Guianan savanna Guianan savanna The Guianan savanna (NT0707) is an ecoregion in the south of Venezuela, Guyana and Suriname and the north of Brazil. It is in the Amazon biome. The savanna covers an area of rolling upland plains on the Guiana Shield between the Amazon and Orinoco basins. It includes forested areas, but these are shrinking steadily due to the effect of frequent fires, either accidental or deliberate. The ecoregion includes the Gran Sabana region of Venezuela. The ecoregion includes three large unconnected areas totaling . The main section is in southeast Venezuela, the Brazilian state of Roraima and western Guyana.
Geology of French Guiana the Paramaca series, which corresponds to a series of micaschists, aluminous paragneisses and black quartzites whose total thickness is about 1 km. The central granite massifs consist of granite plutons, granodiorites and quartz diorites dating from 2.05 to 2.15 billion years ago. The north of French Guiana corresponds to a synclinorium composed of the Paramaca series on which sandstone and fluviatile conglomerates lie unconformably. Shield rocks in Guyana are all dated between 1.6 and 2.5 billion years ago. The Quaternary lands are located in the northern part of Guyana, near the coast, unconformably on the Paleozoic lands. The coastal plains