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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
Graphic design and productionMarie Lake, Maria Bentley, Alissa Harding, Katharine Hagan, Adrian Yee
CartographySilvio Mezzomo, David Arnold, Chris Evenden, Veronika Galinec, Daniel McIlroy
Digital appendixJulie Silec, James Navin
EditorsSue Turner; Biotext Pty Ltd
IndexingDesignemergency – Tracy Harwood
Project coordinationSuzy Domitrovic, Bobby Cerini
Additional photographyChris Fitzgerald, Adrian Yee
PrintingBook printing by Paragon Printers, Canberra DVD printing by Replicat, Melbourne
Published by Commonwealth of Australia (Geoscience Australia) and ANU E Press, Canberra, Australia.
This title is also available online at http://epress.anu.edu.au
Address for correspondence (print edition): Geoscience Australia Cnr Jerrabomberra Avenue & Hindmarsh Drive Symonston ACT 2609 Australia Email: [email protected]
Address for correspondence (online edition): ANU E Press R.G. Menzies Building (#2) The Australian National University Canberra ACT 0200 Australia Email: [email protected]
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
Printed on Monza Recycled stock. Monza Recycled is certified carbon neutral by the Carbon Reduction Institute (CRI) in accordance with the global Greenhouse Protocol and ISO 14040 framework. Monza Recycled contains 55% recycled fibre and is FSC Mix Certified, which ensures that all virgin pulp is derived
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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
2
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
6
7
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