayfield

Setting:

Exploration Licence 6358 contains the Mayfield copper/gold Prospect as well as a number of other mineralised occurrences. The Mayfield Prospect is the main focus of exploration as it is host to a drill defined mineral gold and base metal occurrence. The style of mineralisation is related to intrusive induced skarn mineralisation.

Location:

The Mayfield tenement area straddles the boundary between the Molong-South Coast Anticlinorial Zone in the east and the Captains Flat-Goulburn Synclinorial Zone in the west. The location of the tenement in relation to the regional geology is illustrated in Figure 1.

Figure 1: Mayfield Project licence area
showing regional geology and mineralisation

Geology:

The eastern portion of the project area covers the Adaminaby Group flysch sediments (quartz-rich greywackes, shales, slates, cherts and siltstones) of Late Ordovician age. The western half of the tenement is underlain by Late Silurian age sediments, tuffaceous sediments and a series of acid volcanics intruded by the Boro Granite.



The only known mineralisation within the Silurian rocks is the Boro lead, silver lead and copper stockwork vein deposit in the north east at Cullula, the Mayfield gold mine in the south and a number of outcropping gossans such as Hanging rock, Mayfield, Glenrossal, and Ennisclare which contain variable gold, zinc, copper and lead values. These later deposits have been categorised as exo-skarn type mineralisation.


Previous Exploration:

During the 1990’s a number of comprehensive exploration programs were conducted. Work entailed airborne magnetic and radiometric surveying, mapping, gridding, rock chip sampling, ground magnetic surveying. This was followed by several percussion and diamond drilling programs which resulted in the delineation of the a small mineral occurrence at Mayfield grading 1.04 g/t gold, 0.3% copper, 0.1% lead, 0.5% zinc and 7 g/t silver.

Figure 2: Mayfield gossan outcrop illustrating
strong iron and manganese development

Exploration Activities Conducted by Monaro Mining:

Consultants specialising in the evaluation and compilation of exploration data, have been commissioned to review the Mayfield Prospect data and compile and digitize all of the available geological and drilling data into a useable format. The purpose of this work was to provide a basis for estimating the tenor and extent of the known mineralisation as well as provide guidance to further exploration.

Figure 3: Close up of the Mayfield basemetal and gold bearing
gossan highlighting the extensive colour soil anomaly over the gossan.

Figure 4: View looking north-easterly along the strike of the skarn zone. Drilling has been
undertaken along this zone to beyond the tree line (along creek in middle ground)
– a distance of approximately 1000 metres, with mineralisation recorded in all drill holes.

A review of the data indicates that the mineralisation is open at depth within the central portion of the Mayfield Prospect area (just beyond the outcrop in Figure 4). In particular, gold and base metal values combined with the logged geological information indicate an open mineralised zone with a strike length of approximately 300 metres. The available geological logs suggest a near vertical zone of favourable rock types and mineralisation. It is considered that this zone warrants further definition by percussion/diamond drilling. Drilling data within this zone is illustrated in Figure 5.

In addition, past drilling at the northern extremity of the prospect (beyond the first tree line in Figure 4), has revealed a similar favourable rock package with low level mineralisation. This zone appears to be offset from the orientation of the main zone and warrants further investigation.

The Boro and Cullalla mine areas were also assessed during the last quarter. The Boro mine area has potential for the discovery of both VMS and skarn lead and zinc deposits. Although the main prospect, the Boro mine, has been thoroughly drill tested elsewhere in the area, there is potential for a concealed skarn base metal deposit associated with limestone and granite intrusions.
The Cullulla mine area also has some potential for the discovery of a skarn type base metal deposit in reactive sediments on a structure intruded by granite. The Cullulla mine and the nearby prospects have been only partly drill tested and the area is incompletely explored. The presence of metal zoning about the Cullulla mine and an intermediate dyke suggest the possibility of porphyry copper gold mineralization.

Figure 5: Section 13 across Mayfield Prospect

Proposed Exploration Activities

Gold and copper values intersected by previous drilling campaigns have delineated a broad zone of mineralisation over a considerable strike length. Whilst this mineralisation is not economic by itself, it does represent a potential vector to a mineralised system which may improve with depth and along strike. Hence, four new drillholes are proposed to test the along strike and down-dip extent of the Mayfield Prospect mineralisation. The proposed drillhole PDHMA24 is illustrated in Figure 6. Should the proposed drilling be successful, the potential for the rest of the licence is considerable as the Mayfield Prospect represents one of many such skarn type occurrences in the area.

Figure 6: Proposed drillhole PDHMA24