Auroch Minerals Ltd.'s shares fell 42.5% in Dec. 4 trading on the ASX, after the company reported receiving "disappointing" assays for the first two holes completed as part of a 12-hole drill program at its Tisová cobalt-copper-gold project in the Czech Republic.

While gold results came in closer to the company's expectations, cobalt and copper results did not line up in terms of grade and width.

The company reported assay highlights including 8.0 meters at 0.05% cobalt, 0.97 g/t of gold and 0.2% copper and 2 meters at 0.06% cobalt, 0.79 g/t of gold and 0.1% of copper.

"Thick zones logged as disseminated sulfides have returned lower than expected values for the target metals and where grades are reasonable, thicknesses are narrow and below minimum mining widths," Auroch CEO Andrew Tunks said. "This points to a strong metal zonation within the Tisová orebody. We will review the 3-D model of the sulfides and look to investigate geophysical methods to identify further sulfide bodies as a possible source of cobalt mineralization in the dumps."

Auroch said it sent samples from the final two drillholes to the lab, with assays expected by the end of the month, after which the company plans to make a decision regarding its option on the Tisova project.

Exploration activity is suspended in the Czech Republic due to the winter season and will resume after the snow melts in 2018.