## 5 Conclusions  
This paper presents for the first time the use of the magnetic susceptibility to evaluate the impacts of wildfires on archaeological areas. Portable susceptometers allow for measuring quickly and non-destructively the magnetic susceptibility in a large number of sampling points. Thus, this technique is suitable for protected areas or heritage assets in which destructive tests cannot be performed. Laboratory measurements of the rock outcropping in the studied area showed that this technique is capable of providing information about the maximum temperatures reached by rocks in past fires. Besides other applications, knowing the maximum temperature reached by rocks during a fire in an archaeological setting is essential to assess the possible existing damage suffered from these events as the result of mineralogical and physical  
Figure 6: Graphics obtained for induced magnetization (**a**) and the hysteresis cycles (**b**) in the samples previously heated to 1000 \({}^{\circ}\)C in the SNOL 30/1300 oven. These graphics are equivalent to the ones obtained by [PERSON] et al., (2017) for the mineral HCSLT (see Figure 1 in that paper). changes. It also facilitates planning preventive conservation for long-term effects favoured by fire damage. The results in this paper show that measurements obtained with portable susceptometers allow establishing zones with different magnetic susceptibility in regions that underwent fires and, therefore, have the capability of characterising qualitatively the areas that were more intensely affected by temperature increase without further tests. Previous studies have used different techniques, such as Ultrasound Pulse Velocity or Leeb Hardness to assess the intensity of fire damage. However, these techniques are quite ineffective in plutonic rocks that underwent temperatures higher than the \(\alpha\) to \(\beta\)-quartz transition (573 \({}^{\circ}\)C) due to the intense fracturing this transition causes in the material. Our results show that magnetic susceptibility changes are particularly noticeable above 600 \({}^{\circ}\)C. Therefore, magnetic susceptibility is especially useful above that threshold in which other existing techniques used to characterize the effects of fires on rocks are more difficult to use. Further research in this area is needed to widen the database of relationship between magnetic susceptibility and the temperatures reached in different rock types. However, the results in the field study performed in this paper allowed us to prove the usefulness of the use this tool in areas affected by wildfires. More studies in different areas, with different fire temperatures and rock types will enable a better understanding of how magnetic susceptibility of rocks changes with fires, improving the usage of this technique to assess fire damage of Cultural Heritage. Conceptualization, B.O.-U. and M.G.-H.; methodology, B.O.-U. ; software, A.S.-R.; validation, A.S.-R. and B.O; formal analysis, A.S.-R.; investigation, A.S.-R., B.O.-U. and M.G.-H.; resources, M.G.-H.; writing--original draft preparation, A.S.-R.; writing--review and editing, B.O.-U. and M.G.-H.; visualization, A.S.-R., B.O.-U. and M.G.-H.; supervision, B.O.-U. and M.G.-H.; project administration, M.G.-H.; funding acquisition, M.G.-H. All authors have read and agreed to the published version of the manuscript. This research was funded by \"Top Heritage (P2018/NMT-4372) programme from the Regional Government of Madrid (Spain)\" and \"Grants PIC2020-116896 RB-C21\", \"PIC2020-116896 RB-C22\" funded by MCIN/AEI/10.13039/501100011033. Not applicable. Data Availability Statement: Data available on request to authors. The authors thank to the Direccion General de Patrimiono de la Consejeria de Cultura de la Junta de Castilla y Leon for providing technical reports on the fire of El Bernveco and the permissions granted to work in the archaeological areas.