Lithology sense of displacement across the zone. In igneous rocks, small-scale structures are mostly observed in lavas such as pahoehoe versus ʻAʻā basaltic flows, and pillows showing eruption within a body of water or beneath ice. Unconsolidated surficial materials may also be given a lithology. This is defined by grain size and composition, and is often attached to an interpretation of how the unit formed. Surficial lithologies can be given to lacustrine, coastal, fluvial, aeolian, glacial, and recent volcanic deposits, among others. Examples of surficial lithology classifications used by the US Geological Survey are, "Glacial Till, Loamy", "Saline Lake Sediment", and
Natural history of Africa Natural history of Africa The natural history of Africa encompasses some of the well known megafauna of that continent. Natural history is the study and description of organisms and natural objects, especially their origins, evolution, and interrelationships. The vegetation of Africa follows very closely the distribution of heat and moisture. The northern and southern temperate zones have a flora distinct from that of the continent generally, which is tropical. In the countries bordering the Mediterranean, there are groves of orange and olive trees, evergreen oaks, cork trees and pines, intermixed with cypresses, myrtles, arbutus and fragrant tree-heaths. South of the