Archaeological excavation of Han-Ming ancient site in Suning square

       Suning square urban complex is a key urban construction project of Xuzhou municipal government. It is located to the east of Pengcheng Road, the south of Heqing Road, the north of Huaihai Road and the west of Jiefang Road in Xuzhou City. It covers an area of more than 40000 square meters. The project is located in the center of the old city of Xuzhou, which has been designated as the key cultural relics burial area of Xuzhou. According to the literature records and the excavation in the old city of Xuzhou over the years, there are abundant cultural relics in the ancient site of Suning square. Therefore, since the excavation of the foundation pit of Suning square project in August 2012, Xuzhou Museum has continued to carry out rescue archaeological excavation. The excavation adopts two methods, namely follow-up cleaning and exploration cleaning. The actual excavation area is about 600 square meters (plate I, area B exploration).

       1、 Stratigraphic accumulation

       Taking the south wall of TG1 as an example, the cultural layer can be divided into 14 layers except the arable soil layer and silt layer (the silt layer is about 6m thick), as follows:

       There are 1-5 layers, which are black and loose deposit layer of Ming Dynasty, including a large number of humus and ashes. They are continuously distributed in the excavation area of the site, about 2 meters thick. The earth objects mainly include porcelain, stone tools, tiles, iron, bronze, coins, pottery, etc. The bottom layer is deposited in Ming Dynasty

       There are 6-10 layers of yellowish brown hard bottom layer, which are distributed successively in the site. The soil objects mainly include blue (white) porcelain,  ironware, coins, etc.; the shape of the utensil mainly includes shallow bowl with supporting foot, engraved pattern plate, etc.; this layer is about 1.5m thick, which is accumulated in Tang and Song dynasties.

       11-13 layers, light yellow brown, loose soil, including rope pattern tiles, shells, etc., coarse sand greenish ceramic pieces, gray pottery pots, etc.,  the layer is 0.20-0.30 m thick is the stratum accumulation from the pre-Tang Dynasty to Han Dynasty .

The 14th layer is yellowish brown, with loose soil. The unearthed objects mainly include tiles, shells, bricks, and fragments of glazed pottery. The depth is 11.1-11.45m, and the thickness is about 0.30-0.40m. This layer is the Eastern Han Dynasty.

The 15th layer is grayish brown with slightly hard soil. The unearthed relics are mainly slate, cylinder tile, brick and some fragments of grey pottery, 11.5-12.4m deep. This layer was the Western Han Dynasty. The following is raw soil.

       2、 Main collection

A total of 45 pits, 7 houses, 7 water wells and 1 drum-tower building relic were found and cleaned in each dynasty. A large number of more than 2000 pieces of cultural relics, such as blue and white porcelain, blue porcelain, stone missiles , stone cannonball, silk and hemp fabrics, were unearthed. The most important discovery of this excavation is that the remains of the wall of the Western Han Dynasty were found 10.8 meters below the surface of the earth. In addition, the steles of Wang Yan's morality and politics in the Five Dynasties and the Confucian temple steles of "the restoration of Xuansheng temple in Xuzhou" in the Ming Dynasty were also unearthed. They are described as follows.

       （1） Wang Yan's stele is about 7 meters away from the earth's surface. The body and seat of the stele are found. The body of the stele is rectangular, the upper end is incomplete, the residual height is 1.9, the width is 1.4, the thickness is about 0.5 meters, and the weight is about 6 tons. The head of the Bixi(turtle-liked animal) stele is residual, the height is 1.37, the width is 1.76, the length is 3.5 meters, and the weight is about 20 tons.

       （2） The stele of Shengxuan temple restoration , unearthed in the middle of the ancient site of Suning square, is about 6 meters away from the earth's surface. It is composed of three parts: the forehead, the body and the pedestal of the stele. The forehead of the stele is semicircle, with two dragon playing beads carved in circular engravure. In the middle of the stele, there are eight large characters in seal script, says”the stele of Shengxuan temple restoration”, which is 1.7 in height, 1.54 in width and 0.5 in thickness. The body of the stele is rectangular, 2.7 in height, 1.54 in width and 1.54 in thickness and 0.52M long, with mortise and tenon at the bottom; it is a stele seat with a damaged head, 3.74 long, 1.37 high and 1.66M wide. There is an oval seat at the bottom, 3.0 long, 1.58 wide and 0.3m thick. There are 24 lines in the first half of the inscription, including the list of senior officials who wrote, as well as the list of Xuzhou officials who built the stele. The discovery of the stele is an important archaeological and historical material of the Ming Dynasty in Xuzhou. It has an important value of landmark reference for the layout of the city wall in the Ming dynasty and the layout of the buildings in the city (plate 3, Xuansheng Temple stele in Xuzhou).

       （3） The remains of the city wall in the Western Han Dynasty

The wall remains found are located on the west side of Suning square site, with a north-south direction. The top of the wall is overlaid by the strata of Tang Dynasty, and the wall extends westward out of the construction area. The excavation of the city wall is mainly concentrated in two places, one is the cross-section of the city wall, the other is the passage on the city wall. So far, the overall appearance of the wall remains is basically clear.

       ① It was found that there were two stages of city walls piled up sooner or later.

The first phase of the wall is built on the surface of raw soil. In order to strengthen the wall foundation, a foundation trench with a depth of 0.2-0.5m is dug down at the bottom, and the wall is piled up in layers. The color of each layer of stacked soil is different, which is mainly grayish yellow, with a lot of ginger stone particles. The highest part of the wall can be divided into 5 layers with a height of 1.3m. The width of the exposed part of the wall base is about 18 meters. In this period, the city walls were poorly preserved, most of them did not exist, and their direction and distribution range were unknown,

       The second phase of the city wall was built on the basis of the first phase of the city wall. The section shows that the first phase of the city wall was submerged and silted up by the river water in a period of time after it was abandoned, forming a silting layer with a thickness of nearly 1 meter, which contains a large amount of silting. The second phase of the city wall is also excavated at the bottom of the foundation trench, which is 0.2m deep. The first phase of the city wall is partially built and repaired. The wall is constructed by ramming. The soil color is light yellow and there are a lot of ginger stone particles. The ramming layer is clear, 10-20cm thick, with obvious ramming pit and round shallow round bottom, with a diameter of 4-5cm. The second phase of the city wall is relatively well preserved, slightly northwest southeast, basically running through the western part of the site, with an exposed length of about 190m and more 1-1.2m high walls. The eastern boundary of the city wall is basically clear, while the western boundary is still outside the construction area. At present, the widest part of the wall base exposed is 27m, so the width of the bottom of the city wall should be more than 27m (plate 4, cross section of the city wall site).

       ② A three-stage access of the city wall was found.

For the convenience of narration, the access road is temporarily defined as the city gate. The gate is located in the middle of the city wall. The excavation completely exposed the gate part within the construction range, with a total length of 24 meters. It is unable to reveal the diplomatic interface between the wall and the gate, because the eastern boundary of the wall has been damaged by construction

       In the first stage, the city gate was stacked under the second stage gate, breaking through the raw soil, only two pillar pits were found, which were nearly circular, with pillar foundation stones at the bottom.

The gate of the second phase is consistent with the above-mentioned second phase of the city wall. When the city wall is built, the gate position is reserved. The gate of this phase is 3.2 meters wide, with stone slabs on both sides. Some of the gates remain, with a maximum of 1.5 meters. The gate is made of more than 10 layers of stone slabs. Footprints were found at the bottom of the gate, which should be caused by long-term use. In the second period, the pottery pieces unearthed in the abandoned accumulation of the city gate were mostly fragments of rope pattern tiles and semicircle-shaped tiles, which was first judged to be in the Western Han Dynasty.

       In the third phase, after the second phase was abandoned, the north wall of the original city gate was used and another stone wall was built to narrow the city gate. In this phase, the gate is about 2 meters wide, and the masonry is also made of stone slab. In the abandoned accumulation of the city gate in this period, several copper coins "Huoquan" of Wangmang period were found, which can prove the lower limit of age about the third period (plate 5, wall passage). From the above archaeological excavation, it can be concluded that:

       The second phase of the city wall is consistent with the second phase of the city gate, which is the early and middle period of the Western Han Dynasty. The arrangement of unearthed relics will be conducive to the further evaluation of the city wall era. The third phase of the city gate is formed on the basis of the continuous use of the second phase of the city wall. The first phase of the city wall has no direct connection with the first phase of the city gate, but it is earlier than the Western Han Dynasty, which should be the earliest in the whole site.

       According to the documents, the remains of the city wall found in the ancient site of Suning square should be part of the east wall of Pengcheng, the capital of Chu state in the Western Han Dynasty.

       3、 Unearthed relics
       More than 3000 pieces of relics were unearthed in various periods, including more than 2000 pieces of porcelain, ironware, stone artifacts, wooden artifacts, bone artifacts and coin in Ming and Qing Dynasties; more than 500 pieces of blue (white and yellow) glazed porcelain, pottery, coin and bronze mirror in Tang, Song and Yuan Dynasties; more than 200 pieces of arched cap, coin and pottery in Qin and Han Dynasties.
       Xuzhou is the birthplace of Han culture and the hometown of Han culture. For a long time, archaeological work has focused on Tomb archaeology. However, due to various factors, the archaeological work of Pengcheng, the capital of Chu state, has not made great progress, especially the specific location of Pengcheng has never been determined. As one of the important vassal states of the Han Dynasty, Chu has a strong economic strength. It can be seen from the scale, engineering degree and burial objects of the tombs of the king of Chu that have been excavated and discovered. Then Pengcheng, the capital of Chu, as the place where the kings of Chu lived, as the political and economic center of that time, the development and research of its archaeological work undoubtedly has an important significance for the study of the social outlook of the whole Chu state. The remains of the city wall found in the ancient site of Suning square are part of the east wall of Pengcheng, the capital of Chu state. The achievement of the location of the east wall can indicate the location of the capital of Chu, which has a strong guiding significance for the archaeological work of the Han Dynasty in Xuzhou, especially for the archaeological work of Pengcheng, the capital of Chu state.