Experimental analysis of fire-cracked rocks from varied use contexts: Fracture attributes

Abstract

This experimental study of fire-cracked rocks sought to determine if varied rock fracture attributes could be correlated with specific past uses of heated stones. A total of 864 rocks were heated in 41 fires that replicated hearth, stone boiling, sweat lodge, and earth oven uses of quartz, quartzite, and sandstone cobbles as heating elements. Analysis of experimental results considered three fire-cracked rock attributes (fracture rate, fragment type, and fragment shape) which can be correlated with some of the specific uses of rocks as heating elements. These attributes can be applied to fire-cracked rock assemblages from archaeological contexts to determine their past uses with relatively consistent results as long as the archaeological context of the fire-cracked rocks is carefully considered.