Summary:
The Condor Project's geology is both diverse and complex, particularly in the Condor North area. This region is characterized by distinctive low- to intermediate-sulphidation epithermal vein swarms located in the northern part. These vein swarms form a series of north-northwest-striking, narrow, high-grade gold and electrum-bearing manganoan carbonate veins, often accompanied by base metals and hosted in dacite porphyry.
Notably, the Chinapintza vein district extends along strike for 1.5 km over a zone 0.6 km wide, traversing the former Jerusalem concession and continuing into Peru. In the 1990s, TVX conducted more than 45,000 m of drilling followed by underground trial mine development to explore these veins. Although sufficient data for an accurate Mineral Resource evaluation is lacking, artisanal mining continues to exploit these veins.
Immediately south of the Chinapintza vein district lies the Condor breccia, dyke, and dome complex. This complex is hosted by Early Cretaceous rhyodacite to dacite intrusions and volcaniclastics of the Chinapintza Formation, encircled by the Zamora Batholith. Within this area, several diatreme breccias, dykes, plugs, and sub-volcanic domes are associated with these intrusions. Rhyolite dykes, in particular, play a crucial role in localizing vein mineralization. The Condor breccia, dyke, and dome complex is further divided into four main zones: Los Cuyes, Soledad, Enma, and Camp. Gold-silver mineralization in these zones is linked with sphalerite-pyrite/marcasite veins, which typically occur within breccias, along the contacts of rhyolite dykes, and as replacements and disseminations. These veins are often disrupted by post-mineral extensional faults.
Mineralization
The Condor breccia, dyke and dome complex hosts the Camp, Los Cuyes, Soledad, Enma and the Chinapintza vein deposits and the un-drilled Prometedor prospect.
Camp
The Camp deposit features gold and silver mineralization linked to a swarm of northwest-striking rhyolite-dacite dykes, likely originating from a larger buried rhyolite intrusion. These dykes are concentrated at the contact between a volcanic/intrusive complex and a major granodiorite intrusion. The mineralized zone, dipping steeply at 85° to the northeast, extends over 500 m along strike and is 80 to 130 m wide.
Gold occurs within veins containing pyrite, marcasite, iron-rich sphalerite (marmatite), galena, ± chalcopyrite, pyrrhotite, quartz, and rhodochrosite gangue. Host rocks include altered granodiorites, breccias, flow-banded rhyolite, and phreatomagmatic breccia. The area is capped by 30 to 80 m of trachyte to rhyolitic welded tuff, with the Camp ridge bounded by the Camp Fault and Piedras Blancas Fault.
Anomalous surface copper mineralization and stockwork porphyry clasts with molybdenite in the nearby Los Cuyes diatreme suggest a deeper common mineralized porphyry underlying the Condor breccia, dyke, and dome complex.
Los Cuyes
Los Cuyes is hosted within an oval-shaped diatreme measuring 450 m northeast-southwest, 300 m northwest-southeast, and extending to at least 350 m in depth. This diatreme, resembling an inverted cone plunging approximately 50° to the southeast, consists of an outer shell of polymictic phreatomagmatic breccia and an internal fill of well-sorted rhyolitic lapilli tuffs, breccias, and volcanic sandstones. Amphibolite and quartz arenite fragments occur around its periphery, with dacite and rhyolite ring dykes intruding the steep margins.
Alteration within the diatreme is primarily sericite-illite, with localized carbonate and intense phyllic alteration at the margins, indicating focused hydrothermal fluid flow. Gold and silver mineralization occurs in veins containing pyrite, sphalerite, galena, chalcopyrite, and pyrrhotite. The entire diatreme exhibits a low background level of gold, primarily in disseminated pyrite and sphalerite. The highest gold values are found in veins of massive sphalerite, pyrite, and marcasite, with minor quartz, galena, and rhodochrosite, similar to the nearby Chinapintza veins.
Soledad
The Soledad Zone features a 700-meter diameter oval-shaped rhyolite intrusion within the Zamora Batholith, surrounded by discontinuous pyritic breccias. It includes individual mineralized zones named Soledad, San Jose, Bonanza, and Guayas. Epithermal gold-silver mineralization at Soledad resembles that of the Camp deposit, with patchy matrix replacement by sulphides, grain-scale replacement of rhyolite feldspars by sphalerite and pyrite, and irregular sphalerite veinlets. Unique to Soledad are the pyritic hydrothermal matrix breccias at the upper margins of the intrusion at San Jose and Guayas.
The overall mineralization at Soledad is described as a north-south elongated wine glass-shaped body, tapering between 200 to 300 m below the surface and extending approximately 110 m northwest by 50 m northeast. Sphalerite transitions to pyrite as the dominant sulfide at around 100 m below the surface, leading to diminished gold and silver grades similar to Los Cuyes.
Enma
Gold and silver mineralization at Enma is hosted in a west-northwest-trending rhyolitic breccia that occurs at the contact between andesite lapilli tuffs and the Zamora batholith. The deposit has dimensions of 280 m east-northeast, is approximately 20-75 m wide, and has a vertical extent of 350 m. Alteration mineralogy is primarily chlorite with minor quartz-sericite ± alunite-kaolinite. Gold is associated with pyrite-sphalerite-quartz and locally rhodochrosite veins. At depths greater than 200 m, gold-poor, pyrite-pyrrhotite ± chalcopyrite veins are more dominant.
Deposit Types
In the Condor North area, gold and silver mineralization within the Condor breccia, dyke and dome complex, and the adjacent Chinapintza veins, as well as at the newly identified Nayumbi prospect located in the Condor South area, is consistent with low to intermediate sulphidation epithermal mineralization (Hedenquist et al., 1996). Notable examples of epithermal gold deposits include Fruta del Norte (Ecuador), McLaughlin (California), Hishikari (Japan), Waihi (New Zealand) and parts of Porgera (Papua New Guinea). The Condor Project is reported to display the characteristics of low to intermediate sulphidation epithermal deposits (as described by Sillitoe, 1993; White and Hedenquist, 1995; Leary et al., 2016).
The Camp, Los Cuyes, Soledad, and Enma prospects are consistent with low to intermediate sulphidation epithermal mineralization. Characteristics of such deposits are:
- Occur at convergent plate settings, typically in calc-alkaline volcanic arcs.
- Form at shallow depths (<2 km) from near-neutral pH, sulphur-poor hydrothermal fluids, often of meteoric origin, with metals derived from underlying porphyry intrusions.
- Structural permeability created by hydrothermal fluid over-pressuring allows for mineralized fluids to permeate, with gold precipitated by boiling.
- Sub-types include sulphide-poor deposits with rhyolites, sulphide-rich deposits with andesites/rhyodacites, and sulphide-poor deposits with alkali rocks.
- Hydrothermal alteration is zoned and subtle, characterized by sericite, illite, smectite, and carbonate.
- Features quartz, quartz-carbonate, and carbonate veins with various textures.
- Sulphide content varies (1-20%), typically <5%, with pyrite, sphalerite, galena, and low copper (chalcopyrite).
- High gold, silver, arsenic, antimony, mercury, zinc, lead, selenium, and low copper, tellurium.