Spence
The Spence porphyry copper deposit is related to three stocks of dacitic porphyries and tourmaline-bearing hydrothermal breccias, which were emplaced in andesitic volcanic rocks of the Upper Cretaceous–Lower Tertiary. Laser 40Ar/39Ar plateau ages in magmatic biotites of pre- and post-mineralization dacitic stocks show evidence that hypogene mineralization (chalcopyrite, pyrite, molybdenite, and lesser amounts of bornite and tennantite) occurred between 56 and 57 Ma.

Unconsolidated gravel deposits and a leach cap cover an oxidation blanket characterized by atacamite, chrysocolla, and minor brochantite, in which the Cu-hydroxychloride is by far the dominating mineral. Underlying the oxide zone is a well-developed chalcocite- and lesser covellite-bearing supergene enrichment blanket.

Representative samples from pit walls and drill cores were selected in order to cover most of the hypogene and supergene zones, including chalcopyrite from the hypogene-enriched sulfides and hypogene zones, chalcocite from the supergene-enriched sulfides and hypogene-enriched blankets, chrysocolla from the oxide blankets, and atacamite from the oxide zone within the host rocks and gravels and leach cap.

Cerro Colorado
The Cerro Colorado porphyry copper deposit is the northernmost currently active copper mine in Chile. It belongs to one of the Paleocene to early Eocene porphyry copper deposits that are distributed along the western slope of the main Andean Cordillera in Northern Chile.

The geological evolution of Cerro Colorado area can be generalized as follows. The Cretaceous Cerro Empexa Formation, consisting of a sequence of volcanic rocks, mainly andesitic lava and breccia, lahars, some ignimbrite intercalations and dacitic tuff, was intruded by tonalitic to dioritic magma in Middle-Eocene. Magmatic activities generated brecciated rocks accompanying with different alteration zones radiate outward from the intrusion. The mineralized hypogene protore later interacted with ground water, creating the supergene blanket, which is now the principal mining target of Cerro Colorado.

Pampa Norte consists of two assets in the Atacama Desert in northern Chile – Spence and Cerro Colorado.

Spence
Spence is Open-cut. Enriched and oxidised porphyry copper deposit containing in situ copper oxide mineralisation that overlies a near-horizontal sequence of supergene sulphides, transitional sulphides, and finally primary (hypogene) sulphide mineralisation.

Cerro Colorado
Cerro Colorado is Open-cut. Enriched and oxidised porphyry copper deposit containing in situ copper oxide mineralisation that overlies a near-horizontal sequence of supergene sulphides, transitional sulphides and finally primary (hypogene) sulphide mineralisation.

Spence
Spence produces copper cathodes and, since December 2020, copper concentrate. Crushing facilities feed concentrator and leaching processes. 1 copper concentrator plant with 95 ktpd capacity (by-products: gold and silver), molybdenum plant and a 1,000 lps desalinated water plantunder a Build, Own, Operate, Transfer (BOOT) agreement. Dynamic leach pads, solvent extraction and electrowinning plant Nominal capacity of tank house: 200 ktpa copper cathode.

Cerro Colorado
Cerro Colorado produces copper cathodes. Crushing facilities, dynamic leach pads, solvent extraction plant, electrowinning plant. Nominal capacity of tank house: 130 ktpa copper cathode.