Architecture and Chronology at the Site of Sechín Alto, Casma Valley, Peru

Abstract

The Initial Period, between 2150 and 1000 cal B.C., was a critical time in the development of civilization within the Andean area of South America. About 2100 cal B.C., within several river valleys along the north-central coast of Peru, sudden changes occurred in subsistence, settlement pattern, and level of cultural complexity. These changes were especially notable within the Casma Valley where labor was mobilized to build large flat-topped pyramids and plaza systems that occupied the centers of large cities. The site of Sechin Alto, with an estimated population of 18,000, is the largest Initial Period site in the Casma Valley on the north-central coast of Peru. Our research has shown that successive changes in the construction and use of the main Sechin Alto mound can be used to document the rise and fall of a state-level Initial Period polity. We illustrate this development by describing the chronological sequence for the main mound of Sechin Alto, the site's relationship with other sites within the Casma Valley area, and the reuse and abandonment of the site during the Early Horizon (1000–200 cal B.C.). These features of what may be the earliest Andean state provide critical comparative data for scholars of societal development worldwide.