Stratigraphy, sedimentology, chronology and palaeohydrology of Quaternary lacustrine deposits at Madigan Gulf, Lake Eyre, south Australia

摘要: Abstract Madigan Gulf is a large bay at the southern end of Lake Eyre North, major ephemerally flooded playa in arid central Australia southwestern margin vast (1,300,000 km2) internal drainage basin. The stratigraphy and chronology Quaternary sequence gulf described from 8 cores cliff exposure margin. A number depositional environments are recognised their distinctive sedimentary components described. Facies include deep- shallow-water lacustrine environments, dominated by surface-water processes, dry or groundwater-controlled processes. Sedimentary terrigenous clastics river inflow shoreline erosion, carbonates detrital, inorganic biological origin gypsum halite evaporites. Carbonates evaporites, precipitated within basin, frequently reworked as clastic components. establishment preliminary for sequence, application thermoluminescence, uranium/thorium disequilibrium, amino acid racemization radiocarbon dating techniques, has allowed reconstruction last 130 ka palaeohydrology. wettest phase occurred during interglacial (early oxygen isotope stage 5) when an enlarged was up to 25 m deep. Subsequently there been periods separating successively less effective wet phases culminating deposition substantial salt crust around time glacial maximum. interludes characterised deflation salts sediment process controlled lowering watertable. record demonstrates dramatic repetitive impact lake on Eyre. In early Holocene minor, but mostly perennial, event terminated about 3–4 modern ephemeral regime established. catchment located monsoon-watered areas northern Australia. As demonstrated floodings regime, episodes must indicate enhanced monsoon precipitation not risen levels achieved 5 lacustral phase, indicating marked reduction effectiveness present comparison with its predecessor.