Commodity: Au - Ag - Cu
Ivan project is located 32 km north of the town of Los Menucos, in the province of Río Negro, Argentine Republic. Its central coordinates are approximate 2.560.000 E and 5.505.000 N (Gauss Krugger Campo Inchauspe). The area of interest is covered by 2 mines with a total of 5,995 hectares.
Ivan project presents an area of hydrothermal alteration of approximately 7.5 square kilometres separated into two sectors. Between both sectors was determined the presence of a wide corridor with silicified structures interpreted as residual silica. Similar structures were found in the northern part of La Luz project, at only 7 kilometres to the southwest of the explored area.
The Northwest area is characterised by andesitic rocks with argillic and siliceous alteration, showing sectors with abundant alunite. The central part of this sector is constituted by hills with advanced argillic alteration (dickite) and structures type "vuggy silica" filled with abundant hematite. Surrounding these areas, the rocks present silica-alunite and argillic (illita-caolinita) alteration. There is primary alunite, pink color, forming the silica-alunite association. Abundant secondary alunite, in the form of yellow veinlets were also observed. The dickite has an excellent crystallization degree and appears in the form of nests inside the argillized rock like matrix of brecciated sectors and in the form of veinlets. Also were observed sulphur veins cutting the argillized sectors.
In the Southeast sector also broad sectors with propylitic alteration were identified.
In the central part of the project, between the altered areas of Northwest and Southeast, a mineralized corridor of strike N 60º, 4,000 meters length and 1,500 meters wide was recognized. The presence of a number of silicified structures interpreted as residual silica product of rock leaching by acidic solutions were determined. Individually these structures have a run of up to 800 metres, and are formed by grey silica, massive to slightly hollowness. Only known sulfide is pyrite, and patinas formed by copper carbonate was observed in some sectors, but these are rare.
The type of alteration found is related to high sulphidation epithermal systems. Given the vast expanse of the above-mentioned alteration is expected to be linked in-depth to a major epithermal system.
51 geochemical samples were taken, which revealed anomalies in Ag, Cu, Pb, Zn, Hg, S and Ba. In relation with gold, only 3 samples showed anomalous values of 80 ppb. In silicified sectors, were identified Cu oxides and pyrite. In order to identify different alteration minerals, were analyzed 35 samples by PIMA method.
Likewise, a geophysical campaign was developed consistent in 22 electromagnetic profiles, separated by 320 m and totalizing 59 Km. Besides were executed 18 SEV with the purpose of determine the profile range of depth.