Tectonic Origin of Desert Wetlands at Pozuelo, Peru

Summary

This is an abstract from the "SAA 2024: Individual Abstracts" session, at the 89th annual meeting of the Society for American Archaeology.

The Pozuelo site, one of the oldest in the region, is composed of four Formative Period mounds (circa cal yr 1230 BCE) in southern, coastal Peru. Archaeological excavations at the site exposed both mound and pre-mound stratigraphy. Sediments beneath the mound showed a sharp transition from alluvial fan/eolian sediments to a thick (approx. 1 m) clay deposit containing evidence of freshwater plants. Discovery of this wetland environment was unexpected in what is now desert terrain, and has implications for the pre-mound occupation of the area. Hypotheses for the formation of a standing water body include fault-induced topographical and hydrological changes, perhaps influencing a distributary channel, in this tectonically active region. In 2022, additional excavations revealed clastic dikes associated with earthquake-induced liquefaction cutting the clay layer in sediments beneath a mound. An electrical resistivity tomography (ERT) survey conducted in 2022, showed results consistent with faulting in the area immediately adjacent to and beneath the excavated mound. This information suggests the pre-mound wetlands may be the result of seismically controlled ground warping and water impoundment, followed by disruption by a large magnitude earthquake. Subsequent eolian activity created the sand dune which forms the base of the excavated mound.

This Resource is Part of the Following Collections

• SAA 2024: Individual Abstracts   •
• Society for American Archaeology 89th Annual Meeting, New Orleans, LA (2024)

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Record Identifiers

Abstract Id(s): 38539.0