Rimfire’s acceleration in regional exploration is defining many new and emerging targets across the three main deposit styles (Click Here to Introduction).
Anomalous base metals (up to 0.38% Cu, 0.63% Co, 0.41% Pb & 0.29% Zn, Ag up to 8.3g/t & pathfinder elements have been discovered associated with ironstone and gossanous / manganese rich breccia float, primarily concentrated within a >500m long linear SW-NE trending corridor termed the Eurimbla prospect.
The base metal rich gossanous rock chip samples are spatially associated with low level multi-element (Incl. Cu up 979ppm) soil geochemical anomalies, a magnetic high anomaly & historic prospecting pits. The base metal targets have affinities with Sorpresa style epithermal carbonate base metal Ag-Au mineralisation & Tritton style VHMS Cu-Au mineralisation.
In addition a >600m long x >50m thick, NW-SE striking, panned gold in soil anomaly centred on a historic prospecting pit has been defined semi-coincident with up to 1.25g/t Au in quartz veined rock chip float samples. This target is a structurally controlled, sediment-greenstone hosted, orogenic gold system, analogous to Carlisle & Golden Green prospects.
A systematic auger drilling program (100m x 20m grid) or infill / extension soil geochemical grid, along with a high resolution 3DIP or EM survey is proposed to progress the base metal, silver & gold targets to RC drill ready status.
Hydrothermal alteration and sulphide mineralisation at Eurimbla is subtle but common within basalt and diorite host rocks and includes selectively pervasive, veined, vesicle infill & replacement ‘patches’ of epidote-carbonate-silica ±chlorite ±pyrite alteration and localised chlorite-sericite-pyrite alteration assemblages.
Pervasive magnetite-silica-epidote-chlorite-pyrite alteration associated with a ‘bullseye’ magnetic high anomaly with disseminated & veined pyrite-pyrrhotite with rare chalcopyrite, which appears to increase in intensity to the SW of the bullseye magnetic high anomaly.
Quartz veining is common including Colloform-cockade banded quartz-chalcedony-limonite (after iron & base metal sulphides & carbonate) veining, commonly with drusy quartz lined cavities & bladed silica after calcite indicative of boiling – interpreted as low temperature, low sulphidation epithermal style veins. Gossanous sub-angular, monomictic to polymictic, ‘crackle’ breccia has also been observed.
Rock chip samples of altered, veined or mineralised (sulphide/boxwork textures) outcrop & float samples have returned significant gold, silver, base-metal & pathfinder anomalism up to:
Proposed Exploration Programs include possible 3DIP or EM surveys to detect sulphide bodies at depth to provide direct drilling targets, particularly given the base metal flavour to the targets at Eurimbla. Contemporaneous systematic auger geology & geochemical grids are also proposed to define RC drill targets.
The Glen Iris prospect is comprised of minor historic workings located within an outcropping folded BIF horizon with manganese rich breccia zones and an associated gold in soil anomaly. Highly anomalous Au (up to 5.97g/t Au), Cu (up to 0.35%), Co (up to 1.08%), Ni (up to 0.10%), Zn (up to 0.12%), Ba (up to 0.50%) & pathfinders were returned from a first pass rock chip sampling program (17 samples).
Previous soil sampling (100m x 25m grid) has defined three low level but coherent gold anomalies >4ppb Au, up to 77ppb Au, which are all open to the south. The central & eastern anomalies are >300m long & associated with the anomalous rock chip results. The anomalous geochemistry in soils and rock chips & historic workings are associated with a coincident ‘bullseye’ magnetic high anomaly (400m x 400m) & basement high.
The Glen Iris prospect is located in a favourable structural setting within the LTZ (Lachlan Transverse Zone) at the intersection with the NE-SW striking, curvilinear Eclipse structure which is mineralised (base & precious metals) to the south at the Eclipse & Eurimbla prospects. Interpretation of acquired magnetic data, suggests Glen Iris occurs on the western margin of an ovoid shape postulated buried intrusion (1.4km x 1.1km).