Introduction

Torrens’ exploration licence EL5455 covers the northern, strongly geochemically anomalous, extension of the Buldah Shear Zone, a structural splay off the regional-scale Combienbar Fault in East Gippsland, Victoria, along which there are number of reported gold and base metal mineralisation occurrences. Torrens’ objective is the discovery of one or more ‘stand alone’ gold or base metal resources amenable to processing at a suitably located mineral processing plant.

Tenure and Location

EL5455, which covers 23sqkm in the headwaters of Buldah Creek in East Gippsland, Victoria, abutting the NSW border, was granted to Terrace on 21 October 2013, for 5 years.
The Project is located within State Forest, much of which has previously been harvested for timber. The area is centred 40km north of Cann River township and adjacent to the small Buldah farming district. The Eastern Gas Pipeline and an all-weather access road pass through the eastern sector of the Project area. The area is readily accessed by the sealed Cann River Highway thence by numerous roads and tracks.

Previous Exploration

Previous explorer Oroya Mining Limited (Oroya) explored the Project area between 2006 and 2012, as part of late EL4934, focussing on the mineral potential along the regional-scale Combienbar Fault zone. Initial drainage geochemical sampling along the Buldah Shear Zone in the headwaters of Buldah Creek defined large copper, zinc and gold anomalous zones, along with other anomalous metals.

Exploration undertaken during 2009 by Independence Group NL (IGO), in joint venture with Oroya, included geochemical grid soil sampling over an area of approximately 7sqkm in two phases, the first at a sampling density of 200m by 200m and the second, infill phase, at a sampling density of 100m by 100m, in the headwaters of Buldah Creek. Zones of gold, lead, zinc, silver, copper, arsenic, molybdenum, bismuth and antimony anomalism were defined, including a gossanous zone of quartz veined and brecciated metasediments, from which rock chip assays of 0.3 g/t Au and up to 1.77% Pb were reported. These anomalies are spatially associated with the regional-scale, sulphide-mineralized and quartz-veined Buldah Shear Zone.
IGO, however, withdrew from the Project without conducting any drilling to test the geochemical anomalism delineated by the soil, rock chip and stream sediment sampling.

Earlier exploration by other companies extended only into the southern-most part of EL5455. This exploration was largely driven by 1890’s reports of gold mineralization in the Buldah Shear Zone. The Granite Creek prospect, just to the south of EL5455, was drill tested in the 1980’s. A silicified, strongly pyritic (5-10% pyrite over 25 metres width) shear zone was intersected, however with only trace gold reported.

Figure1 buldah
Figure 1 - Location Plan EL5455
pink = Devonian granite, purple = Devonian ‘red-bed’ sediments,
blue = Ordovician sedimentary rocks, solid and dashed black lines represent faults.

 

Geology

The Project area is located within the Mallacoota 1:250,000 and the Craigie 1:100,000 geological sheet areas.

The oldest rocks in the area are Ordovician Pinnak Sandstones, a thick sequence of turbiditic sandstones, mudstones and black shales which were tightly-folded and deformed during Silurian-Devonian orogenic deformation. During the Lower Devonian, the Pinnak Sandstones were intruded by granitic rocks of the regionally extensive Bega Batholith, which are marginally exposed in the EL area. Later, during the Upper Devonian, the older rocks were unconformably overlain by terrestrial coarse fluvial ‘red-bed’ sediments of the Combyingbar Formation.

Regional deformation in the Buldah area culminated during the Carboniferous with the regional development of the distinctively-shaped en-echelon, fault and shear-bounded Bemm River, Combienbar and Buldah Synclines. Gold and base metal mineralisation is thought to be related to reactivation of faults along the Buldah Shear Zone and other structures during the late Devonian and Carboniferous.

Planned Exploration

The field evidence points to a high certainty that the Buldah drainage and soil geochemical anomalies are directly related to the Buldah Shear, or splays off the main shear/fault. The exploration target is economically significant tonnages of sulphidic, structurally-controlled, polymetallic mineralization. The strike length of known geochemical anomalism within EL5455 is at least 3.5km, considered sufficient to accommodate a body of mineralisation of economic proportions.

Torrens is continuing exploration at Buldah.