Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Nullarbor Region Once Full of Fast-Flowing Rivers

University of Adelaide geologists have shed new light on the origin of Australia’s largest delta, the Ceduna Delta, and the river systems which drained the continent millions of years before the Murray-Darling system came into existence.

It has long been thought that a massive river system, almost 2000km long, extended from Queensland’s eastern margin and entered the sea near Ceduna, depositing enormous quantities of sediment from across the continent.

In contrast, this research has revealed that between 85 and 70 million years ago the river system depositing sediment into the delta was restricted to a series of smaller, fast-flowing rivers in the area around Ceduna. This area was being uplifted as Australia and Antarctica began to break apart, forming a series of hills which were then eroded, producing a more subdued landscape that today encompasses the Nullarbor Plain.

The University of Adelaide researchers are the first to analyse the ages of mineral grains contained in sediments from the only well drilled to date into the centre of the delta in the Great Australian Bight – revealing the nature and original sources of the sediment.

"By analysing this sediment, we’ve been able to reconstruct the landscape and major river drainage systems of the Australian continent about 80 million years ago," said project leader Dr Simon Holford. "It also gives us a better understanding of the hydrocarbon potential – the possibility of economic oil and gas production – from the region.

"To understand the hydrocarbon potential, we need to know the origin and nature of the reservoir rocks."

The 700km-wide Ceduna Delta, off the West Coast of South Australia, is about the same size as the Niger Delta in Western Africa, containing about 0.5 million cubic kilometres of sedimentary rock including sandstones and shales.

Many deltas contain large hydrocarbon reserves, and last year BP announced it would invest up to $1.4 billion exploring the Ceduna Delta for oil and gas.

Analysing the sediment, Dr Holford, PhD candidate Justin MacDonald, fellow researchers and Melbourne-based Geotrack International Pty Ltd, dated almost 1000 grains of the mineral zircon from the well’s core samples.

"By looking at the distribution of the ages of the minerals, we were able to identify different 'age populations' of zircon and produce a model of a river system which transported these minerals and deposited them on the margin of the continent," Dr Holford said.

"Our results showed that most of the sediment was derived much closer to the Great Australian Bight than has been previously thought. It gives us a much better handle on the geology and geomorphology of Australia 85-70 million years ago."

The research has been published in the Journal of the Geological Society.

Dr Simon Holford
Lecturer in Petroleum Geoscience
Deputy Director, Centre for Tectonics, Resources and Exploration (TRaX)
The University of Adelaide
Phone: +61 8 8313 8035
Mobile: +61 424 197 916

Dr Simon Holford | Newswise
Further information:

More articles from Earth Sciences:

nachricht Earth's magnetic field is not about to flip
25.11.2015 | The Earth Institute at Columbia University

nachricht Autumn gales again drive salt into the Baltic: Third Major Baltic Inflow within 1.5 years.
25.11.2015 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Climate study finds evidence of global shift in the 1980s

Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.

Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...

Im Focus: Innovative Photovoltaics – from the Lab to the Façade

Fraunhofer ISE Demonstrates New Cell and Module Technologies on its Outer Building Façade

The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...

Im Focus: Lactate for Brain Energy

Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.

In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...

Im Focus: Laser process simulation available as app for first time

In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.

Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...

Im Focus: Quantum Simulation: A Better Understanding of Magnetism

Heidelberg physicists use ultracold atoms to imitate the behaviour of electrons in a solid

Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...

All Focus news of the innovation-report >>>



Event News

Fraunhofer’s Urban Futures Conference: 2 days in the city of the future

25.11.2015 | Event News

Gluten oder nicht Gluten? Überempfindlichkeit auf Weizen kann unterschiedliche Ursachen haben

17.11.2015 | Event News

Art Collection Deutsche Börse zeigt Ausstellung „Traces of Disorder“

21.10.2015 | Event News

Latest News

Antibody-Drug Compounds and Immunotherapy to Treat Breast Cancer

26.11.2015 | Life Sciences

Get to the point with electric cars

26.11.2015 | Power and Electrical Engineering

Climate study finds evidence of global shift in the 1980s

26.11.2015 | Studies and Analyses

More VideoLinks >>>