Oceana Lithium defines Large Uranium Anomaly at NT Napperby Project

Oceana Lithium has been in the news recently, updating the market about a large uranium anomaly at its 100%-owned Napperby Project in the Northern Territory.

Late last month, Oceana announced that the results of recent soil sampling had defined a uranium anomaly more than 4.5km in length and up to 700m in width. Re-examination of hyperspectral data by HyVista Pty Ltd supports ‘roll-front’ style uranium mineralisation interpretation for the anomaly.

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 uranium, thorium and rare-earth elements (REEs).

Both granite plutons show outstanding uranium/thorium ratios and are almost fully encapsulated within Oceana’s Napperby Project leases EL32836 and ELA32841 (under application), as shown in Figure 1 below.

Figure 1: Granite plutons show outstanding uranium/thorium ratios

A total of 107 samples were collected in the last campaign at 200m spacings for approximately 30 line-km. Although initially targeting lithium, the results from the soil sampling have defined a large arcuate uranium anomaly, as shown in Figure 2 below.

Figure 2: 107 samples were collected in the last campaign at Oceana’s Napperby Project

Oceana further updated the market 15 May, citing historical information from Callabonna Uranium Ltd (“Callabonna”) between 2009 and 2013 further enhance uranium prospectivity at Napperby.

Shallow diamond drilling completed by Callabonna revealed secondary enrichment of uranium with a peak of 1170 ppm U.

Callabonna completed a shallow 3-hole diamond drill program (Table 1) on a granite exposure previously named the Platform Prospect. These holes were designed to target anomalous uranium values (100 to 1000 ppm U) ascertained from rock chip assays and ground radiometrics (collected using a handheld gamma-ray spectrometer), to determine if higher-grade uranium mineralisation occurred at depth or was restricted to the surface weathering profile.

Table 1: Callabonna’s Historical Drill Hole Collars (Geodetic datum GDA94)

A total of 9 intersections were assayed from the 3 holes and revealed a near-surface secondary enrichment of uranium with a peak of 1,170 ppm U at 2cm depth in drillhole DP1 with deeper intercepts (below 17cm) returning uranium values below 100 ppm U (Table 2).

Table 2: Callabonna’s Historical Drill Hole Results

Anomalous uranium values (100 to 1000 ppm U) were ascertained from 35 rock chip assays and ground radiometric data, collected using a handheld gamma-ray spectrometer (Figure 3).

Figure 3: Location of Callabonna’s historical results within Oceana’s EL32836

Oceana’s CEO Caue (Paul) Araujo commented that “The historical information from Callabonna has not only boosted the uranium prospectivity of Napperby but has also provided strategic information for the optimization of our field activities in June. We look forward to firming up targets for drilling as soon as practicable”.