Successful Drilling Program Completed at Tumas 3
• Current drilling campaign of 10,545m at Tumas 3 completed and has identified
uranium mineralisation over a strike length of 4.4km open to the west and east
• Overall drilling success rate of the program high with 284 out of 400 holes
returning mineralisation >100ppm eU3O8 over 1m
• Strongest intersections from the most recent drilling include:
o 7m at 635ppm eU3O8 from 9.1m
o 5m at 565ppm eU3O8 from 13.1m
o 5m at 651ppm eU3O8 from 13.1m
o 3m at 1044ppm eU3O8 from 8.1m
o 6m at 710ppm eU3O8 from 9.1m
• Mineralisation is calcrete associated and hosted in palaeochannels, similar to
the Langer Heinrich uranium mine located 30km to the north east
• A maiden resource estimate for the Tumas 3 discovery is expected late in the
current September quarter
Deep Yellow Limited (DYL) is pleased to report continued encouraging drilling results from the final phase of the ~10,000m drilling program carried out on EPL3496, held by DYL’s whollyowned subsidiary Reptile Uranium Namibia (Pty) Ltd (RUN).
The drilling program at Tumas 3 was completed 1 July 2017 with 400 RC holes for 10,545m drilled. The latest drilling of the target zone has delineated additional uranium mineralisation, extending the discovery even further since last reported (see DYL ASX announcement 22 June 2017) by an additional 1.2km length to a total of 4.4km. Of the total 400 holes drilled 284 returned positive results – an overall 71% success rate. Equivalent uranium oxide (eU3O8) values have been determined for all 400 holes completed in the program.
Although the mineralisation at the western margin of the drilled area has narrowed compared to the central mineralised zone, the Tumas 3 mineralisation still remains open to the west and east, strongly justifying future extension drilling. Drilling has been conducted on a 100m x 100m spacing and is considered sufficient to define a maiden inferred resource, which is expected late in the current quarter.
The Tumas 3 discovery occurs as a distinct mineralised zone separate from the known uranium resources the Company has identified elsewhere within these palaeochannels in its Tumas 1 & 2 and Tubas Red Sands/Calcrete deposits (see Figure 1). The palaeochannels occurring away from these deposits and Tumas 3 have only been sparsely drilled along widely spaced regional lines with large sections completely untested. This leaves abundant opportunity both for continuing to determine the full extent of Tumas 3 and for making further discoveries within an insufficiently tested, highly prospective palaeochannel system of 100km in length.
Figure 1: EPLs 3496, 3497 showing Tumas 3 and main prospect locations over
The mineralisation that has been extended with the additional drilling at Tumas 3 occurs with no surface radiometric expression. It clearly shows that, apart from the benefit gained by the re-interpretation of the existing airborne geophysical data to locate the prospective palaeochannel systems more accurately, discovery is only possible with drilling.
The Company is however, currently testing ground magnetic, gravity, EM and passive seismic geophysical methods over Tumas 3 to determine whether such surveys can help to better define blind uranium targets for future drilling campaigns. The results of this work to further guide the ongoing drilling are expected to be available in the December quarter.
eU3O8 ppm Determinations
The down-hole gamma data for all 154 holes drilled from 10 June 2017 to completion have been converted to equivalent uranium oxide values (eU3O8). The additional 1.2km of palaeochannel identified from this drilling (506200mE to 505000mE – see drill data results with eU3O8 determinations Table 1 in Appendix 1) confirms a zone of essentially continuous though narrowing, mineralisation with eU3O8 grades ranging from 102 ppm to 2865 ppm (0.28%)
eU3O8 over 1m.
The eU3O8 conversion of down-hole gamma data of all 400 holes drilled on this program has verified the existence of an extensive mineralising system. The drilling has delineated a zone of continuous uranium mineralisation with eU3O8 grades ranging from 101 ppm to 7100 ppm (0.71%) eU3O8 over 1m occurring within the 4.4km section tested to date.
The mineralisation remains open to the west and south-east. Contoured Grade Thickness (GT) values (eU3O8 ppm x thickness in metres) are shown in Figure 2. Mineralisation has been defined as anything having a GT of greater than 100ppm eU3O8 over a 1m interval as determined using a fully calibrated Auslog gamma down-hole logging unit. These GT values highlight the continuous, open nature of the uranium mineralisation showing a robust mineralisation well within the norms of this style of uranium occurrence. The average grade over 1 metre using a 100ppm eU3O8 cut-off is 311ppm and, at a 200ppm eU3O8 cut-off, rises to an average grade of 508ppm which compares very favourably with the average grades of Langer Heinrich at similar cut-off grades.
The mineralised channel system that has been identified varies from 200m to 900m in width and uranium mineralisation ranges in thickness from 1m to 12m occurring at depths varying between 1m to 21m.
The drill program demonstrated that the Tumas 3 mineralisation is not confined to one simple, single channel but rather is associated with a complex palaeodrainage system containing several channels that head westward toward the ocean. The mineralisation is still open to the east and west and future drilling programs will test for extensions to this mineralisation.
Appendix 1 Table 1 lists the final 154 previously unreported drill holes of the program which have been drilled since 10 June (the subject of this release) showing eU3O8 ppm, thickness determinations with hole depth and coordinates provided as calculated from down-hole gamma logging. Approximately 750 check samples are also being submitted for geochemical analysis. These have been selected from across the full extent of the Tumas 3 mineralised zone required as part of the normal course of the verification process to validate the radiometrically derived eU3O8 ppm values before the forthcoming resource estimation of Tumas 3 is undertaken.
Drill-hole cross sections (see Figures 3 and 4) show the continuous nature of the uranium mineralisation and also the variability and complexity of the palaeochannel topography. It should be noted that these cross sections as shown are those used in the previous announcement and given here to show the palaeochannel setting and basic geology which has not changed within the drilled Tumas 3 area.
This first drilling campaign conducted under the direction of the new management team has produced a highly successful overall result. More than 70% of the 400 holes drilled (averaging 26m in depth) over the Tumas 3 target zone encountered mineralisation higher than the 100 ppm eU3O8 over 1 metre cut-off tested on a methodical 100m x 100m drill spacing. This work has identified a significant mineralised zone at Tumas 3. This is not only expected to add to the current uranium resource base of this project but, more significantly, emphasises the strong exploration potential of the uranium-fertile, extensive palaeochannel system within which the new Tumas 3 discovery occurs.
Tumas 3 is now the fourth mineralised zone identified (after Tumas 1 & 2 and Tubas Sand/calcrete deposits) occurring within the 125km of palaeochannels (see Figure 1) that occur within the Reptile project tenements. Some 80%, or approximately 100km, of these palaeochannels remain to be properly tested.
These new positive results both from drilling and reinterpretation of historic exploration data provide management with increasing confidence that the existing uranium resource base for Langer Heinrich style deposit/s within the Reptile project area can be further increased.
The next drilling campaign is planned to follow both the completion of the Tumas 3 resource estimation (expected to be reported late in the current September quarter) and analysis of the planned geophysics surveys.
Deep Yellow Limited
Exploration Competent Person’s Statement
The information in this report as it relates to exploration results was compiled by Mr Martin Hirsch, a
Competent Person who is a Member of the Institute of Materials, Mining and Metallurgy (IMMM) in the
UK. Mr Hirsch, who is currently the Exploration Manager for Reptile Uranium Namibia (Pty) Ltd, has
sufficient experience which is relevant to the style of mineralisation and type of deposit under
consideration and to the activity which he is undertaking, to qualify as a Competent Person as defined
in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources
and Ore Reserves’. Mr Hirsch consents to the inclusion in this presentation of the matters based on
the information in the form and context in which it appears. Mr Hirsch holds shares in the Company.