It said this marked a significant milestone in the overall environmental assessment process, which had begun in April 2019.
Marathon said in each of the 15 study areas, the EIS outlined mitigation measures aiming to reduce the project's environmental footprint.
The company expected federal and provincial reviews to occur over the next 12 months.
A prefeasibility study released in April outlined a 12-year mine producing 175,000 ounces annually in years one to nine, for initial capex of C$272 million, with an after-tax NPV5 of $472 million and IRR of 36%.
Marathon is expecting results from a feasibility study in the first quarter of 2021.
It's aiming for first gold in mid-2023.
The company was spending $8.9 million and drilling 44,000m focused on new discoveries this year and added a further 8,000m infill programme at the Berry zone in August.
Marathon had raised $34.5 million in May at $1.50 per unit and had $54 million in treasury at June 30.
Its share price has spanned 71c-$2.62 over the past year and closed down 1c to $2.28 yesterday, valuing it at $474.5 million (US$361 million).
