In pre-colonial times Equatorial Guinea was known for gold and iron production however there are no records of any commercial production during the Spanish era, which ended in 1968. After independence, early investigations highlighted the potential for gold, base metals, bauxite and pegmatite minerals such as tin, tungsten and columbo-tantalite. Initial systematic surveys were conducted from 1975 by Soviet Union geologists and from 1980-1985 BRGM (France) undertook regional and follow-up alluvial heavy mineral and geochemical exploration. Between 1981-1983 GEMSA (a Spain-Equatorial Guinea joint venture) prospected for gold, iron ore, ornamental stone, molybdenite, columbo-tantalite, bauxite and diamond opportunities. In the process, GEMSA undertook airborne magnetic surveys and constructed a SLAR mosaic of the country at 1:1,400,000 scale (about 20m resolution). From 1996 to end 2000, UMCEG (Ocean Energy) held a contract area covering the whole of Rio Muni but with operatorship from 1998 being with joint venture partner BoMc. Early investigations included data compilation and regional reconnaissance work. Detailed sampling was undertaken in the Coro gold area, around nickel anomalies in the southwest and for heavy minerals in beach sands. Programmes included soil and sediment sampling using augers and development of a GIS database.		Coro gold area