Deep seismic reflection characteristics of the continental crust

Four types of seismic reflection “fabrics” appear to characterize the continental crust: (1) a cratonic fabric dominated by diffractions and dipping reflections but lacking a pronounced reflection Moho; (2) regions of thin-skinned foreland deformation with abundant shallow but sparse deep reflections; (3) a unidirectional fabric that dips toward the hinterland and may represent a crustal-scale ramp zone; and (4) zones of highly layered lower crust and high-amplitude reflection Moho. The first three types are commonly observed in transects across single mountain belts, but the fourth appears to correspond to regions of elevated lower crustal temperatures such as those encountered in rift provinces and perhaps elsewhere.