Oceana Lithium Limited (ASX: OCN, “Oceana” or “the Company”) is pleased to add uranium to the target list of prospective elements at its 100% owned Napperby Project in the Northern Territory, Australia.
Highlights
Napperby Project, Northern Territory, Australia
Oceana’s Napperby Project covers some of Arunta Province’s hottest granites plutons, the Wangala Granite (uranium) and Ennugan Mountains Granite (uranium/thorium)Both granite plutons show outstanding uranium/thorium ratios and are almost fully encapsulated within Napperby’s EL32836 and ELA32841Follow-up exploration activities will target uranium and Rare Earth Elements (REEs) in parallel with Lithium-Caesium-Tantalum (LCT) pegmatites
The Paleoproterozoic Wangala and Ennugan Mountains granites have long been recognised as “Hot Granites” and known to be anomalously enriched in a range of elements including U, Th, P, F and REEs.
As shown in Figure 1, both granite plutons show outstanding Uranium/Thorium ratios and are almost fully encapsulated within Oceana’s Napperby Project leases EL32836 and ELA32841 (under application).
Over the years, several mineral occurrences with uranium and uranium/thorium have been recorded by the Northern Territory Geological Survey, with uranium being more common in the Wangala Granite and uranium/thorium occurring in the Ennugan Mountains Granite.
Further to the south in the Ngalia Basin there are several mineral occurrences and deposits recorded including the Napperby Uranium Deposit, with a JORC 2012 Inferred Mineral Resource of 9.54Mt at 382ppm U3O8 (refer to Core Exploration Ltd – ASX Announcement dated 12/10/2018) and the Cappers Deposit where Air Core hole NAC122 intercepted 2.2m @ 211ppm U3O8 from 3.55m (refer to Energy Metals – ASX Announcement dated 17/09/2009).
The following passages are taken from the independent geological report included in the Oceana’s prospectus and are still very relevant today.
Recent publications by the Northern Territory Geological Survey refer to the Wangala Granite as a composite multi-phase pluton that has been subject to a late hydrothermal event of ca 1575Ma (Chewings) age, which has introduced phosphorus, uranium, fluorine, tin, tungsten and REEs.
Of particular interest is a poorly exposed muscovite-rich granite with abundant pegmatite bodies at the eastern end of the pluton, believed to be the final phase of intrusion. This phase is especially fertile for both Niobium-Yttrium-Fluorine (NYF) and Lithium-Caesium-Tantalum (LCT) segregations in pegmatite, yet surprisingly there are very few analyses for lithium. Bed-rock interpretation indicates this phase is extensive in the sub-crop beneath alluvial-colluvial flats.
This area has been subject to shallow geochemical drilling mainly for uranium exploration in the 1970s, but there is no information on the lithological and geochemical nature of the bedrock.
The contact zones and the eastern termination of the Wangala pluton against Lander Formation are highly prospective for rare-element pegmatites and REEs but still totally unexplored.
The Ennugan Mountains Granite of 1621 Ma (post Yambam) age is a two-phase pluton. The southern phase is an I-type biotite-hornblende granite which implies derivation from lower crustal melting. It is characterised by lenses of biotite schist with elevated uranium, thorium, phosphorus, fluorine and REEs.
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