Benquerencia (La Serena - Spain) rock art: An integrated spectroscopy analysis with FTIR and Raman

Abstract

La Serena region is a large plateau with open landscapes bounded in the south by a mountain chain formed by the Benquerencia, Tiros and La Rinconada Sierras. There are more than 300 painted and engraved sites in the region.Cueva Grande, Cueva de En medio and Cueva Pequeña are three Schematic rock art shelters located in the municipality of Benquerencia de la Serena, Badajoz, Spain. Over their panels have been documented more than a hundred of painted schematic figures (anthropomorphic figures, eye-shape figures and symbols) (Neolithic – Copper Age).Paintings are monochromatic with red or black coloration. A total of 13 samples (10 red and 3 black samples) from different panels were collected and analyzed using micro-Raman spectroscopy and ATR-FTIR.Micro-Raman spectroscopy was able to characterize the main mineral component, respectively hematite for the red figures and charcoal for the black paintings. ATR-FTIR was useful to possible ochre and possible organic identification. These latest results are particularly important for understanding manufacturing processes and addressing conservation problems.

Archaeometrical characterization of pigments and paintings on Pre‐Hispanic pottery from the regions of Fiambalá and Chaschuil (Catamarca, Argentina)*

“…However, in some cases, this peak has been attributed to the mineral phase of magnetite (Rosina et al . 2019). Considering XRD results for the samples studied in this paper, we attribute the band around 660 cm −1 to hematite.…”

The colours of Rome in the walls of Cástulo (Linares, Spain)

“…4 c, Raman spectrum 4.1) alongside the typical spectral bands of hematite is controversial in the literature. It has been put down to the occurrence of magnetite 50 and, therefore, to a darkened red pigment 51 – 53 , but it has also been attributed to a disorder-activated mode in the hematite crystalline structure 54 , 55 . The occurrence of this element in only one sample and the attestation of amorphous carbon in the rest of the brown samples suggests that magnetite was not used as a darkening agent.…”

Methodological Approach (In Situ and Laboratory) for the Characterisation of Late Prehistoric Rock Paintings—Penedo Gordo (NW Spain)

“…As known, the recipes of prehistoric paintings most frequently include inorganic substances, mainly red-orange and black pigments that might have been mixed with organic binders of vegetable or animal origin [3][4][5][6]. In Iberia, black pigments were mainly produced from charcoal or soot and red pigments were composed of hematite (Fe 2 O 3 ) or red ochre [6].…”

“…As known, the recipes of prehistoric paintings most frequently include inorganic substances, mainly red-orange and black pigments that might have been mixed with organic binders of vegetable or animal origin [3][4][5][6]. In Iberia, black pigments were mainly produced from charcoal or soot and red pigments were composed of hematite (Fe 2 O 3 ) or red ochre [6]. The latter is a natural earth in which iron oxides and hydroxides are mixed with clay but also with minerals such as quartz (SiO 2 ), dolomite (CaMg(CO 3 ) 2 ), hydromagnesite (Mg 5 (CO 3 ) 4 (OH) 2 •4H 2 O), calcite (CaCO 3 ), aragonite (CaCO 3 ), gypsum (CaSO 4 •2H 2 O), muscovite (KAl 2 (AlSi 3 O 10 )(OH) 2 ), feldspar ((K, Na, Ca, Ba, NH 4 )(Si, Al) 4 O 8 ), etc.…”

“…Ultimately, the results obtained may be applied to support the establishment of preventive conservation measures aiming to delay the degradation of rock art panels. Despite the quantity and quality of the work developed on this subject in recent years [4,[6][7][8][10][11][12][13][14][15][16][17], a comprehensive protocol to guide the characterisation of rock paintings, considering its chemical, mineralogical and physical properties, has not yet been established.…”