RT Journal Article T1 Estudio diagenético en conchas de braquiópodos de la cuenca del Guadiato ( Mississippiense, SO del Macizo Ibérico) T2 Diagenetic study of brachiopod shells from the Guadiato basin (Mississippian, SW Iberian Massif A1 Armendáriz, Maider A1 Rosales, Idoia A1 Quesada Ochoa, Cecilio AB Detailed petrographic and geochemical analyses of brachiopod shells from the Guadiato Carboniferous basin (Córdoba, SW Iberian Massif) has been carried out in order to evaluate their textural and geochemical preservation degree and their potential to be used as indicators of paleoenvironmental changes during the Carboniferous. The preservation degree of the shell´s microstructure has been evaluated by petrographic microscope, cathodoluminescence (CL) and scanning electron microscope (SEM). Under CL, ventral valves are mainly nonluminescent (NL) or nonluminescent with small slightly luminescent areas (NL-SL). In contrast, most of the dorsal valves are luminescent with moderate luminescent areas (ML-L). Under SEM, the samples show very well preserved lamellar and fibrous microstructures. The elemental contents (Ca, Mg, Sr, Mn and Fe) for the NL portions agree with elemental contents of modern brachiopods in equilibrium with ambient seawater and that have not undergone significant diagenetic modification. Therefore, our findings reveal a better microstructural preservation of the ventral valves of Gigantoproductids than the dorsal valves. The NL and NL-SL shell portions present the better microstructural and geochemical preservation and are interpreted to reflect the original isotopic and chemical composition of the marine water from which they precipitated. PB Sociedad Geológica de España SN 0213-683X YR 2007 FD 2007 LK https://hdl.handle.net/20.500.14352/102973 UL https://hdl.handle.net/20.500.14352/102973 LA spa NO Comisión Interministerial de Ciencia y Tecnología DS Docta Complutense RD 17 abr 2025