Early stage results of a diamond drilling campaign at the Cortadera copper-gold porphyry discovery in Chile have expanded the growth potential of the project for owner Hot Chili (ASX: HCH).
While assays are expected within the fortnight, the company has confirmed the initial two drill holes point to a “significantly larger potential scale” of the main porphyry than first thought.
The first hole was designed to test and close-out the northwest extent of the Cuerpo 3 porphyry – the largest of the three porphyry centres discovered to date at Cortadera.
It recorded a wide intersection of porphyry from much deeper downhole and further north than expected.
“While the majority of the wide porphyry intersection appears to be moderately mineralised, it highlights a distinct change in the orientation of the porphyry body towards the north,” the company said.
“This is important as it indicates Cuerpo 3 is now extending north with approximately 300m of width not closed off by any drilling.”
A second hole to test the extent of a potential higher grade core of Cuerpo 3 is currently at 840m depth and will extend to approximately 1,000m depth following visual confirmation of increasing alteration and vein intensity associated with copper-sulphide mineralisation.
The company said further diamond holes have been planned to test the potential for increasing copper and gold grades with depth across the main porphyry, as evidenced in the project’s historical diamond drilling results.
Prior to the diamond drill campaign, Hot Chili drilled several deep reverse circulation holes (pre-collars to the current holes) across the near-surface extent of Cuerpo 3.
Drilling ended in wide intersections of mineralisation at the limit of reverse circulation depth penetration, approximately 350m downhole.
The results confirmed significant up-dip extensions to copper-sulphide mineralisation recorded in deeper historical diamond drilling.
They included 156m grading 0.4% copper and 0.1 grams per tonne gold from 206m; and 64m grading 0.5% copper and 0.2g/t gold from 140m depth, both ending in mineralisation.
Also recorded was 154m grading 0.4% copper and 0.1g/t gold from 64m depth.
Acquired by Hot Chili in February, Cortadera is a major copper-gold porphyry discovery located along the Chilean coastal range.
The project lies 14km from the company’s large-scale Productora copper development and adjacent to its high-grade El Fuego satellite copper project.
The combination of Productora and Cortadera is at the centre of Hot Chili’s plan to develop a large copper production hub in the region.
By early afternoon trade, shares in Hot Chili were up 7% to $0.03.