A technique developed at the University, the use of rare earth elements, traces the human mobility in prehistory

  • Scientific Culture and Innovation Unit
  • January 31st, 2022
The researcher Mirco Ramacciotti, with the ICP-MS equipment, in the  ArchaeChemis laboratories of the Department of Analytical Chemistry (UV).
The researcher Mirco Ramacciotti, with the ICP-MS equipment, in the ArchaeChemis laboratories of the Department of Analytical Chemistry (UV).

The analysis of archaeological materials based on their chemical characterisation is a line of great interest in assessing the mobility of human groups, the strategies of exploitation of different materials or the mechanisms of their spread. This technique, the analysis of rare earth elements, developed by the ArchaeChemis Research Unit of the University of Valencia (UV), has allowed to characterise that the inhabitants of the Cueva de la Cocina in Dos Aguas (Valencia) used materials obtained over 50 kilometres of distance, a data that allows to know that its mobility was greater than previously thought.

In this study, published this month in the journal Geoarchaeology, this technique has been applied to the siliceous outcrops used by the last hunters and gatherers about 8,500 years ago. Researcher Oreto García Puchol (UV Department of Prehistory, Archaeology and Ancient History) has confirmed the potential of the application of rare earth analysis (technique created in 2014) to discriminate between different siliceous outcrops as a basis for development hypotheses on the supply of raw materials and patterns of mobility in Prehistory.

As can be seen from the analysis of rare earth elements, the hunter-gatherers of the Cueva de la Cocina collected flint from local outcrops, but it has also been observed that flint arrived from more distant outcrops, such as from the Serpis Valley. La Cueva de la Cocina is an archaeological site excavated and researched in recent years through funds from the Museum of Prehistory of Valencia in the framework of various projects of the Ministry of Science and Innovation and the Palarq Foundation.

The UV ArchaeChemis Multidisciplinary Research Unit is developing rare earth elements (REE) characterisation methods in order to help solve issues related to the identification of different types of rock. In 2016, the REEs of a set of dolerites of natural outcrops of the Valencian Community were analysed for the first time and were compared with archaeological pieces found in the sites of Arenal de la costa and Ereta del pedregal (Valencia), and Bancal de Satorre (Alicante) with the aim of relating its origin to the outcrops of origin.

Researchers Gianni Gallello, from the Department of Prehistory, Archaeology and Ancient History, coordinator of ArchaeChemis, and Agustín Pastor, from the Department of Analytical Chemistry at UV, comment: “The procedure followed in this study was also used to identify of the origins of the pains used for the construction of Stonehenge in a recently published study (2021)”.

Rare earth elements are common chemical components in the Earth’s crust essential to the development of new technologies. To determine them, mass spectrometry (ICP-MS) is used, a technique whereby ions produced in argon plasma are injected into the mass spectrometer, thus separating the ions based on their mass-to-charge ratio. Thus, samples of lithic objects and rocks from potential outcrops are digested with an acidic solution that includes the use of hydrofluoric acid, to then study their proportions and concentrations and compare them statistically between the samples studied.

These early works served as the basis for ArcheChemis to use REEs in the identification of silica rocks, used for the manufacture of lithic utensils in Prehistory. A methodological work (2019) addressed the characterisation of various flint outcrops in the Serpis Valley (Alicante), a material widely exploited in prehistory. The processing of REEs using multivariate statistics provided promising results for distinguishing between different outcrops located within a radius of less than 20 km.



Ramacciotti, M., García‐Puchol, O., Cortell‐Nicolau, A., Gallello, G., Morales‐Rubio, A., & Pastor, A. (2022). “Moving to the land: First archaeometric study of chert procurement at Cueva de la Cocina (Eastern Iberia)”. Geoarchaeology. https://doi.org/10.1002/gea.21903


Gallello, G., Orozco, T., Pastor, A., de la Guardia, M., & Bernabeu, J. (2016). Regional provenance of dolerite prehistoric objects through mineral analysis. Microchemical Journal, 124, 167-174. https://doi.org/10.1016/j.microc.2015.08.018


Bevins, R. E., Pearce, N. J., & Ixer, R. A. (2021). Revisiting the provenance of the Stonehenge bluestones: Refining the provenance of the Group 2 non-spotted dolerites using rare earth element geochemistry. Journal of Archaeological Science: Reports, 38, 103083. https://doi.org/10.1016/j.jasrep.2021.103083


Ramacciotti, M., Gallello, G., Pastor, A., Diez Castillo, A., & García Puchol, O. (2019). Chert nucleus and cortex characterization for archaeological provenance study tested in the Prebaetic system region (Valencian community, Spain). Lithic Technology, 44(3), 166-180. https://doi.org/10.1080/01977261.2019.1618043