PREHISTORIC UTILIZATION OF SPHERULITIC AND FLOW BANDED RHYOLITES FROM NORTHERN NEW HAMPSHIRE

Spherulitic rhyolite is a variety of rhyolite that is characterized by small cryptocrystalline to glassy, spherical grains which range in size from less than 1 millimeter to 1.5 centimeters. In cross section these spherical grains appear circular or oval in shape. Spherules may become aligned through flow during emplacement. These aligned spherules are referred to as flow bands. Recovered artifacts composed of spherulitic rhyolite range from important to minor components in archaeological sites in northern New England and southeastern Quebec. The spherulitic rhyolite artifacts under consideration in this study were derived from two sources located in northern New Hampshire. One is near the city of Berlin, and the second in the town of Jefferson. The Berlin, source is a thin rhyolite dike located on Mount Jasper to the west of the city. The Jefferson source comprises blocks in glacial deposits which are 24 km from Mount Jasper. Artifacts from both sources have been recovered from Paleoindian sites throughout northern New England and southeastern Quebec. Changing environments during late Paleoindian time effectively closed the Jefferson source by Archaic times. Hence, the dike on Mount Jasper from which approximately 200 cubic meters of rock were mined became the principal source of this rock type for Archaic and Woodland peoples.