Stewardson Lake

Property and Land Status

100% Uravan, consisting of 5 mineral dispositions (S107738, S-108181-184 inclusive) totaling 21,349 hectares.  Project area is located adjacent to Cameco's Centennial uranium deposit on the South and overlies the Dufferin Lake fault within the Virgin River structural corridor.  The project is a joint exploration effort between Uravan and Cameco Corporation pursuant to the Halliday/Stewardson Option Agreement [press release link]. Cameco is earning an interest and funding work programs. Uravan is the operator.

Project History

1995

Surficial boulder sampling program identified a substantial boron-rich sandstone boulder surface anomaly. This occurrence is suggestive of a hydrothermal alteration system at depth. 

1997

DDH VR-01 was completed to 1180 meters (unconformity at 1135 meters) and positioned near the center of a previously identified surface boulder anomaly. VR-01 intersecting anomalous boron concentrations in the upper 700 m, followed by predominantly illite and chlorite clay alteration (>80%) below 700 meters, local uranium enrichment up to 3.78 ppm U308 in the sandstone, and anomalous lead (Pb) isotope values (207Pb/206Pb isotopic ratios) below 500 meters.

Uravan Project Work

2011

Uravan completed a property wide surface geochemical sampling program. Three sample media were collected on 500m spacing consisting of: B/C horizon soils, spruce/pine vegetation and tree-cores.  The sampling program identified several radiogenic Pb (207Pb/206Pb isotopic ratios) clusters and trends.

2013

A property-wide airborne electromagnetic (EM) geophysical survey was complete. The survey was conducted by Geotech Ltd. using their Z-Axis Tipper Electromagnetic (ZTEM) system. A total of 779 line-kilometers at 500 m line spacing was completed.  The 3D inversion modeling of the ZTEM data resulted in identifying two (2) prominent basement conductive corridors. These conductive features are interpreted to be the northern extension of the C- and E-conductors identified on Cameco’s Virgin River project.  Three (3) significant targets, identified as Area A, B and C, are associated with conductors C and E. 

2014

Uravan completed a three phase exploration program: (1) follow-up ground EM survey(s) over Area A (SQUID fixed loop TDEM and Internal Field Gradient (IFG)), (2) infill surface geochemical sampling programs over Area A and  B and (3) two diamond drill holes (SL14-001 and SL14-002) positioned on the E-conductor in Area A.

The preliminary evaluation of SL14-001 and SL14-002 is the source of the basement conductivity from the E-conductor and the source of the surface geochemical patterns in support of the conductor is deeper than originally considered. Given this results, this puts a potential uranium-bearing target in basement rocks at depths greater than currently drilled.

 

 

Strip Log 001
 
Strip Log 002
Strip Logs DDH SL14-001  Strip Logs DDH SL14-002

2015 Stewardson Exploration Program

  1. From surface sampling programs conducted in 2011 and 2013, the surficial geochemical media collected over the C-conductor (Area B) reveal a number of compelling multi-element and multi-media anomalies (Figure 6). Radiogenic lead (207Pb/206Pb ratios) and uranium (U) anomalies in the soil clay-size fraction are supported by elevated MET values and high concentrations of K, Ca, Mg, Rb, Be.  The strong correlation of anomalous K, Mg and Rb in the soil clay-size fraction with a historic surface boron (B) anomaly is significant as these elements accompany hydrothermal alteration associated with unconformity-type uranium mineralization in the form of illite (K, Rb), chlorite (Mg) and dravite (Mg) clay alteration. A correlation of Na with B in the tree cores is also compelling as these are chemical constituents of dravite clay alteration.  All of these anomalous surface alteration features cluster over the eastern margin of the C-conductor, which is highly suggestive of a hydrothermal 'alteration chimney' breach to the surface from a potential uranium deposit at depth.
  2. In June to August 2015, two diamond drill-holes (DDHs), SL15-003 and SL15-004, were completed in Area B (C-conductor) along section L1330N (ZTEM flight line) totaling 2576 meters drilled.

  1. SL15-003 tested the interpreted 2D and 3D inversion-modeled conductor traces based on the 2013 airborne ZTEM2 geophysical survey focusing on where these conductive features were strongly supported by surface geochemical anomalies, such as radiogenic lead (207Pb/206Pb ratios), uranium (U) and other pathfinder elements in the soil clay-size fraction, and elevated MET3 values.
  2. SL15-003 intersected anomalous uranium mineralization grading 0.025% eU3O8 over 6.3 m in the basal Athabasca Group sandstone (MFa) at the unconformity. The thickness and level of radioactivity intersected is considered indicative of potentially higher-grade uranium mineralization nearby.
  3. Following the completion of SL15-003, a borehole time-domain electromagnetic (BHTEM) survey determined that no significant in-hole nor off-hole conductive response could be detected nearby.  The off-conductor characteristics of the uranium intersection in SL15-003 could be analogous to the Centennial uranium deposit; commonly referred as 'off-conductor' uranium mineralization.
  4. SL15-004, positioned east of the interpreted Dufferin fault, targeted the western edge of the 2D inversion defined conductive unit. This vectoring strategy was based on Cameco's experience knowing the analogous position to the Centennial deposit.

  1. SL15-004 intersected above background radioactivity (173 CPS over 3.65 m with several values >300 CPS) occurring 33 m above the unconformity, hosted by a conglomerate sequence of the basal Athabasca Group sandstone (MFa).
  2. Both drill-holes intersected alteration 'chimneys' extending >300 m into the sandstone section above the unconformity. This significant hydrothermal alteration feature is defined by:
  • Visual observations of drill core, such as sandstone bleaching and secondary hematite alteration over broad intervals;
  • Systematic drill core lithogeochemical analysis identifying substantial radiogenic 207Pb/206Pb ratios of <0.41 through the sandstone section, and consistent U >1 ppm throughout the lower sandstone (>240m) coincident with several pathfinder elements;
  • Systematically scanned drill core with SWIR instrumentation to determine clay mineralogy, highlighting moderate to intense chlorite + kaolinite + dravite clay alteration, coincident with secondary hematite alteration;
  • Well-developed fracturing extending from the basement into the overlying sandstone section, indicative of post-Athabasca basement fault reactivation and;
  • The presence of smoky-quartz in sandstone fractures and veins suggestive of radiation-induced defects from uranium-bearing fluids.

  1. More drilling is certainly required in Area B as we move closer to potential discovery. Our strategy and time-lines for more drilling in 2016 will be announced in January 2016.