First-pass delineation drilling at Deep Yellow’s (ASX: DYL) Tumas East 1 prospect within the Reptile project in Namibia, has identified a 16 kilometre region of extensive uranium mineralisation within a system of previously-unknown tributary channels.
The newly-defined area is believed to contain at least seven tributaries with calcrete-associated mineralisation hosted within palaeochannels similar to the nearby Langer Heinrich uranium mine owned by Paladin Energy (ASX: PDN) and has been targeted for follow-up drilling this month.
The tributaries were identified during drilling of 35 holes for 419 metres, with 50% of the holes returning more than 100 parts per million uranium oxide equivalent over 1m.
Best intersections recorded included 3m at 306ppm uranium oxide equivalent from 5m; 5m at 430ppm uranium oxide equivalent from surface; and 9m at 221ppm uranium oxide equivalent from 7m.
The main tributary 1 target has shown continuous calcrete-type uranium mineralisation along a 4.6km length, ranging in widths of up to 900m and located at shallow depths to 12m below surface.
Tributaries 2 and 3 are reported to be less mineralised although the eastern headwaters of tributary 2 have shown “encouraging results” along 2km of channel way.
Results from tributaries 4 and 5, situated north of tributary 1, indicate possible uranium mineralisation along a further 10km of channel length, while tributary 6 has to date been defined only from air photo interpretation and geological mapping and remains to be tested.
Deep Yellow said all channels have been targeted for follow-up resource drilling commencing this month.
A second rig has been contracted to simultaneously conduct resource drilling over the highly-prospective western extension of the Tumas 3 discovery.
High success rate
Deep Yellow completed a total of 180 reverse circulation holes in the Tumas 1 East area for 2173m designed to broadly test the region for mineralisation.
The broad exploration delineation drilling program tested the headwaters east of the Tumas 1 deposit and identified a multi-pronged channel system comprising, at this stage, seven tributaries draining into the main Tumas palaeochannel.
Of the 180 holes, 103 returned positive results of more than 100ppm uranium oxide equivalent over 1m, reflecting a success rate of almost 60%.
Average grade of the 1m intersections of more than 100ppm uranium oxide was 295ppm, and more than 200ppm uranium oxide was 433ppm, which is the cut-off used by Deep Yellow in its earlier resource estimates for the project.
Complex channel system
Deep Yellow managing director John Borshoff said the results of ongoing exploration have shown potential to expand the known mineralisation at Tumas East 1.
“[We now know] the uranium mineralisation is not confined to one simple, single channel but rather is associated with a complex palaeodrainage system containing several channels and tributaries,” he said.
“This is expected to add to the current uranium resource base of this project and continues to emphasise the strong exploration potential of the extensive, uranium-fertile palaeochannel system surrounding these new discoveries.”
Mr Borshoff said Deep Yellow’s focus will now change to resource drilling at Tumas 1 East and Tumas 3 West and continue to year end.
An updated inferred resource estimation for the Tumas 1 East zone, incorporating Tumas 1 and 2 and Tumas 3 West, is expected early next year.
At midday, shares in Deep Yellow were trading 3.45% higher at $0.450.