Phase

A term generally referring to an archaeological unit defined by artifacts and cultural traits that distinguish it from other units. It is an archaeological unit defined by characteristic groupings of culture traits that can be identified precisely in time and space. It lasts for a relatively short time and is found at one or more sites in a locality or region. Therefore, it is an interval of time in the archaeological record, especially a relatively limited time within a specific locality or region and often used to represent a distinct prehistoric people. The archaeologist abstracts the phase from a number of components which occupy a certain area in space and the same span in time and which share many or most of their distinctive features with each other. These components may represent units as small as tribal camps or as large as cities. It is similar to "focus" in the Midwestern Taxonomic System and to "culture" in the Old World.

Stage of the early Bronze Age in North China defined by two strata at Zhengzhou Erligang in Henan province. The Erligang phase is assumed to belong to the earlier part of the Shang dynasty. It follows immediately on the Erli-tou phase and precedes the historical Anyang period (cl300-cl030 bc; see Shang, Gaocheng). Two radiocarbon dates obtained from the Lower and Upper Erligang levels at Zhengzhou are cl600 bc and cl550 bc respectively. Remains comparable to those from Erligang are very widely distributed in North China, reaching from the Wei River valley in the west to Shandong in the east, as far south as Panlongcheng near the Yangzi River, and in the north to parts of Shanxi and Hebei provinces and to Beijing. The Erligang phase may correspond to the widest sway of the Shang empire. The period is notable for its highly developed bronze-casting industry. Until recently the Erlitou and Erligang phases were often referred to as Early Shang and Middle Shang respectively; these terms have gone out of use since radiocarbon dates raised doubts as to whether Erlitou is a Shang site. Some Chinese archaeologists have even begun calling the Erligang phase Early Shang.