Physicochemical analysis of Permian coprolites from Brazil

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 189; pp. 93 - 99
• Main Authors: Rodrigues, M.I.C., da Silva, J.H., Santos, F. Eroni P., Dentzien-Dias, P., Cisneros, J.C., de Menezes, A.S., Freire, P.T.C., Viana, B.C.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-01-2018
• Subjects: Coprolites; Fossil; Physicochemical analysis; Vibrational spectroscopic; Coprolites; Fossil; Vibrational spectroscopic; Physicochemical analysis
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2017.08.011

In this paper we performed the study of two coprolites (fossilized feces) collected from the exposed levels of the Pedra de Fogo Formation, Parnaiba Sedimentary Basin, and Rio do Rasto Formation, Paraná Sedimentary Basin, both of the Palaeozoic era (Permian age). They were characterized using X-ray diffractometry, infrared, Raman and energy dispersive spectroscopy techniques in order to aid our understanding of the processes of fossilization and to discuss issues related to the feeding habits of the animals which generated those coprolites, probably cartilaginous fishes. The results obtained using a multitechnique approach showed that although these coprolites are from different geological formations, 3000km away from each other, they show the same major crystalline phases and elemental composition. The main phases found were hydroxyapatite, silica, calcite and hematite, which lead to infer that those coprolites were formed under similar conditions and produced by a similar group of carnivore or omnivore fishes.
[Display omitted]
•Coprolites were characterized using a multitechnical approach (EDS, XRD, FTIR and Raman spectroscopy).•The main phases found were hydroxyapatite, silica and silicates, calcite and hematite.•Coprolites were related to a similar group of animals, cartilaginous fishes.•Information about the ancient environment where the fossils were collected are furnished.