IMPORTANT NOTICE © Copyright Commonwealth Scientific and Industrial Research Organisation (‘CSIRO’) Australia. All rights are reserved and no part of this publication covered by copyright may be reproduced or copied in any form or by any means except with the written permission of CSIRO Division of Land and Water. The data, results and analyses contained in this publication are based on a number of technical, circumstantial or otherwise specified assumptions and parameters. The user must make its own assessment of the suitability for its use of the information or material contained in or generated from the publication. To the extend permitted by law, CSIRO excludes all liability to any person or organisation for expenses, losses, liability and costs arising directly or indirectly from using this publication (in whole or in part) and any information or material contained in it. The publication must not be used as a means of endorsement without the prior written consent of CSIRO. NOTE This report and accompanying maps are scanned and some detail may be illegible or lost. Before acting on this information, readers are strongly advised to ensure that numerals, percentages and details are correct. This digital document is provided as information by the Department of Natural Resources and Water under agreement with CSIRO Division of Land and Water and remains their property. All enquiries regarding the content of this document should be referred to CSIRO Division of Land and Water. The Department of Natural Resources and Water nor its officers or staff accepts any responsibility for any loss or damage that may result in any inaccuracy or omission in the information contained herein. Survey of the Barkly Region, Northern Territory and Queensland, 1947-48 Comprising papers by C S. Christian, L. C. Noakes, R. A. Perry, R. O. Siatyer, G. A. Stewart, and D. M. Traves Land Research Series No. 3 Commonwealth Scientific and Industrial Research Organization, Australia Melbourne 1951 "3 KEY TO LAND SURFACE O STABLE A EROSIONAL GULF OF CARPENTARIA • DEPOSITIONAL RELIEF MODEL OF BARKLY REGION CONTENTS PAGE Foreword 7 Recommendations 8 Summary 9 PART I. INTRODUCTION TO SURVEY OF THE BARKLY REGION. By C. S. Christian 13 I. GENERAL DESCRIPTION OF THE REGION 13 II. SURVEY PROCEDURE 15 III. ACKNOWLEDGMENTS 15 PART II. CLIMATE OF THE BARKLY REGION. By R. 0. Slatyer and C. S. Christian 17 I. GENERAL CLIMATIC CHARACTERISTICS 17 (a) Rainfall 20 (b) Temperature and Humidity 21 II. CLIMATIC FACTORS OF SIGNIFICANCE TO PLANT GROWTH 24 (a) Climate in Relation to Agriculture 24 (b) Climate in Relation to Growth of Natural Pastures 28 PART III. OUTLINE OF THE GEOLOGY OF THE BARKLY REGION. By L. C. Noakes and D. M. Traves 34 I. INTRODUCTION 34 II. PRE-CAMBRIAN 35 (c) Lower Proterozoic 35 (b) Upper Protenraoic 3(5 III. PALAEOZOIC 37 IV. MESOZOIC 38 V. CAINOZOIC 39 (a) Tertiary 39 (6) Pliocene to Recent 41 PART IV. GEOMORPHOLOGY OF THE BARKLY REGION. By G. A. Stewart 42 I. GENERAL TOPOGRAPHY 42 II. GEOMORPHOLOGICAL DIVISIONS 42 4 CONTENTS PAGE III. ORIGIN OF LAND SURFACES 43 (a) The Geomorphological History of the Gulf Fall Division 45 (&) The Geomorphological History of the Georgina Basin Division 45 (c) The Geomorphological History of the Barkly Basin Division 46 IV. GEOMORPHOLOGICAL UNITS . 46 (a) The Stable Land Surface and its Geomorphological Units 47 (5) The Erosional Land Surface and its Geomorphological Units 52 (c) The Depositional Land Surface and its Geomorpho- logical Units 56 PART V. HYDROLOGY OF THE BARKLY REGION. By D. M. Traves and G. A. Stewart 59 I. SURFACE WATER RESOURCES 59 (a) Gulf Fall 59 (6) Georgina Basin . 60 (e) Barkly Basin 60 II. UNDERGROUND WATER RESOURCES 61 III. QUALITY OF WATER IN THE SUB-ARTESIAN BASIN 68 IV. FUTURE SUPPLY OF SUB-ARTESIAN WATER 64 PART VI. SOILS OF THE BARKLY REGION. By G. A. Stewart 65 I. INTRODUCTION 65 II. GROUPING OF THE SOILS 65 III. DESCRIPTION OF THE SOILS 68 IV. AGRICULTURAL CHARACTERISTICS OF THE SOILS 75 PART VII. VEGETATION OF THE BARKLY REGION. By R. A. Perry and C. S. Christian 78 I. INTRODUCTION 78 II. DESCRIPTION OF THE MAJOR PLANT COMMUNITIES 87 (a) Communities on Poorly-drained Areas (Heavy Clay Soils) under Low to Medium Rainfall 87 CONTENTS 5 PAGE (b) Communities on Fairly- to Excessively-drained Areas (not Heavy Clay Soils) Mainly under Low Rainfall 94 (c) Communities on Well- to Excessively-drained Areas (not Heavy Clay Soils) under Medium to High Rainfall 102 (d) Communities of High-rainfall Areas Other than Those with Excessive Drainage 105 III. DESCRIPTION OP THE MINOR PLANT COMMUNITIES OCCUR- RING IN MISCELLANEOUS HABITATS 109 (a) Fringing Communities 109 (6) Communities of Saline Areas 111 (c) Communities of Sand Dunes 111 (d) Communities of Lagoons and Areas Subject to a Long Period of Flooding Each Year 112 PART VIII. THE LAND SYSTEMS OF THE BARKLY REGION. By G. A. Stewart, C. S. Christian, and R. A. Perry 113 I. INTRODUCTION 113 II. STABLE TERTIARY LAND SURFACE 115 III. EROSIONAL LAND SURFACES 126 IV. POST-TERTIARY DEPOSITIONAL LAND SURFACE 140 PART IX. THE LAND-USE GROUPS OF THE BARKLY REGION. By C. S. Christian and G. A. Stewart 150 . I. CLIMATE IN RELATION TO LAND USE " 150 II. VEGETATION IN RELATION TO LAND USE 153 III. PASTURE IMPROVEMENT 158 IV. PASTURE MANAGEMENT AND UTILIZATION . 159 V. STOCKING RATES OF NATURAL PASTURES . 161 VI. THE LAND-USE GROUPS AND PRESENT LAND USE 163 (a) Mitchell Grass Country (Area 28,700 sq. miles) 163 (6) Northern Mitchell Grass Country (Area 900 sq. miles) 165 (c) Inferior Mitchell Grass Country (Area 3,900 sq. miles) 166 (d) Noi-thern Inferior Mitchell Grass Country (Area 1,400 sq. miles) ' 167 (e) Bluebush Swamp Country (Area 1,400 sq. miles) 167 (/) Drybog Country (Area 2,200 sq. miles) 169 (fir) Broken Mitchell Grass Country (Area 7,000 sq. miles) 169 6 CONTENTS (h) Hilly Country (Area 29,000 sq. miles) 170 (t) Southern Desert Country (Area 24,700 sq. miles) 170 0) Northern Desert Country (Area 14,700 sq. miles) 171 (k) Coastal Country (Area 6,100 sq. miles) 171 VII. LAND USE ON THE BARKLY TABLELAND IN RELATION TO WATER SUPPLIES 172 VIII. AGRICULTURAL POTENTIALITIES OF THE REGION 174 IX. PASTORAL POTENTIALITIES OP THE REGION . 175 X. REGIONAL LAND-USE POTENTIALITIES IN RELATION TO DEVELOPMENT 178 SUMMARY OP THE MAIN CHARACTERISTICS OF THE LAND SYSTEMS OF THE BARKLY REGION 181 LIST OP MAPS Land Systems of the Barkly Region Land-use Groups of the Barkly Region Geomorphological Units of the Barkly Region Land Traverse Map (showing bore sites and spot heights) FOREWORD A field survey of the Barkly region of the Northern Territory and Queensland was conducted in 1947 and 1948. This was one of a series of surveys initiated by C.S.I.R.O. at the request of the Northern Australia Development Committee in order that an accurate knowledge of the nature of the country and its potentialities might be made available for the formulation of policies concerning development. These surveys therefore have the objectives of describing, classifying, and mapping the country, including its surface geology, topography, soils, and vegetation; and of broadly assessing land-use potentialities by con- sideration of these inherent land characteristics in relation to the prevailing climate and possibilities of irrigation. In order that country might be subdivided in a fundamental rather than superficial way, and that the lands of large regions may be so classified and mapped at a relatively rapid rate, it has been necessary to examine land characteristics in a comprehensive manner and to develop scientific methods for land classification. The general method of these surveys was initially described in reports on the survey of the Katherine- Darwin region. The method has been further developed in the survey of the Barkly region and in the more recent survey of the Townsville- Bowen region, of which a report has been published. A preliminary report of the first year's field work in the Barkly region was distributed in mimeographed form in 1947. RECOMMENDATIONS It is recommended that the following additional specific investi- gations be conducted: (i) An ecological study in regions of low productivity to determine principles whereby desirable modifications of natural pastures can be economically achieved by dispersal of introduced species, or by other means. An excellent opportunity for such a study is provided by the existence of the Stuart Highway, which links Alice Springs and Darwin, and so traverses a wide range of rainfall and other environmental conditions. (ii) A study of the efficiency of pasture utilization in relation to the distance that cattle have to travel from water whilst grazing, with special reference to the Mitchell grass plains of the Northern Territory. (iii) A hydrological study of the Gregory River basin to determine the scope for water conservation and irrigation of the flood plains of that river and its tributaries, (iv) Preliminary trials of the growth of a wide range of fodder crops under dry-land conditions in- the northern areas receiving more than 25 in. rainfall per annum, (v) An examination of the possibilities of establishing cypress pine plantations in northern areas. SUMMARY (1) A comprehensive survey of the Barkly region of the Northern Territory and Queensland was conducted in 1947 and 1948 by the C.S.I.R.O. Northern Australia Regional Survey (now Land Research and Regional Survey Section). (2) The region includes the area popularly known as the Barkly Tableland, a contiguous portion of the Georgina River basin and the inland "desert", and the country extending to the Gulf of Carpentaria. It covers an area of 120,000 square miles.