GEOLOGIC MAPPING: THE FIRST STEP OF RAW MATERIAL PROVENANCE RESEARCH IN THE ARCHAEOLOGICAL SCIENCES. GEOLOGICAL MODELS FOR PRE-CONTACT QUARRY PROSPECTION

In the eastern United States, archaeological remains are of lithologic character. Cultural items made of wood, shell, or textile frequently do not survive burial in moist, acidic and organic soils. Archaeological studies uncover the final resting place of objects. However, much information about the life trajectory of the object can be hypothesized when the origin place of the archaeological object can be discerned. In essence, what is the provenance of the raw material? Where was it quarried?

The first step in locating provenance is the generation of a map that documents geologic units serving as raw materials used by preContact peoples. A geologic map is a database elucidating the spatial distribution and thickness of raw materials, their orientation on the landscape, structural/metamorphic deformation that may change the quality of the material for prehistoric needs, and other observations of interest. This data serves as a predictive model aiding archaeologists with locating/studying the source areas of raw materials, and thus discovering where preContact populations altered the environment. Geologic maps of archaeological sites, as created by state, federal and academic investigations, do not typically address the archaeologists' needs. A map is the product of the research questions under investigation. There are many purposes that a map may serve, from prospecting for economic ore deposits, basic bedrock mapping, structural and tectonic features. Funding constraints also dictate the level of detail, and scale of the map produced. Oftentimes, geologic features of importance to an archaeologist, are a minor part of a question being investigated by geoscientists. As such, mapping with the goal of elucidating raw materials of importance to archaeological questions, is a critical first step in understanding the context of a site under examination.

Geologic mapping of the Kittatinny Supergroup of tri-state New York, New Jersey and Pennsylvania elucidated greater than 2,000 prehistoric bedrock quarries in the Wallkill Valley prehistoric quarry type section (LaPorta, 2009 and references therein). This method has been used successfully in a number of CRM and academic projects on a global scale, but particularly in a number of states east of the Mississippi in Section 106 and SEQRA investigations.