Guiana Lowland

a lowland in northeastern South America, within the boundaries of Guyana, Surinam, and French Guiana. It is situated at the foot of the eastern part of the Guiana Highlands, along the coast of the Atlantic Ocean between the delta of the Orinoco River and 4° N lat. The lowland ranges from several to 200 km in width and is made up of marine and alluvial deposits. In places ancient crystalline rocks protrude, forming isolated uplands. The coast is even, with offshore bars that constrict the mouths of small rivers. The mouths of the large, deep rivers (the Essequibo and its tributary the Cuyuni, the Courantyne, the Maroni, the Approuague, the Oyapock) are primarily of a liman type. The climate is subequatorial, hot (average monthly temperatures from 26° to 28° C) and humid (up to 3,300 mm of precipitation a year, with the minimum in September and October). Green forests predominate in the north and south, savannas in the central region, and swamps and mangrove thickets along the coast. There are rice and sugarcane plantations (on artificial polders). Cacao, coffee, tropical fruits, and food crops are also grown, and there is a fishing industry.