Technologies and complexities as reflected in small cast iron fragments recovered from medieval sites in eastern Mongolia

Abstract

Technological innovation often occurs in unexpected places far from the origin of pertinent invention. This may be prompted by a range of factors including constrained access to human, material, or informational resources as might be expected during periods of political change and uncertainty. Such experiments in both technique and technology can be a useful way to promote multiple options and flexibility in production, especially given shifting sociopolitical settings. A clear example of this case was observed based on cast iron fragments recovered from several medieval period sites within the Delgerkhaan Uul area of eastern Mongolia. These fragments were consistently small in size and mostly irregular in shape, suggesting no specific usage of practical value in the local steppe environment. However, results from visual, microstructural, compositional, and radiocarbon analyses produced strong evidence that cast iron objects, both of medieval and earlier periods, were collected to serve as a raw material for further treatments evidently in small-scale steelmaking processes. While the production of small amounts of high-quality steel was the end goal of these treatments, significant differences visible in microstructures indicate that the process was not standardized and subject to substantial variation. These results suggest a technological environment characterized by the use of non-local cast iron materials subjected to micro-steelmaking under non-standardized processing conditions. We interpret this unique technology as an example of nomadic steppe communities innovating within the constraints of their local geographical, technological, and sociopolitical setting to maintain flexible alternatives during a period of sociopolitical transformation and uncertainty.