Taphonomic alterations in upper Viséan dissepimented rugose corals from the Sierra del Castillo unit (Carboniferous, Córdoba, Spain)

Abstract

Dissepimented rugose corals are common in the Sierra del Castillo Unit (upper Viséan from SW Spain). A complete taphonomic study has been made of the corals from three localities, each representing different environmental conditions: Antolín rocks are interpreted as mid-ramp and contains mainly reworked corals from reefs, Sierra del Castillo rocks are regarded as originating on a shallow-water platform, and Sierra de la Estrella rocks are typical of the middle to outer platform. The occurrence and distribution of taphonomic features are different at each outcrop and even in each bed, but a general temporal scheme with the timing of all processes is proposed. Borings, encrustations, fragmentation, abrasion, recrystallization, compression, stylolitization, silicification, cleavage, dissolution, and ferruginization are documented. Some processes which are generally regarded as biostratinomic (borings and encrustations) and even as fossildiagenetic (cementation) began before the death of the polyps. Other processes occurred only during the biostratinomic phase (abrasion) or during the fossildiagenetic phase (silicification, stylolitization, cleavage), but many processes occurred during both the biostratinomic and fossildiagenetic phases (fragmentation, cementation).