The company reported 24m at 3.37g/t gold and 29m at 2.27g/t among the highlights from the Main Zone deposit last week.
It is about 44% through its planned 2019 drilling programme, which is scheduled to wrap up in August and feed into a fully-funded prefeasibility study early next year.
"Resource estimation for the PFS will begin once the metallic screen assays are back for Leprechaun deposit," president and CEO Phillip Walford said.
Marathon's shares touched a 52-week high on Friday of C$1.12, with the company's IR manager Chris Haldane telling Mining Journal recently its share price had also been boosted following ASX-listed St Barbara's bid this month for miner Atlantic Gold in the region.
Marathon had C$19.4 million (US$14.4 million) in cash at the end of March after selling a 2% NSR royalty to Franco-Nevada for $18 million in February.
Its shares closed up 8.8% on Friday to $1.11, a gain of 44% year-to-date, capitalising it about $178 million.