Caldas, which was spun out of Gran Columbia Gold in February with the producing Marmato gold project in Colombia, had acquired Juby in July to provide geographic diversification.
It updated the resource to reflect NI 43-101 requirements and 2018 drilling by Tahoe Resources.
Juby now comprises an indicated 21.3 million tonnes at 1.13g/t gold for 773,000 ounces and an inferred 47.1Mt at 0.98g/t for 1.49Moz.
"The Shining Tree gold district is an under-explored area in the southern part of the Abitibi greenstone belt and we are encouraged by the increase in the level of interest and investment in this area, including recent news related to the development of a new mine at Iamgold's Cote Gold deposit and exploration programmes commencing on neighbouring properties owned by Orefinders and Platinex," chairman and CEO Serafino Iacono said.
He said Caldas was planning a drilling campaign targeting resource expansion in 2021.
The company had raised C$14 million through a private placement with Gran Columbia to fund the acquisition of South American Resources Corp, which gave it 100% of Juby and 25% of certain adjoining claims in the Shining Tree area.
Gran Columbia owns 57.5% of Caldas' shares, according to a September presentation.
Caldas recently raised US$83 million in subscription receipts towards its Marmato expansion and was moving to complete the project's final funding phase, a $110 million streaming transaction with Wheaton Precious Metals.
Caldas shares have ranged so far from C$1.30-$3.07 and closed up 2.5% yesterday to $2.48, valuing it at $192 million (US$145 million).