Nittetsu Mining holds a 2% interests in the Namosi Joint Venture, which is located 30km north west of Suva (the capital city of Fiji) in Viti Levu island (Fig.1). This area has been recognized as a copper prospecting area for more than 40 years. The indicated copper mineral resources at December 2019 is estimated as 1,300 million tons (0.35% Cu).
The geology of Namosi area is mainly consisted of Wainimala Group which includes metamorphosed basic and andesitic rocks (Late Oligocene to Middle Miocene) and Medrausucu Group which includes Namsoi andesite and Korobasabasaga pyroclastics (Middle Miocene to Pliocene) (Fig.2).
Porphyry-type copper mineralization is accompanied with diorite porphyry and quartz diorite porphyry. Mineralization were formed where Wainimala Group and Medrausucu Group intruded by diorite porphyry and quartz diorite porphyry. The high grade parts, associated with diorite porphyry, occur within zones of intense quartz veining and potassic alteration accompanied with chalcopyrite and bornite.
Photo.1 Namosi area
Photo.2 DDH drilling survey