structural:reformatting, stylistic:tone
Construction

Archaeological excavations determined that prior to the construction of the earthworks, prehistoric workers leveled the land around the site and filled in gullies and other low places to create the flat central plaza and surfaces on which to build the mounds and ridges. The main building material was loess, a type of silt loam soil which is easy to dig but erodes when exposed to water. For this reason, clay may have been used to cap the loess constructions to protect the surfaces from erosion. The earthworks were constructed by dumping basket loads of dirt in piles and then filling in the gaps between them. The baskets, depending on the size of the bearer, could hold between 30–50 lb (13.6–22.7 kg) of dirt, suggesting that men, women, and children participated in the construction.