The problems with visual identification of Dover and fort Payne Chert
Similar characteristics including color, luster, texture, and mineral inclusions of both Dover and Fort Payne chert types coupled with the wide geologic and geographic distribution of these deposits compound interobserver errors associated with visual identification methods. Samples were obtained from outcrops of Dover from Kentucky and Tennessee and Fort Payne chert from Alabama, Georgia, Illinois, Kentucky, Mississippi, and Tennessee demonstrating their extensive geologic distribution as well as the great similarity in macroscopic traits. A logistic regression analysis upon the sample database demonstrates successful differentiation of the chert types. However, the Dover/ Fort Payne case study provides a cautionary example of the potential pitfalls with sourcing studies solely reliant upon visual attributes to assign artifact provenance. In general, the use of visual chert identification should be a "first approximation" and it is argued here that large type databases systematically sampled from both primary and secondary sources highlight the possible wide range of macroscopic variation present.
Parish, R., & Durham, E. (2015). The problems with visual identification of Dover and fort Payne Chert. Southeastern Archaeology, 34 (1), 71-83. https://doi.org/10.1179/2168472314Y.0000000003