Scientific publications

There are two types of noble-metal mineralization in the Hattunoja prospect. Type I is a complex (Mo, Cu, W, Au,) gold-porphyry mineralization located at the diorite (sanukitoid) contact of the Jalonvaara intrusion. High quality native gold, up to 0.2-0.3 mm in size, is associated with native bismuth, bismuthine and bismuth sulphotellurides. Its content is up to 5.3 g/t. Mineralization of type II is gold-polysulphide in shearzones, and is restricted to low temperature metasomatic rocks (propylitoids-beresitoids, often with abundant tourmaline) that evolve mainly after andesitic-dacitic and agglomeratic tuffs. Magnetic and electrical prospecting methods were used to locate the mineralization indicated by two anomaly zones that have a thickness of up to 100 m, a length of up to 700 m and an echelon structure. Native gold, up to 1 mm in size, is associated with pyrite (less commonly copper-base-metal) mineralization and bismuthine. Maximum gold content is 4.75 g/t per thickness of 1 m and 9.53 g/t per 8 m. An economic complex noble-metal deposit, comparable in size to some gold deposits in the Hattu belt (Finland), is likely to be discovered at Hattunoja.