Twenty Seven Co. (ASX:TSC) reports Rio Tinto Exploration (RTX), a wholly owned subsidiary of global mining giant Rio Tinto (ASX:RIO) has exercised its farm-in option to the North Rover Project, located in Western Australia to drill for lithium targets.
Twenty Seven entered a binding term sheet with RTX in March, with the company paying $25,000 up front for an exclusive initial 6-month option to explore North Rover for non-gold minerals.
During the initial option period, RTX identified a sub-cropping weathered pegmatite unit that may be prospective for lithium (spodumene) and tantalum mineralisation, with an area prioritised for follow-up drill testing.
Stream sediment, soil and rock chip sampling were then undertaken in the area of interest to better assess the potential for the pegmatite to host lithium mineralisation.
On the basis of the sampling results, in particular coherent tantalum and related geochemical anomalism over an area of the interpreted pegmatite unit, RTX believes that drill testing of the pegmatite unit to test for potential spodumene mineralisation is warranted.
Rio Tinto and Twenty Seven cautions that due to the significant chemical and physical weathering at surface (which has leached many alkaline elements such as Li, Cs and Rb), the interpretation of geochemical anomalism for spodumene is relatively uncertain and the drill targets should therefore be considered high risk.
Planning for the drilling program is currently being finalised. Following the completion of the initial exploration program, RTX has exercised its option to earn an 80% joint venture (JV) interest in the non-gold mineral rights E57/1134 by sole funding of non-gold exploration.
Twenty Seven Executive Chairman and CEO Mark Caruso said the company is encouraged that Rio Tinto has opted to exercise its option to farm-in and advance the North Rover Project in Western Australia.
“The positive early results of first stage exploration has indicators that warrant the drill testing to assess the sub outcropping pegmatite target in the northern area of the tenement for potential lithium mineralisation.
“Securing the support of a global miner such as Rio Tinto demonstrates the underlying potential of the North Rover Project”
“Securing the support of a global miner such as Rio Tinto demonstrates the underlying potential of the North Rover Project, and we look forward to working closely with the Rio Tinto exploration team during the farm-in.”
Rio Tinto’s exploration activities during the Option Period (from April to September) were focused on the northern section of the North Rover Project area and comprised:
- Review of historical exploration information and satellite imagery.
- Acquisition and review of existing airborne magnetic-radiometric survey data.
- Field reconnaissance mapping undertaken via walked traverses that identified an area of interest containing sub-cropping weathered pegmatite and banded aplite.
- Collection of 23 stream sediment samples from mostly first order drainages from the identified area of interest, which were assayed for a broad element suite.
- The collection of 51 soil samples in a notional 100m by 50m grid over the catchment with the highest stream sediment Ta anomalism that were assayed for a broad element suite.
- Collection of 12 rock chip samples from selected weathered pegmatitic rubble within the area of interest that were assayed for a broad element suite.
In the context of highly (chemically and physically) weathered terrain, samples (whether steam sediment, soil or rock chip) with Ta anomalism of over 14ppm (and or Li over 150ppm) were considered anomalous by Rio Tinto.
Twenty Seven Co’s 100% owned Rover Project is located near Sandstone in a base metals and gold mineral rich area associated with Archean greenstone belts.
The Rover Project consists of 3 exploration licences (E57/1085, E57/1134 and E57/1120) which make up a ‘large’ 460km-square tenure package covering two linear Archean greenstones, with a combined length of around 160km.
Historically the area is relatively underexplored and is currently undergoing a resurgence in exploration.
The North Rover project that is subject to the Rio Tinto farm-in relates to just the northernmost Rover Project exploration licence (E57/1134).
Twenty Seven Co is an ASX-listed explorer, and its assets comprise two tenure groupings including the WA Archaean Gold projects, Mt Dimer Project, Yarbu Project and Rover Project; and the NSW iron oxide-copper-gold and tin projects including the Midas Project, Perseus Project and Trident Project.
Images: Twenty Seven Co Limited