Academic archaeologists, especially those working in western North America and Central America, have long sought to answer sophisticated research questions concerning the trade and exchange behavior of cultures with the aid of petrographic and geochemical provenance techniques. More recently, contract archaeologists and geoarchaeologists have also shown an increasing interest in attempting to address cultural questions through more in-depth analyses of stone, ceramic and metal artifacts. Such interests hold especially for prehistoric cultural studies of the eastern U.S., where climate and acidic soils result in the poor preservation of materials other than stone and ceramics.
Determining which techniques are best suited for a particular study can be a difficult decision. Archaeologists unfamiliar with the strengths and limitations of various petrographic and geochemical techniques may request inappropriate analyses, or draw erroneous conclusions because they do not understand what the analytical results mean. At the same time, geologists and geochemists unfamiliar with the archaeological research questions being asked, or the geographic context of the investigation, may inadvertently provide the wrong information. Worse yet, they may simply act as "black boxes," churning out analyses without adequately conveying the limitations of the data.
LaPorta Geological Consultants has developed a unique approach to lithic provenance studies guided by both classical geological methods and archaeological perspectives. Since every study is different, we tailor our approach to lithic provenance questions as appropriate. However, underlying each of our studies are several core components that provide a robust framework for identifying lithic raw material sources and their spatial distribution:
Geological mapping of the site area
The construction of a geologic catchment
Comparison of lithic artifacts to the raw material holdings in our lithic database
Standard petrographic analysis
Scanning electron microscopy/energy dispersive x-ray (SEM/EDX) analysis and/or X-ray diffraction analysis
As a result of our unique approach, LaPorta Geological Consultants has been highly successful in providing our clients with detailed, precise descriptions of raw material sources and their distribution at a level unmatched by the standard provenance methods typically applied in archaeological studies.
*** Last updated: Spring, 2012