摘要：The Pedra do Atlas archaeological site is a sandstone shelter, located in the rural area of the municipality
of Piripiri, Piauí, Brazil, decorated with 423 rupestrian paintings, as well as some engravings. Recently, ceramic
fragments, mineral pigments and some lithic artifacts were found on the surface of the sheltered soil. Samples of the
reddish mineral pigments were analyzed by energy dispersive X-ray fluorescence (EDXRF), Fourier-transform infrared
spectroscopy (FTIR) and 57Fe Mössbauer spectroscopy, aiming to determine the elemental chemical composition and to
identify the ferruginous species of these pictorial materials. The iron contents for the ochres, as determined by EDXRF,
expressed as Fe2O3
, is ~56 to ~60 mass%. From the Mössbauer spectra, the hematite (aFe2O3
) was unequivocally
identified as the iron oxide responsible for the red color of the ochres. Fe3+ doublets, which are assignable to
superparamagnetic species, more likely including hematite or goethite of very small particles, or the paramagnetic iron
in the crystalline structure of aluminosilicates, were also found.
关键词：Ochre; Iron oxide; Mössbauer spectroscopy; FTIR; EDXRF; Archaeometry;
