Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nullarbor Region Once Full of Fast-Flowing Rivers

25.01.2013
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
simon.holford@adelaide.edu.au

Dr Simon Holford | Newswise
Further information:
http://www.adelaide.edu.au

More articles from Earth Sciences:

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

nachricht Canadian glaciers now major contributor to sea level change, UCI study shows
15.02.2017 | University of California - Irvine

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>