Research is one way to foster and develop technological innovations and applications that enhance the preservation of archaeological sites, landscapes, materials. NCPTT conducts its own research; provides assistance to independent external research projects; and actively seeks to build new partnerships to leverage research dollars and knowledge. Below are a few examples of recent and ongoing research endeavors.
A New Approach to Geophysics Pedagogy
The "Prospection in Depth" course, currently in its second iteration, offers a new approach to archaeological pedagogy. The National Center training course followed a well-worn path in professional development and student training by incorporating multiple geophysical techniques, hands-on equipment use, and data collection at genuine archaeological sites. However, we offered several unique twists:
- we partnered with a large-scale research project so that the training was embedded in a rich matrix of theory, method, and purpose;
- we provided workshop trainees and their instructors the opportunity to investigate the actual archaeological correlates of their remotely-sensed data; and
- we offered an on-line, virtual course component to the general public that greatly enhanced the workshop's effectiveness and visibility.
This type of learning environment is seldom, if ever, offered in professional development contexts outside of formal university field schools, despite the apparent benefits that both partners would enjoy and the multitude of contract or academic field projects underway around the country at any given moment.
When it comes to geophysics training most courses for professionals stress field methods, which is a viable, activity-centered instructional technique. However, because they prioritize instrument operations over anomaly interpretation, ironically they never move far beyond the teacher-centric model. Students simply do not possess the decades of experiential knowledge necessary to interpret anomalies, and have no basis to make the inferential, intuitive leaps from anomaly to archaeological correlate. In the absence of excavating, students remain wholly reliant on the intellectual capital of their teachers. The activity-based component of most geophysics courses thus applies only to the mechanics of instrumentation and application; students actively learn how to operate the machines, set up grids, and download data. What interpretation is present is necessarily done as part of a hierarchical, teacher-centric process largely bereft of true dialogue.
Prospection in Depth, in contrast, places geophysics instruction in the context of an ongoing academic excavation project, and teachers and students jointly excavate select anomalies to better understand exactly what it is that structures them. NCPTT's approach thus carries the activity model into the interpretive realm in what is best characterized as a constructivist approach to learning. In the latter theory, students actively interact with with information and peers to construct new knowledge for themselves. Participants know their exercises directly inform legitimate, active archaeological questions. This gives participant's work an importance, an immediacy lacking in teacher-centric models that build off canned data sets.
In practical terms, the academic project obtained survey coverage of 2400 m2 of the site that they would not otherwise have had, along with the interpretive assistance of five experts, at little to no fiscal or logistical cost. The workshop participants not only gained experience in geophysics, but also experienced the mental stimulation of engaging in the type of research dialogue only generated by a mature research project and a constructivist pedagogy.
Information on the NCPTT model was provided to the professional public in the following forum:
Arntzen, Katherine and David W. Morgan
2007 "Prospection in Depth: The Educational Benefits of Fusing Geophysical Prospection Training with Mature Research Projects." Paper presented at the 40th Annual Conference on Historical and Underwater Archaeology, Williamsburg, Virginia.
Mound Chronology through Pedogenesis
NCPTT, Washington University at St. Louis (Dr. T.R. Kidder), the University of Minnesota's Institute for Rock Magnetism (Dr. Peter Solheid and Dr. Subir Banerjee), and the Louisiana Division of Archaeology (Dr. Joe Saunders) have teamed up to explore how soil formation might be used to determine the relative age of prehistoric earthworks.
Sediments used to build earthworks break down into identifiable soil horizons over time. Previous and on-going studies show that older earthworks have a more developed soil sequence with a well defined and thick accumulation of clay. Thicker clay accumulations at greater depth indicate a longer passage of time from the initial construction. Comparing the depth of clay accumulations between earthworks may allow the creation of a relative history of earthwork construction, a dating technique that becomes more robust when combined with radiometric dating of organic material within the soil sequence. Because it is possible to study clay accumulation in small diameter solid soil cores, this method offers the possibility of a rapid and relatively inexpensive means of assessing site chronologies that is also minimally damaging to archaeological resources.
Such a study has been hypothetically possible for many years, but the promise of this method is limited because of three factors:
- minimal investigation of variables possibly affecting clay translocation processes,
- extant hydrometer sediment analytical techniques require too much time to make translocation studies worth pursuing, and
- the technique usually results in the sacrifice of the entire core.
This research collaboration will employ a geological and commercial technique never applied for sediment study in archaeology: laser diffraction particle size analysis. Using a laser diffraction particle size analyzer (LDPSA) to categorize sediment size represents a marked technological advance, because, compared to the traditional hydrometer method, the LDPSA process is roughly 90 times faster (circa 30 samples processed every 8 hours) and sample sizes can be as much as 92.3 percent smaller (5 grams, rather than 65 grams). In short, LDPSA makes practical for the first time an effort to develop a new technique for the relative age assessment of earthworks through translocation studies.
Soil cores from non-archaeological contexts in the vicinity of the Poverty Point earthworks, a World Heritage site in northeast Louisiana, are currently undergoing magnetic and laser diffraction particle size analyses to determine if the proposed research is viable. If so, the project will seek permission to continue investigating in archaeological contexts at the site itself.
1996 Poverty Point: A Terminal Archaic Culture of the Lower Mississippi Valley. 2nd edition. Anthropological Study Series No. 7. Department of Culture, Recreation and Tourism, Office of Cultural Development, Division of Archaeology, Baton Rouge.
Shepard, F.P. 1954 Nomenclature Based on Sand-Silt-Clay Ratios. Journal of Sedimentary Petrology 24:151-158.
U.S. Department of the Interior, U.S. Geological Survey
2003 Surficial Sediment Data from the Gulf of Maine, Georges Bank, and Vicinity: A GIS Compilation. U.S.G.S. Open-File Report 03-001. Available on the World Wide Web at:
http://www.ncptt.nps.gov/Archeology-and-Collections/Research.aspx. Last updated on August 14, 2003.