The origin of a timber circle surrounded by the earthen mounds of Fort Ancient (Ohio, USA) is a mystery to archaeologists slowly unearthing its remains, but the site has yielded something remarkable. The Hopewell tradition Native Americans that constructed the ring 2,000 years ago were able to align the circle's gateway with the rising sun on the summer solstice, the longest day of the year. The astronomical find derived from computer modeling is one of the few things archaeologists have discovered that could suggest a use for the circle, named the Moorehead Circle after Warren K. Moorehead, an early 20th century archaeologist who helped preserve Fort Ancient.
     Lacking other physical evidence, the hard currency of archaeology, even the precise nature of the recent find yields no answers. Archaeologist Robert Riordan and an excavation team have dug the site since its 2005 discovery during ground scans to combat erosion at Fort Ancient. Ground-penetrating scans showed a ghostly outline of a 200-foot-wide circle hidden beneath the surface. "We have a tremendous site and a big mystery on our hands," said Riordan, professor of anthropology and chair of the Department of Sociology and Anthropology at Wright State University.
     Subsequent digs each summer since the discovery have gradually revealed irregular rock-filled post holes that once held wooden timbers 10-13 feet high laid in concentric circles and, at that center, a 14-foot-wide circle of reddish burned soil. About 1,000 pieces of pottery fragments have been found around the core, Riordan said, and 2,000 in the greater circle. Estimates place the circle's building within the first or second century CE.
     One purpose for the Moorehead Circle that has been ruled out is a burial ground. No remains have been found by archaeologists, and the burned soil was apparently brought in, probably using baskets, from surrounding areas. Riordan's team has also found evidence of a dwelling within the ring.
     The circle's elaborate construction and its location surrounded by the mounds the Hopewell built over a period of 400 years suggest the wooden post ring was important to whatever the early Ohioans were trying to accomplish with their toils. "Any time we can add another piece to the puzzle of prehistory, that's a great day," said Lynn Hanson, vice president of Collections & Research at Dayton Society of Natural History, which runs Fort Ancient State Memorial through an agreement with the Ohio Historical Society. "At Fort Ancient, there could be other places that are equally important that we just haven't found yet," she said.

Source: Cincinnati.com (31 July 2010)