Cornerstone Capital Resources Inc. ("Cornerstone" or "the Company") announces the following project update for the Cascabel copper-gold porphyry joint venture exploration project in northern Ecuador, in which the Company has a 15% interest financed through to completion of a feasibility study. SolGold Plc is funding 100% of the exploration at Cascabel and is the operator of the project.
- Porphyry stockwork copper-gold mineralization discovered at surface at Trivino Hill
- Five high‐priority porphyry centres now recognized within the Cascabel project, and a total of ten porphyry targets identified to date in the Cascabel cluster
- Detailed geological mapping continues as rock-saw channel sampling begins over the exposed areas
Figures, photographs and tables referred to in this news release can be seen in PDF format by accessing the version of this release on the Company's website (www.cornerstoneresources.com) or by clicking on the link below:
Ongoing expansion of 1:500 scale geological mapping across the growing Cascabel porphyry field has led to another discovery of porphyry copper-gold mineralization in outcrop, along the northern and northeastern slopes of Trivino Hill, which lies 750m due north of Hole 5 at Alpala Central (Figure 1). The porphyry centre at Trivino Hill occurs along the northeastern margin of a deep seated regional northwest trending structure that parallels the Alpala Structural Zone (ASZ), which is inferred to be a zone of crustal weakness tapping into copper and gold rich intrusions at Alpala Central.
The extent of outcropping mineralization has not yet been defined, but is now mapped over an area of approximately 300m x 200m and occurs as classic porphyry stockwork style 'B'-type quartz veins with a centreline of magnetite and chalcopyrite as well as fine disseminated chalcopyrite in the wall rock. The high copper content mineral species chalcocite (70% Cu) has also been observed in the vein and in disseminations. Veins strike northwest and northeast and vein density is very strong, making up 10% of the rock mass in some zones (Figure 2). This material is comparable with the outcrops discovered in Alpala Creek, near Hole 12 (CSD-15-012) at Alpala Central.
The Trivino discovery, like the recent find of outcropping copper and gold mineralization at Aguiñaga, highlights the fertility and potential of the broader porphyry copper-gold system at Cascabel. Mineralized surface outcrops such as these, in such close proximity to the vertically extensive high grade copper and gold mineralization discovered at Alpala, make for certain drill targets. The frequency of mineralized outcrops of porphyry at Cascabel highlights the importance of this system as a potential globally significant discovery.
The Trivino outcrops are located immediately north of the Alpala lithocap where a discrete magnetic high occurs, and forms part of the complex magnetic signature over the wider Alpala area (Figure 3).
The presence of coincident copper, molybdenum, and copper / zinc in soil, supports a porphyry centre characterized by higher temperatures of mineralization. This geochemical signature is typical of the metal zonation around many global porphyry copper‐gold deposits. (Figures 4, 5 and 6).
Outcrop clearing and trenching works are currently underway and mapping and rock saw channel sampling results are expected in early 2016. Further reconnaissance exploration, field mapping, and infill soil-sampling are ongoing, and SolGold expects to bring the Trivino prospect to drill-ready status over the coming quarter.
Solgold has reported it is planning a resource statement at Alpala, the most advanced target at Cascabel, by mid 2016, in addition to drill testing the other key targets at Aguiñaga, Tandayama America and Chinambicito on the Cascabel concession. By the end of 2016 SolGold is planning further metallurgical testing, and completion of early stage mine and plant design and a scoping study for an economic development at Cascabel. Solgold is investigating both high tonnage / low grade open cut and high grade low tonnage underground development as a block caving operation.
SolGold Plc owns 85% of the equity of Exploraciones Novomining S.A. ("ENSA"), an Ecuadorean company that holds 100% of the Cascabel concession in northern Ecuador. Cornerstone owns the remaining 15% of ENSA, which also holds the rights to the La Encrucijada gold-silver project. SolGold is funding 100% of the exploration at Cascabel and is the operator of the project. Cornerstone's 15% interest is financed through completion of a feasibility study.
Cascabel is located in north-western Ecuador in an under-explored northern section of the richly endowed Andean Copper Belt, 60 km northeast of the undeveloped inferred resource of 982 million tons at 0.89% Cu Junin copper project (0.4% Cu cut-off grade; Micon International Co. Ltd. Technical Report for Ascendant Exploration SA, August 20, 2004, pages 28 & 29). Mineralization identified at the Junin copper project is not necessarily indicative of the mineralization on the Cascabel Property.
Yvan Crepeau, MBA, P.Geo., Cornerstone's Vice President, Exploration and a qualified person in accordance with National Instrument 43-101, is responsible for supervising the exploration program at the Cascabel project for Cornerstone and has reviewed and approved the information contained in this news release.
Logging, sampling and assaying
Rock samples are delivered by ENSA employees for preparation at ALS Minerals Laboratories (ALS) sample preparation facility in Quito. Samples are prepared crushing to 70% passing 2 mm (10 mesh), splitting 250 g and pulverizing to 85% passing 75 microns (200 mesh) (ALS code CRU-31, SPL21 and PUL-32). Prepared samples are then shipped to ALS in Lima, Peru where samples are assayed for a multi-element suite (ALS code ME-ICP61, 1g split, 4-acid digestion, ICP-AES finish). Over limit results for Ag (> 100 g/t) and Cu, (> 1%) are systematically re-assayed (ALS code Ag-AA62, 4-acid digestion, AAS finish). Gold is assayed using a 30 g split, Fire Assay (FA) and AA finish (ALS code Au-AA23).
Quality assurance / Quality control (QA/QC)
The ALS Laboratory is a qualified assayer that performs and makes available internal assaying controls. Duplicates, certified blanks and standards are systematically used (1 control sample every 15-20 samples) as part of the QA/QC program. Rejects, a 100 g pulp for each rock and core sample and the remaining half-core are stored for future use and controls.