Not until recently has the mid-Atlantic Piedmont region of the Appalachians been viewed from plate tectonic theory. Eight papers derived from 1995 and 1997 symposia of the Northeastern section of the Geological Society of America help fill in this gap. With chapters arranged by geographic location f

The thermal evolution of mountain belts is recorded inthe distribution, origin and ages of magnatism. In this volume, petrologic, isotopic and geochemical evidence is presented to highlight the contribution of igneous rocks to the evolution of the Appalachian Orogen in both Canada and the United States. These papers emphasize the use of modern geochemical and petrologic data to discriminate the sources yielding magmas, and thus the nature of the crust and mantle.