Archaeologists map hidden NT landscape where first Australians lived more than 60,000 years ago

Red Lily Lagoon in West Arnhem Land is an important archaeological landscape with significant implications for understanding the First Australians

FLINDERS UNIVERSITY

Red Lily Lagoon Modern Day — IMAGE: RED LILY LAGOON MODERN DAY VISUALISATION. CREDIT: DR JARRAD KNOWLESSAR, FLINDERS UNIVERSITY RESEARCH ASSOCIATE. view more
CREDIT: DR JARRAD KNOWLESSAR, FLINDERS UNIVERSITY RESEARCH ASSOCIATE.

Scientists at Flinders University have used sub-surface imaging and aerial surveys to see through floodplains in the Red Lily Lagoon area of West Arnhem Land in Northern Australia.

These ground-breaking methods showed how this important landscape in the Northern Territory was altered as sea levels rose about 8,000 years ago.

Their discovery shows that the ocean had reached this, now inland region, which has important implications for understanding the archaeological record of Madjedbebe—the oldest archaeological site in Australia.

The findings also provide a new way to understand the rock art in the region, which is recognised globally for its significance and distinctive style.

By examining how sediments now buried beneath the flood plains changed as sea levels rose, the researchers can see how the transformation of Red Lily Lagoon had resulted in the growth of mangroves that have supported animal and marine life in a region where ancient Indigenous rock art is located. This transformation has, in turn, fostered an environment that has inspired the subjects and animals in the ancient rock art.

In their findings published in in the scientific journal PLOS ONE today, the researchers say environmental changes at the lagoon are reflected in the rock art because fish, crocodiles and birds were featured in the art when the floodplain transformed to support freshwater habitats for new species.

Senior Author and Research Associate in the College of Humanities, Arts, and Social Sciences at Flinders University, Dr Jarrad Knowlessar, says the mapping fundamentally changes our archaeological understanding of the stunning landscape in Arnhem Land.

"This is a key landscape for understanding the early human occupation of Australia. Our reconstruction of Red Lily Lagoon enables effective predictive modelling of prominent cultural sites and provides an important method to interpret the presence and provenance of Indigenous cultural material."

"The timing of rock art aligns with the broader environmental changes we understand took place in this landscape. This is evident through changes in subject matter in the art, such as large macropods, and the appearance of estuarine animal species such as fish and crocodiles in the art. The inclusion of freshwater species, such as fish and birds, occurs in the most recent artistic styles of this region, and this reflects the phases of environmental change when the freshwater floodplains made up the landscape."

"Based on the results of this study, all Pleistocene sites in western Arnhem Land were near the ocean and, subsequently, mangrove swamps at some point during the transformation of the landscape. This has important implications for the paleogeographic settings of these sites, which must be considered when interpreting changes in stone artefacts, food resources, and the isotope composition of materials from this period of the first Australians."

Co-author, Associate Professor Ian Moffat, says Electric Resistivity Tomography (ERT) is a rapid, low-cost, non-invasive method that can map large areas of the Australian landscape to better understand their ancient history.

"We are showcasing how ERT data can be used to develop landscape models that are useful when it comes to understanding known locations as well as predicting where buried archaeological sites might be. We have demonstrated that the landscapes of this region can be effectively mapped using non-invasive methods. This has important implications for locating new sites but also for developing a more nuanced understanding of the regional geography, and its impact on past human behaviour."

"Red Lily Lagoon has exceptional archaeological significance in Arnhem Land as it is situated at one of the easternmost points of the East Alligator River floodplain, where the modern river, the Arnhem Plateau, creates a significant boundary between the low-lying floodplains and the sandstone highlands, which have been occupied by humans for over 60,000 years and are the location of countless significant sites, including some of the most iconic rock art panels in Australia."

Traditional owner and co-author Alfred Nayinggull described the importance of this research as “We want people to see and want people to know what’s been happening many thousand years ago in the past. “

The new PLOS ONE paper “Reconstructing archaeological palaeolandscapes using geophysical and geomatic survey techniques: An example from Red Lily Lagoon, Arnhem Land, Australiais will be available at https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0283006.

Red Lily Lagoon Modern Day Visualisation 2. Credit: Dr Jarrad Knowlessar, Flinders University Research Associate.

Red Lily Lagoon Pleistocene (Ice age) 9,000 years ago visualisation. Dr Jarrad Knowlessar, Flinders University Research Associate.

Red Lily Lagoon Pleistocene (Ice age) 9,000 years ago visualisation 2. Dr Jarrad Knowlessar, Flinders University Research Associate.

Sea level flooding - Mangroves Image. Dr Jarrad Knowlessar, Flinders University Research Associate.

Sea level flooding at Red Lily Lagoon area. Credit: Dr Jarrad Knowlessar, Flinders University Research Associate.

Sea level flooding 2. Credit: Dr Jarrad Knowlessar, Research Associate at Flinders University.

JOURNAL

PLoS ONE

DOI

10.1371/journal.pone.0283006

METHOD OF RESEARCH

Survey

ARTICLE TITLE

Reconstructing archaeological palaeolandscapes using geophysical and geomatic survey techniques: An example from Red Lily Lagoon, Arnhem Land, Australiais

ARTICLE PUBLICATION DATE

4-May-2023

Research reveals longstanding cultural continuity at oldest occupied site in West Africa

Peer-Reviewed Publication

MAX PLANCK INSTITUTE OF GEOANTHROPOLOGY

stone tool — IMAGE: A CORE FROM THE MIDDLE STONE AGE STONE TOOL ASSEMBLAGE FROM BARGNY 1 view more
CREDIT: KHADY NIANG

Evidence from West Africa about human evolution remains scarce, but recent research has indicated unique patterns of cultural change in comparison to other regions of the continent. A new article in the journal Nature Ecology and Evolution adds to our understanding with a study of the oldest directly dated archaeological site in West Africa. The site shows technological continuity spanning roughly 140,000 years and offers insights into the ecological stability of the region.

Our species emerged in Africa around 300 thousand years ago and until around 30-60 thousand years ago typically used tools and tool-making techniques referred to as Middle Stone Age toolkits. Around that time, distinct Later Stone Age toolkits began to emerge in northern, eastern, and southern Africa. While recent evidence suggests Middle Stone Age toolkits persisted in West Africa much later, to around 10 thousand years ago, the antiquity of these technologies is poorly understood.

The new study, led by scientists from the Max Planck Institute of Geoanthropology, Université Cheikh Anta Diop de Dakar, University of Sheffield, and University of South Florida, extends the timeframe in which Middle Stone Age toolkits are known from West Africa to 150 thousand years ago, based on excavations from the near-coastal site of Bargny 1.

“The stone tool assemblage dating from 150 thousand years ago shows classic features of the Middle Stone Age, with the use of Levallois and discoidal reduction methods and the use of small retouched flake tools rather than larger implements,” says Dr Khady Niang, lead author of the study. “The assemblage from Bargny 1 is closely comparable to those of a similar age from across the continent, and is the first site from West Africa dating to the Middle Pleistocene, prior to the onset of substantial technological regionalization elsewhere in Africa.”

The site itself is located close to the modern coastline, south of Dakar, Senegal. While no artefacts indicating direct human engagement with coastal resources were recovered at the site, study of the associated environments offer a wider perspective.

“We found mangrove and brackish wetland plant microfossils associated with the site’s occupation,” adds Dr Chris Kiahtipes of the University of South Florida, co-author on the study. “This is particularly interesting because it shows that the site was located near an estuary and demonstrates how important these habitats are to humans past and present.”

The study highlights long-term durability of core elements of Middle Stone Age toolkits in West Africa without evidence for the appearance of specialized technological developments observed elsewhere.

“Middle Stone Age populations adapted to a wide range of habitats and engaged with climatic changes across Africa. But in West Africa, we see considerable environmental stability over the past 150 thousand years,” adds Dr Jimbob Blinkhorn. “One explanation for the enduring cultural continuity we observe is that it was a stable behavioural adaptation to stable environmental conditions, whilst potential isolation from other populations across Africa may have led to demographic stability too. Ultimately, our study helps illustrate the persistent utility of Middle Stone Age technologies to inhabit the diverse habitats found across Africa.”

150-thousand-year-old sediments at Bargny 1 that contain West Africa’s oldest Middle Stone Age toolkits

CREDIT

Jimbob Blinkhorn

Pollen from the Bargny 1 including Avicennia (top) and Typha (bottom), that demonstrate the proximity of the site to estuary environments in the past. Scale is 25 microns.

CREDIT

Chris Kiahtipes