Natural Site Formation Processes Research Articles

Does the evidence at Arroyo del Vizcaíno (Uruguay) support the claim of human occupation 30,000 years ago?

ABSTRACT Researchers at Arroyo del Vizcaíno (AdV), Uruguay, have argued that human occupation dates prior to the Last Glacial Maximum (33,000–31,000 cal BP) based on the presence of purported stone tools and cutmarks on bones. We provide a summary of their research and critically evaluate these claims. We conclude that the claims of a pre-LGM occupation at AdV are unsupported due to: (1) equivocal evidence that the purported stone tools are culturally modified; (2) insufficiently documented spatial and contextual information; (3) inadequate geological research leading to an unconvincing site formation model; and (4) inadequate testing of alternative hypotheses for bones with surface modifications. We conclude that the site is best interpreted as a natural time-transgressive accumulation of mammal bones and other organic and inorganic materials within a fluvial setting spanning four millennia, and that bone surface modifications are the product of natural site formation processes rather than human agency.

Recent excavations at Owl Ridge, interior Alaska: Site stratigraphy, chronology, and site formation and implications for late Pleistocene archaeology and peopling of eastern Beringia

AbstractThe early archaeological record of Beringia is complicated by the occurrence of several lithic industries. Site assemblages, dating from 14,000 to 12,800 years ago and located from the Yana‐Indigirka Lowlands of Siberia to the upper Tanana River basin, contain artifacts characteristic of the Nenana technological complex. After 12,800 years ago, site assemblages contain artifacts diagnostic of the Denali technocomplex. To explain the variation in lithic industries, we first and foremost need well‐stratified and well‐dated sites with multiple components so we securely know their ages and depositional relationships. We present excavation results of one such site located in interior Alaska, Owl Ridge, with the goal of assessing site stratigraphy, radiocarbon chronology, and natural site formation processes. Owl Ridge was visited three times during the Pleistocene‐Holocene transition with a Nenana‐complex occupation at 13,380–12,800 years ago followed by two Denali‐complex occupations at 12,540–11,430 years ago and 11,270–11,200 years ago. Assemblage change at Owl Ridge was diachronically patterned, as at the nearby Dry Creek archaeological site, and separated by two climatic events, a brief extremely windy Younger Dryas (lasting 300–250 years) and a very brief wetter period (lasting ~160 years). Our results indicate these climate and environmental conditions played a role in settlement of eastern Beringia.

Integrating geoarchaeology and magnetic susceptibility at three shell mounds: a pilot study from Mornington Island, Gulf of Carpentaria, Australia

In coastal areas of the globe, open shell matrix sites are commonly used to establish regional chronologies of human occupation and identify patterns of cultural change, particularly for the Holocene, post-sea-level stabilisation period. Despite this, many basic sedimentary analyses that are routinely applied to rockshelter deposits (e.g. geophysical characterisation, particle size etc) are rarely applied to these sites. Magnetic susceptibility, occasionally used in rockshelters, has never been used to investigate shell matrix sites in Australia, despite several international studies identifying its efficacy for other types of open sites. This paper reports a pilot project applying a range of conventional sedimentary and archaeological analyses, as well as magnetic susceptibility at three anthropogenic shell mounds on Mornington Island, Gulf of Carpentaria, Australia. Results are compared to, firstly, assess site integrity and, secondly, to ascertain whether magnetic signatures are related to cultural or natural site formation processes. The results establish that the mounds were repeatedly visited, despite the archaeological evidence, including radiocarbon ages, suggesting effectively ‘instantaneous’ deposition. This has important implications for studies of other shell mounds where the limitations of radiocarbon dating precision may also mask multiple deposition events.

Pre-Clovis in Texas? A critical assessment of the “Buttermilk Creek Complex”

Lithic artifacts from the lowest strata of the Debra L. Friedkin site, located on Buttermilk Creek in central Texas, have been interpreted as an undisturbed pre-Clovis assemblage (Waters et al., 2011a). Stone tools and debitage were recovered from sediments stratified just below diagnostic Clovis artifacts and dated by OSL to between 13.2 and >15.5 cal kya. Invoking commonly observed cultural and natural site formation processes, we offer an alternative explanation of the “Buttermilk Creek Complex” as a Clovis assemblage in secondary association with the dated sediments.

Archaeological research on HMS Swift: a British Sloop-of-War lost off Patagonia, Southern Argentina, in 1770

HMS Swift was a British sloop-of-war which sank off the coast of Patagonia, Southern Argentina, in 1770. Since 1997 the Underwater Archaeology Programme of the National Institute of Anthropology has taken charge of the archaeological research conducted at the wreck-site. This article presents an overview of the continuing Swift project and the different research lines comprised in it. The latter cover aspects related to ship-construction, material culture and natural site-formation processes. © 2006 The Authors

Evaluating Natural Site Formation Processes in Eolian Dune Sands: A Case Study from the Krmpotich Folsom Site, Killpecker Dunes, Wyoming

Eolian dune sands commonly contain archaeological material in both surface and buried contexts. However, because of the dynamic nature of dunes, the original context of an archaeological site can be severely modified or destroyed as a result of post-occupational geomorphic processes. This paper examines a Folsom occupation associated with a buried soil in the Killpecker Dunes in southwestern Wyoming. Field and labortory data are compared to determine the likely scenario of natural site formation processes responsible for the current context of the archaeological assemblage. Two primary eolian stratigraphic units are present at the site, and are separated by the buried artefact-bearing soil. Radiocarbon and optical luminescence ages indicate that the Folsom artefacts occur across a temporal hiatus, and that the buried soil is late Holocene in age. Sedimentological data indicate that the highest frequencies of artefacts by depth are associated with an erosional contact characterized by a concentration of coarse-grained material. Thus, the Folsom assemblage appears to have been vertically displaced as a result of post-occupational erosion and deflation. This case study indicates that evaluating the context of an archaeological occupation in a dune setting is best carried out utilizing multiple lines of evidence derived from both field and laboratory work.

A study of natural site formation processes in the Kortallayar Basin, Tamil Nadu, South India

This article presents the results of a study of natural processes influencing the formation of Palaeolithic sites, in a ferricrete landscape, in the Kortallayar basin, Tamil Nadu, South India. The principal points discussed here include the Quaternary geomorphology and Palaeolithic archaeology of the region and the methodology used for the study of site taphonomy. As a result of this research, Palaeolithic sites were categorized into several types based on their sedimentary context, artefact spatial distribution, and morphology and degree of integrity. This work is the first of its kind in establishing a methodology for the study of Palaeolithic sites in ferricrete landscapes in India. The results of this research may be relevant to understanding the study of formation processes at sites in similar contexts elsewhere in the Subcontinent. © 1999 John Wiley & Sons, Inc.

Erosion of archaeological sites: Results and implications of a site simulation model

AbstractA computer simulation model has been developed to investigate the postdepositional changes on archaeological sites due to soil erosion in a semiarid (Mediterranean) environment. Both soil matrix and archaeological artifact movement are accounted for by the model. The model is applied to a series of hypothetical site configurations on hillslopes, using archaeological structures, to observe the morphological changes due to slope form. The results show considerable variation in site preservation potential, relating to different initial spatial patterning of the site and initial slope form. The model predicts thresholds for the start of movement by artifacts, and suggests a correlation between the location of deposition and the potential for disturbance of the artifact record. Implications are drawn from the results of the simulations, both in terms of archaeological theory and practice, and in terms of site conservation and management. The simulation method is recognized as a useful tool for the investigation of natural site formation processes. © 1994 John Wiley & Sons, Inc.

The Size Effect: An Explanation of Variability in Surface Artifact Assemblage Content

The reuse of certain categories of artifacts combined with natural site formation processes, such as sedimentation and erosion, is suggested to result in the disproportionate occurrence of “large” artifacts on the surface of sites. This phenomenon, known as the size effect, is investigated with artifact assemblage data from several stratified Eastern North American sites.