Abstract ref. 1099:
The Lower Cambrian outcrops near Terrades (Gerona province, Spanish Pyrenees) are mainly siliciclastic interlayered with some bioclastic limestones or reef mounds. Previous works (Abad, 1987, 1989) allowed us to recognize three stratigraphic sections representative of the bioconstructed levels, as well as their spatial relationship and correlation. Microbial mounds are mainly formed by calcimicrobes (Epiphyton and Renalcis). Archaeocyathans are the secondary elements in these boundstones and the following genera have been identified: Taylorcyathus, Gloriosocyathus, Rasetticyathus, Erismacoscinus, Mennericyathus, Coscinocyathus and Anthomorpha. These mounds are superimposed and can reach up to 20 m in thickness. Small mounds are present over the big calcimicrobial mounds. These are buildups by branched colonial archaeocyathans with a high cups density mainly of Anthomorpha and Erismacoscinus.
The skeletal metazoans are surrounded by calcimicrobial elements. Lenticular carbonatic beds are located one
km away from the mounds. These beds are bioclastic, nodular and brechoid limestones, interstratified with siliciclastic sediments. The main components in the carbonatic levels are calcimicrobes and archaeocyathans, lacking of building mounds. Sedimentological characteristics suggest a restricted shallow area. Thirty genera of Archaeocyathans have been identified among which nine are new. The Terrades assemblage is typical for the Archaeocyatha Zone VII of the Upper Ovetian (Perejon, 1986 and in press). Some genera are common with Sardinia (i.e. Taylorcyathus, Rasetticyathus, Antoniocoscinus, Porocoscinus) and Morocco (i.e. Inacyathella). The relationship with the folded region of Altai Sayan have been based upon nineteen common genera, i.e. Nalivkinicyathus; and its shares with the Siberian Platform localities sixteen genera, a.o. Gloriosocyathus and Muchattocyathus. 