Tuesday, November 30, 2021

Ancient advanced Chinese civilisation ‘was wiped out by climate change’


Rob Waugh
·Contributor
Mon, November 29, 2021

Liangzhu City in Hangzhou in China's eastern Zhejiang province
 (Photo by - / AFP) / China OUT (AFP via Getty Images)

A highly advanced Chinese civilisation referred to as "China's Venice of the Stone Age" was wiped out in a sudden collapse triggered by climate change, new research has shown.

A highly advanced culture blossomed about 5300 years ago in China’s Yangtze delta, which is considered to be one of the earliest proofs of monumental water culture.

The walled city had a complex system of navigable canals, dams and water reservoirs. This system made it possible to cultivate very large agricultural areas throughout the year.

But it collapsed abruptly, and scientists now believe it was caused by a rapid change in climate.

Christoph Spötl, head of the Quaternary Research Group at the Department of Geology at the University of Innsbruck says, "A thin layer of clay was found on the preserved ruins, which points to a possible connection between the demise of the advanced civilisation and floods of the Yangtze River or floods from the East China Sea.

“No evidence could be found for human causes such as warlike conflicts. However, no clear conclusions on the cause were possible from the mud layer itself."

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Geologist Haiwei Zhang from Xi'an Jiaotong University in Xi'an, took samples of stalagmites from the two caves Shennong and Jiulong, which are located southwest of the excavation site.
 

Liangzhu City in Hangzhou in China's eastern Zhejiang province (AFP via Getty Images)

Christoph Spötl of Innsbruck University says, "These caves have been well explored for years. They are located in the same area affected by the Southeast Asian monsoon as the Yangtze delta and their stalagmites provide a precise insight into the time of the collapse of the Liangzhu culture, which, according to archaeological findings, happened about 4300 years ago.”

Data from the stalagmites show that between 4345 and 4324 years ago there was a period of extremely high precipitation.

Evidence for this was provided by the isotope records of carbon, which were measured at the University of Innsbruck.

The precise dating was done by uranium-thorium analyses at Xi'an Jiaotong University, whose measurement accuracy is plus or minus 30 years.

"This is amazingly precise," says the geologist. "The massive monsoon rains probably led to such severe flooding of the Yangtze and its branches that even the sophisticated dams and canals could no longer withstand these masses of water, destroying Liangzhu City and forcing people to flee."

The very humid climatic conditions continued intermittently for another 300 years, as the geologists show from the cave data.

In the history of human civilisation, this is one of the first examples of highly developed communities based on a water infrastructure. Metals, however, were still unknown in this culture.

Thousands of elaborately crafted jade burial objects were found during excavations.

Liangzhu was declared a UNESCO World Heritage Site in 2019. However, the advanced civilisation of this city, which was inhabited for almost 1000 years, came to an abrupt end. Until today, it remains controversial what caused it.

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