Position, extent and structural makeup of Appalachia
INTRODUCTION A few portions of the earth’s surface naturally stand out as the most logical places in which to initiate studies aimed at the solution of the major problems of geology, and particularly of such problems as deal with the manner of origin of “geosynclines of sedimentation,” with the processes of mountain building, and with the sequences of diastrophic events that characteristically both lead up to, and follow, an “orogenic revolution.” In order to qualify as such a “test area,” a region must meet several specifications: It must present an abundance of varied and easily accessible outcrops; it must contain many mountain uplifts, canyon sections, deep wells, and mine workings to provide a notable third-dimensional component to the purely areal picture afforded by lowland outcrops; it must be, at least in part, a region in which the usual geological exploratory techniques have been long and especially intensively applied—thus providing . . .