Palynostratigraphy of the Murray basin

Abstract

To date, the only published comprehensive zonation for datingand correlating late Tertiary non-marine sequences in Australiais that developed in the 1970s for the offshore Gippsland Basinon the extreme southeastern margin of the continent. In thispaper an analogous zonation scheme is presented for the MurrayBasin, a large intracratonic basin that covers some 300 000 km2of inland New South Wales, Victoria and South Australia. Majorspore and pollen sequences identified within this basin corre-spond with major periods of marine transgression-regression, inthe middle Eocene to early Oligocene, early Oligocene to middleMiocene and late Miocene to Pliocene. Presence/absence dataallow the first two sequences to be subdivided into palynologicalzones that can be confidently correlated with zones establishedfor the Gippsland Basin, viz., equivalents of the middle to lateEocene lower, middle and upper Nothofagidites asperus zones,and the Oligocene to middle Miocene Proteacidites tuberculatusand Canthiumidites bellus zones, respectively. Late Miocene-early Pliocene and late Pliocene-Pleistocene intervals are as-signed to the Monotocidites galeatus Zone and Tubulifloriditespleistocenicus Zone, respectively. Changes in the relative abun-dance of commonly occurring species support the above subdi-visions in a general way only and are not reliable as a basis forbasin-wide correlations. Until some independent geological orgeophysical datum is found to allow a direct comparison ofspecies time distributions across the basin, further formal subdi-vision of the zones is not recommended. Show more