Geomorphic analysis of Hohokam settlement patterns on alluvial fans along the western Flank of the Tortolita Mountains, Arizona

Abstract Geoarchaeological investigations of the alluvial piedmont or bajada emanating from the Tortolita Mountains, Arizona, show that the distribution of Hohokam sites apparent from the surface is complete and undisturbed by geological processes. Late Holocene geomorphic processes and their resultant deposits on the bajada affected the location of prehistoric Hohokam agricultural settlements. Hohokam settlements were commonly situated on small alluvial fans dominated by sheetwash processes and deposition of fine‐grained alluvium, where floodwater farming could be easily pursued with little modification of the natural surface. Large alluvial fans, dominated by channel processes and coarse‐grained alluvium were avoided by the Hohokam farmer because these areas were less suitable for floodwater farming.