Geoscience Reference
In-Depth Information
is feasible if the channel of the Rio Boquillas was stable and did not frequently avulse,
allowing deposition of these fine-grained deposits.
Keywords La Playa
Sonora
Paleosol
Quaternary
Silt
Early Agricultural
period
Alluvial
Pleistocene
Mexico
Introduction
The relationships between environmental change, landscape evolution, and human
activities is a complex web of interactions that have been a focus of various
geoarchaeological studies (Butzer
1978
; Ferring
1986
; Haynes
1991
; Bintliff
1992
;
Davis and Shafer
1992
; Van Nest
1993
; Holliday et al.
1994
; Freeman
2000
; Waters
2000
; Stafford and Creasman
2002
; Hill
2004
; Eitel et al.
2005
; Bubenzer and
Riemer
2007
; Wright et al.
2007
; Huckleberry and Duff
2008
; Nials
2008
). In the
context of modern environmental change, geoarchaeological studies are increas-
ingly informative about the long term effects of landscape and climate change on
human populations. Human responses to environmental variation often relate
directly to subsistence and the effects on the availability of food (Mabry
1998
).
Subsistence-based responses can significantly alter settlement patterns, initiate
demographic changes, and stimulate the adoption of new technologies. A critical
initial step in studies of human-environment interaction is creation of a strati-
graphic and paleoenvironmental framework to understand the overall landscape
change through time. With a model of landscape evolution firmly established, a
more refined examination of these changes on human activity can be evaluated.
The goal of this study was to define a basic stratigraphic and paleoenvironmental
framework for the La Playa archaeological site located in northern Sonora, Mexico.
This site contains an archaeological record that spans 12,000 years and has provided
a wealth of artifacts and human skeletal remains. Much of the previous work at La
Playa has focused on the documentation of cultural features that are being destroyed
by modern erosion of the landscape. As a result, little work has been done to
understand the depositional history of the site. While many studies in the Desert
Southwest have examined human-environment interactions within systems that are
alluvial, sections of the La Playa stratigraphy do not possess the geomorphological
and sedimentological characteristics typically observed in alluvial systems.
Intensively studied alluvial systems, such as the Gila River drainage basin in
southern Arizona (Waters
2008
), record considerable deposition of gravels and
sands, rapid facies changes, terrace formation and multiple episodes of channel
incision and aggradation. The La Playa stratigraphy lacks these indicators of alluvial
deposition; therefore, previously developed models of those systems are not nec-
essarily applicable. Assessment of the Quaternary stratigraphy involved character-
ization of the soil and sediment types at La Playa and compilation of a surficial map of
the site that addresses distribution of the sediment types, surfaces, and cultural
materials. While this study addresses aspects of the stratigraphy and sedimentology,
Search WWH ::
Custom Search