Checo de Cobre area is located about 20km southeast of Copiapó, III region, Chile. This area is in the Central Andean IOCG belt. There are several operating IOCG copper mines in the neighbouring area.
Nittetsu Mining Co., Ltd. selected the area as promising for copper exploration, having reviewed geology and airborne magnetic data, and obtained option rights to exploration. Reconnaissance surveys were carried out from 2005. Since 2006, Japan Oil, Gas and Metals National Corporation has carried out substantial exploration in the area. Geological, geophysical (ground magnetic and AMT resistivity surveys) and drilling surveys have been conducted to date.
Two promising areas were identified by the results of the geological and geophysical surveys. Six drill holes (total length 2, 890m) were carried out in those two areas searching for stratiform copper deposits. However the drillings did not identify high grade copper mineralization.
Five new holes (total length 2, 584m) were drilled across the main structural lines in the exploration area searching for vein copper deposits this time. As the result of the drilling, high-grade copper mineralization at four intervals were identified in the two drill holes and also two types of copper mineralization were distinguished on the area as follows.
Drill hole CCDA-1: Chalcopyrite-pyrite-magnetite, Au mineralization and Silicification.
1.58Cu%, 0.23g/tAu (from 556 to 569m, 13m interval)
Drill hole CCDA-3: Chalcocite-Bornite, Ag mineralization, Chloritization and Epidotization.
1.17Cu%, 45.4g/tAg (from 3 to 22m, 19m interval)
0.99Cu%, 39.2g/tAg (from 102 to 116m, 14m interval)
2.90Cu%, 158.0g/tAg (from 160 to 177m, 17m interval)
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