High above the banks of the Assabet River, in the southernmost tip of Acton (Massachusetts, U.S.A.), archaeologists have found traces of an ancient Native American civilization that dates back as far as 7,000 years, to 5,000 BCE.
      Duncan Ritchie, the senior archaeologist for the Rhode Island-based Public Archaeology Laboratory, said the discovery of thousands of Native American artifacts excavated from the site, called Pine Hawk, includes fragments and bits from stone tools, arrow heads used for spears, hearths and fire pits, storage and refuse pits, workshops where stone tools were made, and post molds for housing circles.
      The site ''is considered one of the most significant discoveries of ancient Native American culture on the Eastern Seaboard,'' said Acton's Bob Ferrera, the founder of the ad hoc committee, Friends of Pine Hawk. Though the dig was conducted three summers ago, details of the Pine Hawk discovery were made available only recently because the site was registered as a historic property by the Massachusetts Register of Historical Places, with an edict that requires that information about such places not be made public until fragments from the site are excavated and studied.
      Pine Hawk was discovered quite by accident five years ago when Acton began planning to build a waste-water treatment plant along the Assabet River. During the survey, the Public Archaeology Laboratory, started digging and found thousands of chipping debris pieces and projectile point fragments that were implanted as arrow tips on spears. In addition, several fire pits were uncovered 4 feet deep in the soil. The pits had traces of charcoal indicating that they were used between 3,900 and 4,600 years ago.
      Since it was not possible to relocate the proposed treatment plant and preserve the Pine Hawk site in place, the archaeologists mounted a program to retrieve the fragments for analysis. Ritchie said a study of the fragments followed with radio carbon-dating tests at a Florida laboratory indicate that the area was occupied by an ancient Native American culture 7,000 years ago in the post-glacial period.
      ''The amazing thing about the fragments is that they weren't buried; they were left on the ground, and time has added more and more material over them,'' said Doug Halley, a Friends of Pine Hawk member and Acton's Board of Health director. ''It's hard to believe that over a period of 4,000 years, almost 4 feet of it has fallen on the ground

Source: The Boston Globe (5 January 2003 http://www.boston.com)