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South Australia's Naracoorte Caves is one of the world's best fossil sites, containing a record spanning more than half a million years. Among the remains preserved in layers of sand are the bones of many iconic Australian megafauna species that became extinct between 48,000 and 37,000 years ago.The reasons for the demise of these megafauna species are intensely debated. But the older the fossils we can find, the better we can understand the species' evolution and extinction.To date, determining the precise age of the caves has been difficult. However our research demonstrates, for the first time, how old Naracoorte's caves...

Extreme dry conditions contributed to the decline of the ancient South Arabian kingdom of Himyar... the droughts left behind a region in disarray, thereby creating the conditions on the Arabian peninsula that made possible the spread of the newly emerging religion of Islam.On the plateaus of Yemen, traces of the Himyarite Kingdom can still be found today: terraced fields and dams formed part of a particularly sophisticated irrigation system, transforming the semi-desert into fertile fields. Himyar was an established part of South Arabia for several centuries.However, despite its former strength, during the sixth century AD the kingdom entered into a...

The Liangzhu excavation site, on the Yangtze River Delta, southwest of Shanghai in China, is home to the remains of a 5,300-year-old civilisation. Liangzhu City was once an advanced culture, with hydraulic infrastructure including dams, reservoirs and canals. Despite not having metals, the Neolithic people of Liangzhu operated a complex water system that allowed agriculture to flourish. There is still much to learn about Liangzhu, which was only declared a UNESCO World Heritage Site in 2019. It was inhabited for 1,000 years, but it’s still not entirely clear what caused the city’s downfall, which was thought to be abrupt... Moisture...

..............After drilling into the stalagmites and pulling out cylinders of rock, the team could see an obvious transition between two layers. On one side were old minerals that were part of the original stalagmites; on the other were newer layers that had been laid down after the fragments were broken off by the cave’s former users. By measuring uranium levels on either side of the divide, the team could accurately tell when each stalagmite had been snapped off for construction. Their date? 176,500 years ago, give or take a few millennia.

A close up of one of the stalagmites analyzed in the study. Credit: Jud Partin When Georgia Tech Assistant Professor Kim Cobb and graduate student Jud Partin wanted to understand the mechanisms that drove the abrupt climate change events that occurred thousands of years ago, they didn't drill for ice cores from the glaciers of Greenland or the icy plains of Antarctica, as is customary for paleoclimatolgists. Instead, they went underground. Growing inside the caves of the tropical Pacific island of Borneo are some of the keys to understanding how the Earth's climate suddenly changed - several times -...

Reference Paulsen, D.E., Li, H.-C. and Ku, T.-L. 2003. Climate variability in central China over the last 1270 years revealed by high-resolution stalagmite records. Quaternary Science Reviews 22: 691-701. What was done In the words of the authors, "high-resolution records of ð13C and ð18O in stalagmite SF-1 from Buddha Cave [33°40'N, 109°05'E] are used to infer changes in climate in central China for the last 1270 years in terms of warmer, colder, wetter and drier conditions." What was learned Among the climatic episodes evident in the authors' data were "those corresponding to the Medieval Warm Period, Little Ice Age and...