Bidjovagge copper-gold deposit in Finnmark, Northern Norway

Abstract

The Bidjovagge copper-gold deposit is located 40 km northwest of Kautokeino in Finnmark, northern Norway. The deposit occurs in the lower Proterozoic Kautokeino greenstone belt and consists of four ore deposits in albitic felsite and graphitic albitic felsite over a strike length of 2.5 km. The orebodies occur on the eastern limb of a north-south-striking anticline. The albitic felsite may represent strongly altered tuffite and diabase or partly metamorphosed chemical sediment. The alteration of the metadiabase in the footwall sequence is complex. Carbonatization is very extensive, but there are also zones with biotite, scapolite, and hematite alteration.The main ore is strata bound and occurs as veins, breccias, and low-grade disseminated mineralization of a more stratiform character. High gold values are usually related to late quartz-carbonate veins containing tellurides and are often associated with weak uranium mineralization. The ore minerals of economic significance are chalcopyrite and native gold. Other common metallic minerals are pyrite and pyrrhotite. Marcasite, magnetite, ilmenite, hematite, tellurides, rutile, sphalerite, galena, davidite, and pentlandite occur in accessory amounts. Preliminary isotopic analyses show that the lead isotope composition is markedly radiogenic ( 206 Pb/ 204 Pb = 22.2-23.8).The association of ore deposits with albitic felsites is also known to the north, in the Kvnangen tectonic window, where similar copper deposits but with low gold values occur in the Bergmark area and to the east near Masi in Big'geluobbal where U-V-Ti-rare earth element mineralization has recently been found. Bidjovagge is similar in its depositional environment to the Viscaria deposit in Sweden and the Pahtavuoma deposit in Finland.