Landscapes variability and the early peopling of the inter-Andean Magdalena Valley, Colombia (South America)

Abstract

The Magdalena River is the longest inter-Andean river in Northern South America. We focus on the middlesection calling attention to the implication of a geoarchaeological approach to understanding the role of depositional and erosional processes over time in the preservation and destruction of archaeological sites. Most likely the majority of the earliest Preceramic deposits - predating ca 12,900 BP - left in ancient shores and terraces, were erased or buried. Archaeological early remains are recorded on the alluvial paleo-terraces and piedmont hillslopes of the lowlands throughout the Pleistocene/Holocene Transition, during and after the El Abra Stadial - equivalent to the Younger Dryas period (ca. 12,900–11,700 cal BP). From the Terminal Pleistocene through the Middle Holocene specialized hunter-gatherers occupied floodplains and alluvial fan surfaces, as well as the relict high terraces remnants. The presence of industries with bifacial tools, - such as triangular stemmed points, and pressure retouched well finished tools (plano-convex scrapers) - occurred only throughout preceramic times. Climatic changes (above all precipitation variability), vegetation belt shifts and volcanism have affected geomorphic shifts in the lowlands of the Magdalena Valley. These changes are primarily responsible for the limited evidence of preceramic occupations. The early archaeological record is a dependent variable in the larger context of an evolving landscape. This relationship is critically important in evaluating the importance of the Magdalena Valley in the early settlement of the Northwest South American lowlands.