South Darwin

The stratigraphy within the South Darwin District is dominated by north-south trending CVC volcanics which have been intruded by the Late Cambrian aged Darwin Granite. The CVC volcanics are composed of massive fine grained rhyolites.

A transition to volcaniclastic and epiclastic rocks is seen in the west of the project area. The granite is a highly fractionated magnetite series I-type granite that is composed of three separate known phases; the main phase is an equigranular pink granite, this is intruded by a white equigranular to porphyritic medium-coarse grain granodiorite, and a microgranite phase.

Near to the contact with the Darwin Granite the rhyolites are seen to be extensively brecciated and altered to an iron oxide dominated assemblage over a strike length of approximately 4km and with widths up to 200m. The South Darwin District is associated with regional k-feldspar-sericite-chlorite-iron oxide alteration extending for some 16.5km.

The project area is dissected by several major NW-SE faults and a N-S fault which appears to be spatially associated with iron oxide alteration and brecciation in the vicinity of the Prince Darwin workings.

Copper-gold mineralisation is associated with iron-oxide alteration and brecciation located within CVC volcanics on the western flank of the Darwin Granite. A 5km strike length of high intensity magnetic targets has been delineated in the recent Corona VTEM-magnetic survey. Eight historic prospects are known to exist within this zone. Mineralisation is present as disseminated chalcopyrite associated with zones of pyrite, silica and iron-oxide alteration. The pyrite and silica alteration possibly form a core to the massive iron-oxide alteration which transgresses to vein dominated and breccia vein dominated iron oxide alteration moving outward from the center of the system. The main working within the South Darwin District is the Prince Darwin adit on the western slope of the South Darwin plateau excavated in the 1900’s. No production is recorded.

The South Darwin District was subject to prospecting at the turn of the 19th century. The new discovery of Mt Lyell had spurred exploration through the region, however, poor infrastructure, rugged terrain and remote conditions hampered any real efforts at establishing profitable mining operations.

The Prince Darwin adit was channel sampled by the then operator of the Mt Lyell mines in 1940 with the innermost 27.4m of the adit assaying 0.61% Cu. Further channel sampling of the adit in 1964 returned 46m @ 0.5% Cu.

Aeromagnetics were flown as part of the tenement wide VTEM survey commissioned by Corona and completed by Geotech airborne Pty Ltd in May 2011. Processing and modelling of the data by Southern Geosciences Consultants Ltd (SGC) has revealed a series of of strong linear magnetic anomalies within the South Darwin District striking NNE. A distinct magnetic anomaly in the vicinity of the Prince Darwin adit is associated with iron oxide breccias within strongly altered felisitic intermediate volcanic. Sampling of the mullock material at the adit( the sample was limited to accessible material on top of the dump ) returned 0.3% Cu, 1.5g/t Ag,0.1g/t Au, 28% Fe and 0.2% TREO (Total rare earth oxide). This particular magnetic anomaly extends for 1.7 km, with a higher intensity centre with a magnetic susceptibility equivalent to 30% magnetite extending for 270m along strike with a width of 70m and depth extension estimated in excess of 500m. It should be noted that the Prince Darwin adit is some 50m to the north of the main core of the magnetic body.

The South Darwin District has good potential to host significant copper-gold + magnetite rich mineralisation. Extensive iron-oxide alteration, brecciation and known copper-gold mineralisation in a setting spatially associated with I-Type granitic intrusions is suggestive of IOCG mineralisation. Modelling the recent magnetics flown by Corona will help target drilling.