Traditionally a venture on magentitie iron ore with a JORC Resource of 126Mt @ 33.8% Fe grade, we are now also exploring for gold on this large tenement.

Significant gold bearing sedimentary sequences have recently been identified by Artemis geologists on the Mt OscarWits tenement that are considered to be part of the Archean Fortescue Group and hence can be correlated with the Purdy’s Reward sequence of mafic sediments and polymictic conglomerates located 21 km to the south-west.  This is contrary to the governmental mapping by DMIRS on the Roebourne 1:100,000 map sheet which interprets the sequence to be at the base of the older Whim Creek Group and accordingly part of the regional Pilbara Supergroup.

 

GOLD

Significant gold bearing sedimentary sequences have recently been identified by Artemis geologists that are considered to be part of the Archean Fortescue Group and hence can be correlated with the Purdy’s Reward sequence of mafic sediments and polymictic conglomerates located 21 km to the south-west. 

The Mt OscarWits sedimentary sequences extend over an east-west strike length of 14 km with true widths up to 75m thick in outcrops at the Churnside Prospect.  The sedimentary sequences at Mt OscarWits appear to have been folded and faulted creating duplication with four units mapped in several places over the significant strike length.

Recent geological mapping, rock chip and stream sediment sampling at Mt OscarWits identified extensive sequences of principally quartz and chert clast conglomerates with anomalous gold mineralisation. The discovery of these watermelon seed nuggets using metal detectors adds to the further prospectivity of Mt OscarWits conglomerate gold potential.

 

MAGNETITE BIF

The magnetite resources at Mt Oscar are hosted in BIF units within the Cleaverville Formation that are structurally deformed and faulted.  The bedding is steeply dipping to sub-vertical and intruded by numerous thick dolerite units. The magnetite iron resource was estimated by Golder Associates in 2013 using all the drilling data available at the time.  

 

Geology and mineralisation

The Mt OscarWits sedimentary sequences extend over an east-west strike length of 14 km, Figure 28, with true widths up to 75m thick in outcrops at the Churnside Prospect, Figure 29.  Artemis geologists have collected gold bearing samples at both the eastern and western ends of these conglomerates.  The conglomerates at Mt OscarWits are more quartz rich and appear ‘cleaner’ than the Purdy’s Reward more mafic rich conglomerates with the matrix at Mt OscarWits primarily quartz sand and the conglomerate clasts composed of quartz and chert pebbles and boulders.

The sedimentary sequences at Mt OscarWits appear to have been folded and faulted creating duplication with four units mapped in several places over the significant strike length.

Mt OscarWits DMIRS regional geology

Mt OscarWits DMIRS regional geology (modified after Hickman et al, 2002 Roebourne)

 

Exploration

A total of 8.3 gm of “watermelon seed” nuggets were found by Artemis by using a metal detector  at the “Fairmont Prospect” along the Mt OscarWits conglomerate trend.

Recent geological mapping, rock chip and stream sediment sampling at Mt OscarWits identified extensive sequences of principally quartz and chert clast conglomerates with anomalous gold mineralisation confirmed over a 14 km strike length. The discovery of these watermelon seed nuggets adds to the further prospectivity of Mt OscarWits conglomerate gold potential.

The Fairmont prospect has returned the highest gold assay in rock chips of 21.5 g/t Au from a ferruginous pebble conglomerate.  A conglomerate unit at White Quartz Hill, 12 km east of Fairmont, returned a peak gold assay in rock chips of 6.38 g/t Au.  Another rock chip sample at the Churnside Prospect, 4 km east of Fairmont, returned a peak assay from a rock chip of 10.93 g/t Au. The Churnside sample was recovered from a coarse-grained clast supported cobble conglomerate and likely represents a primary placer style form of mineralisation in a high-energy environment with a high coarse gold component.

An exploration proposal awaiting approval has been submitted to the Department of Mines, Industry Regulation and Safety (DMIRS) for 3,067 m of trenching, processing 48,000 t of previously disturbed material and an initial 840 m of RC drilling and 250 m of diamond drilling.

 

 

mt oscar tenement boundaries

Artemis reconnaissance sampling and mapped conglomerates at Mt OscarWits

 

mt oscar 75 m conglomerate

Outcropping conglomerates at Mt OscarWits

 

Geology and sample locations of OscarWits Nugget Discovery area

Geology and sample locations of Mt OscarWits Nugget Discovery area

 

 

 

 

 

 

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