Geology and Exploration

Home
Projects
Costa Fuego
Geology and Exploration

GEOLOGY AND EXPLORATION

The Costa Fuego Project region lies at the boundary between the Coastal Cordillera and the Atacama fault system. During the Cretaceous, a thick sequence of andesite and minor sediments (Bandurrias Group) developed in an extensional regime within volcanic island-arc settings. A variety of porphyritic intrusions have been emplaced in this sequence, some of which are probably contemporaneous with the host volcanic rocks. These porphyritic intrusions appear to be responsible for most of the alteration and mineralisation observed in the area.

The project area encompasses a small part of the Chilean Iron Belt. The Iron Belt extends for more than 600 km along a 20 to 30 km wide, north-northeast trending zone at the east side of the Coastal Cordillera. Several large copper deposits within this belt are currently in production including Candelaria, Manto Verde, and Punta del Cobre.

geology and exploration

DEPOSIT TYPES

The Costa Fuego Project encompasses multiple deposit types and mineralisation styles.

Cortadera mineralisation forms a classic copper-gold-molybdenum porphyry deposit, while San Antonio mineralisation is interpreted to be a lode-style copper skarn deposit often found proximal to intrusive sources and porphyry deposits.

Productora is a tourmaline-breccia hosted copper-gold-molybdenum deposit, which also displays some characteristics of both IOCG and Manto-type copper mineralisation. Alice mineralisation, proximal to the Productora deposit, is a copper-molybdenum porphyry deposit lying on the western margin of an outcropping, 6km-long porphyry lithocap. The spatial proximity of Alice and the adjacent porphyry lithocap suggests copper mineralisation at Productora may be related to a larger porphyry system at depth.

Productora

At Productora, mineralisation of copper, gold, molybdenum, and silver is developed mostly within a large intrusive hydrothermal breccia-dominated system that trends in a north-northeasterly direction.
The host breccia has been modelled from drill hole data over a strike length of 7 900 m. The breccia does not outcrop within the lease area although it has been observed extensively in drill core and in the underground workings.
Mineralisation occurs in stratabound disseminated bodies and steeply dipping hydrothermal breccias surrounding barren diorite intrusions with associated veins. The highest grades are typically found in zones of high permeability, such as faults, hydrothermal breccias, dyke contacts, vesicular flow tops and flow breccias. The dominant hypogene sulphide phases are chalcopyrite, chalcocite, and pyrite plus occasional covellite and digenite, with additional minor sphalerite and galena.
Breccias tend to be narrow, north to northeast trending, tourmaline-cemented bodies. Sub-vertical feeder stocks (2 m to 5 m width) increase in thickness near-surface. These wider brecciated zones vary in orientation with central lodes tending to be sub-vertical. Flanking shallower eastern and western lodes dip moderately west and east respectively. There are also some locally steeply east-dipping lodes in the mid zone.

Cortadera

An interpreted WNW-trending fault corridor hosts the three porphyry-style mineralised centres at Cortadera (Cuerpo 1, 2, and 3). Mineralisation continues to at least 1.3 km below the surface.
The Cortadera deposit is characterised by early- and intra-mineralisation, porphyritic tonalitic to quartz dioritic intrusions and adjacent volcano-sedimentary wall-rocks that have locally been recrystallised to hornfels and skarn. Mineralisation tenor and distribution is consistent with that seen in similar porphyry copper-gold-molybdenum deposits; a strong correlation with A- and B- quartz veining and associated chalcopyrite.

San Antonio

San Antonio is a skarn-style deposit, with mineralisation controlled by narrow (1 - 2 m width) north-east trending fault zones. Skarn deposits are developed due to replacement, alteration and contact metasomatism of typically carbonate host rocks by mineralisation-bearing hydrothermal solutions adjacent to an intrusive body.
The dominant sulphide species at San Antonio are chalcopyrite and pyrite, which occur as disseminations around the fault zone. High copper grades (up to 2%) occurring along these fault zones are associated with intense epidote > chlorite ± magnetite ± albite ± calcite and minor specular hematite.

Alice

The Alice copper-molybdenum porphyry mineralisation likely formed deeper than the Productora mineralisation, in terms of genetic emplacement, and has a single porphyry body near a remnant lithocap.
The lithocap overprints Alice and the regional volcanic stratigraphy and can be seen in multiple silica ridges indicating telescoping in this porphyry system. It is comprised of numerous advanced argillic alteration types, including quartz-alunite, quartz-pyrophyllite, alunite-dominant and pyrophyllite-dominant zones.
Within the zones of mineralisation, there appears to be a distinct domain difference between chalcopyrite-dominant and pyrite-dominant areas. Chalcopyrite-dominant zones (i.e. low pyrite: chalcopyrite ratio) correlate with intense A- and B-veins and higher copper grades. Copper mineralisation appears both within veining and disseminated within the groundmass proximal to veining.

Technical Videos

Aug 2023

The GeoHug Talk: The importance of geological mapping, drill-hole logging & 3D geoscientific data inte – Cortadera starts at 40 minutes

Speaker: Steve Garwin, Hot Chili Chief Technical Advisor

Information in Presentation

This presentation (Presentation) contains information about Hot Chili Limited (Hot Chili or Company), its subsidiaries, affiliates and projects, which is current as at the date of the Presentation or as at such earlier date as may be stated or indicated in the Presentation.

This Presentation is for information purposes only, may not be copied, reproduced or distributed to others, at any time, in whole or in part, for any purpose, and may not be used for any other purpose, without the prior written consent of Hot Chili.

This Presentation does not constitute or form part of, and should not be construed as, an offer to sell or issue or the solicitation of an offer to buy or acquire securities of Hot Chili or any of its affiliates or any other person in any jurisdiction or an inducement to enter into investment activity, and does not constitute marketing material in connection with any such securities.

This Presentation should not be construed as providing investment, financial, legal, tax, accounting or other advice or a recommendation with respect to any potential investment in Hot Chili or any other company.

In making any investment decision, you must rely on your own examination of Hot Chili, including the merits and risks involved. You should consult your own advisors as needed to make a future investment decision and determine whether it is legally permitted to make an investment under applicable legal requirements, including securities or similar laws or regulations.

Forward Looking Statements

This presentation may contain “forward-looking statements” and “forward-looking information” concerning the business, operations and financial performance and condition of Company. Forward-looking statements and forward-looking information include, but are not limited to, statements with respect to permitting and legal processes in relation to mining permitting and approvals; the ability to obtain permits for operations; synergies; success of exploration activities; the estimation of mineral reserves (also known as ore reserves) and mineral resources; the realisation of mineral resource and ore reserve estimates; estimated production and mine life of the various mineral projects of the Company; the benefits of the development potential of the properties of the Company; the future price of minerals, including copper, gold, molybdenum and silver; and currency exchange rate fluctuations.

Forward-looking statements may be characterised by words such as “plan,” “expect,” “project,” “intend,” “believe,” “anticipate”, “estimate” and other similar words, or statements that certain events or conditions “may”, “should” or “will” occur.

Forward-looking statements are based on the opinions and estimates of the Company at the date the statements are made and are based on a number of assumptions and subject to a variety of risks and uncertainties and other factors that could cause actual events or results to differ materially from those projected in the forward-looking statements. Many of these assumptions are based on factors and events that are not within the control of the Company and there is no assurance they will prove to be correct.

Factors that could cause actual results to vary materially from results anticipated by such forward-looking statements include variations in ore grade or recovery rates, changes in market conditions, risks relating to the availability and timeliness of permitting and governmental approvals; risks relating to international operations, fluctuating metal prices and currency exchange rates, changes in project parameters, the possibility of project cost overruns or unanticipated costs and expenses, labour disputes and other risks of the mining industry, failure of plant, equipment or processes to operate as anticipated.

The Company cautions that the foregoing list of important factors is not exhaustive. Investors and others who base themselves on forward-looking statements should carefully consider the above factors as well as the uncertainties they represent and the risks they entail and are cautioned not to place undue reliance on forward-looking statements.

Although the Company has attempted to identify important factors that could cause actual actions, events or results to differ materially from those described in forward-looking statements, there may be other factors that cause actions, events or results not to be anticipated, estimated or intended.

There can be no assurance that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. The Company undertakes no obligation to update forward-looking statements if circumstances or the Company’s estimates or opinions should change except as required by applicable securities laws.

The Company considers that the expectations reflected in any forward-looking statements are reasonable, but no assurance can be given that these expectations will prove to be correct and such forward-looking statements included in this Presentation should not be unduly relied upon.

Disclaimer

None of ASX Limited, the Australian Securities & Investments Commission (ASIC), the TSX Venture Exchange (TSXV) and the TSXV’s Regulation Services Provider (as that term is defined in the policies of the TSXV) accept or take responsibility for the content of this Presentation or the adequacy or accuracy of this Presentation in any respect.

May 2021

AIG Technical Talk: The Geometry of the Cortadera Porphyry Cu-Au Deposit in Northern Chile: Implications for Exploration

Speaker: Steve Garwin, Hot Chili Chief Technical Advisor

Information in Presentation

Forward Looking Statements

Disclaimer

COMMON QUESTIONS

What are the deposit types at Costa Fuego?

Costa Fuego is a collection of 4 different deposits, each with unique geology.

Cortadera and La Verde mineralisation are associated with a classic copper-gold-molybdenum porphyry deposits, while San Antonio mineralisation is interpreted to be a lode-style copper skarn deposit often found proximal to porphyry deposits. Productora displays characteristics of both IOCG and Manto-type copper mineralisation, but subsequent structural deformation and alteration had made classification complicated. The Productora proximal Alice mineralisation is a copper-molybdenum porphyry, which suggests mineralisation at Productora may have porphyry sources.
What exploration methods do you use?

At Hot Chili we use a combination of geophysics, geochemical sampling, x-ray fluorescence, mapping and drilling within our exploration activities. Petrology, mineralogy and research studies are also used to enhance our understanding of the geological systems.

Machine learning algorithms can combine data across multiple sources, under the direction of our geologists and geophysicists, to produce probability models for exploration targeting.
How much ground water are you drawing for the exploration activities?

Hot Chili has never drawn ground water from the aquifer to support its exploration activities.

Hot Chili purchases fresh water, and drills using a closed circuit system to recover and reuse this water.
What is the Costa Fuego project?

Read more about Costa Fuego on our project page or in the PFS Infosheet below
READ THE INFOSHEET
What minerals are at Costa Fuego?

The main economic mineral is chalcopyrite, a sulphide containing copper.

The deposit contains other economic elements such as gold, silver and molybdenum which are included within the "copper equivalent" calculation used to describe the value of the deposit.