Precambrian crystalline basement of the Appalachian Blue Ridge deforms inhomogeneously by developing relatively narrow ductile deformation zones (DDZs). The Paleozoic sedimentary cover develops open to tight folds and penetrative fabrics. A transition between these two styles occurs at the base of the sedimentary cover in the Early Cambrian Chilhowee quartzites of the central Appalachians and in the Late Proterozoic arkosic sandstones of the southern Appalachians. On a mesoscopic scale, the transition zone sediments show tight to isoclinal folds with highly deformed overturned limbs analogous to mesoscopic (1 cm to 10 m wide) DDZs in crystalline basement. Deformation zones in the...