Rare Earth Elements to identify archaeological strata in the Cocina Cave

Rare earth elements (REE) have been employed in a variety of different scenarios in order to identify the natural or anthropogenic nature of archaeological soils [1,2] . In this study, REE signatures were employed to better understand the layers formation in a cavity called Cocina cave, a large cavity of 300 m2 located at Barranco de la Ventana, one of the ravines flowing southwards from La Canal valley, a little plateau located in the municipality of Dos Aguas (Valencia, Spain). Cocina cave is characterized of very homogenous sediment deposition where it is difficult to understand layers formation processes just employing the traditional archaeological methods and the standardized soil analyses. The archaeological sequence encompasses last hunter-gatherer Holocene occupations in the regional sequence (Mesolithic) followed by several levels attributed to the Neolithic, Bronze Age and historic occupations until the XX century, these last regarding the use of the cavity as a pen. In order to understand the development history of the strata and the anthropogenic or natural formation of soils a total of fifty samples were taken across six different sections (A, B, C, D, E, F, G) and from each section the sampling was carried out at different depths through 1-2m deep sections. All samples were recovered from current pits excavated at the cavity corresponding with some profiles that encompass different strata including natural deposits and hunter and penning activities together with other possible uses not well defined from archaeological data. Several radiocarbon dates confirm the anthropogenic use of the cavity from the IX millennium cal BP to the contemporary times. Major, minor and trace elements including REE were determined employing XRF and ICP- MS. Results were then statistically processed and cross-referenced with archaeological data to aid interpretation. The results show that REE provide interesting details regarding the strata development history, and therefore help archaeologists to better understand the occupation, use and abandonment phases of the cave. [1] Pastor et al., TrAC 78 (2016) 48. [2] Gallello et al., JAS 40 (2013) 799.