Thermal Curve Fracture (TCF) as a diagnostic tool for the identification of anthropogenic fire

Author(s): Sarah Hlubik; Russell Cutts

Year: 2015


Recognizing fire evidence in the record can be challenging and contentious. Aside from baked earth features – hearths, daub, etc. – a widely reported associated artifact is fire-cracked rock (FCR). Unlike flaked stone assemblages, FCR lacks a standardized description, criteria, test or model; archaeologists often learn identification ‘in the field.’ Recent actualistic studies have demonstrated that a previously undescribed type of FCR has likely been unknowingly lumped with other ‘angular fragments’—another widely reported, but not usually fire associated, artifact class. Termed thermal-curve fracture (TCF), these pieces tend to be proportionally uniform in thickness and width with a curve angle between 173° and 176°. This report details experiments testing three hypotheses: that thermal curve fractures are 1) a distinct angular fragment type, describable and clearly associated with fire; 2) produced in fires that are anthropogenic, as suggested by temperature and duration; and 3) produced primarily when knapped materials are exposed to fire. A cursory survey of 1.5 Ma collections from FxJj20, Koobi Fora, Kenya, revealed a number of potential TCF classed as ‘angular fragments’, suggesting the possibility that fire evidence is present on ESA sites.

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Cite this Record

Thermal Curve Fracture (TCF) as a diagnostic tool for the identification of anthropogenic fire. Russell Cutts, Sarah Hlubik. Presented at The 80th Annual Meeting of the Society for American Archaeology, San Francisco, California. 2015 ( tDAR id: 398111)

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Spatial Coverage

min long: -18.809; min lat: -38.823 ; max long: 53.262; max lat: 38.823 ;