Exploration Potential: Copper
The regional historic exploration data for the 11,240 hectare land holding, combined with exploration activities conducted in the 2007 and 2008 support the interpretation that copper mineralization is related to a very large porphyry-driven, iron-oxide-copper-gold (IOCG) system with an excellent potential for locating additional target areas and resources.
Study of copper and molybdenum soil and rock geochemical patterns in relation to geology indicate that the copper mineralization at San Antonio is controlled by brittle deformation in the form of faults and fractures and by breccia bodies formed by intersecting zones of faults or fractures.
A number of clear structural corridors or trends defined by faults and fractures, airborne linears and importantly the alignment of geochemical anomalies, have been defined. These corridors are aligned in different directions with a NE-SW and NW-SE set being particularly important. WNW-ESE and E-W directions are also present.
A mineralization model in which fracture zones or structural corridors and intersection of these corridors to form breccias, seems an important guide for future exploration. Mineralizing fluids from underlying intrusive events can be trapped in structures parallel to the various corridors or in cross structures within corridor. In areas of greater structural complexity (intersecting fracture directions) breccias appear to form. These often provide ideal sponges for mineralization such as at Luz del Cobre and the large zone of potential copper and molybdenum mineralization in the central portion of the Sapuchi breccia.
Various copper exploration targets have been identified to date:
- Possible extension of Luz del Cobre
- El Tigre
Extension of Luz del Cobre
The Luz del Cobre deposit is open along at least two sides:
- Continuation to the west underneath Calvario,
- Towards the southwest ("Southwest Extension")
Luz del Cobre Extension:
Section through Calvario Extension:
Section through Southwest Extension:
In 2007 and 2008, exploration drilling near Luz del Cobre had defined two additional zones of copper mineralizations which subsequently were included in the resources of Luz del Cobre. The first of these zones (referred to as the southwest extension) is a continuation of the Luz del Cobre body within a north trending structural corridor, on the south-western end of the mineralized body. The second zone is called Calvario and is located 100 metres to the west of the planned Luz del Cobre pit in continuation of the Luz del Cobre mineralization. The limits to these additional mineralizations have not been fully defined and remain open for further expansion.
Along and at the southern flank of the ridge that runs for more than 1 kilometre to west of Luz del Cobre historic exploration work and follow-up work between the years 2006 and 2008 by the predecessor company of Red Tiger Mining has outlined a copper target with potential for copper mineralization, and copper has been found within breccias, in structures and in stockworks zones within the structural corridor. The mineralization is of the oxide-mixed type, however, the possibility of deeper sulphide mineralization cannot be excluded. The currently known mineralization appears to be acid leachable. The goal of the work has been to locate additional mill feed to extend the life of the Luz del Cobre.
Between 1968 and 1972 Minera Trion, a joint venture with Mexican mining group Penoles as the operator, conducted exploration in the Trion area that included surface work, the drilling of 22 core and rotary drill holes and the construction of two short adits.
In the late 2000s, detailed mapping of the Trion area was conducted, accompanies by additional 471 rock chip samples and construction of access roads. 23 cored drill holes to depths between 50 metres and 100 metres were brought down.
The work has identified a 500 metres long and 100 metres wide structural corridor coinciding with copper anonalies and ore-grade copper values (+0.25 % Copper) on surface and in drill holes found within breccias, in structures and in stockworks. The work conducted so far suggests that the zone has potential for additional feed to the Luz del Cobre project (the pit is located just 500 metres to the east.
Future follow-up work would consist of a resource modelling and open pit simulation on the existing data base and, if required and justified, metallurgical testing and further follow-up drilling.
Ventana is a conceptual greenfield target located about 1,000 metres to the northeast of Luz del Cobre following the southwest to northeast structural trend which regionally appears to line up the major mineralizations at San Antonio.
The presence of a strong magnetic (total magnetic field) anomaly and a radiometric high, extending to the northeast from Luz del Cobre combined with visible rock alterations by iron oxide staining and old Minera Sanex reports noting alteration/mineralization similar to Luz del Cobre, combined with the vicinity of Luz del Cobre, makes Ventana a viable follow-up target (mapping and surface rock chip) geochemistry).
El Tigre Target (Copper and Gold)
El Tigre is situated approximately 3 kilometers west southwest from Luz del Cobre. The area initially became of interest because of the persistent strong copper and gold anomaly from soil (and later rock chip) sampling. The prospect occurs along a northeast trending high angle fault contact between (older) quartzite and skarn, both units part of the San Antonio Formation. The contact occurs along the crest of a ridge with prominent exposures of quartzite, while the flanks of the hill are largely covered, but where exposed there is often strong alteration
Five core holes were drilled in year 1995 and one in 2005. All holes encountered copper mineralization at or very near the surface, with the intervals in the first four holes appearing to be leachable oxides. No other holes are present in the area, so the mineralization is open in all directions. Although the grades are modest in the overall intervals, they approach ore grade, and have shorter intercepts of ore grade.
El Tigre largely requires additional drilling to determine the size, grade and mineral species of the mineralized body. Preparatory work will include new road construction that will allow additional mapping and sampling of the area and may assist in better targeting the follow-up holes.
Brindena Taget (Copper and Gold)
This is an area located 2 to 3 kilometres northwest of Luz del Cobre with coincident geochemical and geophysical anomalies. A strong series of east -- northeast magnetic anomalies are present, and soil sampling shows strongly anomalous responses in several elements. The western most line which was sampled has a broad open ended copper, gold and molybdenum anomaly. Geological mapping and continuation of geochemical surveys is recommended.
Moving to the western sector of the San Antonio Property, various oxide copper mineralizations were encountered in an area denominated "Sapo", about 8 kilometres to the southwest of Luz del Cobre. In 2008 the Company reported from this area that mapping, geochemical sampling and trenching identified new targets exposing oxidized copper mineralization.
The areas of mineralization show fine grained, fractured siltstones and slates that have been intruded by andesite dikes, a possible source of mineralizing fluids. Mineralization occurs along steep fractures and also along bedding planes within a typically north easterly structural block The mineralized block appears to have a minimum width of 100 metres, a strike length of at least 200 metres and a vertical thickness measured at over 100 metres. 7 cored drill holes concluded in 2008 encountered copper mineralization in three targets very near the surface, in intervals and grades of potential ore grade magnitude.
This is conceptually one of the prime exploration targets of the San Antonio Property.
It is situated in the middle of the San Javier-San Antonio Mineral District about 6 kilometres to the southwest of Luz del Cobre. Carrizo is a prominent ridge which shows a cluster of geophysical and geochemical anomalies. Worth noting is that uranium anomalies, a common accessory element in iron-oxide-copper-gold (IOCG) deposits shows up at Carrizo, at Sapo as well as at Luz del Cobre along with a few other places.
Petrographic examination of samples from the area suggested the rocks have encouraging potassic alteration. Areas of intensive silification with disseminated pyrite (and traces of aresonpyrite, chalcopyrite and molybdenite) were noted along drill roads along the south flank ("Carrizo Basin") of the ridge. There are a number of old workings in the area, but no information is available on these.
Two inclined deep holes at Carrizo were drilled in 2008 (first drilling ever in this area) to test a large altered breccia with associated geochemical and geophysical anomalies in the remote and previously untested portion of the "Carrizo Basin". Both drill holes remained in the altered breccia or crosscutting dikes over their lengths and contained stockworks and disseminated pyrite with subordinate chalcopyrite and chalcocite. Copper mineralization was encountered persistently over wide sections of the 475 metres and 350 metres deep cored holes. The assay results were strongly anomalous in copper and silver over significant intervals, with potential ore grade in more restricted intercepts.
The Carrizo Target requires follow-up ground geophysical investigations and significant more amounts of deep drilling in order to confirm the interpretation and conclusion that this target is related to a very large porphyry-driven IOGC system with an excellent potential tonnage potential.