GEOlOGICAL SU.RVEY PF . VICTORIA BULLETIN Noo 59 GEOLOGY OF THE MELBOURNE DISTRICT, VICTORIA· .WiJh conm1JUtlons frtJm .~ G. Bell, ~ G~ Bowen, J. G. Douglas, J. S. Hancock, J. J. Jenkin~ PeR. Kenley, J. L. Knight, J9 I. Neilson, D~ SpencermJonest J~ A. Talent, Dq Eor Thoma'S and~ G. Whiting ~ES · DEPARTMENt MELBOURNE, :VICTO~ AUSTRALIA 1961: . I UJv UJa: V) i= Z , 0 <:<: LL. GEOLOGICAL SURVEY OF VICTORIA D. E. THOMAS, D.Sc., Director BULLETIN No. 59 GEOLOGY· OF THE MELBOURNE DISTRICT, VICTORIA Explanatory notes on the stratigraphy, structure and economic geology to accompany the geological map of Melbourne and Suburbs (1959, Scale 1: 31,680) lVitb contributions from : G. Bell, K. G. Bowen, J. G. Douglas, J. S. Hancock, J. J. Jenkin, P. R. Kenley, J. L. Knight, J. L. Neilson, D. Spencer-Jones, J. A. Talent, D. E. Thomas and R. G. Whiting Issued by E. Condon, LL.B., M.Inst.T., Secretary for Mines under tbe autbority of The Hon. T. A. Darcy, M.L.A., Minister of Mines 1967 2288/66. PREFACE In recent years the Mines Department has handled a large and steadily increasing number of enquiries relating to various aspects of the geology, underground water and mineral resources of the Melbourne area. This bulletin on the geology of Melbourne and its environs has been prepared to fill the need for general information of this type. The volume is intended to accompany and provide an explanatory text to the geological map of Melbourne and Suburbs (scale 1 : 31,680) which was published in 1959. It also fulfils the function of a general reference book and introduces the reader to the work that has been done to date and the problems that remain to be solved. The bulletin takes the form of a symposium of articles by various geologists of the Mines Department. Several of the articles are written so as to be readily understood by the interested layman, but others, from the nature of their subject, have required a more technical treatment. Geological information in many fields is accumulating very rapidly and it is hoped that the subject matter may be brought up to date from time to time by the publication of new editions. I trust that this bulletin will prove a valuable addition to the publications of the Department. D. E. THOMAS, D.Sc. Director of Geological Survey. CONTENTS PAGE PREFACE D. E. THOMAS 3 CHAPTER I-INTRODUCTION D. E. THOMAS 11 References 11 CHAPTER 2-THE PHYSIOGRAPHY OF THE MELBOURNE AREA J. L. NEILSON 12 Introduction 12 'J'he Nillumbik Terrain 12 Drainage System of the Nillumbik Terrain 13 The Brighton Coastal Plain 14 The Lava Plains .. 15 The Yarra Delta .. 16 Coastline 16 References 17 CHAPTER 3-GENERAL GEOLOGY OF THE MELBOURNE AREA 19 3-1 SILURIAN .. 19 STRUCTURE AND STRATIGRAPHY R. G. WHITING 19 Geological Structure 19 Folding 19 Faulting 20 Pitch Effects 20 Stratigraphy 21 References Cited 21 Other References 21 SEDE\illNTARY PETROLOGY AND pALAEONTOLOGY .. JOHN A. TALENT 24 Sedimentary Petrology 24 Palaeontology 25 Faunal and Floral Lists 26 Keilorian 26 ? Keilorian 26 Melbournian 26 References 27 Seclim.entary Petrology 27 Palaeontology of the Silurian 28 3-2 TERTIARY P.R. KENLEY 31 Introduction and Geological Setting 31 Major Structural Features 31 General Features of the Tertiary Sediments and their Relationships with the Older Rocks 31 Variation of Sedimentary Facies 31 Marine Transgression and Regression 32 Comparison with Bacchus Marsh 32 Stratigraphy . 32 W erribee Formation 32 Sub-Older Volcanic Alluvials 33 Older Volcanics (" Older Basalts") .. 33 Altona Coal Seam .. 34 Werribee Formation-Newport Formation Contact 35 Newport Formation 35 Newport Formation-Brighton Group Contact 37 Brighton Group ( = Sanclringham Sands) 37 Black Rock Sandstone .. 38 Reel Bluff Sands .. 39 Brighton Group-Newer Volcanics Contact 39 Sub-Newer Volcanic Alluvials 39 CHAPTER 3-continued. PAGE Newer Volcanics (Exford Volcanics) .. 39 Basalts of the Greensborough Phase 40 Basalts of the \Verribee Pla,ins Phase 40 Detailed Geological Structure of the Tertiary Deposits 40 :Monoclines and Flexures 40 Folding .. 42 Jointing .• 43 Structure Contours-Base of Tertiary 43 Acknowledgmnent 43 Appendix 43 Sub-divisions of the Brighton Group 43 References Cited 45 Maps 46 Bathytnetric Charts-Port Phillip Bay 46 3-3 QUATERNARY J. L. NEILSON AND J. J. JENKIN 47 Altona "'"-rea .. 47 :M:aribyrnong Valley 47 Lower Yarra Area 48 Port Melbourne Sand 48 Coolle Island Silt 49 Newer Volcanics .. 49 Fishermen's Bend Silt 49 JYioray Street Gravels 50 Heidelberg Alluvial Terraces 50 Aeolian Deposits 50 References 50 3-4 IGNEOUS ROCKS 53 GRANITIC ROCKS P.R. KENLEY 53 Heferences Cited 53 DYKE RocKs .. K. G. BOWEN 53 Acid and Intermediate Dykes 53 Basaltic Dykes 53 Alkaline Dykes 54 Larnprophyre Dykes 54 Age of the Dykes 54 References 54 BASALTS G. BELL, P. R. KENLEY, AND D. SPENCER-JONES 54 General Re1narks 54 Older Volcanics P. R. KENLEY AND G. BELL 55 Physical Features of the Hocks 55 Petrology 55 Chernical Cmnposition 56 Centres of Eruption 56 References Cited 56 Newer Volcanics . 61 Greensborough Phase P. R. KENLEY AND G. BELL 61 Petrology 61 Chem.ical Composition 61 Werribee Plains Phase D. SPENCER-JONES 61 Physical Features of the Basalt Rocks 61 Composition of the Basalts 62 Iddingsite Labradorite Basalt (Footscray Type) 62 Olivine Labradorite Basalt 62 Zeolite Minerals 63 References 63 PAGE CHAPTER 4-ECONOMIO GEOLOGY 64 4-1 AGGREGATES K. G. BOWEN 64 Basalt 64 Scoria 64 Acid Igneous Rocks 64 Sedimentary Rocks 65 Production 65 1\fethod of vV orking 65 Physical Properties 65 4-2 SAND DEPOSITS K. G. BowEN 66 Classification 66 Pleistocene to Recent Sands 66 Tertiary Sands 66 Concrete Sand 66 Glass Sand 66 Hot Mix Filler 67 Brick Sand .. 67 Moulding Sands 67 1\fiscellaneous Sands 67 Methods of 'iVorking 67 4-3 CLAY AND SHALE DEPOSITS G. BELL 68 Introduction and History 68 Production of Shale and Siltstone 68 Production of Plastic Clay 69 Silurian Clay Shales 69 Cainozoic Semi-Refractory Clays 70 Cainozoic Pipe and Tile Clays 70 Scoresby and Ferntree Gully 70 Tally Ho 70 Oak leigh 70 Cheltenham 71 Residual Granitic Clays 71 Hallam .. 71 Bulla 71 Acknowledgements 71 References 71 4-4 THE BRICK AND TILE INDUSTRY D. SPENCER-JONES 74 Historical Comment 74 Raw Material 74 Production 75 References 75 4-5 EXPAND ED SHALE AGGREGATE , . R. G. WHITING 75 Materials Used as Light Weight Aggregates 75 Expanded Shale 75 References 76 4-6 GOLD R. G. WHITING 76 Historical 76 References 77 4-7 BROWN COAL J. L. KNIGHT 78 CHAPTER 4-continued. PAGE 4-8 THE UNDERGROUND WATER RESOURCES P. R. KENLEY AND J. S. HANCOCK 79 Introduction .. 79 Occurrence of Ground \Yater in the Various Stratigraphic Units 79 Silurian .. 79 Tertiary .. 79 \Verribee Formation 79 Older Y olcanics 79 Newport Fonnation 80 Bl'ighton Group 80 Tertiary-Quaterna,ry 81 Newer Volcanics 81 Quaternary 81 Yarra River Alluvials (excluding the Yarra Delta Sediments) 81 Yarra Delta Sediments 81 Dune Sands between Mordialloc and Frankston .. 81 Aquifer Characteristics 82 Intake Areas 82 Natural Recharge 82 Water QuaUty Distribution 82 Bore Distribution and Construction 82 Utilization of ·water 82 Present .. 82 Fnture 82 Sources of Information 82 Acknowledgements 82 CHAPTER 5-FOSSIL PLANTS IN THE lYIELBOURNE AREA J. G. DouGLAs 84 Silurian 84 Tertiary 84 Tertiary-Quaternary .. 84 Quaternary 84 References 85 GENERAL ACKNOWLEDGEMENT 87 TABLES 1. Mineralogical composition of Silurian " sandstones " of the Melbourne District . 24 2. Chemical analyses of Silurian sedimentary rocks from. New Northcote Brick Pit, Croxton, compared with analyses of two " well-washed " sandstones from. the Ordovician of Victoria . 25 3. Stratigraphic table of Tertiary rocks in the Melbourne area 30 4. Approximate frequency of occurrence of lithological types in the vVerribee Formation, South-western and vVestern Suburbs (based on data from bore logs) . 32 5. Stratigraphic table, Yarra Delta area 48 6. Chemical analyses of basalts from. Royal Park, Tullamarine and Keilor 56 7. Chemical analyses of basalts from Coburg, Footscray and Maribyrnong 62 8. Percentage of the different rock types making up the total production of aggregates in the Melbourne area 65 9. Values of Los Angeles Abrasion Test Loss for different rock types used as aggregates in the Melbourne area 65 10. Production of various clay types in the metropolitan area for the period 1960-1963 69 11. lYiineralogica,J composition and physical properties of clays from the Melbourne area 72 12. Chenlical composition of some typical clay shales from the Melbourne area 74 13. Range of composition in thirteen Werribee Formation waters, south-western suburbs 79 PAGE TEXT FIGURES 1. Idealized plan showing structure of the Silurian bedrock and the approximate relationship between the Melbournian and Keilorian stages 22 2. Cross-sections of the Silurian rocks- Section A-Through Doncaster Junction and Merlynston Station . 23 Section B-Through Camberwell Station parallel to Section A 23 3. Diagrammatic cross-section illustrating the stratig1•aphic relationships of the principal Tertiary formations in the Melbourne area 31 4. Generalized section showing the relationship of the alluvial forrnations on the JYiaribyrnong River near Dry Creek, Arundel 51 5. Plan of Yarra Delta area, showing positions of bores and cross-sections A, B and C (see Plate 3) 52 6. Examples of grading limits for concrete sand aml the grading for a typical washecl concrete sand from Springvale 66 7. Change in grading of sand produced by washing 68 8. Clay and shale deposits, Greater Melbourne area 73 9. Sketch map showing positions of geological cross-sections of the Tertiary rocks (see Plate 7) 83 PLATES 1. Fossils from the Silurian rocks of the Melbourne area 29 2. Base of Tertiary structure contours and geologica,! structure of the Tertiary rocks, Melbourne area facing p.