Manganese was discovered in 1903 in the Matthews Ridge Area in the north-west of the country, but was not put into production until 1960. This operation closed in 1969, although substantial reserves still exist.
Columbite was mined in the Morabisi area of the Mazaruni River from 1952 to 1959, when mining ceased because of a fall in its price in the world market. In the 1960s copper was discovered at Groete Creek; lateritic nickle quantified at Blue Mountain; and molybdnemum (molybdenite, and tungsten (scheelite) identified at Eagle Mountain. Numerous sulphide and iron ore occurrences and industrial minerals such as talc, kaolin and magnesite have also been identified over the years in different parts of the country. Uranium was extensively prospected for in the early 1980s.
Guyana’s hydrocarbon (petroleum and natural gas) potential was noted since the 1850s, with the first well being drilled in the Waini Estuary in 1917. Exploration for hydrocarbons continues today in the coastal onshore, coastal offshore and the Takutu Basin.
The Takutu Basin, which is situated in the southwest of the country and straddles the Guyana/Brazil border, is the only area in which petroleum has so far been found. The Guyana portion of the Takutu Basin is approximately 10,300 sq. km. In 1979 Home Oil Canada conducted a seismic programme and drilled two wells. The second well, Karanambo-1, was a discovery well producing 400 barrels of oil per day, apparently from fractured Apoteri Volcanics. Home Oil was hampered by the remoteness of the discovery area and the absence of infrastructure.
Statistics such as gross unit thickness, net sand/carbonate and porosity indicate good reservoir potential in the Offshore Basin. For the offshore, the reservoir potential seems to be best in the Tertiary Carbonates and clastics even though there is reservoir potential in intra-Cretaceous formations such as the Stabroek Formation.
Ten exploratory wells have been drilled in offshore Guyana since 1967. In that year Teneco drilled the first. Total drilled the last in 1992. However the government of the country has recently entered into an agreement with CGX Energy Inc. giving this company permission to drill offshore, in the Corentyne area. There is, as yet, no petroleum production in Guyana.
Silica sands, which are widely dispersed in the northeast of Guyana, cover about 5,000 square miles of the country. The white sands are a vast resource of high-purity silica oxide.
In 1993, for the first time, silica sands were exported to the Caribbean region, where their superior quality as a feedstock for glass manufacture, as a construction and land fill material, and as a basic input in golf course development has been recognized. Their future development in this regard will, in large measure, depend upon whether the near intractable large bulk transport problem which confronts the Caricom region is solved. Environmental considerations, associated with the preservation of tourism including beaches in Caricom, may make the nearly inexhaustible silica sand deposits of Guyana a shared strategic resource of the region.
The sands are also critical to the civil works and building sectors of the economy. Their utilisation as a land fill, concrete and asphaltic base, and in other industrial processes, such as porcelain and cultured marble manufacture, making them a resource without which development could be seriously curtailed.
The sands were used, in the 1970s and 1980s, in the production of glass at Yarrowkabra. However, the facilities were closed for reasons totally unrelated to the quality and availability of the sand resource.
Coarse grained aggregates
Coarse grained aggregates for roads and other civil works, building construction and sea defences have been produced in Guyana for well over a century.
Because of their relatively low value, and therefore the necessity to access cheap transport, all of the rock quarries were located along the Essequibo, Demerara, Berbice, Mazaruni, and Cuyuni rivers. Over the passage of time, eight quarries were operated in the Essequibo River, nine in the Mazaruni River, one in the Cuyuni River, four in the Demerara River, and one in the Berbice river. At the present time, only the St Mary’s and the Monkey Jump Quarries on the Essequibo River, and the Teperu/Itabu Quarry, now called Mazaruni Granite Products Limited, on the Mazaruni River are being actively worked.