Cutting Graminae Tools and “Sickle Gloss” Formation

Abstract

ABSTRACTThe SEM EDS method was applied to the working surfaces of prehistoric and experimental reaping tools in order to help solve the problem of the origins and development of their characteristic polish, called “sickle gloss.” Experiments with contemporary steel scythes, as well as replicas of flint blade tools, were conducted and were compared with prehistoric Neolithic and Early Bronze Age reaping implements. The most important result of the study was the recognition, on the working surfaces of both steel and flint experimental tools, of the presence of an additional layer, termed here a “crust.” This thin layer consists of calcium, carbon, oxygen, chlorium, phosphorus, aluminum, silica, potassium, and sometimes sulphur. The proportion of silica in this crust (0.8 -1.5% on average in both groups of experimental tools) was considerably smaller than the proportion of silica in the crust of prehistoric tools (5. 4 -11.6%). The most probable explanation for these results is selective chemical weathering. Prehistoric tool users discarded artifacts in silica-rich Holocene soil deposits in which easily dissolved calcium, aluminum and phosphorus oxides were replaced by less easily dissolved silica (SiO2).