Drilling by Thomson Resources in the Thomson Fold Belt of northwest New South Wales has intersected three large polymetallic mineralized systems. The company is currently drilling its high priority targets.
Assay results have been received from 52 core samples from the company's first hole on the Cuttaburra B magnetic anomaly. The hole intersected significant zinc, copper, lead, silver, gold, tin and tungsten in a stockwork-style system of veins of quartz, pyrrhotite and pyrite ranging from millimetre scale to 50cm wide. The veins are within a 300 metre zone of strong carbonate and silica alteration.
Two other prospects have been drilled with similar geology - Cuttaburra Ac and Cuttaburra A, 5km and 17km west, respectively. At Cuttaburra A, multiple instances of zinc and lead mineralization have been logged from 135 metres depth to 614 metres depth. This 480 metre zone of alteration is characterized by silicification, carbonation, veining and brecciation indicating an extensive mineralized hydrothermal system.
At Cuttaburra Ac, the alteration system, although extensive, was less intense. A significant zone of sphalerite galena mineralization was logged at 398 metres depth.
Thomson Resources is now focused on detailed exploration within the anomalies to establish economic grades of mineralization. Each of the magnetic anomalies covers around 1sqkm and several geophysical techniques are being trialled to help refine targeting. These methods include high resolution magnetics, electromagnetic, induced polarization and gravity, both on surface and downhole where possible.
At Cuttaburra B, recently acquired high resolution gravity shows a distinct positive anomaly, corresponding with the silicification already intersected. The magnetic anomaly has still not been satisfactorily explained by the drilling, as only minor magnetic pyrrhotite veining has so far been intersected. The IP data offers a target which is coincident with a magnetic low in the centre of the anomaly. This is possibly due to a pyritic mineralized zone and will be tested in the current phase of drilling. In this context it is notable that the lead-zinc mineralization so far intersected is associated with pyrite rather than pyrrhotite.
Drilling has been slower than predicted due in part to multiple further rain delays. A total of 1972 metres has been drilled to date in five holes - one at Cut B, two at Cut Ac (one abandoned before reaching basement), one at Cut C (abandoned due to excessive deviation) and one at Cut A. The current drilling program has now moved on to F3, another high priority bulls-eye magnetic target.