A Mineral Magnetic Approach to Determine Paleo‐Firing Temperatures in the Neolithic Settlement Site of Mursalevo‐Deveboaz (SW Bulgaria)

Abstract

Archeological remains from the Neolithic period in SE Europe are characterized by the presence of massive burnt daub relics sintered at high temperatures. These findings raised the hypothesis of deliberate house burning as a strategy for ensuring the survival of place and the development of social memory in Neolithic society. Although highly discussed in the archeological community, analytical data on the ancient firing temperatures achieved during burning Neolithic houses are missing except an empirical study determining firing temperatures according to the color of burned clay. The Neolithic site Mursalevo‐Deveboaz (Bulgaria) is one of the largest known settlements consisting of more than 70 houses. Rock‐magnetic analyses are applied for characterization of iron oxides produced during firing, and the firing temperatures were estimated using the magnetic susceptibility method. Results on a collection of 445 samples show the presence of very fine grained magnetite/maghemite and hematite. Magnetic data are supported by elemental analysis, reflectance spectroscopy, and scanning electron microscopy. The data suggest an increase in the magnetic grain size from superparamagnetic toward single domain with increasing firing temperature. Firing temperature estimates for 148 samples of different color vary between 680 and 1,140°C. Comparing the magnetic properties of iron oxides identified and literature data on solution‐combustion synthesis of iron oxides allowed a mechanism behind the extreme firing of Neolithic houses to be suggested. Our study proposes for the first time that combustion synthesis of iron oxides could explain the extreme house burning in many Neolithic settlements achieved through intentional addition of wood, dung and urine.

On‐site non‐destructive determination of the remanent magnetization of archaeological finds using field magnetometers

“…For example, for a roughness of 3 mm depth, which was present on the samples, the response is reduced by 50% (Bartington, n.d.). The median mass susceptibility is in the range also found by Jordanova et al (2018) for brown‐coloured daub samples from Neolithic houses at Mursalevo‐Deveboaz, Bulgaria.…”

Faulting Processes Unveiled by Magnetic Properties of Fault Rocks

“…The thermochemical expression of magnetic phases in a rock should not change unless the rock is heated in the laboratory beyond the maximum temperature it underwent in nature (e.g., Hrouda et al, 2003;Spassov & Hus, 2006). This approach is very similar to estimating temperatures of ancient fires and burnt structures in archeology (Jordanova et al, 2018). In the Japan Trench subduction plate boundary décollement, cored by the JFAST project, maximum temperatures were determined ranging from ~300°C to over 500°C close to the multiple slip surfaces of previous earthquakes (cf.…”

Determining the use of ancient ceramic artefacts through combined morphological and magnetic analyses: the case of Villa del Foro, Northern Italy

“…Among them, archaeomagnetism is a very promising but still under-utilized technique. Even though during the last decades it has been increasingly used as a dating tool (Herries et al 2008;Tema et al 2013;Batt et al 2017;Casas and Tema 2019; or as ancient heating temperature indicator (Spassov and Hus 2006;Rasmussen et al 2012;Kostadinova-Avramova et al 2018;Jordanova et al 2018;, its great potential on pottery use studies is still very little exploited (Francés-Negro et al 2019).…”