Stratigraphy and sedimentology of the lower Neales River, West Lake Eyre, Central Australia: from Palaeocene to Holocene

The stratigraphy of the lower Neales River to the west of Lake Eyre, Austra lia's largest internal drainage system, preserves a detailed record of fluv ial, lacustrine and aeolian deposits of early Tertiary to Holocene age. Thi s stratigraphic framework provides a summary of the region's Cainozoic sedi mentary units. Three units have been identified: an early Tertiary fluvial unit; a mid-Tertiary lacustrine unit; and a Quaternary unit composed of int erbedded fluvial, lacustrine, and aeolian facies. Dramatic changes in depos itional styles within, and between, these three major groups of sediments r eflect the basin's response to changes in climate and sediment supply. Fluv ial facies include perennial multi-channel, single-channel, and ephemeral r iver sequences. Lacustrine and deltaic facies reflect continuous fine-grain ed sedimentation during periods of high water-tables. The aeolian facies ar e evidence of aridity and sediment deflation in the basin. The early Tertia ry fluvial unit is the result of Late Palaeocene-Eocene epeirogenic movemen ts. A dramatic shift in facies to the mid-Tertiary lacustrine unit reflects a significant change in the basins climatic controls. Quaternary sediments reflect major changes in fluvial discharge regimes which may reflect major climatic and associated hydrological changes during past interglacial and glacial cycles. (C) 1998 Elsevier Science B.V. All rights reserved.