San Juan Basin Archaeological Society

Chapter of the Colorado
Archaeological Society

The San Juan Basin Archaeological Society... exploring, learning about, and preserving
archaeological, cultural, and historical resources in the Four Corners region since 1979.


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Next SJBAS Meeting
Thursday, September 11

Fort Lewis College

The next SJBAS meeting will be held on Thursday, September 11th, at the Lyceum in the Center of Southwest Studies at Fort Lewis College. After a brief business meeting, Dr. Raymond Mueller will present: Paleoenvironmental Reconstruction along the Río Verde, Oaxaca, Mexico or how Pre-Hispanic, Human Landscape Degradation Affected the Archaeology of Both the Upper and Lower Regions of a Drainage Basin.

Geoarchaeology is a subset of the field of paleoenvironmental reconstruction and is used to rebuild the environmental setting during some past archaeological site occupation. During the early stages of this project, close to the Pacific coast, it became difficult to explain the differences we were seeing in past environments and archaeology using local information.  After a chance observation during a trip the following year we realized that a possible solution could be found in the highly populated (sites like Monte Alban, Mitla, Yagul, etc.) highlands of the upper drainage. Extensive investigation of arroyo exposures in the Oaxaca Highlands revealed the ubiquitous presence of buried paleosols.  These paleosols represent stable landsurfaces separated by sediments from erosion of adjacent hill slopes. Radiocarbon dating of 36 samples indicated that most of the hill slope erosion and valley alluviation occurred prior to Spanish Conquest. Radiocarbon dates of paleosols show several periods of sedimentation. Mid-Holocene dates are probably associated with climate change; more recent periods of erosion are correlated with major changes in pre-Hispanic land use (primarily deforestation).  Highland erosion led to profound geomorphic and archaeological changes along the lower Río Verde valley near the Pacific Ocean. A network of abandoned stream channels, with little surface expression, was revealed during extensive soil and sediment auguring. Radiocarbon dating of organic-rich channel sediments associated with archaeological sites provided the means to develop a model of changes in floodplain geomorphology. Channels changed both position and form as the sediment load increased due to changing land use in the highland portion of the drainage basin. Increased sediment load also formed bay barrier islands and enclosed previously open bays, creating new food-rich environments. These environmental changes then influenced demography and settlement patterns along the Lower Río Verde and adjacent coastal areas over the last few thousand years. 

Dr. Raymond Mueller (aka, brother of Jim) began his graduate education studying the relationship between Geomorphology and Soil Genesis. His undergraduate education was at SUNY-Buffalo with graduate education at Montana State University and the University of Kansas.  Shortly after getting a faculty position at Richard Stockton College of New Jersey, a series of serendipitous events resulted in a change in interest to Geoarchaeology.  Early research looking at environmental change and archaeology was concentrated in the Mid-Atlantic region.  He has also conducted research in Israel and other locations in the US.  Dr. Mueller’s main area of research is in Oaxaca, Mexico where he has been doing research for the past 26 years. 

Moki Messenger

September 2014

2014 CAS Fundraiser for the Alice Hamilton Scholarship Fund


Follow this link for information about the CAS raffle:

CAS Annual Meeting Event Description

CAS-ANNUAL-MEETING-September26-28-2014 (2).pdf

CAS Newsletter - the Surveyor

The Surveyor


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This site was last edited on August 22, 2014.


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