Palaeogeographic significance of rugose corals: El Guadiato Area (Southwestern Spain) as a case study

Abstract

Carboniferous rugose corals are useful for palaeoecological, palaeoenvironmental and palaeogeographic studies. However, most analyses are qualitative and/or comprise corals from long stratigraphical intervals, and detailed palaeogeographic studies in the Carboniferous from western Palaeotethys are scarce. This report presents a quantitative analysis of the late Visean coral assemblages from the El Guadiato Area (Southwestern Spain), which has been thoroughly studied during the last 30 years. This case study aims to check the utility of rugose corals in detailed palaeogeographic studies, reconstructing tectonic movements in the suture zone between the Ossa Morena and Centroiberian domains in the Iberian Massif. Sixty-one rugose coral species from the El Guadiato Area were included in the analyses. Moreover, two other late Visean rugose coral faunas have been added as an external reference: Los Santos de Maimona (Southwestern Spain) and Kingscourt (Ireland). The presence/absence datasets have been treated with paired group (UPGMA) Hierarchical Clustering and a Detrended Correspondence Analysis. The results of this study support previous observations about the palaeogeography of the El Guadiato Area, backing the hypothesis that the strike slip faults of the area produced large lateral displacements. The results of analyses conducted at this level of detail appear to be conditioned by palaeoenvironmental differences, but the results of the comparison with Los Santos de Maimona and with Kingscourt’s faunas look promising for future larger comparisons between different basins.