January 26, 2019 – 2:00 PM: Linda Scott Cummings, PhD and R.A. Varney, PaleoResearch Institute

Examining Food: Beyond Identification, Calories, and Nutrients – What is the Carbon Content?

Food is essential to life, and is an important and integral part of the archaeological record. Archaeology facilitates examination of ancient food, using those results to define our understanding of culture and chronology. Radiocarbon dating charred food crust presents challenges. We have mastered issues of recovery and lab treatment, but archaeology retains assumptions about food being a simple representation of the past. Now we ask, are these records all they appear to be and only what they appear to be? How do the principles of cooking chemistry help understand radiocarbon dating charred food in vessels?
From one Oneota (Blood Run) vessel sampled in three locations we obtained three radiocarbon dates including two that are congruent (from the rim and the exterior shoulder) and one discrepant (from the upper interior wall), pointing to the importance of understanding your sample of charred material. It also provides an example of the importance of understanding cooking chemistry. Multiple paired charred food crust and annual samples from southeastern Iowa and other locations show the effectiveness of chemical pretreatment to obtain congruent dates.

Our NSF grant was awarded to develop a chemical pretreatment method that would produce congruent dates on paired charred food crust and annual samples. We are studying dates produced on charred food obtained from rim vs. body sherds from the same vessel. A repeat of the concept of dating multiple samples from different areas of the same vessel should be paired with an annual from the same context allows us to confirm which dates are congruent. We combine our knowledge of archaeology, food chemistry, lab chemistry, and radiocarbon dating with a healthy dose of curiosity to produce recommendations and methods that will yield more accurate dates on charred food crust, as well as identify when the food cooked in the vessel just cannot yield an accurate date. We show the pitfalls of attempting a freshwater reservoir correction factor and discuss radiocarbon dates obtained on reference fish and other reference animal bones.



Dr. Linda Scott Cummings is President and CEO of PaleoResearch Institute, Inc., which she founded in 1972. She obtained both her Masters and Ph.D. from the University of Colorado after founding PRI. With a mission to make science more accessible to archaeologists and geologists, PRI works in both the compliance (CRM and Heritage Management) and research industries. Dr. Scott Cummings is an Honorary Fellow at the Center for Climatic Research at the University of Wisconsin, Madison. She participated in the international EARTH (Early Agriculture Resources and Technology Heritage) program sponsored by the European Union, which resulted in multiple publications in their edited volume series published by Oxbow Books. Trained primarily as an archaeologist and palynologist, Dr. Scott Cummings has expanded her expertise to include phytolith and starch identification and interpretation of FTIR and XRF signatures.

Dr. Scott Cummings leads several teams and oversees all of the research at PaleoResearch Institute. She also initiates and oversees original research outside the scope of CRM. Currently she is developing new chemical pre-treatment protocols for dating crusty charred food residues recovered from ceramics with support from the State of Minnesota and NSF. Dr. Scott Cummings directs a team of specialists at PaleoResearch Institute whose experience encompasses the remainder of the services that we offer. She has participated in field sampling and directing both laboratory and analytic operations, often developing new techniques. Her work includes projects from the entire North American continent, as well as other areas of the world such as Pacific Islands and Pacific Rim, Meso and South America, the Middle East, Europe, North Africa, and Oman. She has experience meeting deadlines and participating as a collaborator on large, complex, and small projects. Dr. Scott Cummings brings an innovative approach to field sampling, sample design consultation (to meet the needs of any research design), analysis, and interpretation. She works within a synergistic framework.