Murrumbidgee River at Selected Stations
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University of Wollongong Research Online University of Wollongong Thesis Collection University of Wollongong Thesis Collections 1994 Late quaternary stratigraphy and chronology of the Riverine Plain, Southeastern Australia Kenneth John Page University of Wollongong Recommended Citation Page, Kenneth John, Late quaternary stratigraphy and chronology of the Riverine Plain, Southeastern Australia, Doctor of Philosophy thesis, Department of Geography, University of Wollongong, 1994. http://ro.uow.edu.au/theses/1385 Research Online is the open access institutional repository for the University of Wollongong. For further information contact the UOW Library: [email protected] LATE QUATERNARY STRATIGRAPHY AND CHRONOLOGY OF THE RIVERINE PLAIN, SOUTHEASTERN AUSTRALIA A thesis submitted in fulfilment of the requirements for the award of the degree of DOCTOR OF PHILOSOPHY from IUBRAR THE UNIVERSITY OF WOLLONGONG by KENNETH JOHN PAGE M.A. (Hons), Dip.Ed. (University of Sydney) DEPARTMENT OF GEOGRAPHY 1994 i ABSTRACT This project examines the Late Quaternary fluvial, aeolian and lacustrine evolution of the Riverine Plain of southeastern Australia during the last glacial cycle since approximately 100 ka. The study employs image interpretation, field mapping, stratigraphic investigations and absolute dating of sediments by thermoluminescence (TL). The present landscape of the Plain is dominated by a variety of palaeochannels subdivided by Pels (1971) into two essentially distinctive sequential categories. TL dating of the palaeochannel stratigraphy shows this interpretation to be simplistic. Oscillations between different channel types occurred repeatedly in the last 100 ka with large sinuous mixed load 'ancestral' type rivers evolving into bedload dominated 'prior type' streams, quite the reverse of Pels' interpretation. The stratigraphic record in the Murrumbidgee sector of the Plain shows that four major palaeochannel phases occurred during the last full glacial cycle commencing with the Coleambally from 105 to 80 ka and progressing through the Kerarbury (55 to 35 ka), Gum Creek (35 to 25 ka) and Yanco (20 to 13 ka) phases. All but the last palaeochannel phase included earlier mixed-load laterally migrating channels and terminal aggrading bedload channels. The mixed-load channel phases carried substantially more bedload than the modern rivers and cannot be regarded as simply larger versions of the latter. The Coleambally and Kerarbury palaeochannel phases coincide with enhanced fluvial activity recorded elsewhere in Oxygen Isotope Stages 5 and 3 respectively. The Kerarbury phase during the Stage 3 Sub-pluvial of Nanson et al. (1992a) was also a time of higher water levels at Lakes Urana and Cullivel and appears to coincide with Bowler's (1986a) Mungo lacustral episode. During Oxygen Isotope Stage 2 the Riverine Plain exhibited enhanced fluvial activity and higher lake levels both immediately before and after the Last Glacial Maximum (LGM) and the evidence is consistent with a short arid interval at the LGM itself. The transition to essentially modern environments occurred near the Oxygen Isotope Stage 2/1 boundary between 15 and 10 ka. ii ACKNOWLEDGEMENTS The preparation of this thesis has benefitted greatly from the generous assistance of many people. I am particularly indebted to my supervisor, Gerald Nanson, who offered access to TL dating and encouraged me to commence this project in 1988. Without Gerald's unflagging enthusiasm, perceptive advice, willingness to engage in protracted discussion by telephone, support in field work and careful reading and correction of draft text it is unlikely that the research program and thesis preparation could ever have been completed. David Price also deserves special thanks. He carried out all of the TL dating and generously gave his time to acquaint me with the laboratory procedures involved in TL dating and the peculiar strengths and weaknesses of this relatively new dating method. David's recalculation late in 1993 of TL ages at the 325°C quartz glow peak was greatly appreciated. Per Gunn of the New South Wales Department of Water Resources, Leeton and Coleambally Offices provided invaluable assistance by permitting access to the remarkably detailed records of subsurface exploration of the eastern Riverine Plain carried out mainly during the 1960s. These data underpinned the formulation of the proposed palaeochannel stratigraphic model. My thanks are also extended to, • Tony Dare-Edwards, a colleague at Charles Sturt University, who collaborated with me on the stratigraphic work at Lake Urana and who was present at the discovery of the human skeletal remains in the souther dune, • Geoff Black for splendid technical support and companionship during the two periods of field work using the Gemco 210 drilling rig, • Richard Miller for drafting the diagrams in Chapter 9. These were originally prepared for a publication successfully submitted to the Journal of Quaternary Science, iii • Alan Thome and Steve Webb of the Australian National University for technical descriptions of the Lake Urana skeleton, • Mr D Smith, Stock and Station Agent, Urana, for permision to camp and conduct field work on his property, Bimbadeen Station, • John Owens, John Kerby, Colin Besley, Sue Harding, Paul Frazier, Greg Fawns, Robert Page, Richard Page, Marion Page, Roslyn Nolan and Peter Nolan for field assistance. • John Louis, Mark Williams, Sue Harding and Rod Rumbachs for assistance with my many computing difficulties, particularly with the development of the GIS palaeochannel mapping project. • Wendy Goff, Dianne Sherlock and Karen Hann for typing assistance. The project was funded by the University of Wollongong and the Australian Research Council, the latter being made available by Gerald Nanson from his operating grant. A grant was also provided by Charles Sturt University to release me from certain teaching duties during Autumn Session 1993. Finally, I wish to thank my wife Marion and sons Robert and Richard for their forebearance throughout the durationof the project. Marion also helped with the onerous task of proofreading. iv TABLE OF CONTENTS ABSTRACT j ACKNOWLEDGEMENTS ii TABLE OF CONTENTS iv LIST OF TABLES xi LIST OF FIGURES xiii CHAPTER 1 INTRODUCTION 1 CHAPTER 2 THE RIVERINE PLAIN STUDY AREA 7 LOCATION AND TOPOGRAPHY 7 CLIMATE AND STREAM FLOW 11 VEGETATION, SOILS AND LAND USE 14 CHAPTER 3 LATE CAINOZOIC EVOLUTION OF THE MURRAY BASIN 17 INTRODUCTION 17 MAJOR TERTIARY DEPOSITIONAL EPISODES 18 Palaeocene - Lower Oligocene Sequence 18 Oligocene - Middle Miocene Sequence 18 Upper Miocene - Pliocene Sequence 20 EARLY QUATERNARY SEDIMENTATION 21 LATE QUATERNARY SEDIMENTATION 21 PRIOR AND ANCESTRAL STREAMS 23 V LUNETTES AND RELICT LAKES 24 CHAPTER 4 THERMOLUMINESCENCE DATING 28 GENERAL PRINCIPLES 28 TL METHODOLOGY 29 Palaeodose evaluation 29 Annual dose evaluation 34 Errors 35 COMPARISONS OF TL AND OTHER DATING METHODS 36 CHECKS ON TL DATING OF RIVERINE PLAIN SEDIMENTS 36 URANIUM-THORIUM DATING 37 CHAPTER 5 PALAEOCHANNELS OF THE CADELL FAULT AREA 39 INTRODUCTION 39 TL DATING OF SOUTHERN PALAEOCHANNELS 43 CONCLUSION 46 CHAPTER 6 THERMOLUMINESCENCE CHRONOLOGY OF MURRUMBIDGEE PALAEOCHANNELS 48 INTRODUCTION 48 PALAEOCHANNEL SYSTEMS OF THE MURRUMBIDGEE 49 Existing maps of the palaeochannels 49 GIS based map of palaeochannels 50 Coleambally Palaeochannel System 50 Kerarbury Palaeochannel System 53 Gum Creek Palaeochannel System 56 Tombullen Reach 56 vi Oolambeyan and Carrathool Reaches 57 Uara Reach 60 Yanco System 62 TL DATING OF PALAEOCHANNEL SYSTEMS AND MARGINAL DUNES 64 Introduction 64 Palaeochannels 64 Reliability of TL dates 70 Marginal dunes 70 Correlation with radiocarbon dating 72 Comparison of 325°C and 375°C glow peaks 74 CHAPTER 7 PALAEOCHANNEL STRATIGRAPHY 77 EXISTING STRATIGRAPHIC MODELS OF PALAEOCHANNEL DEPOSITS 77 FIELD STRATIGRAPHY AT PIT EXPOSURES 81 Bedding structures at Kerarbury and Hay Pits 85 Surface sediments and soils 92 WATER RESOURCES DEPARTMENT STRATIGRAPHIC SECTIONS 95 Coleambally Palaeochannel System 95 Bundure Arm 95 Yamma Arm 99 Kerarbury Palaeochannel System 102 McGrath Distributary Arm 105 Older palaeochannels 108 Gum Creek Palaeochannel System 109 vii Narrandera to Yarradda Lagoon 109 Yarradda Lagoon to Hay 112 Hay to Balranald 113 Yanco Palaeochannel System 114 CONCLUSION 117 CHAPTER 8 INTERPRETATION OF MURRUMBIDGEE PALAEOCHANNELS 118 INTRODUCTION 118 Models of channel evolution 119 Channel Equilibrium Model 120 Geomorphic Threshold Model 125 Climates of the last glacial cycle in Australia 127 MURRUMBIDGEE PALAEOCHANNEL DISCHARGES 130 Coleambally and Kerarbury Phases 130 Bundure and Yamma Arms - Coleambally System 131 Waddi Reach - Kerarbury Arm 131 Gum Creek and Yanco Phases 133 Gum Creek Sysytem 133 Meander wavelength based discharge estimate 134 Meander cutoff based discharge estimate 134 Yanco System 135 Meander wavelength based discharge estimate 135 Meander cutoff based discharge estimate 135 VIII Discussion of discharges 136 Discharges of water and sediment in Oxygen Isotope Stages 3 and 5 137 Discharges of water and sediment in Oxygen Isotope Stage 2 138 OSCILLATING PALAEOCHANNEL BEHAVIOUR 141 Introduction 141 Channel change in response to sediment supply 144 Theory of sediment entrainment 144 Palalaeochannel grain size distributions and critical shear stress 146 Upstream confined valley reach 146 Riverine Plain reach 149 Bed aggradation of palaeochannels on the Riverine Plain 151 Discharge variation across the Plain 151 Modelling of bed load transport on the