Chapter 65 Neoproterozoic glacial deposits of the Kimberly Region and northwestern Northern Territory, Australia

Abstract Neoproterozoic glaciogenic formations are preserved in the Kimberley region and northwestern Northern Territory of northern Australia. They are distributed in the west Kimberley adjacent to the northern margins of the King Leopold Orogen, the Mt Ramsay area at the junction of the King Leopold and Halls Creek orogens, and east Kimberley, adjacent to the eastern margin of the Halls Creek Orogen. Small outlier glaciogenic deposits are preserved in the Litchfield Province, Northern Territory (Uniya Fm.) and Georgina Basin, western Queensland (Little Burke Fm.). Glaciogenic strata comprise diamictite, conglomerate, sandstone and pebbly mudstone and characterize the Walsh, Landrigan and Fargoo/Moonlight Valley formations. Thin units of laminated dolomite sit conformably at the top of the Walsh, Landrigan and Moonlight Valley formations. Glaciogenic units are also interbedded with the carbonate platform deposits of the Egan Fm. and Boonall Dolomite. δ13C data are available for all carbonate units. There is no direct chronological constraint on these successions, and dispute over the regional correlation of the Neoproterozoic succession has been largely resolved through biostratigraphic, chemostratigraphic and lithostratigraphic analysis. However, palaeomagnetic results from the Walsh Fm. are inconsistent with sedimentologically based correlations. Two stratigraphically defined glaciations are preserved in northwestern Australia: the ‘Landrigan Glaciation’, characterized by SW-directed continental ice-sheet movement and correlated with late Cryogenian glaciation elsewhere in Australia and the world; and, the ‘Egan Glaciation’, a more localized glaciation of the Ediacaran Period. Future research focus should include chronology, palaeomagnetic constraint and tectonostratigraphic controls on deposition.

[1]  M. Corkeron.  Deposition and palaeogeography of a glacigenic Neoproterozoic succession in the east Kimberley, Australia , 2008 .

[2]  M. Corkeron.  ‘Cap carbonates’ and Neoproterozoic glacigenic successions from the Kimberley region, north‐west Australia , 2007 .

[3]  B. Kendall,et al.  Re-Os geochronology of postglacial black shales in Australia: Constraints on the timing of “Sturtian” glaciation , 2006 .

[4]  A. George,et al.  Glacial incursion on a Neoproterozoic carbonate platform in the Kimberley region, Australia , 2001 .

[5]  M. Wingate,et al.  SHRIMP zircon age for an Early Cambrian dolerite dyke: An intrusive phase of the Antrim Plateau Volcanics of northern Australia , 2000 .

[6]  D. Evans.  Stratigraphic, geochronological, and paleomagnetic constraints upon the Neoproterozoic climatic paradox , 2000 .

[7]  Zheng‐Xiang Li.  New palaeomagnetic results from the ‘cap dolomite’ of the Neoproterozoic Walsh Tillite, northwestern Australia , 2000 .

[8]  N. Christie‐Blick,et al.  Paleomagnetic polarity reversals in Marinoan (ca. 600 Ma) glacial deposits of Australia: Implications for the duration of low-latitude glaciation in Neoproterozoic time , 1999 .

[9]  K. Grey,et al.  Neoproterozoic (Cryogenian) stromatolites from the Wolfe Basin, east Kimberley, Western Australia: Correlation with the Centralian Superbasin , 1999 .

[10]  Kathleen Grey,et al.  Late Neoproterozoic stromatolites in glacigenic successions of the Kimberley region, Western Australia: evidence for a younger Marinoan glaciation , 1998 .

[11]  M. Kennedy.  Stratigraphy, sedimentology, and isotopic geochemistry of Australian Neoproterozoic postglacial cap dolostones; deglaciation, delta 13 C excursions, and carbonate precipitation , 1996 .

[12]  P. Schmidt,et al.  The Neoproterozoic climatic paradox: Equatorial palaeolatitude for Marinoan glaciation near sea level in South Australia , 1995 .

[13]  M. Brookfield.  Problems in applying preservation, facies and sequence models to Sinian (Neoproterozoic) glacial sequences in Australia and Asia , 1994 .

[14]  W. Preiss,et al.  Stratigraphic and geochronological reinterpretation of late Proterozoic glaciogenic sequences in the Kimberley Region, Western Australia , 1980 .

[15]  D. B. Dow.  Evidence of a Late Pre-Cambrian Glaciation in the Kimberley Region of Western Australia , 1965, Geological Magazine.

[16]  M. Corkeron.  Neoproterozoic glacial events in the Kimberley Region, Western Australia : sedimentology and regional correlation in the context of continental- and global-scale Neoproterozoic glaciation , 2002 .

[17]  C. Henderson,et al.  Electron Microprobe Analysis and Scanning Electron Microscopy in Geology: Frontmatter , 2005 .

[18]  T. J. Griffin,et al.  Structural development of the King Leopold Orogen, Kimberley region, Western Australia , 1990 .

[19]  G. E. Williams.  Sedimentology, stable‐isotope geochemistry and palaeoenvironment of dolostones capping late Precambrian glacial sequences in Australia , 1979 .

[20]  I. Gemuts,et al.  Geology of the Kimberley region, Western Australia : the East Kimberley , 1969 .

[21]  W. Perry,et al.  Late Precambrian glaciated pavements in the Kimberley region, Western Australia , 1968 .

[22]  V. M. Bofinger.  Geochronology in the East Kimberley area of Western Australia , 1967 .

[23]  D. Guppy.  The geology of the Fitzroy basin, Western Australia , 1958 .