Highlights from infill and depth extension drilling include 242m at 1.01g/t gold and 0.3% copper from 10m; and 138m at 1.87g/t gold and 0.54% copper from 92m.
The new zone was defined by holes stepped out from the project's highest-grade intercept to date revealed in June.
The inferred resource announced in January contains 4 million ounces of gold, 423 million pounds of copper and 4.6 million ounces of silver.
Lumina expects to update the resource this quarter to feed into a preliminary economic assessment in the second quarter of 2018.
Metallurgical testwork has begun, along with a geotechnical characterisation and stability review for pit slope design.
The company said Ausenco had completed a preliminary study on the sites for proposed infrastructure.
Meanwhile, Lumina said in August that an easement process was ongoing to allow the company to start exploration in an area where Mauricio Mendieta had certain surface rights.
Mendieta has sought recourse in the Supreme Court of Justice over the Ministry of Mining voiding his mining concession that Lumina acquired as part of the Cangrejos 20 concession.
Shares in the company have fallen about 25% this year but closed up 3.33% yesterday to C$0.62.
