The Yarraloola Project in the West Pilbara is located about 120km southwest of Karratha, adjacent to the RioTinto-owned township of Pannawonica that services the Mesa-A and Mesa-J Iron-ore Mines and 60 to 100 km south of the magnetite-shipping port at Cape Preston. The tenements are well serviced by established infrastructure. There is bitumen-sealed access along the North-west Coastal Highway and Pannawonica road and unsealed station tracks to more remote prospects. There is a gas pipeline from the Northwest Shelf to Perth and another from the same pumping station to power stations at iron-ore mines in the East Pilbara that traverse the tenements. Mobile phone communication is available over a large area. Proposed infrastructure includes a haul-road from Iron-Ore Holdings (ASX:IOH) Bungaroo South deposit to a new multi-user port at Cape Preston East and a railway for the Australian Premium Iron (API) Joint Venture from deposits to the south and south-east of Yarraloola to Anketell Port.
The Yarraloola tenements cover parts of the Hamersley Basin, adjacent Ashburton Basin and overlying Carnarvon Basin that are each prospective for deposits of iron-ore that can be summarised as follows and are outlined on Fig 1.
Other prospectivity at Yarraloola includes:
In 2014 outlined the Robe Mesa and adjacent areas as a target for pisolitic iron-stone mineralization. Results from three programmes of RC drilling have generated independently calculated JORC-2012 compliant resource statements using a Fe-cut-off at 50% for the Robe Mesa, Robe East Extension and the P529 deposits (Fig 1; Tables 1 to 3). The Robe Mesa includes a higher grade component with the Fe>55% cut-off (Table 1a).
*FeCa = calcined iron is the iron content after the removal of the volatiles (mostly water) from the goethitic mineral structure.
Mapping and drilling shows that the 12km long by 1km wide high-order magnetic anomaly covering parts of E08/1686 and E08/1826 outlines intervals of magnetite schist in a sequence of andesitic, dacitic, and rhyolitic volcanics and clastic sediments in the Ashburton Basin. This new setting for mineralisation in the West Pilbara, that outcrop in parts, is weathered to less than 30m, has magnetite within a matrix of quartz, white and green mica and carbonate, and does not contain crocidolite (blue asbestos).
RC drilling has recovered intercepts up to 200m in length with the iron (Fe) in 1 m interval samples ranging from 26 to 40% that produce a magnetite mass-recovery by Davis Tube in excess of 30% and Fe-contents in excess of 67%.
The Ashburton is a high priority target because it represents a new, large-scale setting for magnetite mineralization in the West Pilbara. The magnetite-rich rocks outcrop in part and are weathered to less than 30m. The magnetite is hosted by finely bedded micaceous metasediments with quartz and carbonate but no blue asbestos (crocidolite) that allows rapid RC drilling rates. The magnetite concentrate produced by an initial programme of crushing and grinding of the first diamond core was a high-grade, low impurity product that is becoming the preferred feed-stock for steel making.
The Yarraloola Project covers about 50km of strike length of the Marra Mamba, Brockman and Boolgeeda Iron Formations from the Hamersley Group. CZR sampling has recovered rock-chips with Fe > 60% at some prospects that require follow-up with drilling.