The Amadeus Basin is a large (~170,000 km2) intracratonic sedimentary basin in central Australia, lying mostly within the southern Northern Territory, but extending into the state of Western Australia.
Lake Amadeus viewed from space (November 1994)
Sedimentary basins are region-scale depressions of the Earth's crust where subsidence has occurred and a thick sequence of sediments have accumulated to form a large three-dimensional body of sedimentary rock. They form when long-term subsidence creates a regional depression that provides accommodation space for accumulation of sediments. Over millions or tens or hundreds of millions of years the deposition of sediment, primarily gravity-driven transportation of water-borne eroded material, acts to fill the depression. As the sediments are buried, they are subject to increasing pressure and begin the processes of compaction and lithification that transform them into sedimentary rock.
Simplified schematic diagrams of common tectonic environments where sedimentary basins are formed
Typical rift formation in cross-section
Schematic cross-section of a typical convergent plate boundary showing formation of back-arc and forearc basins
Trench fill sedimentary basin in the context of a convergent plate boundary
