Document Type

Thesis

Date of Degree Completion

Spring 2016

Degree Name

Master of Science (MS)

Department

Resource Management

Committee Chair

Dr. Steven Hackenberger

Second Committee Member

Dr. Lisa Ely

Third Committee Member

Narcizo Guerrero Murillo, MS

Abstract

Mapping and Radiocarbon Dating Archaic Period Monuments: La Alberca Structure Complex, Highland Michoacán, Mexico

by

Mark F. Steinkraus

June 2016

Ongoing collaborations with the Comunidad Indígena de Nuevo San Juan Parangaricutiro hold great potential for exploring the origins of sedentary ranked communities that predate others in Mesoamerica by as much as one thousand years. Three carbon samples from the lower buried portions of the Central Structure at La Alberca Complex yield a date range of 7245-6470 cal B.P. The carbon sample laying on an upper tier of the feature yields a date of 4780 cal B.P. These dates suggest that the feature is 7000 to 6000 years old and may have been in use as recently as 5000 to 4000 years ago (in calibrated radiocarbon years). These radiocarbon dates fall in sequence and overlap the dates for the burial in the nearby La Alberca Rockshelter (6650 -3985 cal B.P.). The Central Structure as well as above ground Structures 1 and 5 (labeled Yacata) are buried below a coarse consolidated tephra. Although more weathered, this tephra is similar to the oldest tephra in the bottom of La Alberca Rockshelter. The tephra is at least 7000 to 8000 years old (calibrated).

Test trenching and probing, when combined with 3-D ArcMap visualization, reveal important details about the fully buried Central Structure. It appears to have been built on top of, rather than into an elevated natural landform. It is ovoid in shape (24x32 meters, with a NE-SW orientation) and three meters in height. The structure was built using three tiers formed from rock walls backfilled with sediments to create gently sloping steps or terraces. The middle tier is consistently five meters in width. Each tier is between 60 and 90 cm high. Configuration of the surface and first tier of stones suggest that the structure has been robbed of stone for fence building, tree planting, and/or field clearing. The Central Structure is devoid of artifacts apart from the one concentration of resinous charcoal dated to 4780 cal B.P. The earliest ceramic sherds recovered from the Structure Complex (50-80 centimeters deep) are found above the lower tephras (1-2.5 meters deep) that superimpose rock construction.

The Central Structure and Structures 1 and 5 (Yacata) are the oldest known stone and earth structures in West Mexico. They are most likely precursors to the Late Formative guachomontanes, and may cover burials if not shaft tombs. West Central Mexico is now identified as home to the closest genetic relatives to maize and beans and includes the earliest archaeological evidence for maize. It follows to hypothesize that sedentism, social ranking, and ritual structures would also develop very early within this region. The Late Archaic ritual burial in La Alberca Rockshelter and the earlier structures of the La Alberca Complex predate similar developments in the Early Formative Period in West Mexico. The burial and preservation of ritual structures in the Parangaricutiro Highlands by tephra from several eruptions provides challenges for both geoarchaeologists and tephrochronologists hoping to refine models of the nature and extent of the influences of volcanoes on early cultural developments.

Key Words: Late Archaic, Early Formative, Archaeology, Earthen Structures, Tephrochronology, Central Mexico, and Parangaricutiro Highlands.

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