AusQuest Confirms Porphyry Hydrothermal System at Lantana Copper Discovery

AusQuest Confirms Porphyry-Related Hydrothermal System at Lantana Copper-Gold Project in Peru

The AusQuest Lantana copper discovery in southern Peru has reached a significant milestone, with the company completing its maiden reverse circulation (RC) drilling program at the Lantana copper-gold project. Results confirm the presence of a hydrothermal alteration system consistent with a buried porphyry copper source. The nine-hole, 2,794 metre program identified advanced argillic alteration and multiple high-temperature pathfinder elements across the project area, providing directional targeting information for the next phase of work.

According to the announcement, lithocaps — zones of advanced argillic alteration — were identified in every drill hole collared north-east of a major north-west trending fault that crosses the prospect. This spatially consistent pattern has given AusQuest a defined vector toward what the company describes as one or more buried porphyry copper systems beneath the alluvial cover.

What the Drilling Program Revealed

The nine RC holes were drilled across a wide-spaced, semi-reconnaissance grid, targeting geological and geochemical anomalies identified through earlier rock-chip sampling, geological mapping, and ground magnetic surveys. Drilling intersected altered andesite and dacite volcanics, varying in thickness from tens of metres in the south to more than 300 metres in the north, sitting above a monzodiorite intrusion linked to the regional Coastal Batholith.

That intrusion has been down-faulted by approximately 150 metres on the north-east side of the major fault, which the company considers a potential conduit for mineralising fluids in the area.

Down-hole copper values reached a peak of 0.4% Cu in LANRC002, recorded within the broader alteration footprint mapped across the prospect.

Geological Vectors Point North and East of Current Drilling

Beyond confirming alteration, the announcement outlines several independent indicators that, taken together, suggest a porphyry copper source lies to the north and east of drill holes LANRC004 and LANRC007.

Pyrophyllite, a mineral associated with the deeper and hotter portions of a porphyry lithocap, was identified within the advanced argillic alteration zones. High-temperature pathfinder elements — including molybdenum, tin, tellurium, bismuth and arsenic — were more strongly developed in LANRC004 and, to a lesser extent, LANRC007. This suggests these holes sit closer to a heat source than the others.

High crystallinity white mica was also noted as supporting evidence of proximity to a high-temperature hydrothermal centre. Furthermore, multiple narrow structures, described as dykes less than 8 metres wide, were intersected in both the volcanic sequence and the underlying monzodiorite intrusion. These structures carried anomalous metal values as summarised below.

According to the announcement, these narrow mineralised structures support the inference of a strongly mineralised system in the area, consistent with fluids having migrated outward from a central porphyry source.

"This first phase of RC drilling at Lantana has provided further encouragement that we are getting closer to locating the source of the basal lithocaps, which are known to reflect hydrothermal systems invariably related to porphyry intrusions." — Managing Director Graeme Drew

Understanding Porphyry Lithocaps

A central concept in this announcement is the porphyry lithocap, and understanding it helps explain why AusQuest regards these results as meaningful.

A lithocap is a zone of altered rock that forms above and around a porphyry intrusion as hot, metal-bearing fluids rise from a cooling magmatic body at depth. Lithocaps are characterised by advanced argillic alteration — a suite of minerals including alunite, kaolinite and pyrophyllite. Pyrophyllite specifically indicates higher temperatures, meaning its presence points to greater depth and closer proximity to the porphyry source below.

Why Does This Matter for Investors Evaluating Exploration Companies?

Lithocaps are a recognised exploration tool used in the discovery of porphyry copper deposits worldwide. In numerous major discoveries, the lithocap was mapped before the underlying, higher-grade mineralisation was identified. The lithocap effectively functions as a marker that a hydrothermal system existed, directing subsequent exploration toward the alteration vectors that lead down and inward toward the potential core.

At Lantana, the identification of pyrophyllite alongside a coherent suite of high-temperature pathfinder elements indicates that AusQuest's drilling has intersected a genuine hydrothermal system — rather than isolated surface-level geochemical anomalies.

Key Terms Explained

• Porphyry copper deposit: A large-scale, typically lower-grade copper deposit, often with associated gold or molybdenum, formed by hydrothermal fluids linked to a cooling magmatic intrusion.
• Lithocap / advanced argillic alteration: A zone of intensely altered rock situated above a porphyry system, used as a key exploration indicator.
• Pyrophyllite: A high-temperature alteration mineral whose presence signals the deeper, hotter portion of a lithocap.
• Pathfinder elements: Elements such as molybdenum, tin, tellurium, bismuth and arsenic that, when elevated, can indicate proximity to a mineralising system.
• RC drilling: A method that circulates air to bring rock chips to surface for geological sampling and assay.
• Monzodiorite: An intrusive igneous rock type; at Lantana, this forms the intrusive basement intersected below the volcanic cover.

Regional Setting Within the Pirata Corridor

Lantana forms part of the broader Pirata/Cerro de Fierro project area, located approximately 50 kilometres east of the town of Chala in southern Peru, within what the company describes as the highly prospective E-W Iquipa-Clavellinas structural corridor.

The project sits within the same mineralised belt that hosts the Cangallo porphyry copper discovery, located approximately 30 kilometres to the west. Drew noted that this regional association provides confidence in the exploration model being applied at the AusQuest Lantana copper discovery in southern Peru.

"Lantana occurs within the same mineralised belt that contains the Cangallo porphyry copper discovery, ~30km to the west, so we are confident that this prospect will add to the copper inventory we have found in this region." — Graeme Drew

AusQuest holds Lantana through Questdor, a wholly owned subsidiary, across 13 granted mineral concessions. A drill permit was issued by Peru's mining regulatory authority, INGEMMET, following environmental and community approvals. In addition, the company reported no major tenure or access impediments during the program.

Next Steps in the Exploration Program

With the maiden drilling program deliberately designed as a wide-spaced reconnaissance test, AusQuest's attention now turns to refining its targeting ahead of any further drilling commitment. The company outlined several planned steps:

1. Completing assessment of assay results across the full dataset before defining follow-up drill targets.
2. Considering geophysical surveys to help identify subsurface targets beneath the alluvial cover.
3. Prioritising the area north and east of LANRC004 and LANRC007, where lithocap development and pathfinder element intensity were most pronounced.
4. Planning further drilling, once geophysical and assay data have been integrated, to test for a porphyry core beneath the cover.

"Targeting to optimise future drilling at Lantana now becomes the Company's main consideration and we look forward to keeping our shareholders up to date with progress." — Graeme Drew, Managing Director

Assessing the Exploration Significance for Investors

The Lantana results add a new dimension to AusQuest's broader exploration portfolio in southern Peru. Several factors from the announcement are relevant to how investors might interpret this milestone.

The presence of pyrophyllite, a coherent high-temperature pathfinder suite, and consistent advanced argillic alteration across multiple holes moves the interpretation beyond isolated surface geochemistry toward a confirmed hydrothermal system at depth. Rather than an ambiguous outcome, the maiden program has generated a defined directional vector — with the interpreted system positioned north and east of LANRC004, giving the next phase of work a specific area to prioritise.

Operating within the same belt as the Cangallo porphyry copper discovery provides a regional geological reference point, though this does not guarantee similar results at Lantana. AusQuest holds the project in its entirety through Questdor, meaning exploration outcomes accrue fully to AusQuest shareholders rather than being shared with a joint venture partner.

The technical work underpinning these results includes hyperspectral analysis using TerraSpec instrumentation and aiSIRIS software for mineral identification, alongside standard assay methods and quality control protocols involving standards, blanks and duplicate samples, overseen by a JORC Code Competent Person.

Outlook for the Lantana Project

The maiden RC program represents a meaningful step in AusQuest's broader exploration of the Pirata corridor. The confirmation of a basal lithocap environment, combined with a coherent pathfinder element pattern, has provided the company with a drill-defined target area rather than a broad geochemical anomaly.

The next phase — involving geophysical surveys followed by targeted drilling — will be the key catalyst investors may wish to monitor. Whether these surveys identify a compelling subsurface target consistent with a buried porphyry system will consequently determine the scope and priority of any subsequent drill program.

Consequently, the AusQuest Lantana copper discovery in southern Peru has confirmed a porphyry-related hydrothermal system, with geological indicators pointing toward a buried copper source north and east of current drill holes. Geophysical surveys and follow-up drilling represent the next milestones as the company works to refine its targeting within the broader Pirata structural corridor.

Want to Follow AusQuest's Progress at Lantana as Drilling Advances?

With a confirmed porphyry-related hydrothermal system, a defined directional vector, and geophysical surveys and follow-up drilling on the horizon, AusQuest's Lantana copper-gold project in southern Peru represents a compelling exploration story for investors to watch closely. To learn more about AusQuest, its 100%-owned Lantana project, and its broader exploration portfolio in southern Peru, visit www.ausquest.com.au.