Message #250: From: AzTeC SW Archaeology SIG To: "'Matthias Giessler'" Subject: Wood Sourcing Physical Methods And Resource Depletion Date: Mon, 07 Jul 1997 10:37:36 -0700 From: Brian Kenny I attended an archaeology lecture of the Colorado Archaeological Society in Cortez CO on July 3rd. Dylan Schwindt
presented an highly interesting and significant report on the chemical and physical methods of wood sourcing. Mr Schwindt provided an abstract of his paper (reproduced below): Tree Chemistry: A New Method for Addressing Ancient Resource Depletion A Wood Sourcing Study of Utah Juniper (Juniperus osteosperma) Trees Growing in Sand Canyon, Southwestern Colorado by Dylan Schwindt Summary Can the chemistry of roof beams recovered from archaeological sites be employed to determine wood sources used by ancient people? This research takes the first step toward answering this question by identifying variations in the chemical composition of modern trees in a small area of southwestern Colorado. Further research into sourcing construction timbers in archaeological sites appears promising, and may help archaeologists determine whether resource depletion contributed to the final Pueblo abandonment of the Four Corners area around AD 1300. Abstract The objective of this research is to evaluate variation in the elemental composition of Juniperus osteosperma sapwood growing on different sandstone substrates. This will aid in assessing the feasibility of tracing Ancestal Puebloan Juniperus construction beams and Juniperus fuelwood in the Sand Canyon locality to their harvesting sites. Ten samples of Juniperus osteosperma sapwood, two samples of soil, and two samples of bedrock were collected on each of four different types of sandstone substrates present at Sand Canyon in southwestern Colorado. Flame Atomic Absorption Spectroscopy (FAAS) and Flame Atomic Emission Spectroscopy (FAES) were employed to analyze the concentrations in parts per million (ppm) of six elements ( Ba, Ca, Mg, Mn, Sr, Zn ) in all samples. Discriminant analysis of these data suggest that trees growing in the four locations tested can be differentiated with varying success rates for different formations. Analysis of soil and bedrock samples suggest that these differences are likely to be caused by variations in substrate. These results indicate that further research into the sourcing of construction timbers in archaeological sites appears promising.