New Archaeological Evidence for an Early Human Presence at Monte Verde, Chile

New Archaeological Evidence for an Early Human Presence at Monte Verde, Chile

Abstract

Questions surrounding the chronology, place, and character of the initial human colonization of the Americas are a long-standing focus of debate. Interdisciplinary debate continues over the timing of entry, the rapidity and direction of dispersion, the variety of human responses to diverse habitats, the criteria for evaluating the validity of early sites, and the differences and similarities between colonization in North and South America. Despite recent advances in our understanding of these issues, archaeology still faces challenges in defining interdisciplinary research problems, assessing the reliability of the data, and applying new interpretative models. As the debates and challenges continue, new studies take place and previous research reexamined. Here we discuss recent exploratory excavation at and interdisciplinary data from the Monte Verde area in Chile to further our understanding of the first peopling of the Americas. New evidence of stone artifacts, faunal remains, and burned areas suggests discrete horizons of ephemeral human activity in a sandur plain setting radiocarbon and luminescence dated between at least approximately eighteen thousand five hundred and fourteen thousand five hundred calendar years before present. Based on multiple lines of evidence, including sedimentary proxies and artifact analysis, we present the probable anthropogenic origins and wider implications of this evidence. In a non-glacial cold climate environment of the south-central Andes, which is challenging for human occupation and for the preservation of hunter-gatherer sites, these horizons provide insight into an earlier context of late Pleistocene human behavior in northern Patagonia.

Introduction

The initial peopling of the Americas is a long-standing topic of much interdisciplinary debate. Most of this debate has centered on the timing and place of initial human arrival, the number of migrations, the character and integrity of the archaeological evidence, and the extent to which North American technologies and economies spread southward, affecting the first peopling of South America. In recent years, there is an emerging consensus that people arrived in North America at or before fifteen thousand years ago, as suggested by several site discoveries over the past few decades. There also is general agreement that people migrated from Asia to North America across Beringia, and then dispersed to Central and South America and that the old Clovis-first model of human entry around thirteen thousand years ago no longer explains the peopling of the New World. With the recent demise of this model, new questions are being addressed and new models proposed: such as whether there were multiple migrations by different peoples from different places, whether they arrived by land, along coastlines or both, and whether the first inhabitants of the Americas were the same people whose descendants inhabited the hemisphere upon the first arrival of Europeans in the fifteen hundreds.

Human genetic and skeletal studies provide different types and scales of information and varying opinions on the origin and diffusion of early South Americans. Archaeologists generally disagree about the origin of South American material culture. Two different perspectives have been proposed to explain the earliest known stone tool technologies, each with varying implications for the interpretation of early sites. The first is that Clovis bifacial technologies reached South America approximately thirteen thousand calendar years before present in the form of Fishtail projectile points. This model is based on diffusion and comparative morphological analyses of fluted point styles and leaves little room for independent technological development in South America. The second is that North and South American tool assemblages, including both bifacial and unifacial industries, are different adaptations to different environmental and cultural conditions, yet both derived from an earlier currently undefined technology somewhere in East Asia. The arguments advanced in support of the second model at present hinge on evidence recovered from sites such as Monte Verde Two in south-central Chile, Gault and Friedkin sites in Texas, Cactus Hill in Virginia, Paisley Cave in Oregon, and possibly other sites, all of which contain varying types of bifacial and unifacial assemblages dating approximately fourteen thousand calendar years before present or earlier. There is no doubt that some lingering influences and contacts existed between North and South America, but some of these appear to have taken place after the initial colonization of the southern hemisphere and, in some later cases, may even represent reverse migrations from south to north.

For almost four decades the late Pleistocene site of Monte Verde Two has played an important role in interdisciplinary research on the dating and nature of the initial peopling of South America. Recent excavations at the site and the nearby locality of Chinchihuapi have revealed new cultural evidence that strengthens the possibility of an earlier human presence on the continent. The new evidence is multiple, spatially discontinuous, low-density occurrences of stratigraphic in situ stone artifacts, faunal remains, and burned areas that suggests discrete horizons of ephemeral human activity radiocarbon dated between approximately fourteen thousand five hundred and possibly as early as nineteen thousand calendar years before present. The character of some of these horizons may not meet the traditional criteria used by some archaeologists to define valid early sites, such as spatially continuous and multiple activity areas with numerous features, artifact clusters, and diagnostic bifacial stone tool assemblages. In recent years, however, these expectations have been challenged by the discovery of new evidence suggestive of a wider diversity of tool types and of more ephemeral human behavior, landscape use, and site size and structure. These data suggest that people might have been in South America before

Fifteen thousand years ago, were highly mobile, and seasonally adapted to a wide variety of environments, including cold non-glacial environments.

Previous work at Monte Verde revealed one valid human site dated approximately fourteen thousand five hundred calendar years before present and adapted to a cool, temperate rainforest and an older possible cultural horizon associated with a cold, non-glacial environment. Monte Verde Two is a campsite buried in the north terrace of Chinchihuapi Creek, which formed around fifteen thousand calendar years before present, and associated with the remains of a long tent-like dwelling, the foundation of another structure, hearths, human footprints, economic plants, and wood, reed, bone, and stone artifacts. Although bifacial projectile points, flaked debitage, and grinding stones were recovered, most lithic tools were edge-trimmed pebble flakes and sling and grooved bola stones. Also investigated previously was the Chinchihuapi site, represented by two distinct localities, Chinchihuapi One and Chinchihuapi Two, located on the south side of the present-day creek approximately five hundred meters upstream from Monte Verde Two. Although only preliminarily investigated, it also dated approximately fourteen thousand five hundred calendar years before present and yielded a few burned areas and fragments of scorched animal bone directly associated with a few pebble flakes similar to those recovered at Monte Verde Two. Monte Verde One dated approximately thirty-three thousand years before present and initially defined by scattered occurrences of three clay-lined, possible culturally-produced burned areas and twenty-six stones, at least six of which suggest modification by humans. This prior archaeological evidence from Monte Verde One was too meager and too laterally discontinuous to falsify or verify its archaeological validity. Monte Verde One is buried in a sandur plain, the Salto Chico Formation, which formed as part of the Llanquihue drift during the last glaciation by meltwater from glaciers located seven point five kilometers to the southeast. Previous research did not record any cultural material in strata spanning the multi-millennia time period between the Monte Verde One and Monte Verde Two sites.

The principal goal in undertaking new research at Monte Verde was to conduct a preliminary, discontinuous geo-archaeological reconnaissance of the Monte Verde area to determine whether we had previously defined the wider horizontal and deeper vertical extent of the site for the National Council of Monuments in Chile. It was not intended to be a full-scale excavation to resolve previous research questions. The subsurface testing and excavation plan thus was largely designed by the National Council of Monuments in Chile. Within this plan, we developed three specific objectives: One to explore previously unknown geo-archaeological deposits in sites MV-One, MV-Two, CH-One and CH-Two; Two to investigate the long time span between sites MV-One and MV-Two; and Three to further assess the geological setting of the sites by applying sedimentological, microstratigraphic, magnetic, optically stimulated luminescence dating, and macro- and micro-botanical analyses. Based on our previous findings at MV-One, which revealed possible cultural evidence laterally dispersed in deeper, sandy levels of the sandur plain, our recent work centered on spatially intermittent excavations and core drillings across a five hundred meter area between the MV-One and Chinchihuapi sites in search of additional scattered remains down to and below these levels. The result was the discovery of twelve small, discrete burned features directly associated with fragments of burned and unburned faunal remains, spherical and manuport stones, and human-knapped flakes dated by carbon fourteen and optically stimulated luminescence means between at least eighteen thousand five hundred and fourteen thousand five hundred years ago. The features and associated lithics and bones are spatially limited within discrete lenses, averaging approximately thirty-three by forty-two centimeters in spatial extent and approximately one point zero to two point eight centimeters in thickness. Only one excavated unit, measuring five by five meters in size, contained more than one feature, indicating their widespread and intermittent dispersion across the study area. Although both horizontally and vertically discontinuous, these remains appear to represent ephemeral seasonal activities laterally spread across uneroded, slightly elevated surfaces, approximately zero point five to zero point eight meters high, between small, narrow and shallow channels of a braided drainage system buried in the SCH-Fm.