Castile Resources (ASX: CST) announced that the inaugural drilling program at the Rover 1 IOCG prospect within its Rover Project in the Northern Territory has intersected high-grade intercepts including 30.4 metres at 35.6 g/t gold.
The company said that the gold assays from the first hole by Castile produced a stunning intercept of 30.4 metres @ 35.6 g/t Au (uncut) from 506.5 metres downhole in diamond hole 20CRD001 including, 6.5m @ 7.48g/t Au (uncut) from 506.5 metres, and 13.2m @ 76.27 g/t Au (uncut) from 518.95 metres.
Rover project
Castile’s 100% owned Rover Project is located 80 km southwest of the township of Tennant Creek in the Northern Territory. The total tenement area is approximately 1,054 km² covering a significant proportion of the Rover Mineral Field.
The main mineralisation style within the Project is Iron Oxide Copper Gold (IOCG). The Rover Mineral Field is interpreted to be a southern repeat or extension of the Tennant Creek Mineral Field.
Tennant Creek IOCG’s have historically produced approximately 157t of gold, 345,000t of copper, 14,000t of bismuth, 220t of selenium, and 56t of silver from 130 mines, with the majority of production derived from 12 deposits.
A key driver of IOCG formation globally is broadly coeval major thermal events – generally this manifests as widespread granitoid intrusion. In the case of Tennant Creek this is the Tennant Creek Super Suite associated with the Barramundi Orogeny. Within the Rover Mineral Field, aerial magnetics have identified several intrusive bodies under cover in proximity to favourable stratigraphy. Importantly for the Project, a large 40 x 20km intrusive body is interpreted on the southern tenement boundary.
Three advanced deposits
The Rover project has three advanced deposits with mineral resources in the Rover Mineral Field – Rover 1, Explorer 108, and Explorer 142. Explorer 108 is a lead-zinc deposit while Explorer 142 and Rover 1 are IOCG deposit type.
Geology and mineralisation
The Rover Project area is covered entirely by recent sediments which blanket extensive flat-lying Cambrian siltstone, dolomitic siltstone, and sandstone units of the Wiso Basin. This basinal sedimentary sequence unconformably overlies Proterozoic basement, with a thickening trend from less than 70 m in the east to in excess of 200 m in the west. Outcrops of the Woodenjerrie Beds, the Junalki Formation (both age correlatives of the Warramunga Formation), the Ooradidgee Group, and the Hatches Creek Group, with minor granite and porphyry, have been mapped about 20 km east of the project area.
Rover 1 prospect
Rover 1 is an IOCG deposit type with strong similarities to Warrego in the Tennant Creek field. A current JORC 2012 Mineral Resource has been estimated of 6.9 Mt at 1.74 g/t Au, 2.07 g/t Ag, 1.2% Cu, 0.14% Bi, 0.06% Co for 386koz gold, 459koz silver, 83kt copper, 9.4kt bismuth, and 4.1kt cobalt inclusive of indicated and inferred classified material. The Mineral Resource is reported at a 2.5 g/t AuEq (gold equivalent) block cut-off.
A scoping study and Mineral Resource completed in 2011 on the Rover 1 Deposit calculated over 1 million ounces of gold equivalent when taking only copper credits into account at prevailing metal prices. The Rover 1 Deposit is also known to contain cobalt, bismuth, and silver.
Castile had launched a Pre-Feasibility Study (PFS) on Rover 1 in early March that included current $A gold prices, modern mining and processing techniques, assessing the by-products value, and flexible financing options to suit the high-grade boutique nature of this asset. The company said that it has the benefit of all the data from the previous drilling programs (approximately 85,000m) and technical assessment and study work completed by the previous owners of Castile, mainly Metals X, and Westgold Resources.
Drilling at Rover 1
The company had recently commenced an inaugural diamond drilling program at the Rover 1 prospect within the Rover Project.
The objective of the first hole (20CDR001) was to extend several high tenor gold zones associated with the Jupiter Ironstone. The company said that these gold zones extend over 150m vertical, 100m along strike, encompassing up to 20m in width, plunging moderately westwards in the roots of the ironstone.
High-grade intercepts
CST said that stunning gold assays were reported from the first drill hole in its inaugural drilling program at the Rover 1 prospect. The company said that the estimated true width of the main intercept is a massive 28 metres enhancing the gold zone.
Significant intercepts include 30.4 metres @ 35.6 g/t Au (uncut) from 506.5 metres downhole in diamond hole 20CRD001 including, 6.5m @ 7.48g/t Au (uncut) from 506.5 metres, and 13.2m @ 76.27 g/t Au (uncut) from 518.95 metres.
The company said that in addition, a sub-parallel zone higher up in the hole returned an intercept of 3.1m @ 12.34 g/t Au from 492m.
What’s next?
The company said that the ongoing exploration and mine planning assessment would continue to take place at the Rover Project.
Management comments
Castile’s Managing Director Mark Hepburn commented: “These are stunning results from Castile’s first drill hole into what is already a significant ore body. It’s a great result for our shareholders that we are finally drilling at Rover 1 and returning these fantastic intercepts.
Our program continues to progress well with the second hole now completed. Samples have been prepared and sent to the laboratory for processing.
Drilling is well progressed on our third hole into the Western Deeps conceptual gold target.”