in the area. Faults as young as Holocene cut across alluvium.
Christenson and Purcell deal with the correlation of alluvial-fan deposits in a wide area of the Basin and Range Province. They differentiate three fan ages based on drainage pattern, incision depth, surface morphology, the degree of desert pavement and varnish development, soil development, and morphostratigraphic relations. They conclude that a similarity of fan development throughout the Basin and Range Province suggests regional depositional controls with local variation. Most young fans are less than 15,000 years old. Intermediate fans range from 10,000 to 700,000 years old, and the oldest group is greater than 500,000 years old.
Morrison summarizes extensive work on Pliocene and Quaternary geology of the Colorado Plateau and Basin and Range Provinces of Arizona. Quaternary sedimentation is cyclical over hundreds of thousands of years and is mainly climatically controlled. Many faults in the region are less than 3.5 million years old and some are as young as 4000 years.
North American geoarchaeologists will probably find little of direct importance in this volume because much of what is discussed greatly predates the known appearance of early man on the continent. However, the volume should be valuable to areas of neotectonics and alluviation, especially in the Great Basin, and should therefore be useful to geomorphologists. The papers on accumulation of soil carbonates and clay mineral formations are important in the area of soil genesis and may be indirectly important to geoarchaeology.