MOD's shares were down 17.65% Monday to A28c (US20c).
The fall came despite the company, which has teamed up with Metal Tiger (AIM:MTR) in Botswana and recently listed in London, saying it had intersected wide zones of visible disseminated copper sulphides within an interval from 85m to 385m down hole depth at the third hole drilled at T23.
These were similar to the mineralisation intersected in the first two holes drilled at the target, although the previous discoveries pushed MOD shares higher.
It said the drilling of the hole had also intersected a strongly mineralised vein at 268.1m down hole depth, which confirmed the potential for high-grade mineralisation similar to several other copper discoveries along the Kalahari copper belt.
It is awaiting assay results to determine the copper grades for the third hole.
The first hole's assay results highlighted a shallow intersection of 25m at 0.36% copper and 4g/t silver from 65m downhole depth, including 3m at 9.7% copper and 10g/t silver from 65m and 1m at 1% copper and 13g/t silver from 80m.
The joint venture partners are planning a substantial drilling campaign for early 2019 to target some of the most compelling domes and structural targets in the T23 Dome area after electromagnetic (EM) data indicated the copper potential could extend over a wider area at shallow depth beyond T23.
MOD managing director Julian Hanna said the company was encouraged by the first drilling results at T23.
"Having confirmed the prospectivity if this area, our exploration team can now start testing the potential for high-grade mineralisation within specifics structures defined by the EM," he said.
MOD and Metal Tiger also collaborate on the nearby T3 copper project, with the A4 and A1 Domes also recently explored.