added by archaeologs [hang-t’u]. A kind of rammed-earth construction used for walls, foundations, and shaft tombs in China throughout the Shang and Zhou periods. Earth was packed between wooden forms in successive thin layers, each layer being pounded hard before the next was added. In the Shang city wall at Zhengzhou, which is about 20 metres thick at the base and 7100 metres long, the clearly distinguishable layers are 70-100 mm deep. Hangtu walls have been found at only two late Neolithic sites, Chengziyai (see Longshan) and Hougang, and it is uncertain whether these walls actually pre-date the use of hangtu at early Bronze Age sites such as Erlitou. In the latter part of the Zhou period hangtu constructions were often faced with stone. Much of the Great Wall was originally built of rammed earth.
The Macmillan dictionary of archaeology, Ruth D. Whitehouse, 1983