The Tabac Cobalt-Gold Project (Tabac Project or the Project) represents a significant cobalt-gold exploration target with its scale and grade potential demonstrated in prior drilling.
The Tabac Project is located on the Goldfields Highway 30km west of Wiluna and 135km east of Meekatharra in the Northern Goldfields Region of Western Australia. The Project sits adjacent to the Paroo Station Mine and camp (previously known as the Magellan Lead Mine).
The Project consists of two exploration licence applications (ELA’s), 53/1891 and 53/1895 , covering a combined area of 111.5km2.
Australian Consolidated Minerals (ACM) drilled 10 stratigraphic holes across the Yerrida Basin between 1982 and 1984. Of the 10 holes, two (PP009 and PP011) reportedly intersected cobalt-bearing stromatolitic carbonates, returning significant intercepts of:
- PP011: 80m at 0.77% Co from 170m, including 10m at 1.47% Co & 40m at 0.73g/t Au from 210m
- PP009: 30m at 0.3% Co from 358m including 10m at 0.86g/t Au from 358m
These were the only holes to test the cobalt position. Both holes ended in mineralisation and intersected similar down hole stratigraphy (siltstones and pyritic shales before entering carbonate-rich stromatolitic horizons) attesting to the stratabound nature of the carbonaceous target and the contained mineralisation.
The two holes are separated by a distance of 7.3 km.
The Tabac Project is located within the Yerrida Basin (referred to previously as the Glengarry Sub-basin), which lies on the northern margin of the Archean Yilgarn Block, and forms part of the Capricorn Orogen. The Yerrida Basin represents an intracratonic sag basin containing siliciclastic rocks and evaporites of the Windplain Group overlain unconformably by siliciclastics and mafic extrusive and intrusive rocks of the Mooloogool Group. Within the Project area, outliers of the Yelma Formation of the Earaheedy Group unconformably overlie rocks of the Yerrida Basin.
The Windplain Group includes the Juderina Formation, which crops out in the southern third of the Project. The Juderina Formation comprises of siliciclastics (deposited as continental “red beds” or haematite-rich sandstones and siltstone), evaporates, argillites, and locally turbidites. It includes the chertified stromatolitic carbonate and evaporitic sedimentary units of the Bubble Well Member, which is the likely mineralised host at Tabac.
The depositional environment for the Windplain Group is thought to be a shallow epicontinental (or inland) sea, locally with sabkha (salt flat) environments.
Archean rocks of the adjacent Joyner’s Find Greenstone Belt formed a number of basement highs (or coastal headlands) during the shelf sedimentation phase. Sediments deposited west of the headlands predominantly comprise shales, whereas those deposited between or east of the headlands are mainly composed of carbonates.
Within the southern parts of the Yerrida Basin, sediments are commonly flat-lying. Any folding is very gentle, and where described comprises north-northwest and northeast open folds. The overlying Earaheedy Group sediments appear to have undergone relatively minor structural deformation.
The palaeoenvironment at Tabac, including the types of rocks deposited (evaporites and carbonates), their age (Proterozoic), site of deposition (platform sediments), and the broader geological context of a developing fold and thrust belt, is analogous to Zambian Copperbelt and/or Kuferschiefer-style mineralisation.
Dragon will utilise geophysical mapping methods to outline the subsurface geology and potential geometry of the cobalt-gold bearing unit at Tabac. This boost in understanding of the geometry and deposit structure will improve targeting and accuracy in future drilling and therefore control exploration costs.