First Mining Gold Corporation has completed a geotechnical drilling programme to investigate the sediments and bedrock for the dykes at its Springpole Gold Project in Canada.
The geotechnical drilling programme undertook to investigate the lake bed sediments and bedrock along the proposed alignment of the coffer dam.
Results showed that the thicknesses of soft lake bed sediments were much thinner than anticipated and are absent in some areas, which will mean that dredging and removal of the lake bed sediments beneath the footprint of the dykes may not be necessary.
Springpole is one of Canada’s largest undeveloped gold projects, covering 32,448ha.
First Mining Gold president and CEO Jeff Swinoga said: “We are very pleased that the preliminary findings show the bedrock beneath the proposed dykes will provide a competent foundation.
“We see this as a significant step forward in advancing our Springpole Project since this confirms that the dykes can be constructed in the area that was proposed in Springpole’s preliminary economic assessment published last year.
“We have also engaged Tetra Tech to complete the next step which is to finalize the design work on the dyke structures”.
Packer tests undertaken within the underlying bedrock gave inflow rates of less than 1.5x10-5m/s.
The pre-feasibility level geotechnical drilling programme has been completed over the 800m long footprint of the dykes which are required to dewater the north bay of Springpole Lake.
Eleven holes were drilled totaling 171.6m of rock, 17.5m of overburden, and 55.7m of water.
Water depth over the planned dykes ranges from 1.6m to 11.7m, averaging 5m deep. Packer testing was undertaken in all boreholes to measure the bedrock hydraulic conductivity, which showed low to very low values generally ranging between 1.5×10-5m/s and 1.6×10-7m/s.
Tetra Tech will use this data to design and develop a construction cost estimate for the dykes as part of the prefeasibility level study.