• Skip to main content
  • Skip to site footer
img MENU MEMBERSHIP img
  • Home
  • Donate
  • Join
  • Login
img
  • About Us
    • Mission
    • History
    • Values
    • Advocacy
    • Partners
    • People
  • Get Involved
    • What You Can Do
    • State Chapters
    • Become a Member
    • Donate
  • Resources
    • Photo Gallery
    • Conferences
    • Courses
  • Latest News
    • 2023
    • 2022
    • 2021
    • 2020
    • 2019
    • 2018
  • Blog
    • 2023
    • 2022
    • 2021
    • 2020
    • 2019
    • 2018
  • Podcast
  • Contact Us
Australian Coastal Society

Australian Coastal Society

We are the voice of the Australian coast

Cootamundra Shoals Survey 1982

November 24, 2022
Image by Nicholas Flemming. Cootamundra Shoals Expedition, 1982, sampling coral layers below an algal crust to obtain dates of the inundation of the shoal areas that could have been occupied 50,000 years ago.

Cootamundra Shoals Survey 1982

Occasionally one embarks on something that is adventurous, a little crazy, intellectually and physically satisfying, but incomplete. Here I am outlining an experience that should have been properly written up yet for a variety of reasons is documented only in places hard to access.

Forty years ago, I was invited to join The Sirius Expedition to undertake an offshore survey of the Cootamundra Shoals. These shoals occur approximately 240 km northwest of Darwin in the Timor Sea. As shown on bathymetric charts, it is an area of rugged relief with flat upper surfaces and steep- sided valleys. What formed this topography which would have been exposed above sea level during periods of Pleistocene low sea levels?

First a little background. In 1975 a symposium at the Pacific Science Congress in Vancouver on prehistory of the Australian-Melanesian axis prompted three prehistorians from ANU to publish the multi-disciplinary findings of those with a growing interest in the changing habitats and human occupance of the region. The resulting book, “Sunda and Sahul, Prehistoric Studies in Southeast Asia, Melanesia and Australia”, was edited by Jim Allen, Jack Golson, and Rhys Jones (1977, Academic Press).  John Chappell and I were invited to contribute a chapter on “Sea levels and coasts” (p 275-292). Our interest in the problems of changing shorelines and its link to human movements attracted the attention of a British maritime archaeologist, Nicholas Flemming, famous for his underwater discoveries in the Mediterranean Sea.

Nick had secured support from a philanthropist named Arthur Weller. Excited by the potential to find geological and archaeological material on the seabed that could relate to migration of peoples during times when sea level was lower, Arthur established the Australian Submarine Prehistory Foundation with HRH The Prince of Wales as Patron. An expedition was mounted assisted by the Australian Navy who saw the need for more detailed charts covering the seabed so near Darwin.

A team of divers (some with scientific experience), photographers, and others was assembled to gather in Darwin in May 1982. The diving team was to work from a vessel equipped with satellite navigation, recompression chamber, and various bottom sounding and sampling equipment (sadly no seismic). Nick asked John Chappell, Rhys Jones and me to join the team along with a group from the UK. The expedition was conducted in three phases or legs: I was on the first leg lasting 10 days, then John took over, and Rhys came on the final leg. Of the three of us I was the only diver and so was extremely privileged to be among the first to encounter the seabed on the Cootamundra Shoal.

Prior to the first leg we had a great time hypothesizing. There were many questions and so little information to assist our thinking as no one had sampled the shoals or the valleys between them. Our best guess was this dissected terrain was an extension of the bedrock geology of Bathurst Island, hopefully with caves at a diving depth with artifacts as evidence of human habitation. Alternatively, was this an area of drowned limestone karst composed of superimposed coral reefs of different Pleistocene ages? Could we find remnant submerged shorelines and get material to C14 date? What do the sediments on the shoals and valleys tell us about the environments of deposition past and present on this continental shelf?

It was quickly apparent after a few dives that the shoals were not formed of living reefs. Growing corals are sparsely scattered on a calcarenite surface. Nick Flemming in his summary of findings to the 7th International Diving Science Symposium in Padua in September 1983 (published 1986) concluded that the flat-topped banks are relict coral platforms. Samples from the flanks of valleys to depths of over 50m showed the presence of ferruginous sandstone so the reefs appear to be built on terrestrial strata.

On that first leg we were able to use an underwater suction dredge and hammers to get below a calcarenite crust. This initially involved diving to depths of 20-30m. What we found was an abundance of coral including branches of Acropora under the crust. One set of radiocarbon dates ranged from 5500 to 8000 years BP. I was most excited to do repeat dives during the first leg to sample the corals and the crust. However, the dive on the 5th May involving digging the first pit underwater was most memorable.  We dug down 70cm through a 10cm calcarenite crust with coral rubble and sand into a 60 cm layer of stick coral loosely bound with some sticks in apparent growth position.

I commented in my dive log: “Stick coral clearly Holocene in age with no signs of oxidation or weathering. They are encrusted in places with attached organisms well preserved”. Thatled me to hypothesize that I was observing an “Acropora garden that grew during the Postglacial Marine Transgression giving a modern reef cap to an older Pleistocene coral core. As sea level rose plus 10m over the shoal the habitat for growth became less attractive and the surface of the corals was destroyed forming a detrital layer that became encrusted”. I then estimated the age of the coral sticks at 7-8000 years. The C14 date from this site later came back at 7700+- 100 (ANU 3257)! Of course, this was very satisfying especially as other dates fell within the range from other pits on the shoal as noted above. Without deeper drilling and dating it was not clear how thick was the Holocene transgressive coral unit. Why was there a switch to crust formation over extensive coral growth over the last 5000 or so years on the shoal platform at depths 15-20 plus metres?

We collected so much information including underwater images taken by a diving photographer as well as a camera lowered from the boat. Bathymetric surveys provided very detailed charts of the shoal platform, valley side terraces and floors. Hundreds of samples from different depths were collected. All this was brought together in a 4-volume survey report compiled by Flemming in late 1982. Few copies were made. I do not possess one only some draft sections. Copies were deposited with the Navy, and I know there is one at the Western Australian Museum. Anyone interested in what I have, including my dive logs, please contact me.

Nick tried to get more funds for seismic and submersible exploration in 1985 but to no avail. We saw the need to go back and do more work. Of course, now there are much improved acoustic methods and other technologies that may even pick up lithic flake signals on the seabed. We did not find any evidence for human occupance during lower sea level times. I guess that turned off the interest from some of us. Nevertheless, we should have done more to publish the findings of the 1982 expedition.

Footnote: Arthur Weller played a major role in the British Government’s bicentennial gift of replica of Cook’s Endeavour in 1988. He helped pay for oceanography equipment that came with the HMB Endeavour in 1993 to help with training. Sadly, within a short period an Australian Navy decision was made to remove this equipment; why?

Bruce Thom       

Words by Prof Bruce Thom. Please respect the author’s thoughts and reference appropriately: (c) ACS, 2022. For correspondence about this blog post please email admin@australiancoastalsociety.org.au

#228

Category: BlogTag: ACS Blog, Bruce Thom Blog, Cootamundra Shoals
Previous Post:US Coastal Zone Management Act 1972: A Model for Australia?
Next Post:Yorke Peninsula Coastal Forum

Sidebar

2023 (6)
  • Thursday, March 23 Federal Coastal Legislation – Public Trust Principles
  • Thursday, March 9 Public Trust Doctrine Part 1: Tribute to Jim Titus
  • Tuesday, February 28 Coastal Adaptation in Aotearoa New Zealand
  • Wednesday, February 15 US Coastal Barrier Resources Act: Model for Strategic Federal Intervention?
  • Tuesday, January 31 Philosophers and the Coast
  • Tuesday, January 17 Ocean Pools
2022 (24)
  • Thursday, December 22 Protecting Nature: Art of the Impossible?
  • Tuesday, December 13 Drainage Window Concept
  • Thursday, November 24 Cootamundra Shoals Survey 1982
  • Thursday, November 10 US Coastal Zone Management Act 1972: A Model for Australia?
  • Wednesday, October 26 Great Barrier Reef—More or Less Gloom
  • Wednesday, October 12 Bondi Pavilion Reopened and Rejuvenated
  • Wednesday, September 28 Coastal Journey Begins: September 1962
  • Monday, September 12 Protection For Sydney Harbour: Berrys Bay Case
  • Thursday, August 25 Coastal Inundation: A Hazard Not to be Underestimated
  • Tuesday, August 9 Beach Access – An International Perspective
  • Wednesday, July 27 SoE 2021 and Coasts
  • Tuesday, July 19 Human Rights and Beaches
  • Wednesday, July 6 Coastal Walks and Local Councils
  • Thursday, June 23 EPBC Act and Regional Landscape and Resilience Plans
  • Wednesday, June 15 29th NSW Coastal Conference
  • Thursday, May 19 Lament for Estuaries? (0)
  • Wednesday, April 27 East Coast Floods 2022 (0)
  • Monday, April 11 East Coast Weather ‘Traffic Jam’ (0)
  • Tuesday, March 29 VALE: PAUL BISHOP (0)
  • Thursday, March 24 IPCC Throws Down the Gauntlet on Australian Institutional Deficiencies
  • Friday, February 25 Recent federal coastal initiatives – February 2022
  • Tuesday, February 8 Resourceful ‘lucky’ country
  • Friday, January 28 FUTURE EARTH AUSTRALIA: SUSTAINABLE OCEANS AND COASTS NATIONAL STRATEGY 2021-2030
  • Monday, January 10 Sunflowers and hope
2021 (27)
  • Wednesday, December 22 DISCOVERING MORUYA 1971-2021
  • Sunday, December 12 PROTECTING A BIG CITY: NEW YORK DECISION MAKING
  • Wednesday, December 1 ICA REPORT: CLIMATE CHANGE IMPACT “ACTIONS OF THE SEA” AND FUTURE RISKS
  • Friday, November 12 NATIONAL CLIMATE RESILIENCE AND ADAPTATION STRATEGY (NCRAS)
  • Thursday, October 28 COASTAL FAMILY—THE ELIOTS
  • Sunday, October 10 COASTAL CLIMATE CHANGE ADAPTATION: ROLES FOR THE AUSTRALIAN GOVERNMENT
  • Monday, September 27 Sydney Harbour: Impact of contamination studies
  • Friday, September 17 Geological indicators of seabed mobility – Narrabeen Beach (Sydney, Australia)
  • Monday, August 30 LAST INTERGLACIAL SEA LEVELS: RECENT RESEARCH AND MEET “STROMBUS BUBONIUS”
  • Wednesday, August 18   COASTAL NEWS – AUGUST 2021
  • Monday, July 19 Reflections on past coastal recommendations by the Australian Government
  • Monday, July 5 LARGS: A GEOHERITAGE SITE?
  • Thursday, June 24 PROPERTY RIGHTS: WHAT CONDITIONS PREVAIL IN A CIVIL SOCIETY?
  • Monday, June 14 UNIVERSITY RESEARCH—PERSONAL SADNESS
  • Saturday, May 29 SEAHORSE MONITORING BY WOOLLAHRA COUNCIL, NSW
  • Tuesday, May 18 US Climate Indicators
  • Saturday, May 8 AUSTRALIAN GOVERNMENT MARINE AND COAST INITIATIVES 2021
  • Sunday, April 25 Travelling west of the sandstone curtain – to Orange (NSW) and back
  • Tuesday, April 20 Big surf at Port Fairy (Victoria) – April 2021
  • Thursday, April 8 LAND: OWNERSHIP AND RIGHTS
  • Sunday, March 14 ESTUARY WETLANDS AND SEA-LEVEL RISE
  • Saturday, February 20 COASTAL ZONE AND CATCHMENT BOUNDARIES
  • Sunday, February 14 Coastal Archaeology Revisited
  • Saturday, January 30 JUDITH WRIGHT – POET, COASTAL CONSERVATIONIST AND MUCH MORE
  • Monday, January 18 COASTAL STORIES FROM THE FIELD,1970-2020
  • Monday, January 11 US COASTAL MANAGEMENT UNDER TRUMP
  • Monday, January 4 2020: A COASTAL PERSPECTIVE
2020 (26)
  • Wednesday, December 23 EPBC ACT CHANGES –WILL THEY BE WORTH THE EFFORT?
  • Monday, December 14 TWO JIMS—BOWLER AND COLEMAN
  • Thursday, November 26 AUSTRALIA UNDER THREAT—WHAT TO DO NEXT?
  • Saturday, November 7 SHORELINE RESPONSES TO SEA-LEVEL RISE
  • Sunday, October 25 Port Stephens-Myall Lakes 1960 – Research Opportunities
  • Wednesday, October 14 Port Stephens – Myall Lakes 1960 – the journey.
  • Monday, September 28 LEGACY ISSUES AND COASTAL MANAGEMENT
  • Friday, September 11 TYPHOONS AND HAINAN ISLAND, CHINA
  • Tuesday, September 1 Impact of sea-level rise on coastal natural values in Tasmania
  • Saturday, August 29 ENVIRONMENTAL VALUES REMAIN THREATENED
  • Thursday, August 6 HAMELIN POOL (Shark Bay, Western Australia) —AN ESTUARY?
  • Thursday, July 16 Estuary Health
  • Friday, July 3 UNIVERSITY RESEARCH AND TEACHING—THE NEXUS IS IT BROKEN?
  • Sunday, June 21 Sandy beach morphodynamics – a new book
  • Sunday, June 7 Cliffs in the Narrabeen Group, Sydney
  • Thursday, May 21 PROGNOSIS FOR A CHOKING MOUTH: THE RIVER MURRAY
  • Wednesday, May 6 Geomorphologic Mapping
  • Wednesday, April 22 DOVER HEIGHTS CLIFFS, SYDNEY
  • Sunday, April 12 Recent Coastal Legal Cases
  • Tuesday, March 24 CHALLENGE AND RESPONSE—THE CURRENT CRISIS
  • Wednesday, March 18 Recent papers in the journal Nature
  • Thursday, February 27 HOLOCENE SEA LEVELS AND COASTAL EVOLUTION
  • Monday, February 17 Brian Caton ‘a coastal legend’- RIP 9 February 2020
  • Tuesday, February 4 NATIONAL COASTAL ADAPTATION AGENDA 2010: A RETROSPECTIVE
  • Wednesday, January 22 TIME FOR ADAPTATION ACTION
  • Friday, January 10 EAST COAST FLOODS 2022 (0)
2019 (29)
  • Monday, December 30 Parsley Bay in the Summer
  • Monday, November 25 Australian Coastal Systems: A New Book from Andy Short
  • Tuesday, November 19 South Australian 2019 Coastal Conference and the ACS AGM
  • Wednesday, November 6 28th Annual NSW Coastal Conference – Terrigal, 2019
  • Sunday, October 27 Coastal Incidents
  • Tuesday, October 8 Coastal morphostratigraphy: two papers from Denmark
  • Friday, September 27 Climate Change Attribution
  • Tuesday, September 10 Vale Jack Davies at age 97 – leader, teacher and mentor
  • Wednesday, September 4 Coastal erosion and accretion beyond the historical timescale in NSW
  • Monday, August 19 Rethinking Landscape in Aotearoa
  • Friday, August 2 Collaborative Science and Coastal Adaptation
  • Saturday, July 20 CLIMATE CHANGE AND RELATIVITY – SOME PARALLELS
  • Sunday, July 14 DOUGLAS W. JOHNSON 1919 AND BEYOND
  • Tuesday, July 2 The Sandiford Line
  • Saturday, June 22 A Curiosity of Cusps
  • Monday, June 3 Federal Election 2019 and Coasts
  • Monday, May 13 Mangrove Generations
  • Sunday, May 5 John Sinclair of K’Gari (Fraser Island) 1939 – 2019
  • Monday, April 22 The Mighty Ord
  • Thursday, March 28 Climate change adaptation: perspectives from Canada and England
  • Monday, March 18 Foreshore land grants in eastern Sydney
  • Friday, March 15 The right to bath on the beach
  • Wednesday, March 6 Victorian Coastal Monitoring Program
  • Thursday, February 21 Future national need for a healthy environment
  • Wednesday, February 13 ANZGG CONFERENCE AT INVERLOCH, VICTORIA
  • Wednesday, February 6 Coastal science and the Murray River mouth
  • Saturday, February 2 INDIA COASTAL MANAGEMENT
  • Tuesday, January 15 Sydney Harbour Sea Fog – Summer of 2018/2019
  • Saturday, January 5 COASTAL RESILIENCE AND ADAPTATION
2018 (31)
  • Monday, December 17 CLIFF-TOP DUNES
  • Saturday, December 15 The whereabouts of climate change adaptation
  • Sunday, December 2 Observations from a long time marine debris collector.
  • Sunday, December 2 Backbarrier flats – a relic coastal landform
  • Monday, November 19 King Tides in Venice
  • Wednesday, November 14 27TH NSW COASTAL CONFERENCE 2018
  • Monday, November 12 Is the coast losing out with NRM? Proposed changes for South Australia
  • Saturday, November 3 Slicks (Part 2)
  • Tuesday, October 16 Twofold Bay – A Great Coastal Laboratory
  • Sunday, October 7 VALE: Professor John Chappell FAA (1940-2018)
  • Thursday, September 27 Coasts and Legal Systems
  • Sunday, September 16 Moods of Sydney Harbour
  • Sunday, August 26 Community Consultation
  • Saturday, August 18 Managing water quality through regenerative agriculture
  • Friday, August 3 Tomorrow’s Coasts – Complex and Impermanent
  • Thursday, July 12 Murray-Darling Basin Royal Commission
  • Monday, July 2 New South Wales Coastal Reforms – NSW Coastal Council’s first meeting
  • Tuesday, June 26 Victoria’s Coastal Reforms – ‘fit for purpose’ or an opportunity lost?
  • Wednesday, June 20 New SA Government promises improved coastal management
  • Thursday, June 14 OCCUPATION OF THE AUSTRALIAN CONTINENTAL SHELF
  • Wednesday, May 30 National Budgets – Some Thoughts
  • Wednesday, May 16 Guiding Principles for Marine and Coastal Management
  • Friday, May 4 Last Interglacial Marine Deposits at Mary Ann Bay, Tasmania
  • Sunday, April 29 Coast to Coast Hobart 2018
  • Thursday, April 5 Coastal Reforms in New South Wales – The Next Stage
  • Monday, March 26 Coastal Archaeology
  • Monday, March 12 Barrier Islands – An American Obsession?
  • Monday, February 26 Climate Change Adaptation in Australia – A Loss of Momentum
  • Thursday, February 15 Bruce Thom Blog – SUMMERAMA
  • Wednesday, January 31 King tides and extreme events
  • Sunday, January 14 Coastal Geomorphology 101
2017 (39)
  • Friday, December 29 Bruce Thom Blog – Speaking Truth to Power
  • Wednesday, December 20 National Surfing Reserves
  • Thursday, December 14 Beachrock
  • Saturday, December 9 Higher Tides
  • Monday, December 4 Keeping the Murray Mouth open
  • Monday, November 27 Victorian Coastal Management in 2017
  • Thursday, November 16 26th NSW Coastal Conference at Port Stephens
  • Thursday, October 26 Ancestral rivers and terraces
  • Monday, October 16 Murray Valley: a recent visit
  • Wednesday, October 11 The National Construction Code and coastal planning
  • Tuesday, September 19 Geomorphic evolution of Coorong, Lower Lakes and Murray Mouth
  • Wednesday, September 13 Queensland Coastal Conference 2017 – Ten years in the making
  • Tuesday, September 5 Hurricane Harvey and its implications
  • Friday, September 1 Gippsland (Victoria) and relative sea level rise
  • Sunday, August 27 US Office of Naval Research and the Australian Coast
  • Monday, August 21 Managing the unique wetlands of Gippsland Lakes
  • Thursday, August 10 Lifecycle of coastal environmental law
  • Friday, July 28 Charlie Veron – A Life Underwater
  • Sunday, July 23 Coastal Sediment Management
  • Friday, July 7 Coastal walks -Malabar Headland National Park, Sydney
  • Friday, June 30 Honeycomb Weathering
  • Friday, June 23 Disaster preparedness
  • Wednesday, May 31 Sept-Iles: Managing a migrating foreland
  • Wednesday, May 24 Achievements of the National Climate Change Adaptation Research Facility
  • Saturday, May 13 Coastal Shacks
  • Wednesday, April 26 Empress Augusta Bay, Bougainville
  • Thursday, April 20 The Blue Mud Bay case – Aboriginal property rights in the Northern Territory
  • Tuesday, April 4 Botany Bay Sands
  • Saturday, March 25 Wave Energy Resource
  • Wednesday, March 15 Clustering of Storms
  • Wednesday, March 15 Cape to Cape: A voyage around Botany Bay
  • Tuesday, March 7 The “Venice Effect”
  • Monday, February 27 Port Stephens Bioherms
  • Thursday, February 9 Coast Ambassadors
  • Friday, February 3 Coastal Graphics
  • Tuesday, January 31 Irukandji on the move
  • Tuesday, January 24 Acceleration in mean sea level
  • Wednesday, January 11 Concerns of an American coastal scientist under a Trump presidency
  • Sunday, January 8 EXTREME STORM EVENTS IN THE USA, AUGUST-SEPTEMBER 2021
  • About us
  • Get involved
  • News and events
  • Resources
  • Blog
  • Contact us

Banner Photography by Pixabay

© 2023 Australian Coastal Society. All Rights Reserved.

  • Facebook
  • Twitter
  • Mail
  • LinkedIn