skip to main content
Menu
Original Article

The Enigmatic Upper Ordovician of the Naturtejo UNESCO Global Geopark (Portugal)

Authors

Abstract

Naturtejo UNESCO Global Geopark (Portugal) area includes deposits from the Neoproterozoic to the Quaternary. Despite its limited exposure area in major Variscan folded structures, the Ordovician series hosts some of its most famous geological heritage features, such as the Penha Garcia Ichnological Park.  The Upper Ordovician of the Central Iberian Zone is still far from being as well-understood as it is in other areas. Extensional tectonics, magmatism, global eustatic and climatic changes generated a great variability of sequences in a reduced geographical area. The Upper Ordovician of the Naturtejo region, often considered poorly represented, is here demonstrated to have a great potential and to be more complete than previously assumed. New stratigraphic and paleontologic data are presented for the three Upper Ordovician-bearing structures within Naturtejo: Fajão-Muradal, Vila Velha de Ródão and Penha Garcia synclines. Remobilized upper Katian fossiliferous clasts were found for the first time within the Hirnantian Casal Carvalhal from the Fajão-Muradal Syncline and a new fossil site is added to the Orvalho GeoTrail. In the Vila Velha de Ródão Syncline, the Barroca da Senhora stream fossil site constitutes a new geosite within the protected area of Portas de Ródão Natural Monument, presenting the most complete Upper Ordovician sequence of this structure. Finally, the stratigraphic and paleontologic record of the Vale Feitoso estate offers all the conditions to propose a new theme geotrail, diversifying the tourism in the Monfortinho village (Penha Garcia Syncline).

Read the full text of the article

Keywords

Main Subjects

References

Álvaro J, Colmenar J, Monceret E, Pouclet A & Vizcaïno D (2016). Late Ordovician (post-Sardic) rifting branches in the North Gondwanan Montagne Noire and Mouthoumet massifs of southern France. Tectonophysics. 681: 111-123. https://doi.org/10.1016/j.tecto.2015.11.031
Bergström SM, Chen X, Gutiérrez-Marco JC & Dronov AV (2009). The new chronostratigraphic classification of the Ordovician System and its relations to major regional series and stages and δ13C chemostratigraphy. Lethaia. 42:97-107.
Brenchley PJ, Romano M, Young TP & Štorch P (1991). Hirnantian glaciomarine diamictites – evidence for the spread of glaciation and its effect on Upper Ordovician faunas. [ In C.R Barnes, S.H Williams (Eds.). Advances in Ordovician Geology]. Geological Survey of Canada. Paper 90-9: 325-336.
Colmenar J, Pereira S, Sá A.A, Silva CM da & Young T.P (2017). A Kralodvorian (upper Katian, Upper Ordovician) benthic association from the Ferradosa Formation (Central Portugal) and its significance for the redefinition and subdivision of the Kralodvorian Stage. Bulletin of Geosciences. 92(4): 443-464. https://doi.org/10.3140/bull.geosci.1643
Cooper AH (1980). The stratigraphy and palaeontology of the Ordovician to Devonian rocks of the area north of Dornes (near Figueiró dos Vinhos), central Portugal. PhD Thesis, University of Sheffield.
Costa JCS (1931). O Paleozóico Português (Síntese e Crítica). PhD Thesis, Universidade do Porto.
Delgado JFN (1908). Système Silurique du Portugal. Étude de stratigraphie paléontologique. Memórias da Commissão dos Serviços geologicos de Portugal.
Fortey RA & Cocks LRM (2005). Late Ordovician global warming – The Boda event. Geological Society of America Bulletin. 33:405–408.
Hammann W (1992). The Ordovician trilobites from the Iberian Chains in the province of Aragon, NE Spain. I. The trilobites of the Cystoid Limestone (Ashgill Series). Beringeria. 6: 1-219.
Meireles CAP (2011). Litostratigrafia do Paleozóico do Sector a Nordeste de Bragança (Trás-os-Montes). PhD Thesis, Universidade do Porto.
Metodiev D, Romão J, Dias R & Ribeiro A (2009). Sinclinal de Vila Velha de Ródão (Zona Centro-Ibérica, Portugal): litostratigrafia, estrutura e modelo de evolução da tectónica Varisca. Comunicações Geológicas. 96: 5-17.
Metodiev D, Romão J, Dias R & Ribeiro A (2010). Sinclinal Varisco de Serra do Moradal-Fajão (Zona Centro-Ibérica, Portugal Central): padrões estratigráficos e estruturais. E-Terra. 11(1): 1-4.
Mitchell WI (1974). An outline of the stratigraphy and palaeontology of the Ordovician rocks of Central Portugal. Geological Magazine. 111: 385-396.
Neto de Carvalho C, Rodrigues J, Baucon A (2014). “Fossil Art”: the importance and value of the palaeobiodiversity in the Naturtejo Global Geopark, under UNESCO (Portugal). Comunicações Geológicas. 101(1): 91-99.
Neto de Carvalho C, Rodrigues JC & Gonçalves D (2013). Património Geológico de Oleiros: inventário de geossítios e propostas para a sua valorização. Açafa On-line. 6: 4- 61.
Paris F (1979). Les chitinozoaires de la Formation de Louredo, Ordovicien Supérieur du synclinal do Buçaco (Portugal). Palaeontographica Abteilung A. 164(1-3): 24-51.
Perdigão JC (1971). O Ordovícico de Fajão, Unhais-o-Velho, Salgueiro do Campo e Penha Garcia. I Congresso Hispano-Luso-Americano de Geologia Económica, Madrid/Lisboa. 2: 525-541.
Pereira S (2017). Trilobites do Ordovícico Superior da Zona Centro-Ibérica portuguesa. PhD Thesis, Universidade de Lisboa.
Pereira S, Colmenar J, Sá A, Pires M & Silva CM da (2017). A associação macrofossilífera da Formação Ribeira da Laje (Berouniano superior, Portugal): as últimas comunidades endémicas ordovícicas peri-gondwânicas. [ In S Barrios de Pedro S, C Blanco Moreno, A de Celis et al. (Eds) A Glimpse of the Past. Abstract book of the ] XV Encuentro de Jóvenes Investigadores en Paleontología/XV Encontro de Jovens Investigadores em Paleontologia (pp. 305-309). Pombal.
Pereira S, Jacinto A, Sá AA & Silva CM (2015). First report of Upper Ordovician fossils from Vila Velha de Ródão, Portugal: preliminary data. [ In LEG 2015, Volume, Scientific Programme & Abstracts ], V Congresso Jovens Investigadores em Geociências (pp. 69-72). Estremoz.
Romano M & Diggens JN (1974). The stratigraphy and structure of Ordovician and associated rocks around Valongo, north Portugal. Comunicações Serviços Geológicos de Portugal. 57: 23-50.
Romano M (1982). The Ordovician biostratigraphy of Portugal – A review with new data and re-appraisal. Geological Journal. 17:89-110.
Romão JMC (2006). Carta Geológica de Portugal na escala de 1:50.000. Notícia explicativa da folha 28-A (Mação). Lisboa: Serviços Geológicos de Portugal.
Sá A, Meireles C, Coke C, Gutiérrez-Marco JC (2005). Unidades litoestratigráficas do Ordovícico da região de Trás-os-Montes (Zona Centro-Ibérica, Portugal). Comunicações Geológicas. 92: 31-74.
Sequeira AJD, Proença Cunha P & Ribeiro ML (1999). Carta Geológica de Portugal na escala de 1:50.000. Notícia explicativa da folha 25-B (Salvaterra do Extremo). Lisboa: Serviços Geológicos de Portugal.
Teixeira C (1955). Notas sobre a Geologia de Portugal. O Sistema Silúrico. Lisboa.
Vaz N (2010). Palinoestratigrafia da sequência Ordovícico-Silúrica do Sinclinal Amêndoa-Mação. PhD Thesis, Universidade de Trás-os-Montes e Alto Douro.
Young TP (1988). The lithostratigraphy of the upper Ordovician of Central Portugal. Journal of the Geological Society. 145:377-392.
Young TP (1985). The Stratigraphy of the Upper Ordovician of Central Portugal. Dissertation, University of Sheffield.