Geomorphic and isotopic indicators of anthropogenic change from Holocene-length alluvial deposits in the Rio Blanco watershed

Summary

Recent geoarchaeological investigations in southern Belize have focused on the Paleoindian to Archaic site of Tzib’te Yux located in the Rio Blanco watershed and dating between 3000-12500 BP as well as adjacent river terraces. Landscape-level vegetation changes are apparent within the area in the form of forest clearance by 5000 BP. Evidence of pedogenesis derived from four years of excavations and sedimentation rates established through modeling and high-precision 14C AMS dating have produced an erosional history of the wider watershed reflecting the extent of land clearance throughout the Holocene. Combined with compelling evidence for contemporaneous human occupation, these data facilitate an assessment of geomorphic, and ecological change with underlying climatic, geologic, and anthropomorphic drivers. Stable carbon isotopic signatures of insoluble components of soil organic matter (SOM) reveal the impact of human occupation on vegetation regimes within the Rio Blanco watershed with δ13C values of humins and humates reflecting a C3 dominated landscape prior to a rapid shift of up to 4‰ following the introduction of C4 crops (maize) to the region. Values remain at relatively less negative values through the Classic Period, declining only after the abandonment of nearby Maya polities.

This Resource is Part of the Following Collections

• Interdisciplinary Approaches to Studying Human Social Dynamics: A Case Study from Southern Belize   •
• Society for American Archaeology 82nd Annual Meeting, Vancouver, BC (2017)

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Record Identifiers

Abstract Id(s): 17057