Evolution of the upper proterozoic continental deposits from «La Serena», (Southern Central Iberian Zone) Badajoz, Spain

[Resumen] Se describen por primera vez afloramientos, recientemente descubiertos, del Alcudiense Superior, en «La Serena», Badajoz. Se demuestra el carácter continental de la parte basal de varias secuencias, y se esboza un esquema paleogeográfico, que implica una línea de,costa hacia el Oeste, y la diferenciación de tres ciclos sedimentarios.[Abstract] Sorne recently discovered Upper Alcudian outcrops, from «La Serena» region in Badajoz province, are described in this paper for the first time. The basal pan of most of the studied logs shows continental characteristics here depicted; a paleogeographical scheme is also submitted. This latter implies moving the suggested coast line westward for the first cycle. Three local sedimentary cycles are here proposed and correlated with those from well known areas

Las sucesiones estratigráficas del Paleozoico Inferior y Medio

p. 31-43Ya se ha visto que la formación del Macizo Ibérico, donde aflora el basamento de la Península Ibérica, está íntimamente ligada al desarrollo de la orogenia Varisca del Paleozoico Superior. La consecuencia fue el acortamiento y deformación intensa de los sedimentos marinos depositados previamente a lo largo de los extensos márgenes continentales de Gondwana durante el Paleozoico Inferior y Medio. El Macizo Ibérico contiene los afloramientos más extensos y fosilíferos de cuantos componen la Cadena Varisca europea. Sus distintas zonas estructurales y paleogeográficas albergan importantes sucesiones estratigráficas de los períodos Cámbrico a Devónico (García-Cortés et al., 2000, 2001; Gutiérrez-Marco, 2006), que configuran uno de los contextos geológicos clave para conocer la evolución fini-precámbrica y paleozoica de la Península Ibérica y de Europa Occidental, y en donde se registran numerosos eventos geológicos y biológicos de alcance global

Discordancia intra-Alcudiense en el anticlinal de Agudo (Ciudad Real-Badajoz)

The Proterozoic unconfomity, also known more to the East, is described in the Agudo Antic/ine at the base of the Upper Alcudian (Upper Vendian) and extended to the whole antic/inory. This allows the extension of the Intra-Alcudian unconformity to the W.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Paleontological novelties from the Ordovician of the Cabañeros National Park (Castilla-La Mancha, central Spain)

Lower and Middle Ordovician rocks outcropping in the Cabañeros National Park (Central Iberian Zone) are being explored within a mapping project aimed at identifying geosites representative of the geological and paleontological heritage on this natural area. Ongoing field-work has led to the discovery of three fossil localities that bring out significant paleontological data relevant to the whole Iberian Massif. The oldest comes from the upper part of the Armorican Quartzite Fm. (Floian/middle Arenigian) and is a large ichnofossil identified as Tumblagoodichnus? isp., which probably represents a shallow burrow filled by collapse of sand from above, and dug as a temporary refuge by a large arthropod. The trace is 45 cm wide, much bigger than the large arthropod traces previously reported from the Iberian Ordovician (rare Cruziana reach up to 26 cm in width). The second fossil locality lies towards the middle part of the overlying Marjaliza Beds (Dapingian to lower Darriwilian/middle-upper Arenigian) and is represented by a thick coquina of paleotaxodont and paleoheterodont bivalves, apparently formed due to a catastrophic event (an exceptional storm?) that transported and entombed en masse millions of individuals now preserved as complete specimens with closed valves. This local abundance strongly contrasts with the scarcity of Arenigian bivalves preserved in the Cruziana sandstone facies of SW Europe. Finally, the youngest locality is a rich fossiliferous bed of lower Oretanian (Darriwilian) age recorded in the Navas de Estena Shales, where the brachiopod genus Eodalmanella (Ranorthidae) makes its second European occurrence and reinforces the Ibero-Bohemian paleobiogeographic affinitie

Episodios sedimentarios en el Alcudiense Superior (Proterozoico) y su tránsito al Cámbrico en la zona centro meridional del Macizo Ibérico

The evolution of the Upper Alcudian-Lower Cambrian basin is studied in the eastern Lusitanian-Alcudian Zone. Five sedimentary episodes with distinctive characteristics are considere