Person:
Fuenlabrada Pérez, José Manuel

First Name

José Manuel

Last Name

Fuenlabrada Pérez

URI

https://hdl.handle.net/20.500.14352/87137

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Geológicas

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Now showing 1 - 10 of 24

A two-stage collision at the origin of Pangea: the allochthonous Variscan terranes
(Geotemas, 2016) Arenas Martín, Ricardo; Díez Fernández, Rubén; Sánchez Martínez, Sonia; Gerdes, Axel; Fernández Suárez, Javier; Albert, R.; Fuenlabrada Pérez, José Manuel
The Variscan suture exposed in NW Iberia contains two allochthonous terranes with Gondwanan provenance (upper and basal units), separated by ophiolites with protolith ages at c. 395 Ma. The tectonothermal evolution of the continental terranes records two consecutive events of deep subduction. The upper units record an initial high-P/ultrahigh-P metamorphic event that occurred before 400-390 Ma, while the basal units were affected by a second high-P/low-to-intermediate-T metamorphic event at c. 370 Ma. Repeated continental subduction affecting the most external margin of Gondwana occurred in a setting of dextral convergence with Laurussia. The two high-P events alternated with the opening of an ephemeral oceanic basin, probably of pull-apart type, in Early Devonian times. This ephemeral oceanic domain is suggested as the setting for the protoliths of the most common ophiolites involved in the Variscan Orogen. Current ideas for the assembly of Pangea advocate a single collisional event in Carboniferous times. However, the new evidence from the allochthonous terranes of the Variscan Orogen suggest a more complex scenario for the assembly of the supercontinent, with an interaction between the colliding continental margins that started earlier and lasted longer than previously considered.
A peri-Gondwanan arc in NW Iberia I: Isotopic and geochemical constraints on the origin of the arc—A sedimentary approach
(Gondwana research, 2010) Fuenlabrada Pérez, José Manuel; Arenas Martín, Ricardo; Sánchez Martínez, Sonia; Díaz García, Florentino; Castiñeiras García, Pedro
The arc-derived upper terrane in the NW Iberia Variscan belt contains a 3000 m thick turbiditic formation at its structural top. Most of the sandstones are feldspathic greywackes with a framework of quartz and weakly altered plagioclase. Rock fragments of vitric and microgranular texture are common in polymictic conglomerates and coarse-grained greywackes, together with slates, cherts and bipyramidal volcanic quartz fragments. Although recrystallization under greenschists facies conditions (chlorite and biotite zones) and the presence of two cleavages hinder detailed textural analysis, the sandstones appear to be typically immature, first-cycle sandstones. The metagreywackes have average major and trace element compositions similar to PAAS (Post Archean Australian Shale), which is considered to reflect the composition of the upper continental crust. Their trace element composition is very consistent and records deposition within a convergent tectonic setting, probably in an intra-arc basin located in a volcanic arc built on thinned continental margin. Detrital zircon populations suggest a Middle Cambrian maximum depositional age (530–500 Ma) and a Gondwanan provenance located at the periphery of the West African Craton. Nd isotope data suggest mixing Ediacaran and Paleoproterozoic sources for the provenance of the greywackes, with TDM ranging between 720 and 1215 Ma with an average of 995 Ma (n=20)—an age range unrepresented in the detrital zircon population. The Nd model ages are similar to those exhibited by West Avalonia, Florida or the Carolina terrane, but younger than those of Cambrian and Ordovician sandstones and shales from the autochthonous realm. These data suggest a westernmost location along the Gondwanan margin for the upper terrane of NW Iberia relative to other terranes located in the footwall of the Variscan suture, consistent with several previously proposed paleogeographic models for the NW Iberia terranes.
Geochemistry in earth sciences: a brief overview
(Journal of iberian geology, 2020) Fernández Suárez, Javier; Sánchez Martínez, Sonia; Fuenlabrada Pérez, José Manuel
In this contribution we present a succinct overview of the role of Geochemistry in the Earth Sciences. Our idea is to offer a “bird’s eye” perspective of the advent of Geochemistry and its historical development and the advances and milestones in analytical techniques that led Geochemistry to its actual place in the context of Earth Sciences. Finally, we offer a summary of some relevant applications of Geochemistry in the study of a variety of geological problems.
Sm–Nd isotope geochemistry and tectonic setting of the metasedimentary rocks from the basal allochthonous units of NW Iberia (Variscan suture, Galicia)
(Lithos (Oslo. Print), 2012) Fuenlabrada Pérez, José Manuel; Arenas Martín, Ricardo; Díez Fernández, Rubén; Sánchez Martínez, Sonia; Abati Gómez, Jacobo; López Carmona, Alicia
The basal units of the allochthonous complexes of NW Iberia are formed by thick metasedimentary rock sequences intruded by granitoids, ranging in composition from calc-alkaline (c. 493 Ma) to minor alkaline– peralkaline massifs (c. 475–470 Ma), and mafic rocks. The granitoids were transformed into variably deformed othogneisses and the associated mafic rocks were transformed into amphibolites, blueschists and eclogites during eo-Variscan high-P metamorphism dated at c. 370 Ma. Two different superimposed metasedimentary rock sequences can be distinguished. The lower sequence (maximum depositional age at c. 560 Ma) is mainly composed of metagreywackes, while the upper sequence (maximum depositional age at c. 500 Ma) consists of mica schists and other minor types. Major and trace element geochemistry of the metagreywackes of the lower sequence suggests that they were generated in relation to a peri-Gondwanan arc system built on the thinned continental margin, although some chemical transition to passive margin greywackes is also observed. This sedimentary sequence was probably deposited in an Ediacaran–Early Cambrian back-arc setting or retro-arc setting, closer to the thinned platform of the continental margin. The geochemical features of the sedimentary rocks of the upper sequence suggest some affinity with passive margin sediments; they were probably deposited closer to the continental domain and to certain distance from the most active zones of the magmatic arc. The Nd model ages of 23 analysed samples are Paleoproterozoic and range between 1782 Ma and 2223 Ma (average value 1919 Ma). The Nd model ages are slightly younger in the upper sequence than in the lower sequence, but altogether they define a single population, and therefore the two metasedimentary rock sequences can be clearly related. Sedimentation probably took place within the same basin located in the continental platform of Gondwana, the main source areas of these sedimentary rocks did not change during the Late Neoproterozoic and Cambrian times. The Nd model ages are very old and they seem to be compatible with Paleoproterozoic or Archean source areas, with only minor participation of younger sources probably represented by intrusive Cadomian–Pan-African granitoids.
Paleogeografía geoquímica de las series metasedimentarias del Macizo Ibérico
(Geotemas, 2016) Fuenlabrada Pérez, José Manuel; Arenas Martín, Ricardo; Sánchez Martínez, Sonia; Díez Fernández, Rubén; Pieren Pidal, Agustín Pedro
Las características geoquímicas e isotópicas de las series turbidíticas del Macizo Ibérico reflejan distintos escenarios tectónicos en la periferia de Gondwana. Estos cambios se observan en el registro sedimentario de la transición Ediacarense-Cámbrico, que tuvo lugar en el contexto general de un margen continental activo. TDM jóvenes y ɛNd menos negativos resultan característicos de cuencas sedimentarias más exteriores, con una importante contribución de material juvenil derivado del sector más activo del arco volcánico (metagrauvacas culminantes de las Unidades Superiores del Complejo de Órdenes). Las cuencas sedimentarias más próximas al continente se caracterizan por mayores aportes desde dominios alejados del arco activo que dan lugar a valores de TDM más antiguos y ɛNd muy negativos (metagrauvacas de las Unidades Basales del Complejo de Malpica-Tui). Una evolución desde contextos activos hasta otros más propios de márgenes pasivos se detecta con claridad en la transición Ediacarense-Cámbrico, y debe relacionarse con una disminución de la actividad del arco volcánico y la transición hacia un margen pasivo. El diagrama de fSm/Nd vs ɛNd confirma esta variación de los escenarios tectónicos asociados al margen de Gondwana, perfectamente registrados en los metasedimentos de diferentes sectores y unidades del Macizo Ibérico.
Geochemistry and Sm–Nd isotopic sources of Late Ediacaran siliciclastic series in the Ossa–Morena Complex: Iberian–Bohemian correlations
(International journal of earth sciences, 2021) Rojo-Pérez, Esther; Fuenlabrada Pérez, José Manuel; Linnemann, Ulf; Arenas Martín, Ricardo; Sánchez Martínez, Sonia; Díez Fernández, Rubén; Martín Parra, Luis Miguel; Andonaegui Moreno, María Del Pilar; Matas, Jerónimo; Fernández Suárez, Javier
The Cadomian basement in central and southern Europe is composed by Ediacaran–Early Cambrian sequences that appear dismembered along the Variscan Orogen. These ancient series contain geochemical and isotopic keys related to their deposition in different basins located along the paleo margin of Gondwana. The southwest of Iberian Massif (Ossa–Morena Complex) contains an excellent representation of Cadomian basement. The oldest sedimentary succession of this region, the Serie Negra Group (c. 600–541 Ma), is composed by the Montemolín Formation which consists of metapelites, metagreywackes and abundant amphibolites; and the Tentudía Formation which consists of metagreywackes, black quartzites and metapelites. The whole-rock and Nd isotopic geochemistry of the Montemolín and Tentudía formations, are consistent with a deposition in a back-arc or fore-arc setting. Their Nd isotopic composition shows highly negative εNd(t) values in a range between − 6.9 and − 11.5, resulting in old Paleoproterozoic Nd model ages between 1.9 and 1.7 Ga. The Nd isotopic signatures obtained for the Cadomian basement in the Iberian Massif are almost identical to those obtained for equivalent sedimentary series in the Saxo-Thuringian Zone (Bohemian Massif), where Nd model ages range between 2 and 1.6 Ga. The limited variability of these Nd-TDM ages suggests that the southwestern Iberian and North Bohemian series shared a common source during Ediacaran times, which would be located close to the periphery of the West African Craton. The Nd isotopic data considered herein provide solid evidence about the peri-Gondwanan location and correlation between the Cadomian basement of southwestern Iberia and North Bohemia.
Geochemical and isotopic (SmNd) provenance of Ediacaran-Cambrian metasedimentary series from the Iberian Massif. Paleoreconstruction of the North Gondwana margin
(Earth-Science Reviews, 2020) Fuenlabrada Pérez, José Manuel; Arenas Martín, Ricardo; Sánchez Martínez, Sonia; Díez Fernández, Rubén; Pieren Pidal, Agustín Pedro; Pereira, M. Francisco; Chichorro, Martim; Silva, José B.
The geochemical and isotopic (SmNd) features of the Ediacaran-Cambrian siliciclastic series from the Central Iberian Zone and the Iberian Allochthonous Domains indicate a significant paleogeographic change at the northern margin of Gondwana, associated with the development of the Avalonian-Cadomian arc. During the Neoproterozoic, the opening of a peri-Gondwanan back-arc basin and its subsequent widening during the Cambrian led to a progressive separation of the sedimentary basins from the main focus of the probably waning Cadomian magmatic arc activity. This work presents a paleogeographic reconstruction of the distribution of the Iberian terranes along the North Gondwanan margin during Ediacaran and Cambrian times, based on the geochemical and Nd-isotope data from the Iberian Allochthonous and Autochthonous Domains. These results suggest a location close to the West Africa Craton for both the allochthonous and autochthonous terranes, but they would be distributed laterally along the northern margin of Gondwana, occupying arc- or continental-ward positions within a wide back-arc basin. In this context, the peri-Gondwanan volcanic arc acted as the main supplier of the abundant juvenile material, as reflected in positive values of εNd and young TDM model ages (720–1215 Ma) of the Middle Cambrian siliciclastic series from NW Iberia Upper Allochthonous Units. On the other hand, the rather equivalent geochemical and isotopic features of the sedimentary series of the NW and SW Iberia Basal Allochthonous Units suggest a common paleolocation for those series, yet within the back-arc basin but closer to the mainland and older isotope sources. The sedimentary series of these terranes present the oldest TDM ages (1499–2156 Ma), clearly greater than the TDM ages that characterize coeval sedimentary series of the Iberian Autochthonous Domain (1256–1334 Ma). This finding allows us to place Iberian Basal Allochthonous Units very close to the West Africa Craton, from where they received a dominant contribution of old crustal materials, whereas the Iberian Autochthonous Domain occupied a more eastern paleoposition closer to the Sahara Metacraton.
A Peri-Gondwanan arc active in Cambrian-Ordovician times: the evidence of the uppermost terrane of NW Iberia
(2011) Arenas Martín, Ricardo; Abati Gómez, Jacobo; Sánchez Martínez, Sonia; Andonaegui Moreno, María Del Pilar; Fuenlabrada Pérez, José Manuel; Fernández Suárez, Javier; González Cuadra, P.; Gutiérrez-Marco, Juan Carlos; Rábano, Isabel; García-Bellido, Diego
Geochemistry of the Ediacaran–Early Cambrian transition in Central Iberia: Tectonic setting and isotopic sources
(Tectonophysics, 2016) Fuenlabrada Pérez, José Manuel; Pieren Pidal, Agustín Pedro; Díez Fernández, Rubén; Sánchez Martínez, Sonia; Arenas Martín, Ricardo
A complete Ediacaran–Early Cambrian stratigraphic transition can be observed in the southern part of the Central Iberian Zone (Iberian Massif). Two different stratigraphic units, underlying Ordovician series, display geochemical and Sm–Nd isotopic features in agreement with an evolving geodynamic setting. Pusa Shales (Early Cambrian) rest unconformably on greywackes of the Lower Alcudian Formation (Late Ediacaran). Both sequences present minor compositional variations for major and trace element contents and similar REE patterns, close to those of PAAS (Post Archean Australian Shale). Trace element contents and element ratios suggest mixed sources, with intermediate to felsic igneous contributions for both units. Tectonic setting discrimination diagrams for the Ediacaran greywackes indicate that these turbiditic series were deposited in a sedimentary basin associated with a mature active margin (volcanic arc). However, the compositions of the Cambrian shales fit better with a more stable context, a back-arc or retro-arc setting. εNd(T) and TDM ages are compatible with dominance of a similar cratonic source for both sequences, probably the West Africa Craton. εNd565 values for the Ediacaran greywackes (−3.0 to −1.4) along with TDM ages (1256–1334 Ma) imply a significant contribution of juvenile material, probably derived from the erosion of the volcanic arc. However, εNd530 values in the Cambrian shales (−5.2 to −4.0) together with older TDM ages (1444–1657 Ma), suggest a higher contribution of cratonic isotopic sources, probably derived from erosion of the adjacent mainland. Coeval with the progressive cessation of arc volcanism along the peri-Gondwanan realm during the Cambrian, there was a period of more tectonic stability and increasing arrival of sediments from cratonic areas. The geochemistry of the Ediacaran–Cambrian transition in Central Iberia documents a tectonic switch in the periphery of Gondwana, from an active margin to a more stable context related to the onset of a passive margin.
The Galicia–Ossa-Morena Zone: Proposal for a new zone of the IberianMassif. Variscan implications
(Tectonophysics, 2016) Arenas Martín, Ricardo; Díez Fernández, Rubén; Rubio Pascual, Francisco J.; Sánchez Martínez, Sonia; Martín Parra, Luis Miguel; Matas, Jerónimo; González del Tánago y del Río, José; Jiménez Díaz, Alberto; Fuenlabrada Pérez, José Manuel; Andonaegui Moreno, María Del Pilar; Garcia Casco, Antonio
Correlation of a group of allochthonous terranes (referred to as basal, ophiolitic and upper units) exposed in theNW and SW of the Iberian Massif, is used to propose a new geotectonic zone in the southern branch of theVariscan Orogen: the Galicia–Ossa-Morena Zone. Recent advances in SW Iberia identify most of the formerOssa-Morena Zone as another allochthonous complex of the Iberian Massif, the Ossa-Morena Complex, equiva-lent to the Cabo Ortegal, Órdenes, Malpica-Tui, Bragança and Morais complexes described in NW Iberia. Thenew geotectonic zone and its counterparts along the rest of the Variscan Orogen constitute an Internal VariscanZone with ophiolites and units affected by high-P metamorphism. The Galicia–Ossa-Morena Zone includes aVariscan suture and pieces of continental crust bearing the imprint of Ediacaran–Cambrian events related tothe activity of peri-Gondwanan magmatic arcs (Cadomian orogenesis). In the Iberian Massif, the general struc-ture of this geotectonic zone represents a duplication of the Gondwanan platform, the outboard sections beingjuxtaposed on top of domains located closer to the mainland before amalgamation. This interpretation offersan explanation that overcomes some issues regarding the differences between the stratigraphic and paleontolog-ical record of the central and southern sections of the Iberian Massif. Also, equivalent structural relationships be-tween other major geotectonic domains of the rest of the Variscan Orogen are consistent with our interpretationand allow suspecting similar configurations along strike of the orogen. A number of issues may be put forward inthis respect that potentially open new lines of thinking about the architecture of the Variscan Orogen.