27 shallow refraction spreads, totalling 2835 metres of traverse, were part of the feasibility study. Principal objectives were to confirm depth of soil / completely weathered rock, provide an indication of excavation conditions and detect geological anomalies. For the Saddleworth Formation, average velocity was 3520 metres / sec with depth of weathering generally less than 10 metres, while for the Stonyfell Quartzite the average velocity was 2770 metres / sec with depths of weathering commonly 15-20 metres.