Tolu Minerals (ASX:TOK) started surface geological mapping, trench sampling, and multi-element surface geochemical survey over gold mineralized veins between the Tolukuma gold mine and the Kimono vein area in Papua New Guinea, according to a Monday filing with the Australian bourse.

The magneto-telluric survey over the Tolukuma prospect area, including the Tolukuma mining lease 104 and surrounding exploration licenses, identified near-surface linear targets, the filing said.

Mapping and sampling are being conducted to prepare for diamond drilling, which is expected to begin in the third quarter of the year, per the filing.

Shares fell 2% in midday trade Monday.