Critical Resources Limited (ASX:CRR) (“Critical Resources” or the “Company”), is pleased to advise that it has received interpretation of the airborne survey flown over the company’s Mavis Lake Lithium Project ("the Project”) in Ontario, Canada in October 2021. The interpretation has provided a significant basis for the potential of a further 28 new drill targets across the property.


  • 28 new target areas identified from litho-structural interpretation including 11 high priority targets
  • Exploration works on new targets will be undertaken to develop a drilling strategy to expand on the current 5,000m program
  • Current drilling program is approximately 20% complete of which the first 8 of 9 holes have intersected visual spodumene with estimates of spodumene content up to 40%.1, 2
  • New targets provide further growth potential at Mavis Lake

The Company is pleased to announce it has received a highly positive litho-structural interpretation from the geophysical airborne survey flown across the Mavis Lake property in late 2021. The interpretation is based on magnetic, radiometric and VLF electromagnetic data.

Drilling is ongoing at the Project with the ~5,000m drill program approximately 20% complete. Of the first 9 holes 8 holes have intersected visual spodumene with estimates of spodumene content up to 40%.1, 2

Critical Resources Managing Director Alex Biggs said:

“In conjunction with the recent drilling success at Mavis Lake, confirming further growth potential is extremely encouraging. The interpretation of the geophysical data in combination with visual results from the current program are critical in the development of future drilling campaigns and gaining further confidence in Mavis Lake’s potential”.

Geophysical Data Interpretation

Litho-structural interpretation at a scale of 1:10 000 over the Mavis Lake project area was completed using flown magnetic/radiometric/VLF and DEM survey with the help of other supportive data and information from previous exploration efforts. Due to significant forest/forest soil cover over the project area, the structural interpretation was based primarily on the aero magnetics and to some extent also on VLF data. Radiometric, DEM, satellite data have been studied and analysed, however, these make a minor contribution to the interpretation.

The interpretation was primarily concerned with the identification of pegmatite bodies, prospective for lithium mineralisation. With no significant property contrasts between the pegmatites and the typical host rocks, (direct) targeting lithium bearing pegmatites with geophysics is difficult. The targeting strategy was therefore focused on indirect leads: a) lithological associations (proximity to granitoid bodies, associations with mafic/ultramafic sequences) b) structural context and structural complexity (looking for structures and traps that may act as conduits for Li-bearing fluids to flow and precipitate) c) reduction of the search area by eliminating strongly magnetic sequences and looking for distinct magnetic lows, consistent with presumed felsic lithology. In general, preferred were areas of significant structural deformation/fragmentation that produce favourable conditions for pegmatite precipitation and formation of structures that may act as fluid conduits.

Based on information derived from the geophysical data, a total of 28 target areas have been selected for follow up. The target areas require follow-up surface mapping, geochemical surveys and reconnaissance drilling to obtain further information about the underlying geology. The 28 targets have been ranked as high, moderate and low priority, with little to no difference between high and moderate priority. These areas are seen in the following two figures, with numerical values (High – 1, Moderate – 2 and Low – 3) placed in each target area to highlight their respective priority.