Exploring the Ruins of Chicken Crow City in Lixian County, Hunan Province

  A glimpse into prehistoric human construction skills from a mansion built 4,700 years ago

  As one of the top ten new archaeological discoveries in the country in 2021, the Neolithic site in Li County, Changde City, Hunan Province, the Jijiaocheng Site, has a very special discovery: this is a Qujialing built more than 4,700 years ago. During the cultural period, it is a large-scale "mansion" with a total area of ​​420 square meters and a total area of ​​630 square meters.

Archaeologists believe that the house, numbered F63, is the earliest and most complete remains of wooden buildings in China, and its volume, scale and construction method are unprecedented.

  A few days ago, reporters from the West China Metropolis Daily and the cover news "Archaeology China" reporting group came to the site of Jijiaocheng to touch the life fragments of prehistoric people through the foundations and wooden pillars buried for 4,700 years.

 "Exquisite" mansion

  The first time the F63 building remains revealed the "tip of the iceberg" was in 1998.

At that time, in order to confirm the age of the site, the staff of the Hunan Provincial Institute of Cultural Relics and Archaeology conducted an autopsy on the west wall of the Jijiaocheng site and found some wooden components, but due to the area of ​​​​the excavation, they could not judge their nature at that time.

In 2006, it was excavated again, because the excavation area was limited and the puzzle was still not solved.

Until 2018, when the archaeological work was resumed at the Jijiaocheng site, from October 2020, the project leader Guo Weimin, the executive team leader Fan Xianjun and other archaeologists excavated 4 times before and after, and it took a year to reveal the whole picture of F63.

  Judging from the remaining foundations and wooden components, F63 has a clear structure, with five bays and seven rooms plus peripheral corridors, with a total area of ​​630 square meters.

In terms of construction method, F63 lays narrow and long wooden boards in the excavated foundation groove, builds the foundation and then erects wooden pillars, so that the house is more stable and not easy to sink.

  In mid-July, Fan Xianjun said in an interview with reporters: "Perforations have been found on well-preserved wooden pillars, most of which are oblique perforations with an inward angle of about 45 degrees on both sides. There are currently two speculations about the role of perforations. It is believed that sticks are inserted and fixed with ropes to form a triangular structure to make the foundation of the house more stable.

  Guo Weimin still remembers the joy of discovering F63, "I have never seen it before. This house provides important information for understanding the prehistoric architectural forms and technologies in the Yangtze River Basin."

 Uncover the truth layer by layer

  The excavation of F63 took a whole year, the excavation area is large, and the rich cultural accumulation is superimposed above, which makes the excavation more difficult.

  Due to the long-term and continuous human activities at the Jijiaocheng site, people of different ages left traces here, so during the excavation process, archaeologists should distinguish the accumulation of different ages according to different soil layers.

"The above piles are definitely older than the ones below, so we can judge their relative age by typological comparison based on the relics unearthed in the piles that were superimposed and broken by it."

  In Fan Xianjun's view, the most difficult part of excavating the F63 is to uncover its layers.

There are more than 50 exploration squares in the excavation area where F63 is located (the excavation area is divided into several equal squares, and the squares are used as the unit to divide the labor for excavation. These squares are called "exploration squares"), the top is complicated and the remains are There are many, and it is necessary to unify the horizons and number them during the excavation process. The situation of each exploration party is different. It is very challenging to maintain synchronous excavation, and to record and protect them in time.

 key rope

  In the process of gradually uncovering the upper layers, the age of F63 is always a concern of archaeologists.

  Guo Weimin said: "There are several very important periods at the Jijiaocheng site. In the early days, the ring trench was excavated and a large amount of grain chaff was accumulated after the ring trench was abandoned. A trench was dug on top of it, and wooden boards were laid in it. Large-scale houses are built, these are very critical ages, in addition to the preliminary relative age judgment of archaeology, more accurate scientific methods such as carbon 14 should be used to detect."

  Fortunately, the archaeological team found three ropes, which became the key to pinpointing the date of F63.

Guo Weimin explained: "There are rattan ropes and bamboo ropes in the three ropes. Unlike other woods, vines and bamboos have relatively short growth and survival periods, so the age of these ropes is basically representative of the construction of the house. Era."

  To this day, Fan Xianjun still remembers how he felt when he discovered the rope, "I was surprised and surprised to see such a well-preserved rope at that time. The rope was used to lift the wooden board, and one of them was directly nested under the wooden board. Small grooves were also chiseled, which shows that it must have been used in construction. It is not easy to keep these ropes, on the one hand, it can be used to detect the construction age of the house, and on the other hand, it can also understand the weaving process at that time.”

  After a number of data research and testing, archaeologists have come to a more accurate conclusion that F63 was built in the Qujialing Culture period about 4,700 years ago.

 a public event place

  The area of ​​F63, which has been excavated, is larger than a basketball court. The main body of the house is rectangular, and there are corridors on the periphery. The shape is square and the structure is clear.

"This house is too important. Its volume, structure and construction method are unprecedented, and it can reveal a lot of information." Guo Weimin said.

  The first is the construction method. A long foundation groove is dug out on the foundation of the F63, and wood boards of the same size are laid in the foundation groove. On the wood boards are the pillars of the house. , this way of building is very unique.

The remaining foundation can clearly see the structure of the house. There are a total of 5 bays. Except for the easternmost bay with a larger area, the remaining 4 are completely symmetrical, which is in line with the construction habits of late Chinese architecture.

  Most of the wooden pillars used in the construction of F63 are fifty or sixty centimeters in diameter, and the large ones are even one meter. The wood is mainly nanmu and camphor.

Fan Xianjun said: "This shows that people at that time had a certain knowledge reserve about the choice of wood and tree species, because there must be many kinds of trees on the surrounding mountains, and they chose the most suitable nanmu for construction. In addition, the wood processing technology at that time was very mature. , they have the ability to cut down such thick trees, polish the boards used for laying the foundation square, and the wooden pillars are also in two halves, and the flat side is turned out to make it very beautiful. These require very mature tools and technology." The unearthed stone axes and chisels also corroborated their conjectures.

  In Guo Weimin's view, prehistoric archaeology is like a jigsaw puzzle, piecing together the picture of human life at that time through the excavated fragments.

A large building like F63, completed by many labors, must be public.

"This is obviously not a house where ordinary families live. We think it may be a place for public events, and the user may be the supreme ruler of the social organization."

  West China Metropolis Daily - Cover reporter Hao Ying Yang Feng reported from Changde, Hunan