Stalagmites in caverns located southwest of the excavation website show a climatic cause for the collapse of the ancient Chinese Liangzhu culture. Credit: Haiwei Zhang
Referred to as “Chinas Venice of the Stone Age,” the Liangzhu excavation site in eastern China is considered one of the most substantial testimonies of early Chinese innovative civilization. More than 5000 years earlier, the city currently had a sophisticated water management system. Previously, it has actually been questionable what led to the sudden collapse. Enormous flooding triggered by anomalously extreme monsoon rains caused the collapse, as a worldwide group with Innsbruck geologist and environment scientist Christoph Spötl has actually now displayed in the journal Science Advances.
In the Yangtze Delta, about 160 kilometers southwest of Shanghai, the archeological ruins of Liangzhu City are situated. There, a highly advanced culture blossomed about 5300 years ago, which is thought about to be among the earliest evidence of monumental water culture.
The oldest evidence of big hydraulic engineering structures in China stems from this late Neolithic cultural website. The walled city had a complicated system of navigable canals, dams, and water reservoirs. This system made it possible to cultivate extremely big agricultural locations throughout the year.
Long undiscovered and underestimated in its historical significance, the archaeological site is now thought about an unspoiled record of Chinese civilization dating back more than 5000 years. They enable the restoration of climatic conditions above the caves up to a number of 100,000 years into the past. Because it is still not clear what caused the sudden collapse of the Liangzhu culture, the research study group browsed for suitable archives in order to examine a possible climatic cause of this collapse.
Data from the stalagmites reveal that between 4345 and 4324 years ago there was a period of exceptionally high rainfall. The really humid climatic conditions continued intermittently for another 300 years, as the geologists reveal from the cavern data.
In the history of human civilization, this is one of the very first examples of extremely established neighborhoods based on a water infrastructure. Metals, nevertheless, were still unknown in this culture. Thousands of elaborately crafted jade burial objects were discovered throughout excavations.
Long undiscovered and undervalued in its historic significance, the historical site is now considered a well-preserved record of Chinese civilization dating back more than 5000 years. The advanced civilization of this city, which was inhabited for practically 1000 years, came to an abrupt end.
” A thin layer of clay was discovered on the preserved ruins, which indicates a possible connection between the death of the advanced civilization and floods of the Yangtze River or floods from the East China Sea. No proof might be found for human causes such as aggressive conflicts,” describes Christoph Spötl, head of the Quaternary Research Group at the Department of Geology. “However, no clear conclusions on the cause were possible from the mud layer itself.”
Dripstones store the answer
Caverns and their deposits, such as dripstones, are among the most essential climate archives that exist. They permit the restoration of climatic conditions above the caverns up to several 100,000 years into the past. Because it is still unclear what triggered the sudden collapse of the Liangzhu culture, the research study team looked for ideal archives in order to examine a possible climatic reason for this collapse.
Geologist Haiwei Zhang from Xian Jiaotong University in Xian, who invested a year at the University of Innsbruck as a going to researcher in 2017, took samples of stalagmites from the 2 caves Shennong and Jiulong, which are situated southwest of the excavation site.
” These caverns have been well checked out for many years. They lie in the very same location affected by the Southeast Asian monsoon as the Yangtze delta and their stalagmites provide an accurate insight into the time of the collapse of the Liangzhu culture, which, according to historical findings, happened about 4300 years back,” Spötl describes.
Information from the stalagmites reveal that in between 4345 and 4324 years ago there was a period of incredibly high precipitation. Proof for this was offered by the isotope records of carbon, which were determined at the University of Innsbruck. The exact dating was done by uranium-thorium analyses at Xian Jiaotong University, whose measurement precision is ± 30 years.
” This is astonishingly precise in light of the temporal measurement,” says the geologist. “The huge monsoon rains probably caused such extreme flooding of the Yangtze and its branches that even the sophisticated dams and canals might no longer withstand these masses of water, ruining Liangzhu City and forcing individuals to get away.” The really humid climatic conditions continued periodically for another 300 years, as the geologists reveal from the cavern data.
Recommendation: “Collapse of the Liangzhu and other Neolithic cultures in the lower Yangtze area in response to environment change” 24 November 2021, Science Advances.DOI: 10.1126/ sciadv.abi9275.
