Shaping a Nation

Shaping a Nation

Geoscience Australia

Richard Blewett, Chief Editor

a geology of austr alia

Department of Resources, Energy and TourismMinister for Resources and Energy: The Hon. Martin Ferguson, AM MP Secretary: Mr Drew Clarke

Geoscience AustraliaChief Executive Officer: Dr Chris Pigram

This book is published with the permission of the CEO, Geoscience Australia.

© Commonwealth of Australia (Geoscience Australia) and The Australian National University 2012

With the exception of the Commonwealth Coat of Arms and where otherwise noted, this publication is provided under a Creative Commons Attribution 3.0 Australia licence. <http://creativecommons.org/licenses/by/3.0/au/legalcode>

Unless otherwise acknowledged, copyright in all images is vested in the Commonwealth of Australia (Geoscience Australia).

ISBN (print version) 978-1-922103-43-7 ISBN (online version) 978-1-921862-82-3

GeoCat # 73489

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Additional photographyChris Fitzgerald, Adrian Yee

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Published by Commonwealth of Australia (Geoscience Australia) and ANU E Press, Canberra, Australia.

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Address for correspondence (print edition): Geoscience Australia Cnr Jerrabomberra Avenue & Hindmarsh Drive Symonston ACT 2609 Australia Email: sales@ga.gov.au

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CitationBlewett RS (ed.) 2012. Shaping a Nation: A Geology of Australia, Geoscience Australia and ANU E Press, Canberra.

Recommended citation for individual chaptersBrodie RS, Lawrie KC & Commander DP 2012. Groundwater—lifeblood of the continent. In: Shaping a Nation: A Geology of Australia, Blewett RS (ed.), Geoscience Australia and ANU E Press, Canberra, 332–379.

Cover imageKings Canyon, Northern Territory. Image by Jim Mason

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Minister’s introductionThis book holds a mirror to

timeless geological processes

that have shaped a magnificent

country. It shows how our nation has evolved by

utilising the natural endowment of this continent

that has formed on the back of nearly four billion

years of geological processes.

This absorbing documentation of Australia’s

geological history and how it has shaped our society

highlights the value of geoscience information and

how it underpins our economy and well-being. A

very strong reflection of this history is how plate

tectonics has placed Australia adjacent to the

fastest growing region on the planet, thus enabling

Australians to rise to the challenges that our global

economy now faces: energy security, developing

cleaner and alternative energy technologies,

the impact of climate change and the safety

and resilience of communities to recover from

devastating natural hazards.

Australia’s history has been influenced by the

relationship between people and natural resources.

This relationship will continue to shape our way

of life in Australia, including our families, culture,

safety and well-being, society, prosperity and future.

Geoscientists have built a knowledge base that puts

Australia at the forefront of resource exploration

and development. Future generations will build on

this knowledge. They will invent technologies that

are perhaps beyond our imagination at this point

in time. Currently, geoscientists are exploring and

investigating new minerals and energy sources,

knowing that we have a responsibility to contribute

to the sustainable management of the Australian

continent and the planet.

This book takes a journey that covers every

landscape, seascape and climate, from the tropics

to the Antarctic, across more than twenty seven

million square kilometres of our planet. It also

takes a journey through deep time, from the oldest

evidence of Earth’s crust in Western Australia to

modern coral reefs in Queensland.

Most of Australia’s natural tourism features are

products of geological processes that began more

than 20 million years ago—the Warrumbungles in

New South Wales, the Flinders Ranges in South

Australia and the Great Barrier Reef in Queensland.

Another significant cultural and tourism site is the

Uluru–Kata Tjuta National Park. Uluru, ‘the rock’,

was laid down in an inland sea about 540 million

years ago. Uluru and the National Park have a

cultural and natural heritage that dates back tens

of thousands of years, and which the Anangu

traditional owners have looked after over that time.

This exciting book demonstrates the fundamental

importance of the study of Earth sciences to our

society. It is upon all of us, in every corner of the

world, to understand the geological processes of

the land on which we live and to continue working

together to solve the challenges for our future

well-being.

The Hon Martin Ferguson AM MP

Minister for Resources, Energy and Tourism,

Australian Government

F SHAPING A NATION | A Geology of Australia

i

ContentsForeword 1Editors’ note 5Acknowledgements 5

Australia and the Australian people 7A sense of place 9The Australian people 10Australian geology: the foundation that shapes the people 21Knowing Australia’s limits 38Bibliography and further reading 44

Australia in time and space 47Australia’s current tectonic setting 49Mapping Australia 56Australian lithosphere 79Measuring Australia’s record of ‘deep’ time 85Australia through time: a summary of the tectonic evolution 89To sum up 116Bibliography and further reading 117

Living Australia 121Life in Australia 123The beginning 123The Cambrian explosion 128Beginning to build the modern world 147Arrival of humans 164Final comments 170Bibliography and further reading 171

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3The Pinnacles, Western Australia.

Image by Jim Mason

ii

Out of Gondwana 173Gifts of Gondwana 175Petroleum systems and hydrocarbon resources 176Gondwana to island continent 180The search for Australia’s petroleum 206Why is Australia gas rich and oil poor? 220Postscript 222Bibliography and further reading 223

Old, flat and red —Australia’s distinctive landscape 227Regolith 229Cenozoic climate changes of the Australian landscape 230Why so flat? 234Regolith—everything between fresh rock and fresh air 250How old is the Australian landscape? 256How regolith enriches Australia 261Seeing through the regolith 270Plainly speaking 273Bibliography and further reading 274

Living on the edge —waterfront views 277Our coastal home 279Australia: a maritime nation 281Formation of the edge 289The shifting edge—Quaternary climate and sea-level 292Beautiful one day, perfect the next: the modern Australian coast 300Muddying the water: environmental pressures on the coast 313Hazards of living on the edge 319Final say—better valuing the edge 327Bibliography and further reading 329

Groundwater—lifeblood of the continent 333Real dry 335Groundwater: a critical resource 337Groundwater: a geological agent of change 354A groundwater future for the driest inhabited continent 367A geoscience systems approach to future hydrogeology 374Going with the flow 377Bibliography and further reading 378

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5

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iii

Foundations of wealth—Australia’s major mineral provinces 381Sources of wealth 383A short history of discovery and mining in Australia 384Australia’s giant mineral systems 390Victorian goldfields—the gold rush that changed a nation 392The Eastern Goldfields—Australia’s Fort Knox 400Proterozoic Zn–Pb deposits: Broken Hill and Mt Isa 408Olympic Dam IOCG Province: new era of discovery 416Giant Australian mineral systems 422Metallic exploration and mining: future challenges 425Bibliography and further reading 428

Sustaining Australia’s wealth—economic growth from a stable base 433Resources from a stable base 435A brief economic history of Australia 437Living in contemporary Australia 442The carbon wealth of Australia: coal and the Australian people 456From the red centre to greenbacks: Australia’s iron ore and steel 461Bauxite: a legacy of Australia’s deeply weathered past 466Gas, the ‘greener’ hydrocarbon 470Marriage of the giants: adding value to the bulk commodities 477Unearthing our past and future 478Bibliography and further reading 480

Deep heat—Australia’s energy future? 483Future energy 485Beyond fossil fuels? 485Australia: the hot continent 489Why Australia? 492The heat-producer’s guide to Australia 496Radioactivity—a potential energy and heat source for Australia 514Is the past the key to Australia’s energy future? 520Bibliography and further reading 524

Advance Australia Fair 527Lucky country? 529Fragile Earth 543Bibliography and further reading 543

Index 544

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iv SHAPING A NATION | A Geology of Australia

1

ForewordThis book demonstrates not only how the

geological history of the Australian continent has

shaped where we live, but how it has influenced the

way the Australian people have responded to the

endowment bestowed by that geological history

to build a prosperous and peaceful nation located

between the east Indian and southwest Pacific

oceans. Our location as an island continent is the

product of many hundreds of millions of years of

plate tectonic processes, which have left the country

in a mid-plate tectonic setting with a latitude

band that results in a highly variable climate.

The interaction of these tectonic and climatic

forces has shaped the landscape and environment

of the continent. Our position within middle to

low latitudes has left the continent without recent

continent-wide glacial activity to replenish and

refresh the soils, unlike much of Eurasia and North

America. Furthermore, the continent’s position

within the Australian Plate has meant that the

processes that shape it operate at a time-scale that

is orders of magnitude slower than the processes

that operate at plate boundaries, thereby making

it difficult to measure these processes and hence

understand their role in shaping the continent.

The geological record is, however, clear. Even at

very slow rates, enormous changes can and do

occur when they have the opportunity to operate

over tens to hundreds of millions of years.

The very long geological history preserved

within Australia has delivered a great natural

endowment of mineral, energy and groundwater

resources that have formed and accumulated over

close to four billion years. The resources and

landscape of Australia have strongly influenced

the first Australians—the Aboriginal and Torres

Strait Islander people—and, during the past

two centuries, the development of Australia as a

nation. This influence occurred from the early

Asian and European encounters with the west

and north coast—which led to a perception

of a difficult, inhospitable coastline backed by

a commercially uninteresting continent, with little

or no potential—to the early exploration of eastern

Australia, when the passive margin mountains

of the Great Divide initially prevented inland

exploration. Once the interior of the continent

was being explored, it was often the discovery of

mineral resources that led to the establishment of

major settlements. As this book recounts, many

of the significant changes in Australia during

the past 200 years have been driven by major

population spurts that were the outcome of

minerals booms in one form or another, from the

19th century gold rushes to the modern iron ore-

and energy-driven boom.

One decade into the 21st century, what does this

view of Australia, shaped by nearly four billion

years (4 Ga) of geological processes, tell us about

how we should, as geoscientists, tackle the many

challenges we face in maintaining a sustainable,

vibrant, wealthy and healthy Australia over the next

100 years? Although we have learnt a lot and know

a great deal about the evolution and development

of our continent, there is much still to learn.

The challenge for the nation is to better understand

the processes that have generated the resource

endowment that we are currently exploiting, Windjana Gorge, Western Australia.

Image by Jim Mason

2 SHAPING A NATION | A Geology of Australia

3

In some geological environments, the tools

are superb and give excellent results. In other

environments, our ability to interpret and integrate

this information in a way that generates meaningful

geological information, while developing, still lags

well behind where we would like to be. Our capacity

to measure the rate of change of the continent’s

surface down to millimetre-scale accuracy and

to image deep into the continent means that we

have the opportunity to tackle some of the great

geological questions of our time. We will therefore

have a very much enhanced prospect of being far

more predictive and confident in answering many

of the big questions that determine the behaviour

of our continent in an ever-changing world. In this

way, geoscientists can more confidently contribute

to the sustainable management of the planet.

The book is the largely voluntary effort of many

people from across the geological community in

Australia. Geoscience Australia, in collaboration

with The Australian National University, is

delighted to bring this publication to fruition

in time for the 34th International Geological

Congress, and trusts that it will be an enduring

contribution to the knowledge of the Australian

nation through the lens of its geological evolution.

Dr Chris Pigram

Chief Executive Officer

Geoscience Australia

and to identify the location, at depth and under

cover, of the next generation of resources that will

underpin the nation’s economic future. Although

we understand many of the first-order factors that

drive the processes that affect our endowment, as

well as the geological hazards that occur in Australia,

we cannot predict or convincingly explain many of

the phenomena that we observe. For example, our

understanding of intraplate processes is deficient

and represents a significant gap in the research

focus of our geoscience community.

Much of what we know comes from investigation

of the relatively accessible, near-surface geological

record. By contrast, we know much less about

what lies below that near surface and, perhaps

more importantly, how the solid earth behaves

in three dimensions through time in response to

the processes that shape our world. We are not

yet able to answer important questions about why

and where the events of Australia’s long geological

history have placed the next generation of resources

that are currently hidden at depth or beneath

cover. Although technology has given us tools to

image the subsurface in various ways and to various

depths (with highly variable resolutions), these

tools are measuring a range of physical properties

that are surrogates for the geology. We will need

to deploy and integrate the full suite of tools

and techniques available to provide the necessary

geologically meaningful results that will lead to

a comprehensive understanding of earth systems

processes as they have operated in Australia.

Kermit’s Pool, Hancock Gorge, Karijini National Park, Western Australia.

Image by Jim Mason

4 SHAPING A NATION | A Geology of Australia

Southern AustralianAbyssal Plain

AUSTRALIA

NEW ZEALAND

WallabyPlateau

ExmouthPlateau

NaturalistePlateau

AUSTRALIAN ANTARCTIC TERRITORY

Kerguelen Plateau

KerguelenIslands

Heard andMcDonald

Islands

MacquarieIsland

Mac

quar

ie R

idge

CedunaTerrace

SOUTHEAST INDIAN RIDGE

AUSTRALIAN-ANTARCTIC BASIN

MADAGASCAR

SOUTHWEST IN

DIAN R

IDGE

NIN

ETYE

AST

RID

GE Cocos

(Keeling)Islands

ChristmasIsland

PAPUA NEWGUINEA

INDONESIA

CROZETBASIN

WHARTONBASIN

South Tasman Rise

PACIFIC-ANTARCTICA RIDGE

TASMANBASIN

CampbellPlateau

NEWCALEDONIA

LordHoweIsland

NorfolkIsland

Lord Howe Rise

VANUATU

MarionPlateau

Capel Bank

Sunda Trench

Diamantina Fracture Zone

Bruce Rise

Broken Ridge

CEN

TRA

L IND

IAN

RI D

GE

EnderbyAbyssal

Plain

Elan Bank

FIJI

Hjort T

renc

h

SOLOMON ISLANDS

AUSTRALIAN ANTARCTIC TERRITORY

MALAYSIABRUNEI

PHILIPPINES

VIETNAMTHAILAND

SRI LANKAINDIA

SOMALIA

ETHIOPIA

KENYA

TANZANIA

MOZAMBIQUE

TIMOR-LESTE

0 2000 km

Depth (metres)Sea-level

–10 425

–2000

–4000

–6000

–8000

Frontispiece: The limits of Australia. The white line shows the treaty boundaries with adjacent states, combined with Australia’s outer limit of extended continental shelf. Major geomorphological features of the surrounding ocean basins are also shown.

5

Southern AustralianAbyssal Plain

AUSTRALIA

NEW ZEALAND

WallabyPlateau

ExmouthPlateau

NaturalistePlateau

AUSTRALIAN ANTARCTIC TERRITORY

Kerguelen Plateau

KerguelenIslands

Heard andMcDonald

Islands

MacquarieIsland

Mac

quar

ie R

idge

CedunaTerrace

SOUTHEAST INDIAN RIDGE

AUSTRALIAN-ANTARCTIC BASIN

MADAGASCAR

SOUTHWEST IN

DIAN R

IDGE

NIN

ETYE

AST

RID

GE Cocos

(Keeling)Islands

ChristmasIsland

PAPUA NEWGUINEA

INDONESIA

CROZETBASIN

WHARTONBASIN

South Tasman Rise

PACIFIC-ANTARCTICA RIDGE

TASMANBASIN

CampbellPlateau

NEWCALEDONIA

LordHoweIsland

NorfolkIsland

Lord Howe Rise

VANUATU

MarionPlateau

Capel Bank

Sunda Trench

Diamantina Fracture Zone

Bruce Rise

Broken Ridge

CEN

TRA

L IND

IAN

RI D

GE

EnderbyAbyssal

Plain

Elan Bank

FIJI

Hjort T

renc

h

SOLOMON ISLANDS

AUSTRALIAN ANTARCTIC TERRITORY

MALAYSIABRUNEI

PHILIPPINES

VIETNAMTHAILAND

SRI LANKAINDIA

SOMALIA

ETHIOPIA

KENYA

TANZANIA

MOZAMBIQUE

TIMOR-LESTE

0 2000 km

Depth (metres)Sea-level

–10 425

–2000

–4000

–6000

–8000

life in Australia, development of post-Gondwana

hydrocarbon systems, evolution of the landscape,

the coastal zone, groundwater, minerals and bulk

commodities, and, finally, future energy. The

concluding chapter considers the major challenges

facing the nation and the vital role that geosciences

will play in meeting these challenges.

The time-scale we use is the September 2009

chart issued by the International Commission on

Stratigraphy. The appendices are a very important

component of the book. They are available on a

dual-layer DVD bound with the hard-copy printed

version. This DVD contains an Australian Common

Earth Model and places many of the maps and 3D

objects from Appendix 2 into a 3D viewer (NASA’s

World Wind). Other large-scale maps, reports,

animations, tables and documents are arranged

by chapter and can be viewed through a browser.

The Common Earth Model is, in essence, an atlas

of continental-scale maps that were previously

published in the 1980s as the BMR Earth Science

Atlas. These plates have been updated since, but here

they are compiled together in one easy resource.

The book has 54 contributing authors from across

Australia and as many external reviewers from

across Australia and the world. Many others have

also contributed; it has been a community effort

(see acknowledgements). The Editorial Board

would like to acknowledge all these people for their

time, expertise and enthusiasm. We would also like

to acknowledge the considerable investment by

Geoscience Australia in making this book a reality.

Richard Blewett, Keith Scott, Brian Kennett, Phil McFadden, Marita Bradshaw, Phil Cummins (Editorial Board)

Acknowledgements*J Aitchison, M Alcock, J Alexander, M Allan,

H Apps, M Archer, M Barley, A Barnicoat,

P Betts, B Birch, K Black, S Blewett, C Boreham,

C Brown, P Butler, C Butt, C Carson, L Carson,

P Cawood, R Chopping, J Claoue-Long, D Clark,

B Collins, K Condie, C Consoli, M Cornelius,

R Costello, S Cox, R Cresswell, A Cross, D Curnoe,

G Davidson, J Dawson, P De Caritat, P De Dekker,

K Derrington, T Eggleton, P English, R Evans,

N Exon, S Fishwick, I Fitzsimmons, D Flint,

C Foster, G Fraser, J Frazier, E Fredericks, J Gehling,

D Giles, A Gill, B Goscombe, J Greenfield, K Grey,

L Halas, L Hall, B Handke, A Harris, L Head,

P Henson, S Holland, J Hollis, O Holm, D Hopley,

M Hutchinson, T Ireland, S Jaireth, L Jaques,

N Jarosz, B John, D Kay, M Kendall, J Kennard,

B Kohn, R Korsch, I Lambert, R Langford,

R Large, D Le Heron, K List, J Long, S Maclaren,

J Magee, D Mantle, G Marinelli, J Mason,

H Maxwell-Stewart, P McCabe, C McCuaig,

A McKay, A McPherson, Y Miezitis, P Milligan,

B Minty, T Moore, D Müller, C Murray-Wallace,

M Nichol, B Nicoll, M Norvick, Ian Oswald-Jacobs,

J Paterson, J Pettigrew, C Pigram, K Piper,

P Playford, T Press, T Ransley, A Reading,

M Roarty, D Robson, R Rogerson, A Rowett,

R Sait, B Salau, M Salmon, M Sandiford, J Scanlon,

I Scrimgeour, A Short, K Sircombe, P Southgate,

T Stieglitz, A Stewart, G Taylor, T Topper, D Trail,

I Tyler, T Tyne, C Vickers, M Walter, M Wenitong,

M White, T Whiteway, M Williams, N Williams,

E Woehler, J Woodhead, C Woodroffe, T Worthy,

G Young and S Zahirovic.

* Authors are listed at the start of each chapter.

Editors’ noteThis new book on Australia’s geology has been

prepared for release at the 34th International

Geological Congress in Brisbane in August 2012.

The book has been co-published by Geoscience

Australia and ANU E Press. The book is not

intended as a definitive text on all aspects of

Australia’s diverse geology, nor does it follow the

‘traditional’ time-based treatment of the topic.

Rather, the book tells the story of Australia’s

geological evolution through the lens of human

impacts—illustrating both the challenges and the

opportunities presented by the geological heritage

of the ‘lucky country’.

The book showcases the excellence of Australian

geoscience by integrating geoscience disciplines

into a systems framework that address many of

the ‘big questions’ relevant to Australians today.

It is aimed at geoscientists, but the narrative and

messages are relevant to society as a whole. The

Editorial Board has tried to bring together a book

that is as visually stunning as Australia’s geology,

and present much new information with minimal

scientific jargon.

The book is arranged into 11 chapters, each

having a number of breakout boxes and Did you know? panels. These are excursions from the main

narrative where interesting facts and extra details

are presented. Large colour photographs bring

the text to life. The opening two chapters set the

spatial, temporal and cultural contexts for the

book. The following eight chapters are arranged

into themes around the various geological

influences on Australian society, environment

and wealth. These chapters cover the evolution of