Aitor Payros - Profile on Academia.edu (original) (raw)

Papers by Aitor Payros

Proposal for the Global Standard Stratotype-section and Point (GSSP) for the base of the Lutetian Stage at the Gorrondatxe section (Spain)

Influencia de los ciclos de precesión de Milankovitch en los depósitos turbidíticos eocenos de Gorrondatxe

The stratigraphic and sedimentological study carried out at the Gorrondatxe section (Getxo, Bisca... more The stratigraphic and sedimentological study carried out at the Gorrondatxe section (Getxo, Biscay) has shown that periodic climate-change episodes related with precession of equinoxes (Milankovitch cycles of 21 kiloyears) can be recorded in turbiditic deep marine deposits. Alternating pelagic limestones and marls occur in Gorrondatxe. This alternation was driven by precessional Milankovitch cycles. The amount and thickness of turbidites is higher in the pelagic marly intervals and lower in the limy intervals. This correlation suggests that the turbidite-rich marly intervals were related to more humid climatic stages, during which terrestrial sediment supply to the sea increased.

One of the Paleogene Stage boundaries still needing official definition is the Ypresian/Lutetain ... more One of the Paleogene Stage boundaries still needing official definition is the Ypresian/Lutetain (Early-Middle Eocene) boundary. With the aim of contributing to attain this definition, a high-resolution multidisciplinary study, including physical stratigraphy (lithostratigraphy, sequence stratigraphy and magnetostratigraphy) and biostratigraphy (calcareous nannofossil, planktic foraminifer and larger foraminifer), has been carried out over the 700 m thick uppermost Ypresian-lower Lutetian Gorrondatxe section. The results show that the different events traditionally used to place the Ypresian/Lutetian boundary, hitherto thought to be simultaneous (i.e., the planktic foraminifer P9 (=E7) / P10 (=E8) Zone boundary; the calcareous nannofossil CP12a / CP12b Subzone boundary; the larger foraminifer SBZ12 / SBZ13 Zone boundary; and the boundary between magnetic polarity chrons C22n and C21r), actually occur at very different levels. Therefore, before considering any section to place the Ypresian/Lutetian boundary stratotype, the criterion to precisely define this boundary should be selected. To this end, the succession of events pinpointed in the Ypresian/Lutetian boundary interval of the Gorrondatxe beach section might prove a useful database. The Gorrondatxe section fulfils most of the requirements demanded of a prospective stratotype section. In addition, the great sedimentary thickness, which implies a very high deep-marine sedimentation rate, provides the Gorrondatxe section an additional value, as it offers the opportunity to chronologically order successive biomagnetostratigraphic events more precisely than elsewhere. Therefore, we consider that, once the criterion to define the Ypresian/Lutetian boundary is selected, the Gorrondatxe beach section should be deemed a firm candidate to place the Global Stratotype Section and Point of the base of the Lutetian Stage.

Se ha realizado un analisis sedimentologico detallado de la Formacion Guara, a traves de un trans... more Se ha realizado un analisis sedimentologico detallado de la Formacion Guara, a traves de un transecto perpendicular a la Sierra de Santo Domingo (Huesca). A partir de la realizacion de 3 perfiles capa a capa, se han identificado seis episodios de sedimentacion, que en conjunto muestran una evolucion profundizante. El ultimo de estos episodios muestra un cambio lateral de facies entre las margas de la Formacion Arguis, y facies carbonatadas con bivalvos y equinidos de la Formacion Guara. Tanto las facies identificadas como la potencia de la serie evidencian una posicion proxima al borde de la cuenca de Jaca-Pamplona.

A systematic description of the Eocene larger foraminifera recorded in the South Pyrenean Basin (... more A systematic description of the Eocene larger foraminifera recorded in the South Pyrenean Basin (Sierras Exteriores) is presented herein. The large dataset provided in this work includes Nummulites and Alveolina species, along with a variety of other porcellaneous and hyaline taxa with lesser biostratigraphic relevance. Most of the larger foraminifera described in this work correspond to the Lutetian (SBZ13 to SBZ16 biozones) interval, but late Ypresian (SBZ11, Cuisian) and early Bartonian (SBZ17) shallow benthic zones have also been identified. A new species, Idalina osquetaensis, is described. The systematic revision of middle to late Lutetian alveolines led to a reassessment of Alveolina fusiformis and the finding of two new precursor forms, described as Alveolina aff. fragilis and Alveolina aff. elongata. The new taxa fill in the gap existing so far in the middle to late Lutetian alveolinid biostratigraphy. Despite not being exclusive to SBZ16, these forms provide realiable biostratigraphic information in facies where Nummulites are not present. This realibility lies on the correlation of Nummulites and Alveolina biostratigraphic markers in the same sections and their calibration to the global time scale through magnetostratigraphy.

The last Eocene hyperthermal (Chron C19r event, ~41.5 Ma): Chronological and paleoenvironmental insights from a continental margin (Cape Oyambre, N Spain)

Palaeogeography, Palaeoclimatology, Palaeoecology

Abstract The last hyperthermal event in the Eocene, the Late Lutetian Thermal Maximum or Chron C1... more Abstract The last hyperthermal event in the Eocene, the Late Lutetian Thermal Maximum or Chron C19r event, took place at ~41.5 Ma, during a long-term global cooling phase which occurred between the warm Early Eocene Climatic Optimum and the icehouse Oligocene Epoch. This paleoclimatic event was first identified in the Equatorial Atlantic Ocean Drilling Program (ODP) Site 1260 as an abrupt peak in bulk Fe content and a short-lived decline in stable isotopes (δ13C, δ18O) and carbonate content. Additional studies have recently been carried from the Southern Atlantic ODP sites 702 and 1263. However, many issues were not addressed at these deep-sea sites and no land-based record of the event had been studied. Therefore, the beach cliff at Cape Oyambre (N Spain) was analyzed with the aim of identifying the C19r event and investigating its paleoenvironmental impact. Using magnetostratigraphic and biostratigraphic information, the astronomically tuned cyclo-stratigraphic record from Oyambre was accurately correlated with ODP Site 1260. This, combined with stable isotope data, allowed identification of the event in a conspicuous dark marl bed. Given that the associated negative carbon isotope excursion extends for 2/3 of a precession-driven hemicouplet, a 7–11 kyr duration was estimated, which agrees with recent estimates from the Atlantic deep-sea sites. Exceptional insolation conditions were found to have accelerated the hydrological cycle, increasing rainfall and runoff on land and terrestrial sediment input to the sea, which resulted in relatively low carbonate content in the deep-sea sediments. The terrestrial input also caused seawater eutrophication and freshening, leading to low δ13C and δ18O values, increased abundance of autochthonous and reworked calcareous nannofossil taxa, peaks in the abundance of opportunistic Reticulofenestra

Newsletters on Stratigraphy

The early-middle Eocene times were characterized by warm temperatures punctuated by several short... more The early-middle Eocene times were characterized by warm temperatures punctuated by several short-lived (tens to hundreds of kyr) extreme warming events, commonly referred to as hyperthermals (Thomas and Zachos 2000, Zachos et al. 2001). In addition to low δ 18 O values, the hallmarks of these hyperthermal

Journal of Iberian Geology, 2016

Fossil associations from the middle and upper Eocene (Bartonian and Priabonian) sedimentary succe... more Fossil associations from the middle and upper Eocene (Bartonian and Priabonian) sedimentary succession of the Pamplona Basin are described. This succession was accumulated in the western part of the South Pyrenean peripheral foreland basin and extends from deep-marine turbiditic (Ezkaba Sandstone Formation) to deltaic (Pamplona Marl, Ardanatz Sandstone and Ilundain Marl formations) and marginal marine deposits (Gendulain Formation). The micropalaeontological content is high. It is dominated by foraminifera, and common ostracods and other microfossils are also present. The fossil ichnoasssemblages include at least 23 ichnogenera and 28 ichnospecies indicative of Nereites, Cruziana, and ?Scoyenia-Mermia ichnofacies. Body macrofossils of about 80 taxa corresponding to macroforaminifera, sponges, corals, bryozoans, brachiopods, annelids, molluscs, arthropods, echinoderms and vertebrates have been identified. Both the number of ichnotaxa and of species (e. g. bryozoans, molluscs and condrichthyans) may be considerably higher. Body fossil assemblages are comparable to those from the Eocene of the Nord Pyrenean area (Basque Coast), and also to those from the Eocene of the west-central and eastern part of South Pyrenean area (Aragon and Catalonia). At the European scale, the molluscs assemblages seem endemic from the Pyrenean area, although several Tethyan (Italy and Alps) and Northern elements (Paris Basin and Normandy) have been recorded. Palaeontological data of studied sedimentary units fit well with the shallowing process that throughout the middle and late Eocene occurs in the area, according to the sedimentological and stratigraphical data.

Early Eocene climatic optimum: Environmental impact on the North Iberian continental margin

Geological Society of America Bulletin, 2015

The early Eocene climatic optimum, which constituted the peak of the long-term early Cenozoic glo... more The early Eocene climatic optimum, which constituted the peak of the long-term early Cenozoic global warming, had a significant impact on the environmental evolution of terrestrial and oceanic areas. Surprisingly, however, its influence on continental margins is poorly known. New insights are provided from a sedimentological, stable isotope, mineralogical, and micropaleontological study of an 1100-m-thick Lower-Middle Eocene deep-marine succession that accumulated on the North Iberian continental margin. The early Eocene climatic optimum is represented by a 410-m-thick interval characterized by scarcity of hemipelagic limestones, abundance of dark marls, which record a reduction in calcium carbonate content and an increase in kaolinite, and the occurrence of conspicuous red layers with high siderite and pyrite content. Series of stratigraphically significant events frame the early Eocene climatic optimum. Based on this analysis, the environmental influence of the early Eocene climatic optimum started at 52.6 Ma and lasted ~2.3 m.y. Its onset is marked by rapid drops in δ13C and δ18O, which record the addition of 13C-depletedcarbon into the ocean-atmosphere system for 80 k.y. and a concomitant warming. A hotter climate and a perennial rainfall regime increased the supply of terrestrial clays, organicmatter, and iron oxides into the sea. Eventually, these changes affected the deepsea bottom 270 k.y. after the onset of the early Eocene climatic optimum, creating conditions in which opportunistic benthic foraminifera thrived, and leading to increased methanogenesis in the subsurface, which caused the formation of siderite. A subsequent gradual recovery culminated abruptly at 50.3 Ma with a global cooling episode, which is locally recorded by the accumulation of lowstand resedimentation deposits. © 2015 Geological Society of America.

Input of coarse-grained siliciclastics into the Pyrenean Basin during the PETM (2): a river-dominated fan delta within a carbonate platform system

Rendiconti online della Società Geologica Italiana, 2014

Paleocene Strata of the Basque Country, Western Pyrenees, Northern Spain: Facies and Sequence Development in a Deep-Water Starved Basin

Mesozoic and Cenozoic Sequence Stratigraphy of European Basins, 1998

Paleocene sediments are not thick in the Spanish Basque Country (usually less than 200 m), largel... more Paleocene sediments are not thick in the Spanish Basque Country (usually less than 200 m), largely composed of stacks of hemipelagic limestones and marls deposited in a clastic-starved deep basin. In addition to these, resedimented carbonates accumulated on base-of-slope aprons girding the basin, and resedimented carbonates plus lesser amounts of coarse-grained siliciclastics discontinuously plugged a deep-sea channel system incised on the basin floor. Third-order depositional sequences that attest to sea-level changes have earlier been recognized in the apron and channel systems (Pujalte et al., 1993). Further analyses have now demonstrated that these sea-level changes are also expressed in the hemipelagic sections by means of basin- wide variations in sedimentation rates through time, relative proportions of limestones and marls and, locally, the type of turbidite intercalations. The building blocks of these sequences are high-order stratification cycles, probably tuned to Milankovitch frequencies. Since these hemipelagic sections contain a nearly continuous stratigraphic record, a reliable reconstruction of the Paleocene sea-level changes that affected the Basque basin has been possible. A good match has been found between the regional sea-level curve derived from the deep-sea record and that of the global chart of Haq et al. (1988), mainly based on coastal onlap. This correlation clearly demonstrates that the signature of sea-level changes can be confidently unravelled from deep-marine successions, though it remains to be seen whether it reflects an eustatic signature or a bias of the data base.

Astibia, H., Payros, A., Pereda-Suberbiola, X., Elorza, J., Berreteaga, A., Etxebarria, N., Badiola, A. & Tosquilla, J. (2005). Sedimentology and taphonomy of sirenian remains from the Middle Eocene of the Pamplona Basin (Navarre, Western Pyrenees). Facies, 50(6), 463-475

Facies

High-Resolution Integrated Cyclostratigraphy From the Oyambre Section (Cantabria, N Iberian Peninsula): Constraints for Orbital Tuning and Correlation of Middle Eocene Atlantic Deep-Sea Records

Geochemistry, Geophysics, Geosystems

Contrasting environmental effects of astronomically driven climate change on three Eocene hemipelagic successions from the Basque-Cantabrian Basin

Sedimentology, 2016

A siliciclastic braid delta within a lower Paleogene carbonate platform (Ordesa-Monte Perdido National Park, southern Pyrenees, Spain): Record of the Paleocene–Eocene Thermal Maximum perturbation

Palaeogeography, Palaeoclimatology, Palaeoecology, 2016

The La Pardina Formation is a siliciclastic-dominated unit up to 26 m thick intercalated within a... more The La Pardina Formation is a siliciclastic-dominated unit up to 26 m thick intercalated within a 300 m thick Danian–lower Ilerdian succession of shallow marine carbonates in the southern Pyrenees. The unit is composed of four interdigitated facies, three of them of a coarse-grained siliciclastic character (Sf1, Sf2, Sf3), and the fourth one composed of bioclastic packstones with argillaceous matrix (calcareous facies, Cf). The siliciclastic facies make up the bulk of the La Pardina Formation in the Ordesa-Monte Perdido National Park, while the Cf is subordinate in the Park but widespread throughout the southern Pyrenees. Biostratigraphic and isotopic data suggest that the Cf pertains to the Paleocene–Eocene Thermal Maximum (PETM). No isotopic or biostratigraphic information could be obtained from the siliciclastic facies, but they are also assigned to the PETM because of their interfingering with the Cf. The siliciclastic facies were accumulated in a braid delta system fed by either a major river or by several minor rivers draining the Ebro Massif. The Sf3, Sf2 and Sf1 respectively represent the top-set, foreset and bottomset parts of the braid delta, whereas the Cf correspond to the prodelta. In proximal parts of the braid delta the Sf3 overlies a subaerial surface carved into upper Thanetian marine carbonates, a proof of a pre-PETM sea-level fall. In the remainder of the braid delta, the La Pardina Formation exhibits an overall thickening-coarsening-up trend that attests to rapid progradation. The development of the braid delta implies a dramatic increase in the influx of both coarse- and fine-grained siliciclastics, which temporarily halted a long-lasting period of carbonate-dominated sedimentation. This abrupt change demonstrates that the environmental impact caused by the intensification of the hydrological cycle during the PETM was particularly severe at middle latitudes.

Un sistema turbidítico Bartoniense de tipo «channel-levee» en la Cuenca de Pamplona: implicaciones tectónicas y paleogeográficas

... and paleogepgraphicinjpriçatipns A. Payros, V.Pujalte.X. Orue-Etxebarria y JI Baceta [Departa... more ... and paleogepgraphicinjpriçatipns A. Payros, V.Pujalte.X. Orue-Etxebarria y JI Baceta [Departamento.de Estratigrafía y Paleontología, Facultad de Giecias.Uniyersidad del.País Vasco, Apdo. 644; 48080 Bilbao ABSTRACT The.Bartpnian: Ezkaba Sandstone, in the. Pamplona. ...

Revista Espanola De Paleontologia, 2006

La Fm Puerto de La Losa (N de Granada, E de Jaén): una nueva unidad estratigráfica, paleogeográficamente significativa, del Paleógeno Inferior Prebético