Introduction to Raman microscopy of prehistoric rock paintings from the Sierra de las Cuerdas, Cuenca, Spain

San rock art sites are found throughout southern Africa; unfortunately this unique heritage is rapidly being lost through natural weathering processes, which have been the focus of various studies conducted in the uKhahlamba Drakensberg Park since 1992. It has recently been shown that the ability of Raman spectroscopy to identify salts on rock faces on a micro, as well as nano scale, can make a contribution to these projects.In order to test the feasibility of undertaking on-site analyses, a small rock fragment with red and white pigments still attached, which had weathered off the rock face, was analysed with Raman spectroscopy under laboratory conditions, using a Dilor XY Raman instrument and a DeltaNu Inspector Raman portable instrument. A small sample of black pigment (<1 mm 2 ), collected from a badly deteriorated painting and a few relevant samples collected on site, were analysed as well. It was possible to identify most of the inorganic pigments and minerals detected with previous XRD and EDX measurements including whewellite and weddellite coatings, which could be a tool for carbon dating purposes. Two carotenoid pigments were detected for the first time in San rock art pigments. Animal fat was also observed for the first time on both red and white pigments, on the rock face adjacent to the paintings and in highest concentrations on the back of the rock fragment. The spectra quality makes successful on-site measurements a good prospect.

Section: Discussionmentioning

confidence: 99%

Section: Red Pigment On Shardmentioning

confidence: 99%

The first Raman spectroscopic study of San rock art in the Ukhahlamba Drakensberg Park, South Africa

Prinsloo

Barnard

Meiklejohn

et al. 2008

“…Examples of studies concern a wide time span and diverse cultures, from rock art 48,49 and wall paintings 50 -53 (which could also call for the use of mobile measurements) to various supports (paper, 54 -56 wood 57 ). For many of these studies, Raman analysis is involved as a general analytical strategy with complementary measurements as scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), XRF, laser induced breakdown spectroscopy (LIBS) or XRD.…”

Section: Colours Pigments and Technologiesmentioning

confidence: 99%

Raman spectroscopy in art and archaeology

Bellot‐Gurlet

Pagès-Camagna

Coupry

2006

This paper gives a short overview of the Special Issue on Raman Spectroscopy in Art and Archaeology, with the papers collected after the ‘3rd International Conference on the Application of Raman Spectroscopy in Art and Archaeology’ held at the University Pierre et Marie Curie‐Paris 6, Paris, France, from 31 August to 3 September, 2005. The contributions present an extended view of the work in the field, from technical developments and special analytical procedures to various applications. Copyright © 2006 John Wiley & Sons, Ltd.

“…The characterisation of the composition of the pigments, binders, substrata and accretions, as well as their microstratigraphy and chemical alterations, are the main objectives of this investigation. This information is fundamental to consider potential radiocarbon absolute dating, [14 -19] to investigate degradation processes [9,10,13] and to undertake the appropriate conservation action of the paintings. In the present work, we study the painted panel 3, Fig.…”

Section: Introductionmentioning

confidence: 99%

Raman microscopy of prehistoric rock paintings from the Hoz de Vicente, Minglanilla, Cuenca, Spain

Hernanz

Ruìz

Gavira-Vallejo

et al. 2010

Self Cite

The third painted panel of the Hoz de Vicente rock shelter (Minglanilla, Cuenca, Spain) contains a series of prehistoric pictographs which were studied by Raman microscopy. Scanning electron microscopy (SEM), energy dispersive X-ray microanalysis (EDX) and petrographic polarised light microscopy were used as auxiliary techniques. The results obtained indicate that well-crystallised haematite (α-Fe 2 O 3 ) of grain size less than 1 µm was used as red pigment. However, amorphous carbon, probably vegetable charcoal or soot, was used as the black pigment. A patina of whewellite and weddellite covers the areas of the painting panel with pictographs. The microstratigraphic study of a schematic figure revealed that the layer of pigment is sandwiched between layers of these hydrated forms of calcium oxalate produced by the activity of fungi and lichens. These products have also been detected in the layer of pigment. These findings will enable obtaining limiting radiocarbon 14 C accelerator mass spectrometry (AMS) dates for the corresponding pictorial events. On the other hand, crystallisation of gypsum in the external layers of the panel is related to the deterioration observed in the flaking areas. Gypsum and clayish minerals appear as the main components of an ochre-coloured accretion covering several parts of the panel.