Why wall trenches?

Discussions of Mississippian architectural modes have dwelled too much on differentiating flexed-pole and rigidpost buildings, both of which were probably constructed throughout the Mississippian period (A.D. 1050-1350) in the greater Cahokia region. New evidence from recently excavated Richland Complex settlements suggests the innovation of a "curtain-wall construction technique" that, on the one hand, was based on a traditional interior truss structure and, on the other, permitted the prefabrication of exterior walls. Such a hybrid construction mode might have solved the immediate problem of new housing at lateeleventh-century Cahokia while adapting techniques familiar to local builders. Besides highlighting the importance of interior roof-support posts, our conclusion also means that greater attention to post-mold details is required using crosssectioning rather than post-scooping methods of excavation.