Microbes and archaocyaths.
3-5 m thick reef mounds stacked.
Margin of carbonate-siliciclastic platform.

Abstract ref. 1977:
A well-preserved coelobiontic biota of early Ovetian age (Early Cambrian; Moreno-Eiris et al. 1995. Paleozoic Cnidaria and Porifera from
Sierra Morena. Field Trip D. In PEREJON A. (ed.). VII International Symposium on Fossil Cnidaria and Porifera, Madrid, 1-68) is found near
the city of Córdoba (Ossa-Morena, southern Spain). Cryptic cavities occur at the unconformable boundary between an eroded, andesitic paleotopography, which belongs to the Neoproterozoic San Jerónimo Formation, and the giant reef complex of the Lower Cambrian Pedroche Formation (Zamarreño and Debrenne 1977. Sédimentologie et biologie des constructions organogènes du Cambrien inférieur du Sud de l'Espagne. Mémoires du BRGM, 89, 49-61. Moreno-Eiris 1988. Los montículos arrecifales de algas y arqueociatos del Cámbrico Inferior de Sierra Morena. Publicaciones Especiales del Boletín Geológico y Minero, 98, 1-127). The cavities exhibit several phases of growth, in some cases tectonically induced. The coelobiontic biota is preserved on the cavities (i) attached to the walls or encrusting previously attached organisms, and (ii) within the sediments that fill the cavities. The biota was diverse and consisted of encrusting, self-supported calcimicrobes, chancelloriids and archaeocyaths, found attached to walls and roofs of the cavities. Other reworked organisms preserved within the cavities are
trilobites, brachiopods and hyoliths derived from the overlying open-sea communities.