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Sacaton, AZ, United States

Woodson M.K.,Cultural Resource Management Program | Sandor J.A.,P.O. Box 1994 | Strawhacker C.,University of Colorado at Boulder | Miles W.D.,Cultural Resource Management Program

Irragric anthrosols form as a result of prolonged deposition of fine sediments from irrigation water. Ancient irragric soils centuries to millennia old occur in several world regions, especially in arid environments of Asia and the Americas. This article presents evidence for an ancient irragric anthrosol in the North American Southwest, along the Snaketown Canal System in the Middle Gila River Valley, Arizona. This pedostratigraphic unit was formed as a result of a millennium of irrigation by Hohokam farmers from A.D. 450 to 1450. The irragric soil consists of a mantle of silty-to-loamy textures with minimal soil formation overlying a natural argillic horizon on a Pleistocene stream terrace. A soil mapped independently by the United States Department of Agriculture-Natural Resources Conservation Service with these horizons corresponds closely with the canal system. Soil within the canal system tends to be lower in salt, sodium, and pH compared with external soils. This suggests that the irragric process improved soil for crop production through long-term leaching and additions of fresh sediments with the irrigation water. This anthropogenic process of canal sedimentation has had a long-lasting impact on the sedimentary record and soils in this arid environment. © 2015 Wiley Periodicals, Inc. Source

Wright D.K.,Seoul National University | Darling J.A.,Southern Methodist University | Lewis B.V.,Tribal Historic Preservation Office | Fertelmes C.M.,Cultural Resource Management Program | And 3 more authors.
Human Ecology

Dust in its myriad forms impacts human existence in arid environments; but dust is more than an environmental nuisance. It shapes and reshapes adaptive response and human ideology over the short and long term. In 2011, the Gila River Indian Community (GRIC), Arizona, U.S.A. sponsored a study of dust entrainment within the jurisdiction of its airshed. The study's primary objectives were to determine the relationship between sediment sources and sinks in premodern contexts and how indigenous people have coped with eolian activity since intensive settlement of the Middle Gila River Valley began. Ethnographic and archaeological sources indicate that people respect winds and observe cultural procedures consistent with their origin and to reduce their ill effects. Geomorphic data also show stratigraphic correspondence between relic wash channels and adjacent terrace and sand sheet deposits demonstrating a long history of eolian activity derived from fluvial sources. Climatological data from PM10 "exceedance events" corroborate anthropological analyses indicating that extreme dust events are typically westerlies and occur during exceptionally dry periods. Eolian dust is part of the ambient ecosystem of the GRIC and should be viewed as such within the modern cultural and regulatory environment governing these emissions. © 2013 Springer Science+Business Media New York. Source

Purdue L.,French National Center for Scientific Research | Miles W.,Cultural Resource Management Program | Woodson K.,Cultural Resource Management Program | Darling A.,Cultural Resource Management Program | Berger J.-F.,French National Center for Scientific Research
Quaternary International

The Hohokam were a long lived (300-1450 AD) agrarian society in the deserts of southern Arizona with an efficient irrigation system and a complex socio-political organization. Dependent on environmental conditions, they coped with hydrological and geomorphic changes, which potentially had an impact on their cultural evolution. Irrigation canals were regularly maintained and/or abandoned and their fills record secondary signatures of fluvial dynamics, landscape change and land use. Micromorphological studies allow for the creation of a typology of canal fills based on semi-quantitative measurements. A synchronous and diachronic analysis of canal systems can then be undertaken by means of pedosedimentary correlation. As part of cultural resource management projects on the Gila River Indian Reservation, south of Phoenix, studies have been conducted on the prehistoric Santan Irrigation System, in use from the 10th to the 15th century AD. Phases of low flow were identified, followed by alluvial fan flooding, and seasonal deposition between the 10th-14th century AD (Sedentary/Early Classic Period). During the 14th-15th century AD (Late Classic Period), evidence of active erosion is initially recorded in the sediments, followed by seasonal water supply, and ultimately canal abandonment despite probable efficient irrigation. © 2009 Elsevier Ltd and INQUA. Source

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