Search

El grupo minero de Viveiro (minas de A Silvarosa y Galdo) representó en su momento uno de los yacimientos de hierro más importantes de Galicia. Las minas fueron explotadas intermitentemente entre 1896 y 1966, con la mayor parte de su producción destinada a la exportación; aunque en el siglo XVIII ya se habían empleado minerales de la prolongación septentrional del yacimiento, para abastecer a la siderurgia local (horno alto de Sargadelos). La mineralización corresponde a una capa sedimentaria de 2-20 m de espesor (hasta 40 m en la charnela de pliegues). Su textura ooidal y mineralogía originales se vieron muy transformadas por metamorfismo de contacto varisco, hasta generar una mena masiva semifosforosa y rica en magnetita. La revisión estratigráfica de la sucesión ordovícica local permite estimar la edad de la mineralización como Ordovícico tardío (Sandbiense o Katiense temprano), por correlación con los principales horizontes de hierro sedimentario conocidos en otras localidades del margen gondwánico europeo. También se aclara la posible edad y correlación del resto de la sucesión ordovícica posterior al depósito del hierro. Desde el punto de vista del patrimonio minero, la única actuación abordada fue la rehabilitación del antiguo cargadero de mineral de hierro en la ría de Viveiro (Parque Etnográfico da Ínsua, inaugurado en 2002). A ello sería interesante añadir la futura rehabilitación y puesta en valor de la mina de A Silvarosa-Choupín, que podría recuperarse como un nuevo atractivo turístico-cultural para el concejo de Viveiro. En esta iniciativa trabaja actualmente la Asociación Cultural e Deportiva Minas da Silvarosa.

El congreso internacional GONDWANA 15 ha tenido lugar en Madrid en Julio de 2014. Como en ocasiones anteriores, el congreso tuvo como objeto del mismo el supercontinente Gondwana, desde su amalgamamiento en el Paleozoico Inferior hasta su desmembramiento en el Mesozoico Inferior. El congreso precedente (Gondwana 14) tuvo lugar en Buzios (Brasil) en Agosto de 2011. El Comité de Gondwana, que no es una entidad oficial, está constituido por científicos de diversos países y es el promotor de estos simposios, que tienen lugar cada tres años desde 1967 en diversos lugares del mundo. Este es el primero realizado en Europa. El congreso ha abarcado todos los aspectos involucrados en la historia de Gondwana, incluyendo la geología, paleontología, paleoclimatología y los recursos. Además, el congreso ha incluído dos excursiones antes y después del mismo, a regiones clave de la geología Europea y del norte de África, así como dos breves excursiones de un único día, durante el congreso, a regiones relevantes próximas a Madrid. El congreso tuvo lugar en los locales de la Escuela Técnica Superior de Ingenieros de Minas de Madrid, próxima al Instituto Geológico y Minero de España. La Universidad Complutense (UCM) junto con el IGEO (centro mixto de investigación UCM-CSIC) ha contribuído significativamente a este simposio. El comité coordinador ha estado compuesto por el Dr. César Casquet Martín (UCM, IGEO), el Dr. Juán Carlos Gutiérrez Marco (CSIC, IGEO) y el Dr. Javier Fernández Suárez (UCM, IGEO). Las dos instituciones han proporcionado diversas facilidades y se involucraron en la preparación y consecución de las excursiones.

La región de Almadén se integra en la Paleontología mundial del Paleozoico a mediados del siglo XIX, tras el descubrimiento de importantes yacimientos fosilíferos de los sistemas Ordovícico, Silúrico y Devónico, que permitieron establecer correlaciones con el Macizo Armoricano francés y la región de Bohemia (República Checa). Se trata de un área de referencia para la geología española, consagrada por más de siglo y medio de estudios, que alberga las localidades tipo de más de medio centenar de especies paleontológicas entre braquiópodos, trilobites, moluscos, equinodermos, graptolitos, corales e icnofósiles, descubiertos y nombrados por vez primera en la región de Almadén. Desde el punto de vista del patrimonio paleontológico de relevancia nacional e internacional, destacan los yacimientos tipo de muchos fósiles, a veces únicos a nivel mundial, y también el gran número de colecciones paleontológicas de Almadén depositadas en museos e instituciones de España y otros países europeos.

Submitted by Paula Serrano (paula.serrano@ineti.pt) on 2014-08-11T13:54:47Z No. of bitstreams: 1 35096.pdf: 9650452 bytes, checksum: d58a2b0210b4bd09bf275b5dd4560f6d (MD5) Approved for entry into archive by Paula Serrano (paula.serrano@ineti.pt) on 2014-08-11T13:54:56Z (GMT) No. of bitstreams: 1 35096.pdf: 9650452 bytes, checksum: d58a2b0210b4bd09bf275b5dd4560f6d (MD5) Made available in DSpace on 2014-08-11T13:54:56Z (GMT). No. of bitstreams: 1 35096.pdf: 9650452 bytes, checksum: d58a2b0210b4bd09bf275b5dd4560f6d (MD5) Previous issue date: 2011

Submitted by Paula Serrano (paula.serrano@ineti.pt) on 2014-08-11T13:43:34Z No. of bitstreams: 1 35094.pdf: 9460199 bytes, checksum: 41e23f48c2681e182ccdf167338c0435 (MD5) Approved for entry into archive by Paula Serrano (paula.serrano@ineti.pt) on 2014-08-11T13:43:45Z (GMT) No. of bitstreams: 1 35094.pdf: 9460199 bytes, checksum: 41e23f48c2681e182ccdf167338c0435 (MD5) Made available in DSpace on 2014-08-11T13:43:45Z (GMT). No. of bitstreams: 1 35094.pdf: 9460199 bytes, checksum: 41e23f48c2681e182ccdf167338c0435 (MD5) Previous issue date: 2011

Ordovician cephalopods from the Valongo Formation are among the first Ordovician fossils described from the Iberian Peninsula. The present review shows a lower taxonomical diversity than previously reported. Large endocerids and orthocerids are abundant in beds of early Oretanian (Middle Darriwilian) age, and orthocerids and some tarphycerids occur in strata of early Dobrotivian (Late Darriwilian) age. Despite the poor preservation in shales and the absence of internal structures, five different forms of longicones were identified, remaining them in open nomenclature. Tarphycerids are better recognizable and belong to the late Darriwilian forms Trocholites fugax and T. cf. depressus, with the former species recorded over a wide area of Ibero-Armorica and Bohemia, and the second related to a Baltic form. The occurrence of the genus Trocholites among Circumpolar Gondwana cephalopod faunas is consistent with the sporadic transfer of warm to temperate water masses southwards from the vicinity of Baltica, through a period of climatic disturbances affecting the southern hemisphere during the late Darriwilian

Ordovician cephalopods from the Valongo Formation are among the first Ordovician fossils described from the Iberian Peninsula. The present review shows a lower taxonomical diversity than previously reported. Large endocerids and orthocerids are abundant in beds of early Oretanian (Middle Darriwilian) age, and orthocerids and some tarphycerids occur in strata of early Dobrotivian (Late Darriwilian) age. Despite the poor preservation in shales and the absence of internal structures, five different forms of longicones were identified, remaining them in open nomenclature. Tarphycerids are better recognizable and belong to the late Darriwilian forms Trocholites fugax and T. cf. depressus, with the former species recorded over a wide area of Ibero-Armorica and Bohemia, and the second related to a Baltic form. The occurrence of the genus Trocholites among Circumpolar Gondwana cephalopod faunas is consistent with the sporadic transfer of warm to temperate water masses southwards from the vicinity of Baltica, through a period of climatic disturbances affecting the southern hemisphere during the late Darriwilian

The discovery of Didymograptus (Didymograptus) artus Elles and Wood in the Ordovician section of the Vidrias Cape (Atlantic coast of Spain), constitutes the first record of early Oretanian (= mid Darriwilian) rocks in the Cantabrian Zone of the Iberian Massif. The fossil locality lies in a shaly intercalation towards the middle part of an easternmost equivalent of the «Sabugo Quartzite» of the Navia Domain (West Asturian-Leonese Zone), so far unknown in the reference section for the Ordovician of the Cantabrian Zone of the nearby Peñas Cape. Correlations of the studied strata by previous authors are also reviewed, and the existence of a fault is suggested to occur between the «Peñas» and «Vidrias» members of the Luarca Formation on the famous section of the Peñas Cape

pp. 147–160 Late Floian conodonts are recorded from a thin limestone lens intercalated in the lower part of the San Jose Formation at the Carcel Puncco section (Inambari River), Eastern Cordillera of Peru. The conodont association includes Gothodus costulatus LINDSTROM, Protopanderodus rectus (LINDSTROM), Drepanoistodus basiovalis (SERGEEVA), Drepanoistodus forceps (LINDSTROM), Drepanodus arcuatus PANDER, Trapezognathus diprion (LINDSTROM), Erraticodon patu COOPER, and Ansella cf. jemdandica (LOFGREN). This species association can be assigned to the upper part of the well-documented Oepikodus evae Zone. It is the northernmost conodont record of late Floian age in South America. This study updates the preliminary data presented in 2001 from this fossil locality, and it has important consequences for the paleogeographic reconstruction of the Peruvian part of the Central Andean Basin. In accordance with trilobites and brachiopods documented for the same strata, the conodont association represents a relatively cold-shallow-water platform environment. The record of late Floian conodonts towards the middle part of the San Jose Formation shows that the base of this unit in the studied section is considerably older than other sections of the distribution area, where its lowermost part is dated as early Darriwilian by the record of graptolites from the Undulograptus austrodentatus graptolite Zone. The diachronous initiation of the marine sedimentation makes the lower part of the Carcel Puncco shales penecontemporaneous with the volcanigenic rocks related with the Arequipa Massif, which transitionally underlie the San Jose Formation in other places of the Altiplano and the Eastern Cordillera of Peru.

Late Floian conodonts are recorded from a thin limestone lens intercalated in the lower part of the San José Formation at the Carcel Puncco section (Inambari River), Eastern Cordillera of Peru. The conodont association includes Gothodus costulatus LINDSTRÖM, Protopanderodus rectus (LINDSTRÖM), Drepanoistodus basiovalis (SERGEEVA), Drepanoistodus forceps (LINDSTRÖM), Drepanodus arcuatus PANDER, Trapezognathus diprion (LINDSTRÖM), Erraticodon patu COOPER, and Ansella cf. jemtlandica (LÖFGREN). This species association can be assigned to the upper part of the well-documented Oepikodus evae Zone. It is the northernmost conodont record of late Floian age in South America. This study updates the preliminary data presented in 2001 from this fossil locality, and it has important consequences for the paleogeographic reconstruction of the Peruvian part of the Central Andean Basin. In accordance with trilobites and brachiopods documented for the same strata, the conodont association represents a relatively cold-shallow-water platform environment. The record of late Floian conodonts towards the middle part of the San José Formation shows that the base of this unit in the studied section is considerably older than other sections of the distribution area, where its lowermost part is dated as early Darriwilian by the record of graptolites from the Undulograptus austrodentatus graptolite Zone. The diachronous initiation of the marine sedimentation makes the lower part of the Carcel Puncco shales penecontemporaneous with the volcanigenic rocks related with the Arequipa Massif, which transitionally underlie the San José Formation in other places of the Altiplano and the Eastern Cordillera of Peru.

4 páginas, 2 figuras.-- Trabajo presentado en la 44ª Sesión Científica, Jaén, 2008., 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 affinities., Acción Estratégica 56/2006 de la Red de Parques Nacionales. Proyecto PATRIORSI, CGL2006-07628/BTE. Proyecto PICG 503 del Programa Internacional de Geociencias (IUGS-UNESCO) y las actividades del Grupo de Investigación Precámbrico y Paleozoico Perigondwánico de la Universidad Complutense de Madrid.

The Iberian Peninsula is home to the most extensive outcrops of Ordovician and Silurian rocks in Europe, being mainly located in the Variscan Iberian Massif of Spain and Portugal. Many of these outcrops are outstanding in terms of their geomorphological value and impressive landscape, but also because of the palaeontological record they hold or their exceptional stratigraphic record of certain Ordovician and Silurian successions. The present work proposes 23 sites that typify the rich Iberian geological and palaeontological heritage of these periods, all of them located in natural areas protected by national or regional laws (National and Natural Parks, European Geoparks, Natural Monuments, National Hunting Reserves, or municipal reservations). Selected geosites add value for these natural areas and are chosen in order to disseminate knowledge of the existence of rocks and fossils with examples that are key to interpreting Gondwanan palaeogeography and the regional palaeoenvironmental conditions (cold peri-polar seas with marine platforms bathing a gigantic deserted continent), physical events of local and global nature (eustatism, tectonic events, volcanism), paleobiodiversity, and evolution. The potential of the Iberian Ordovician and Silurian rocks and fossils as a geotouristic and educational resource require the preparation of fixed information panels, on-site museums, geological viewpoints, georoutes, guided visits, and tourist information guides and pamphlets, which are currently being arranged or already established. The effective use of these 23 Ordovician and Silurian geosites can benefit from the protection afforded to the natural areas in which they are located. This work was performed as part of the PATRIORSI project of the Spanish Ministry of Education and Science (CGL2006-07628/BTE, years 2006-2009) and the Geology and Palaeontology of the Cabañeros National Park project funded by the Spanish Ministry of the Environment (Ref. 56/2006, 2006-2009).

13 páginas, 20 páginas.-- Editor: García Cortés, Angel.-- Capítulo 2.

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 affinities

Deep in the memory of the inhabitants of the region of Montesinho (NE Portugal), there is a legend which talks about the existence of enigmatic pedras escrevidas (="written stones") in the mountains near the village of Guadramil. In the first half of the 20th Century, what used to be considered some kind of rock engravings in quartzite, were studied by archaeologists, which interpreted these signs as a kind of very old (and unknown) pre-Roman writing. A modern geological mapping of the area of the Montesinho Natural Park allowed us to rediscover the original sites of these structures and interpret them as ichnofossils. They occur on the Lower Ordovician quartzites, towards the top of the lower member of the Marao Formation (Floian), which crops out extensively in the area, generating the mountainous relief of the Barreiras Brancas-La Culebra sierra. The study of the locality required two excavating campaigns, supported by the Portuguese Ministry of Science, which involved 40 highschool students during the summer of 2002 and 2003 in an area located 5 km north of Guadramil and very close to the Spanish border. It resulted in the exposure and cleaning of an exceptional surface of 40 square meters with a very vast ichnofossil accumulation, reaching a maximum of 2,000 individual specimens by square metre. All of them correspond to horizontal sections of conical structures created by the spiral displacement of steeply inclined J-shaped burrows, assigned to the arthrophycid forms Daedalus halli (Rouault) and Daedalus labechei (Rouault). Both ichnotaxa are widely known in the "Armorican Quartzite" facies of the Lower Ordovician of SW Europe, where massive occurrences reflect opportunistic colonization events on storm generated sandstones. The spectacular bedding plane concentration of these conical burrows in the locality, and the good preservation of the active backfill on their typical spreite (wing-like) structure, is currently being mapped with the purpose of determining the mathematical model underlying the burrowing pattern and ecospace interaction between the sedimentivorous producers. Anyway, this outstanding palaeontological site of the "pedras escrevidas" has no other counterpart in the world, and is of undisputable value for the Iberian geological heritage. In the near future the locality will be protected and included in the touristic programmes and guides enhancing the natural heritage of the Montesinho Natural Park. The detailed ichnological study of this outcrop is being financed through the PATRIORSI project of the Spanish Ministry of Education and Science (CGL2006-07628/BTE, years 2006-2009) and by the project "Identification, Characterization and Conservation of Geological Heritage: a Geoconservation strategy for Portugal", sponsored by the Portuguese Foundation of Science and Technology (PTDC/CTEGEX/ 64966/2006, years 2006-2009).

The studied region is situated in the Aveiro district, about 50 km SW of Oporto (northern Portugal) and has a rich geological, biological and cultural heritage. The Arouca Geopark was formally established there in late 2007, under the auspices of Arouca’s Municipal Chamber, to reunite 36 geosites from which some of them involve remarkable Ordovician and Silurian rocks and fossils. Outcrops of both periods belong to the Valongo- Tamames syncline of the Central Iberian Zone. Lower Palaeozoic rocks around the Canelas Slate Quarry are of special interest, leading to the creation of a geotouristic route visiting three Ordovician units (Santa Justa quartzites, Valongo shales and Sobrido quartzite plus glaciomarine diamictites) and one Silurian (graptolitic black shales), as well as a Roman gold mine dug in the Lower Ordovician quartzites. However, the most outstanding geosite is the quarry itself, where Middle Ordovician giant trilobites (up to 70 cm in size) and trilobite clusters (up to thousands of specimens) occur in large slabs of slate and are recovered during the exploitation. The Geological Interpretation Centre of Canelas, located near the quarry and open since 2006, is one of the main tourist attractions of the Arouca Geopark, created to preserve and disseminate knowledge about trilobites and the Ordovician world, and having received more than 10,000 visitors in its first 17 months

Preliminary studies of some stratigraphic sections spanning the Ordovician-Silurian boundary in the southern Cantabrian Zone (Iberian Massif, NW Spain) demonstrate the existence of a record of Hirnantian glaciomarine diamictites and shallow-water quartzites in at least three localities, situated in the Bodón nappe. These rocks, evidenced for the first time in the Cantabrian Zone, are probably related to the infilling of a paleorelief, scoured in the Barrios Formation during the Late Ordovician glaciation. The occurrence of an ubiquitous quartzite unit, generally related to the Ordovician-Silurian boundary in most parts of northern Gondwana, is now extended to the outcrops here analyzed. The Hirnantian quarzite probably occurs in additional areas of the Bodón and Correcilla nappes, where its location and significance might be underestimated, and described as the uppermost part of the Barrios Formation (Middle Cambrian to Arenigian). The same quartzite is probably recognized in the areas with volcanic necks within the Barrios Formation, and also in its stratotype, in which a latest Ordovician/earliest Silurian quartzite overlies unconformably on Middle Ordovician shales

A Silurian fossil has been collected from sandstone pebbles in the red Cenozoic deposits of the famous Roman gold-mine of Las Médulas. It consists on an articulated shell of the cardiolid bivalve Cardiola gibbosa Barrande, of basal Gorstian age (Ludlow). This species is considered as an exotic element to the neighboring Paleozoic outcrops, being most probably reworked from an unknown area souther of the Ollo de Sapo anticlinorium. This hypothesis agrees with the recent geological reinterpretation of the goldbearing units as a system of Paleogene fluvial terraces. The fossiliferous pebble is attributed to the third terrace scoured by an ancient river flowing to the NE, being progressively entrenched during the initial stages of the Alpine convergence which ends with the formation of the compressive El Bierzo Cenozoic basin

A Silurian fossil has been collected from sandstone pebbles in the red Cenozoic deposits of the famous Roman gold-mine of Las Médulas. It consists on an articulated shell of the cardiolid bivalve Cardiola gibbosa Barrande, of basal Gorstian age (Ludlow). This species is considered as an exotic element to the neighboring Paleozoic outcrops, being most probably reworked from an unknown area souther of the Ollo de Sapo anticlinorium. This hypothesis agrees with the recent geological reinterpretation of the goldbearing units as a system of Paleogene fluvial terraces. The fossiliferous pebble is attributed to the third terrace scoured by an ancient river flowing to the NE, being progressively entrenched during the initial stages of the Alpine convergence which ends with the formation of the compressive El Bierzo Cenozoic basin

42 páginas, 17 figuras, 5 fotos., [EN] The Ordovician System outcrops extensively in the northeastern of Portugal, in the septentrional sector of the Central-Iberian Zone. The level of lithostratigraphic knowledge about these materials is notably lower than that of identical materials in other Portuguese regions and in a comparable peleogeographic scope. In this sense, the Ordovician of Trás-os-Montes remains, in many aspects, terra incognita. Recent fieldwork focused in the Ordovician biostratigraphy of northeastern Portugal lead us to consider the conveniente of making a deeper lithostratigraphical revision of these materials. It is a much needed amendment due to the proliferation of informal units and operative divisions that exist in the region, whose significance also varies for each of the authors, and the whole totality was examined under the requirements established by the international Stratigraphic Guide. The new lithostratigraphic scheme here proposed, unified for the entire region, considers the formal definition of 19 lithostratigraphical units, most of them of siliciclastic nature. The stratigraphic succession includes one group, eight formations, seven members and three individual beds. Each unit of equal or lower range than the Formation is clearly defined regarding its lithology and boundaries at the stratotype, considering its regional aspects, subdivisions, dating, sedimentary environment and detailed revision of the synonymy, as well the thickness ascribed from the previous authors to each concrete assemblage. The stratigraphic study allowed us to characterize and contextualize several units attributed to the Upper Ordovician, scarcely or partially unknown in the region until now, as well as the detection of stratigraphic gaps with different ranges and generally with great paleogeograhic interest. The new lithostratigraphic scheme here formalized for the Ordovician of Trás-os-Montes allows a precise knowledge and correlation of this region with the remaining Portuguese Central-Iberian Zone (Valongo, Buçaco, Amêndoa-Maçâo) and in the frame of southwestern Europe., [PT] A recente realizaçâo de trabalhos, centrados no estabelecimento da bioestratigrafia do Ordovícico do nordeste de Portugal (Zona Centro-Ibérica), conduziu a urna profunda revisiâo litoestratigáfica destes materiais, â luz dos requerimentos litoestratigráficos estabelecidos pelo Guia Estratigráfico Internacional e justificada pela grande proliferaçâo de unidades informais e divisôes operativas existentes na regiâo. Esta nova proposta, unificada para a regiâo transmontana, contempla a definiçâo formal de um total de 19 unidades litoestratigráficas, a maioria das quais de natureza siliciclástica, repartidas por um grupo, oito formaçôes, sete membros e três camadas. Este estudo permitiu caracterizar e contextualizar diversas unidades atribuídas ao Ordovícico Superior, até agora praticamente ignoradas na regiâo, assim como a detecçâo de lacunas estratigráficas de grande interesse paleogeográfico. O novo esquema litoestratigráfico, agora apresentado, permite correlacionar de forma precisa e nivelar o conhecimento relativamente à restante Zona Centro-Ibérica portuguesa (Valongo, Buçaco, Amêndoa-Maçâo) e ao restante Ordovícico do sudoeste da Europa.

El mirador de Campodola es el primero de Galicia hecho expresamente para la observación de una estructura geológica, en este caso un gran pliegue acostado (el Sinclinal de O Courel) formado durante la primera fase de deformación varisca y conservado prácticamente intacto desde el Carbonífero inferior, hace más de 320 millones de años. El mirador brinda una buena panorámica de la charnela parabólica desarrollada en la Cuarcita Armoricana del Ordovícico, así como de los flancos subhorizontales y aplastados del gran pliegue, cuyas longitudes superan los 10 km. El Sinclinal de O Courel figura como Punto de Interés Geológico de rango internacional desde 1983, y el actual mirador permitirá un mejor aprovechamiento cultural y educativo de este monumento geológico, tal vez el más importante de Galicia de origen estratigráfico-estructural.

Comunicación presentada en el VI Congreso Geólógico de España, Zaragoza, 12-15 julio, 2004.

Los cistoideos son fósiles sumamente escasos en la Caliza Urbana de la región surcentroibérica, en contraste con otras unidades calcáreas del Kralodvoriense (Ashgill «medio») de la Península Ibérica, donde su registro es abundante y variado. En esta nota se recapitulan y discuten todos los hallazgos previos de estos equinodermos en la Caliza Urbana (7 ejemplares en total), identificándose dos formas distintas de Heliocrinites (Heliocrinites cf. minutus CHAUVEL y Heliocrinites sp. -aff. H. jaekeli? CHAUVEL-) más otro rombífero indeterminable (Rombifera indet.), que se asimilan desde el punto de vista paleobiogeográfico a la «fauna de Heliocrinites». La extrema rareza de cistoideos en la Caliza Urbana se atribuye a factores paleoambientales y sedimentarios desfavorables, verificados en el seno de una plataforma interna muy somera y de escaso gradiente. Entre ellos podría citarse una energía elevada, el influjo terrígeno y el predominio de sustratos semiconsolidados, que tendría su contrapunto en los restantes depósitos ibéricos del tipo de «calizas de pelmatozoos», donde los ambientes más tranquilos o profundos de la plataforma externa serían mucho más proclives a su colonización por equinodermos. [ABSTRACT] Cystoids are very rare fossils in the Urbana Limestone of the southern Central Iberian Zone, in contrast to the fossil content of the remaining Kralodvorian («mid» Ashgill) limestones cropping out in the Iberian peninsula, where these echinoderms display a more abundant and diverse record. After a complete recapitulation and discussion about all findings of cystoids in the Urbana Limestone (only 7 specimens derived from 4 localities among dozens of sections examined), two different species of Heliocrinites (Heliocrinites cf. minutus CHAUVEL and Heliocrinites sp. -the latter perhaps related with H. jaekeli? CHAUVEL-) and one undetermined rhombiferan (Rombifera indet.) have been identified. From a palaeogeographic point of view, these elements belong to the «Heliocrinites Fauna» and its extreme rarity in the Urbana Limestone may be consequence of non-favourable environmental factors, such as a high energetic gradient and terrigenous influx, or the predominance of semiconsolidate substrates within a very shallow and nearly flat inner shelf setting. The opposite scenario, much more suitable to be colonyzed by echinoderms, is characteristic of the «pelmatozoan limestones» known in other Iberian areas, which generally were deposited in quieter and deeper environments of the outer shelf.

Se describe una asociación singular de grandes obólidos, procedente de la parte basal de la “Formación Cuarcítica” de la Serra de Marão (N Portugal), correlacionable con la Cuarcita Armoricana de otras regiones centroibéricas. A pesar de que la mayor parte de los ejemplares están mal conservados y acusan deformación tectónica, se han podido identificar cuatro taxones diferentes que son descritos en nomenclatura abierta: Lingulobolus sp. [próximo a L. hawkei (Rouault)], Ectenoglossa cf. lesueuri (Rouault), “Lingulella” sp., y un obólido indeterminable de ornamentación divaricada (tal vez relacionado con Libecovicella). Esta asociación se adscribe a la biofacies de obólidos gigantes que caracteriza los ambientes epicratónicos de aguas someras en multitud de localidades perigondwánicas de Europa y el norte de África. La especie “Lingulella” major Teixeira, Ribeiro & Silva, descrita con anterioridad en los mismos afloramientos aquí estudiados, también ha sido revisada taxonómicamente, proponiéndose que quede restringida al lectotipo aquí designado, el cual tiene probablemente una edad ordovícica. Del mismo modo se analizan las citas de braquiópodos inarticulados en la Formación Desejosa (anteordovícico), descartándose la presencia de “Lingulella” montana Fenton & Fenton, recogida en las últimas síntesis internacionales del Ordovícico portugués. Por último, se aporta un esquema estratigráfico general de las formaciones ordovícicas en la Serra do Marão, invalidando el llamado “Miembro de Sejarão” citado en la parte inferior de la Cuarcita Armoricana, al tiempo que se presenta una breve actualización y revisión del registro paleontológico del Ordovícico de la región.

[ES] La revisión completa de más de un centenar de localidades fosilíferas del Ordovícico Medio situadas en el noroeste del Macizo Hespérico, muestra que el depósito de las pizarras y limolitas oscuras (Formación Luarca y equivalentes), que siguen a las cuarcitas del Arenig, no fue tan uniforme como se consideraba hasta ahora. Las pizarras se sedimentaron esencialmente durante el Oretaniense en la Zona Asturoccidental-Leonesa y en la parte septentrional de la Zona Centroibérica (Dominio del Ollo de Sapo), donde el techo de la unidad se sitúa muy próximo al límite Oretaniense / Dobrotiviense, sin existir ningún yacimiento paleontológico de probada edad dobrotiviense (= "Llandeilo inferior" en sentido clásico). En la Zona Cantábrica, la sedimentación arcillosa se inicia en el Oretaniense superior tardío y prosigue durante el Dobrotiviense. Para el conjunto del área estudiada se caracterizan, o proponen, diversas lagunas estratigráficas de alcance local o regional, y se discuten las circunstancias paleogeográficas generadas por las hipótesis más recientes, que son contrastadas a la luz de los nuevos datos paleoecológicos y paleobiogeográficos. Éstos indican que la sedimentación tuvo lugar en áreas externas y abiertas de la plataforma, relativamente más profundas que en la región surcentroibérica, con áreas de surco donde ingresan elementos mesopelágicos. Desde el punto de vista paleontológico, se reconocieron un total de 97 formas distintas (67 especies presentes en el Oretaniense y 45 en el Dobrotiviense), entre las que destaca la primera aparición conocida de determinadas especies de trilobites y ostrácodos, el registro más moderno de otros, y algunos taxones en común con Avalonia y Baltica, desconocidos hasta el presente en otras áreas del suroeste de Europa, [EN] A complete review of more than one hundred Middle Ordovician fossil localities, distributed within the north western part of the Hesperian Massif, shows that the sedimentation of the dark shales (Luarca Fo rmation and equivalents) that overlie Arenig quartzites with Cruziana (the 'Armorican Quartzite' facies) was not as uniform as it has been supposed for the whole NW Spain. These shales were mainly deposited during the Oretanian in the West Asturian-Leonese Zone and in nort h e rn Central-Iberian Zone (Domain of the Ollo de Sapo Antiform). In these zones, the top of the unit is close to the Oretanian/Dobrotivian boundary, without any fossils with proved Dobrotivian age., Este trabajo ha sido financiado con cargo al Proyecto PB94-1330 de la DGESEIC ["Investigaciones estratigráficas y paleontológicas en las formaciones Luarca y Sueve (Ordovícico Inferior y Medio de Asturias y León)]", y constituye una contribución a los proyectos nº 410 del PICG (IUGS-UNESCO)e "Iberia" de EURO P ROBE (European Science Foundation). La participación de J.C. Gutiérrez-Marco y de I. Rábano se inscribe igualmente en el Proyecto PB96-0839 (Bioestratigrafía de alta resolución y litorradiometría en el Ordovícico Medio-Silúrico de España) de la DGESEIC (Ministerio de Educación y Cultura). La investigación museográfica en colecciones antiguas, forma parte del Proyecto 06/0006/98 ("Investigación y catalogación de colecciones paleontológicas singulares del Museo Geominero"), financiado por la Comunidad de Madrid.

The holotype of''Echinosphaerites'' murchisoni Verneuil and Barrande 1855 is reviewed, and proposed as the type species of Oretanocalix gen. nov. The new genus is characterised by an elongate theca of medium size, that aborally shows a pair of long and prominent parietal septa interpreted as mesenterical; mouth narrow and elongate, with five very short ambulacra, the anterior comparatively reduced, ending in a set of few brachiole facets. The presence of a 2-1-2 ambulacraI system with an atrophied A-ambulacrum could denote a simplification leading to the 2-2 pattern of Calix or Phlyctocystis. The new genus ranges from Oretanian to Dobrotivian in age, and is distributed in Central Spain, the Moroccan Anti-Atlas and the French Armorican Massif

[ES] En este trabajo se describe con detalle el conjunto de yacimientos con graptolitos silúricos conocidos en la provincia de Zamora, situados todos ellos en el sinforme de Alcañices, de los que se precisa su ubicación y composición taxonómica., [EN] This work describes in detail all known sites with Silurian graptolites in the province of Zamora, located all in the synform Alcañices, specifying the location and taxonomic composition.

En un interesante artículo publicado en el número anterior de esta misma revista, GIL CID el al (1998) aportan la detallada descripción de un nuevo crínoideo procedente de las «Capas con Tristani» centroibéricas, que representa el primer íegistío gondwánico de la familia Eustenocrinidae. Sin embargo, y pese al interés intrínseco del único ejemplar conocido de <

24 páginas, 4 figuras, 2 láminas, 1 tabla., [EN] New palaeontological data from Upper Ordovician formations of NW Spain (Caurel-Peñalba and Truchas synclines) are documented. The «Trigal limestones» of the Casaio Formation, the La Aquiana Formation and calcareous pebbles of the Rozadais Formation have yielded conodont assemblages indicating the Ashgillian Anzorphognathus ordovicicus Biozone. Scabbardella altipes (Henningsmoen), Panderodus gracilis (Branson & Mehl), Anzorplzognathus ordovicicus Branson & Mehl, Amorphogizatlzus sp., Sagittodontiíza robusta Knüpfer, Sagittodontina? sp., Icriodella sp. and Hamarodus europaeus (Serpagli) have been identified and described. Stratigraphic correlations between the different structural units are discussed, as well as the regional context of the Upper Ordovician sedimentation. According to a new model which conciliates the local geotectonic setting with the global paleoclimatic events, the Rozadais Formation underwent a glaciomarine influence during the Hirnantian, and is clearly younger in age that other Ashgill units which consist or include pre-Hirnantian limestones (La Aquiana and Casaio formations)., [ES] Se presentan las asociaciones de conodontos ordovícicos registradas en las «calizas del Trigal» de la Formación Casaio, en la Formación La Aquiana y en los cantos calcáreos englobados en la Formación Rozadais, pertenecientes a afloramientos del sinclinorio de Truchas (norte de la Zona Centroibérica) y del sinclinal del Caurel-Peñalba (sur de la Zona Asturoccidental-leonesa). Las formas identificadas son Scabbardella altipes (Henningsmoen), Paizdei~odus gracilis (Branson y Mehl), Amorphognathus ordovicicus Branson y Mehl, Anzorphognathus sp., Sagittodoiztiiza robusta Knüpfer, Sagittodontina? sp., Icriodella sp. y Hanzarodus europaeus (Serpagli), que corresponden a la Biozona de Aínorphognathus ordovicicus del Ashgill y se describen e ilustran en el apartado sistemático. En función de estos datos y sus circunstancias estratigráficas, se propone una correlación general de las unidades del Ordovícico Superior de la región, presentándose un nuevo modelo que armoniza el marco geotectónico local con los eventos globales del Ashgill comunes a la región nord-gondwaniense. En este sentido, se considera un influjo glaciomarino para la Formación Rozadais (Hirnantiense), cuyo depósito no sería coetáneo con las unidades calcáreas pre-Hirnantienses (Trigal y La Aquiana)., Este trabajo se inscribe en los proyectos PB94-1330 y PB96-0839 de la DGES, y sus resultados son también una contribución al Proyecto 410 del PICG (IUGS-UNESCO), así como al Proyecto «Iberia» del Programa EUROPROBE (European Science Foundation). La participación del primer autor fue posible gracias a una beca postdoctoral de la Comunidad de Madrid, que lleva por título «Aplicación de Conodontos en bioestratigrafía de alta resolución y geotermometría de materiales ordovícicos y silúricos de España» (1998-1999).

La Formación Cuarcitas Botella (Dobrotiviense superior, Ordovícico Medio) contiene, en su parte inferior y media, raras asociaciones de bivalvos que han sido examinadas en cinco localidades centroibéricas. Estas se sitúan al oeste de Cabeza del Buey (Badajoz), al sur de Almaden y en Puertollano (Ciudad Real), norte de Castellar de Santisteban (Jaen) y sureste de Cabanas del Castillo (Cáceres). El material comprende los paleotaxodontos Praenucula costae (Sharpe), Cardiolaria beirensis (Sharpe) y Cardiolaria sp. y los paleoheterodontos Hemiprionodonta lusitanica (Sharpe), Lyrodesma truyolsi nov. sp., Modiolopsis cf. morierei de Tromelin y Modiolopsis sp. El registro de Modiolopsis cf. morierei de Tromelin y de! genero Lyrodesma precede muy probablemente a la aparici6n de estos taxones en el Macizo Armoricano (Arenisca de May superior: Caradoc). El actinodontoide Lyrodesma se describe por vez primera en la Península Ibérica, representado por la nueva especie Lyrodesma truyolsi nov. sp., carente de septo anterior, que representa la forma mas antigua conocida del género.

The holotype of''Echinosphaerites'' murchisoni Verneuil and Barrande 1855 is reviewed, and proposed as the type species of Oretanocalix gen. nov. The new genus is characterised by an elongate theca of medium size, that aborally shows a pair of long and prominent parietal septa interpreted as mesenterical; mouth narrow and elongate, with five very short ambulacra, the anterior comparatively reduced, ending in a set of few brachiole facets. The presence of a 2-1-2 ambulacraI system with an atrophied A-ambulacrum could denote a simplification leading to the 2-2 pattern of Calix or Phlyctocystis. The new genus ranges from Oretanian to Dobrotivian in age, and is distributed in Central Spain, the Moroccan Anti-Atlas and the French Armorican Massif

Se describen diversas estructuras discoidales a subcónicas, cementadas a restos esqueléticos de braquiópodos, moluscos, trilobites y cistideos. que constituyen los primeros elementos de fijación de pelmatozoos a sustratos firmes encontrados en el Ordovícico Medio de la Zona Centroibérica del Macizo Hespérico. El material proviene de cinco localidades de edad comprendida entre el Oretaniense inferior y el Dobrotiviense superior, y ha sido asignado a los morfogéneros Podolithus y Lichenocrinus?, el primero de los cuales se conocía previamente en las calizas del Ashgill de la Rama Aragonesa de la Cordillera Ibérica. Los ejemplares de Podolithus encontrados en las Capas con Tristani pertenecen al menos a dos morfoespecies distintas, tratadas en nomenclatura abierta, que sc diferencian por sus caracteres morfológicos y los fragmentos pluricolumnales asociados. [ABSTRACT] Pelmatozoan holdfasts, in Ihe form of discoid to subeonical multiplated structures, have been observed attached to shelly fragments ol articulate brachiopods. molluscs, trilobites and cystoids from five localities of the Central Iberian Zone of the Hesperian Massif. The described material ranges from lower Oretanian to upper Dobrotivian in age, and represents the first evidence of hard substrate colonization by echinoderms in the Middle Ordovician of Spain. The identified taxa belong to the morphogenera Podolithus and ?Lichenocrinus, the former also recorded from Ashgill limestones in the eastern Iberian Cordillera. At least two morphospecies of Podolithus, which have been left in open nomenclature, are distinguished on the basis of their overall morphology and stem characteristies.

A typical example of the Helminthopsis ichnogulld formed by deep deposit-feeder tiers is presented from an Upper Ordovician shallow marine succession in Central Spain. The monospecific ichnoassociation is composed by Helminthopsis abeli Ksiazkiewicz, massively recorded from a single bed within a sillciclastic alternation with some storm influence ofCaradoc age, in the lower part of the "Bancos Mixtos" Formation, south of the town of Torrenueva (Province of Ciudad Real)

A typical example of the Helminthopsis ichnogulld formed by deep deposit-feeder tiers is presented from an Upper Ordovician shallow marine succession in Central Spain. The monospecific ichnoassociation is composed by Helminthopsis abeli Ksiazkiewicz, massively recorded from a single bed within a sillciclastic alternation with some storm influence ofCaradoc age, in the lower part of the "Bancos Mixtos" Formation, south of the town of Torrenueva (Province of Ciudad Real)

The type specimen ofthe Lower Cambrian (Bilbilian) trilobite «Ellipsocephalus pradoanus» Verneuil & Barrande, 1855 is redescribed and illustrated. It is stored in the Verneuil collection ofthe Claude-Bernard University at Lyon (France). By means of the cranidial characteristics it has been doubtfully related with the genus Realaspis, and the poor preservation of the lectotype of R. ? pradoanus supports the restriction of the species to this unique specimen

Some scarce and bad preserved bivalves have been described from few localities lying at the upper part of the Armorican quartzite facies in Central Spain. Middle Arenig faunas include two palaeotaxodont forms (Praenucula oehlerti and Cardiolaria sp.), and two different palaeoheterodonts (Modiolopsis sp. and ?Actinodontoida indet.). Previous reports of other Arenig bivalves, especially actinodontoids, from coeval quartzites of northwestern, Central and northeastern Spain, as well as from Central Portugal, have been also briefly examined. The Iberian faunas show close affinities with the well known Arenig assemblages from the «Grès armoricain» of Western France, and add new data for the scenic reconstruction of the Lower Ordovician bivalve radiations on the northwestern Gondwanan shelves