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The artifact layer, however, is not itself a product of fluvial transport and
deposition. The large particles of FCR within the layer are very angular and do not
show evidence of significant fluvial transport which would result in more rounded
fragments. If currents were responsible for the artifact layer then there should be
some evidence of clast imbrication indicating the flow direction. The topographic
relief on the cultural layer is inconsistent with a flood interpretation. If a large
flooding event occurred, one might expect to observe a channelized geometry.
Instead, the slope of the layer is similar to the modern topographic surface,
supporting the idea that this is a buried landscape. The grain sizes of the overlying
sediment along with the observed sedimentary structures are more typical of lower
velocity flows possibly in the 20-50 m/s range. The 2-6 cm diameter clasts within
the artifact layer would require more than double the energy to move these
materials and such higher flow velocities would generate a different suite of
sedimentary structures than observed. The age of the sediment interval overlying
the artifact layer is younger than A.D. 150. This age estimate is based on the
earliest introduction of ceramics in the area.
This study recognizes the complexity of site formation and serves to demon-
strate that natural and cultural processes are intimately linked when generating
concentrations of artifacts. Determination of depositional environment and asso-
ciated reconstruction of paleohydrological characteristics is useful in making the
distinction between natural and cultural controls. It is evident from this study that
sites may exhibit cyclical phases where prolonged erosion, exposure of earlier
cultural materials, mixture with artifacts from subsequent occupations, and burial
are all part of the landscape change and long-term development of archaeological
sites.
Acknowledgments This project is a result of undergraduate research by the senior author. We
appreciate the comments and suggestions provided by two anonymous reviewers. We thank John
Carpenter, co-director of the La Playa project and the Consejo de Arqueologia (INAH) for
permission to conduct this study. Funding for the overall La Playa project activities have been
consistently provided by INAH. Funding was also provided by a University of Arizona Faculty
Small Grant. Travel funds were provided by the Richard White Fund through the Bloomsburg
University Department of Geography and Geosciences.
References
Bailey G (2007) Time perspectives, palimpsests and the archaeology of time. J Anthropol
Archaeol 26:193-223
Carpenter JP, Sánchez G, Villalpando ME (1997) Rescate Arqueológico La Playa: Informe Técnico
al Consejo de Arqueología del INAH, Temporada 1997. Archivo Técnico del INAH, México
Carpenter JP, Villalpando ME, Sánchez G, Martínez N, Montero C, Morales JJ, Villalobos C
(2003) Proyecto Arqueológico La Playa: Informe Técnico al Consejo de Aqueología del
INAH, Temporada Verano 2002. Archivo Técnico del INAH, México
Carpenter JP, Sanchez G, Villalpando ME (2005) The late Archaic/early agricultural period in
Sonora,
Mexico
In: Vierra
BJ
(ed)
New
perspectives
on the
late Archaic
across
the
borderlands: from foraging to farming. University of Texas Press, Austin
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