Three archaeomagnetic applications of archaeological interest to the study of burnt anthropogenic cave sediments

Abstract

Recent archaeomagnetic studies carried out on Mid-to Late Holocene burnt anthropogenic cave sediments have shown that under certain conditions, these materials are suitable geomagnetic field recorders. Archaeomagnetic analyses carried out on these contexts constitute a rich source of information not only for geophysical purposes-in terms of reconstructing the variation of Earth's magnetic field in the past-but also from the archaeological point of view, for example by archaeomagnetic dating. Here, we report three different archaeomagnetic applications to the study of burnt cave sediments: (i) archaeomagnetic dating; (ii) determining palaeotemperatures and (iii) assessing postdepositional processes. The first case study is a dating attempt carried out on a Late Holocene (Bronze Age) burnt level from El Mirador Cave (Burgos, Spain). Using the directional European secular variation curve, several dating intervals were obtained for the last burning of this combustion feature. Considering the archaeological evidence and the independent radiometric (14 C) dating available the possible ages obtained are discussed. This is the first archaeomagnetic dating obtained in these contexts so far. The second case study is an application of the method to determine the last heating temperatures reached by the carbonaceous facies of these fires. Stepwise thermal demagnetization of oriented samples can be used to quantitatively estimate heating temperatures. An intermediate normal polarity component interpreted as a partial *Manuscript Click here to view linked References 2 thermo-remanence (pTRM) with maximum unblocking temperatures of 400-450 ºC was systematically identified, revealing the last heating temperatures experienced by this facies. These temperatures were confirmed with partial thermomagnetic curve experiments. Finally, archaeomagnetic analyses on a partially bioturbated burning event were performed in order to evaluate until what spatial extent the burnt sediments were affected by post-depositional mechanical alteration processes. For each case study, the archaeological implications are discussed highlighting the potential of archaeomagnetic methods to retrieve archaeological information.

Combined study of archaeomagnetism and Raman spectroscopy of experimentally burnt limestones from the middle-palaeolithic site of Pinilla del Valle (Madrid, Spain)

“…It is not the scope of this paper to discuss the limits of this method (for details, see Hrouda et al, 2003), however, it has been successfully applied to a wide variety of burnt archaeological and experimental recreated materials as a palaeotemperature indicator (e.g. Carrancho and Villalaín, 2011;Carrancho et al, 2016;Kapper et al, 2014).…”

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

“…Paleo‐firing temperatures are important indicators for reconstructions of characteristics of lava flows and their influence on the host rocks (e.g., Mare et al, ; Silva et al, ), as well as for constraining the maximum temperature achieved in the rupture zone during an earthquake (e.g., Yang et al, ). Furthermore, determination of (paleo)firing temperatures is of great importance in archeology and specifically for pottery characterization in order to ascertain the technological development and/or provenance of the finds (Maniatis, ) or to document the human use of fire in sediments (Barbetti, ; Carrancho et al, ; Kapper et al, ). Different analytical methods are employed for such analysis (mineralogical studies, scanning electron microscopy (SEM), color determination, Mössbauer spectroscopy, thermal analysis, etc.)…”

Characterization of ancient lipids in prehistoric organic residues: Chemical evidence of livestock‐pens in rock‐shelters since early neolithic to bronze age

“…The settlement patterns maintained the same behavior in the North of the Iberian Peninsula along the Early Neolithic and Bronze Age (Chalcolithic Age). One of these patterns was the use of caves and rock‐shelters as livestock‐pens . Commonly and to reduce the volume of dung accumulated in the these sites and clean them from parasites, the dung piles were burnt.…”