Serrated triangular arrowhead, about one inch in length.
This projectile point is interesting, not only because it was made from a decortication flake (a relatively unusual occurrence for any period) but because it is serrated. The maker of this arrowhead used a deer antler or some other soft material shaped like a punch or awl to remove small flakes from around the edge giving the object the sharpness of a serrated kitchen knife. Most triangular points dating to the Late Woodland are not serrated.
Archaeologist Stephen Potter, in his Commoners, Tribute, and Chiefs: The Development of Algonquian Culture in the Potomac Valley (University of Virginia Press, 1993), attributes these kinds of points to the Protohistoric and Historic periods (AD 1500-1650s). They are typically small ( not much more than a half inch in length) and, in Virginia's Northern Neck, are serrated isosceles triangles made from quartz.
Potter discusses movement of Indian tribes back and forth across the Potomac River and the development of the various tribes that formed the Conoy chiefdom, including the Piscataway and Portobacks. Continued excavation around Unit 7 may well contribute to Potter's larger story as it appears increasingly likely that the archaeology team has found a small Indian settlement dating to the first half of the 17th century; a community that was in direct contact with the Jesuit mission and the colonists whose increasing numbers led to the formation of Charles County 350 years ago.