Rio Tinto can earn up to 75% of Arcas by spending US$25 million on exploration, under a 2019 deal.
Arcas is in the Antofagasta region and is under-explored despite being adjacent to a major mineral belt, AbraSilver said.
"Having partnered with Rio Tinto, one of the world's largest and most successful mining and exploration companies, provides a significant opportunity for AbraSilver to unlock additional exploration value for shareholders, while we continue to focus on our Diablillos silver-gold project and advancing our pipeline of exploration projects," president and CEO John Miniotis said.
The company, previously AbraPlata, has been reporting high-grade mineralisation from Diablillos in Argentina and increased its Oculto resource last week to a measured and indicated 1 million ounces of gold and 90.2Moz of silver.
The boost has prompted it to work on updating a preliminary economic assessment for the project.
AbraSilver has about C$20 million in cash, according to a presentation this month, saying it was fully funded to advance Diablillos to a construction decision by 2023.
The company has several other earlier-stage projects in Argentina and Chile.
Eric Sprott and SSR Mining are its major shareholders with 15% and 9% respectively.
AbraSilver rose 8.86% to close at 43c yesterday, having ranged between 26-82c over the past year, capitalising it at $195.5 million (US$153 million).