Precambrian and Triassic diabase in eastern Pennsylvania

Abstract

p. 173-181, [1] folded leaf of plates : map ; 24 cm.Includes 1 bibliographical reference (p. 181).Introduction. Location and general relations -- Topography. Appalachian Mountains. Piedmont Plateau -- Descriptive geology. Geology of the Boyertown Hills. General relations. Graphitic gneiss. Franklin limestone. Granite. Diorite. Gabbro. Palaeozoic rocks. Diabase. Triassic rocks of the Piedmont Plataeu. General relations. Brunswick conglomerate. Brunswick shale. Triassic diabase. Alteration of the shale -- Conclusion