Feature Follow-up: Stratigraphy Reveals Complex Flooding and Migration

Professor T.R. Kidder (featured in the June issue) recently returned from Sanyangzhuang, China. Each trip reveals new insights to buried, but well-preserved, farming villages there.

Research at Sanyangzhuang, China, reveals that flooding and subsequent resettling of the area have occurred at least five times over the last 5,000 years. (Courtesy Photo)

When anthropology and environmental science Professor T.R. Kidder was first asked to join an excavation team digging up the remains of a 2,000-year-old Chinese village, he was ecstatic about the opportunity to learn about an ancient civilization.

At the time, he could not have known that he’d get the chance to view not one village, but five different layers, signifying multiple occupations in the same area over thousands of years.

Multiple floods

Kidder and the other researchers at the site in Sanyangzhuang, China, once thought that the nearby Yellow River suddenly flooded some 2,000 years ago, perfectly preserving a rural, relatively wealthy farming town in a layer of sediment. Further work revealed multiple layers of flooding from the Yellow River dating back 10,000 years ago. And this summer, they discovered the pattern of flooding — especially after the Han occupation — was much more complex.

Humans colonized the area about 5,000 years ago during Neolithic times. Research indicates that after the Neolithic community was flooded, which took place between 5,000–3,800 years ago, people resettled in the area. The next occupation was then subsequently flooded and preserved in another layer of sediment. The whole process of resettling and flooding happened no fewer than five times.

The Han flood entombed the community at Sanyangzhuang, but the researchers were not certain how quickly the flood happened or its effects over a large area. “It’s definitely more complicated than we expected,” Kidder says. “We have a chance to find more human occupation buried within the sediments following the Han Dynasty. But in some ways we confirmed what we suspected, which is there’s a very large area that’s been buried and extremely well-preserved.”

The Han Dynasty ruled China between 206 B.C. and A.D. 220, a time considered to be a Golden Age in Chinese history.

Within the layers

Liu Haiwang, senior researcher at China’s Henan Provincial Institute of Cultural Relics and Archaeology, learned about the site in 2003 when the Chinese government was digging irrigation ditches. The excavation kept getting interrupted by machinery hitting roof tiles and even walls.

Since then, Kidder and Liu have concentrated their work on rural houses (termed compounds) that existed in the Han period. They are buried about 5 meters (16.4 feet) below the surface.

“Their material culture is rich and abundant. These people are not living in mud huts, but in well-built houses with ceramic roofs, nice latrines and wells that were deeply dug,” Kidder says. He also has dug up bronze tools and pottery and can see that there was a gender division of labor, with women doing sewing and weaving.

The research team also has found the remains of agricultural fields that indicate the people in the Han layer grew wheat and other crops.

“We’re pretty convinced that these peoples had a complicated economy,” says Kidder, noting that the rural villages had to trade with other villages many miles away to get bronze. “This was a time when the Han Dynasty was at a zenith, and rural life was certainly by modern Chinese standards quite comfortable.”

Kidder suspects these people lived at a time of peace. No walls have been found around the rural compounds, meaning there was little need for protection. Further, this may mean the walled town nearby dates to an earlier time.

This summer, researchers hoped to excavate that walled town near the original excavations. But Kidder and the team are not yet ready to start analyzing the anthropological aspects of the town. They’re still studying the layers in the sediment — provided by new excavations of irrigation ditches — to date them and to get a better picture of the flooding.

“Because they’re digging these new irrigation ditches deeply, down to five meters, we can see the stratigraphy clearly in the walls,” Kidder says.

Right now, researchers think people lived there 900 years ago; 1,800 years ago; 1,985 years ago; 2,600 years ago; with the bottom cultural layer representing 5,000 years ago.

“So, for whatever reason, people keep coming back to this locality. “Whether they’re the same people or descendants from the original people, we don’t know,” Kidder says.

The oldest layer, dating back 5,000 years, is about 25 feet underground, and it preserves the furrows of a field from the Late Neolithic/Early Bronze Age.

“If their communities and the rest of their fields are as well-preserved, we’ll have a glimpse at daily life back to 4,000 years ago, and that would be pretty exceptional,” Kidder says.

Enthusiasm spreads

Kidder was not alone studying stratigraphy this summer. He brought along graduate student Michael Storozum. This was the second time Kidder was able to take a graduate student with him.

Because he enjoys working with students, Kidder would welcome involving undergraduates in the excavation but is unsure if he can make such arrangements with the Chinese government.

“If, at some point, we’re able to involve them more, it would be wonderful,” Kidder says. “Undergraduate students at Washington University are hardworking, diligent and, obviously, very capable.”

Now that Kidder knows there are so many layers in the sediment, he predicts that the project will last for years. And he’s OK with that.

“It’s just been a blast to do all this stuff,” he says.

Michelle Merlin, Arts & Sciences Class of ’12, is a summer writing intern in University Marketing & Design.

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