Pediment Surfaces and the Creation Model
Another erosional feature that creationists mention in association with flood geology is the pediment surface. A pediment is a gently sloping erosion surface or plain of low relief formed by running water in an arid or semi-arid region at the base of a receding mountain front, or an imaginary borderline between a mountain and a nearly flat plain. A pediment surface is underlain by bedrock that is typically covered by a thin, discontinuous layer of soil and alluvium derived from upland areas. Pediments are seen as evidence of erosion from the receding floodwaters of the Genesis Flood by creationists. Mainstream scientists disagree on the formation of pediments and there are several explanations of their formation. However, none of these explanations describing the slow processes of uniformitarian geology seem to be logical to explain the formation of pediments. Pediments are not observed to be forming today and cannot be explained with uniformitarian principles. Pediments are distinguished from alluvial fans, which are deposits of alluvium deposited by a stream flowing down a mountain or ridge onto a relatively flat surface at the base of the mountain. These alluvial fans produce a deposit that resembles a fan shape when seen from an aerial view and spread outward onto the plain after exiting the mountain stream channel. When several alluvial fans merge or connect together, these are termed bajada or piedmont. Pediments, however, are the eroded rock surface and do not constitute alluvium deposits. These pediments at the base of mountains could only form from the erosive power of catastrophic floodwaters and not from millions of years of gradual erosion as the uniformitarian geologists insist on and use in their explanations.