Tierra Roja Copper Project - Peru
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Tierra Roja Copper Project – Peru
Radius Gold has an option agreement to acquire the Tierra Roja project, a compelling exploration-stage copper porphyry target located in Peru. This project is located in a prolific copper district and is close to infrastructure.
Overview:
Tierra Roja is a large-scale, highly prospective copper porphyry alteration system located in the Arequipa region of southern Peru. The project area covers 1870 hectares, on federal land which is uninhabited and has no registered community.
Tierra Roja has intense silica-serricite alteration and abundant outcropping copper oxide mineralization, exposed over an 800m x 600m area, indicating compelling targets for exploration and discovery. The site is easily accessible, and a low-cost exploration target located in a world-class-copper producing district. Key Highlights include:
Key Highlights
- Tierra Roja is located in Peru’s southern coastal porphyry belt, one of the world’s largest producing copper districts.
- Expanded project area covering 1,870 hectares of prospective ground.
- Recent discovery with no previous systematic exploration or drilling.
- Completion of ground magnetic survey and detailed geological mapping underway.
- Radius is in negotiations for a new access road, connecting to the Pan American Highway, 20km south of the project
- Prospecting continuous rock chip samples grade 1.25% Cu over 35m, and 2.1% Cu over 20m.
- Required environmental, flora, fauna and archaeological surveys to support drill permitting complete
- Drill permits expected within three months with drilling expected in 2025.
- Staged option payments tied to exploration success.
Location
The Tierra Roja is in the coastal desert of southern Peru, at an elevation of 1700 meters above sea level, and 20km from the Pan American highway. The project site is accessible by road and 4x4 tracks. Tierra Roja is located at the northern end of the southern Peru coastal copper belt which hosts some of the largest copper mines in the world. Peru is the second largest copper producer globally.
Figure 1. Tierra Roja project location, at the northern end of the southern Peru porphyry copper belt:
Discovery
Tierra Roja project covers 1,870 hectares, where the core of the property hosts an 800 meter diameter circular anomaly with wide-spread ferruginous, sulphate soil crust developed over strong clay, sericite and silica alteration. In arid climates sulphate crusts can indicate underlying porphyry copper mineralization. The presence suggests that sulfide oxidation and leaching have occurred, which may point to deeper copper enrichment zones.
The rusty clay sulphate crust present at Tierra Roja is a few meters thick and largely hides the underlying copper oxide mineralization. The property optionor, Mr. Montoya, a Peruvian geologist with over 50 years field experience, including senior positions with copper companies: Asarco Inc (Central America, Chile), Lowell Mineral Exploration (Chile, Peru), TVX Gold (Peru, Mexico) and Minsur (Peru), recognized the remote colour anomaly and the significance of the sulphate crust and staked the project. Mr. Montoya cut road access with a bulldozer, breaking the ferruginous sulphate crust, and exposing widespread oxide copper mineralization covering an area of 800m x 600m.
Figure 2. Tierra Roja project, copper oxides mineralization exposed below thin ferruginous sulphate soil cover:
663 original rock chip channels (2 to 3m) were sampled by Mr. Montoya from the road cuts, tracks and drainages. As part of Radius’s due-diligence, 50 duplicates and control samples were collected. These 713 samples define a large-scale copper system hosted in a multiphase intrusive complex.
Figure 3. Tierra Roja project copper geochemistry, showing widespread and high-grade copper in rock chip channel sampling:
Copper mineralization occurs as copper oxides, predominately malachite, chrysocolla and brochantite, both disseminated within the intrusives and concentrated in wide structural zones. High grades above 3% copper (max 12.5%) have been sampled at multiple locations over the property (Figure 2). Relict sulphide halos indicate that the intrusive host is the likely source of the copper mineralization which has been leached, oxidized and remobilized.
Geology
Figure 4. Tierra Roja project geology
Classic Porphyry Alteration Zonation
Initial mapping indicates classic porphyry copper alteration zonation. The main intrusive host is intensely silicified, with strong sericite clay alteration (phyllic) combined with intense leaching of sulphides and supergene secondary enrichment of copper oxides. Wide halos of epidote, chlorite (propylitic) alteration are observed on the distal margins of the system.
Figure 5. Intrusive, leached, intense silicified, clay sericite altered and veined:
Figure 6. High grade 6% copper oxides as malachite, chrysocolla, and brochantite in silicified intrusive:
Supergene Copper’s Economic Impact in Southern Peru’s Coastal Deposits
Southern Peru hosts several large porphyry copper deposits, including: Toquepala, Quellaveco, Cuajone, Los Calatos,Tía María, Cerro Verde, Chapi and Zafranal. These deposits are located along the coastal belt where arid conditions and proximity to the Pacific Ocean contribute to supergene processes. Supergene copper enrichment plays a crucial role in enhancing the economic viability of these deposits. The process occurs as a result of weathering and leaching of primary sulfide minerals in the near-surface environment, and results in the formation of a higher-grade secondary copper blanket comprised of minerals such as malachite, chrysocolla, chalcocite, and brochantite. These supergene copper minerals are distributed widely, disseminated and in structures over a 600m x 800m area at Tierra Roja.
Supergene enrichment blankets typically form beneath a leached cap, creating a secondary enrichment zone that is typically softer, easier to mine, accessible, heap leachable, high-grade resources close to surface. In the coastal desert of southern Peru, most of the major copper porphyries have benefited from the development of an enriched supergene copper zone and have turned many of these deposits into world-class producers.
Access and Permitting
Tierra Roja is located on federal land, 20km from the coast and the Pan American Highway. Topography is low rolling hills, accessible by pre-existing tracks. The climate is arid and there are no residents, artisanal miners, or registered communities located on the property. Thus, the drill permitting and access process is expected to be straightforward and rapid. The field component of environmental surveys, flora, fauna and archaeological studies have been completed and the permit application is being prepared. Radius has contracted a specialist permitting consultancy and expects to have them in 3 months.
Work Plans
There has been no drilling or significant exploration conducted at Tierra Roja. Radius plans to rapidly and systematically explore the property. A high-resolution ground magnetic survey of the core Tierra Roja claims, with 67 line km of surveys has been competed, delineating potential targets. Stream sediment sampling, rock chip sampling, and detailed geological mapping of the entire project is in progress identifying key structural features and mineralization trends. Radius expects to commence drill testing Tierra Roja in 2025. The Radius geological team will lead the project with local input and support from geological and operational staff provided by our project partners.
Quality Assurance and Quality Control
Copper geochemistry consists of 663 rock chip channel samples, collected by a Peruvian mining company and analyzed in a mine laboratory that is not internationally certified. All samples were 2 to 3m chip channels clearly marked with sample numbers. Radius commissioned a senior Peruvian geologist to take 40 duplicate control samples, which were checked in the field by Radius CEO and QP Bruce Smith, who collected an additional 10 duplicates. The 50 control samples, with standards and blanks, were assayed by internationally certified laboratory Certimin S.A. The results of the visual inspections in the field (with visible copper oxides) and combined assays from the 50 control samples confirm the validity of the original samples. There were no significant discrepancies between duplicates. The copper analysis for the 663 original samples is deemed reliable and fit for the purpose of exploration.
