Twenty nine target areas prospective for large copper porphyry style deposits have been selected for follow up exploration work. Early stage ground work has been completed on the first series of initial target areas resulting in the discovery of two copper porphyry prospects, La Paloma and Cerro Barco. Field crews have covered less than 20% of the target areas, initially concentrating on the north-eastern portion of the Property, in the vicinity of Spence Mine, El Tesoro & Esperanza Mines, and Sierra Gorda project. Over 80% of the Atacama Copper Project has yet to be explored.
Data Compilation and Initial Target Area Selection
The Company has completed the majority of the compilation of available data and subsequent processing. Efforts to date have been focused on acquiring and compiling all available data to aid in the target area selection within the extensive 293,500 hectare property package.
Data compiled to date includes:
Satellite imagery (ASTER), primarily utilized to identify outcropping alteration zones and main structural features;
Geophysical airborne magnetic and radiometric surveys covering the entire project area, flown on 500 metre line spacing;
Geochemical data, consisting primarily of greater than 1000 samples within overburden and bedrock material carried out by the vendors;
Geological and structural interpretation maps, including some prospect specific maps from historical archives; and
Historical information from the vendor’s industrial mining and exploration activities, including drilling results and information related to historical mining on the Property.
Processing of the data was undertaken by the Company’s exploration team and consultants, including geophysicists, satellite imagery specialists, and geologists with local and relevant porphyry copper exploration expertise. Desktop target selection resulted in 29 target areas that warrant further exploration, defined by a combination of alteration signatures, structural components, geochemical anomalies, copper-molybdenum-gold anomalous mineralization, geophysical anomalies, and geological setting.
Vern Arseneau, Vice President of Exploration for Arena Minerals, commented, "Having completed our desktop portion of the exploration program, we are now systematically following each target on the ground. It is important to note that the vast majority of a typical target area is overburden covered, and an individual target can cover in excess of 16 square kilometers. We have an excellent team of geologists and prospectors with many years experience in the Chilean copper belt. It is a testament to the quality of this property package that we have already identified two high quality prospects showing unmistakable copper porphyry signatures in an outstanding location. As we cover more of the ground it is becoming increasingly evident that the claims have had little to no exploration, with large tracts of land which appear to be trackless and unvisited. In addition, it has been a welcome surprise to find shallower overburden depths than expected, in many cases ranging from 2 to 20 metres."
La Paloma & Cerro Barco Prospects
A map of the ACP showing the selected prospects can be accessed here.
The Company has focused groundwork completed to date on the northeastern portion of the Atacama Copper Project, primarily on the area between the producing Spence, Sierra Gorda and Esperanza/El Tesoro mines. During reconnaissance traverses, the La Paloma prospect was discovered, covering an extensive area of approximately forty square kilometers with promising copper porphyry signatures. ASTER imaging initially identified areas of advanced argillic alteration which were confirmed on the ground, as well as abundant copper oxide mineralization and a prominent magnetic anomaly. In many cases copper mineralization was recognized by remnants of ancient artisanal mines, including small shafts and open pits. Thirteen of the 49 outcrop and subcrop samples collected in this first phase of exploration returned highly anomalous copper values ranging from 0.1%Cu to greater than 10%. Some samples also returned anomalous Ag up to 253 g/t. La Paloma displays abundant structural components including intense NNW and EW fracturing and lies in close proximity to the Antofagasta-Calama lineament ("ACL") that hosts the Spence and Sierra Gorda deposits. The target area hosts two individual copper porphyry targets of approximately nine square kilometers each that are believed to lie under between 6 to 20 metres of ground cover.
The Cerro Barco target areas were selected based on the detection of significant advanced argillic and phyllic alteration from ASTER imaging, prominent magnetic and radiometric anomalies and location right on the ACL. Subsequent ground work located areas of extensive copper oxide mineralization on surface, intimately associated with the target area and a large colour anomaly overlying much of the magnetic anomaly. Results of the chip and subcrop sampling of old workings hosted within strongly hematised andesites and altered diorites on the target returned values up to 2.9% Cu and 2.5g/t Au. It is important to note that the northern part of the area of interest close to the ACL lies under cover and was not seen in the field. The copper porphyry target discovered at Cerro Barco covers an area of approximately nine square kilometers.
Further information regarding La Paloma and Cerro Barco target areas will be released as available.
