Las biozonas de nummulitidos del Paleoceno Superior-Eoceno Inferior de la Cuenca Pirenaica

A nummulitid biozonation for the Upper Paleocene-Lower Eocene Pyrenean Basin is proposed in this work, The main contributions are: a) a new biozone proposed for the early Thanetian, b) a better characterization of the late Thanetian biozone, and c) the recognition of  two different biozones within the Lower Ilerdian.The nummulitid biozones established for the Pyrenean Upper Paleocene-Lower Eocene interval were correlated with the corresponding larger foraminiferal biozones Shallow Benthic Zones (SBZ) and integrated in the standard Paleocene-Eocene Time Scale on the basis of magnetostratigraphic data from the Pyrenean Basin and by correlation with the biozonation of calcareous nannoplankton and planktonic foraminifera in the Eastern and Central part of Tethys.The new biozones defined for tbe Pyrenean Upper Paleocene-Lower Eocene are: Nummulites heberti-Ranikothalia sindensis (early Thanetian), N. catari-Assilina yvettae-A. azilensis (late Thanetian), N. gamardensis-A. dandotica (early Ilerdian l), N. bigurdensis-A. aff. Prisca (early Ilerdian 2), N. carcasonensis-A. arenensis (middle Ilerdian l), N. exilis-A. leymeriei (middle Ilerdian 2), N. involutus-A. pomeroli (late Ilerdian), N. planulatus-N. burdigalensis burdigalensis-A. placentula (early Cuisian), N. praelaevigatus-N, cantabricus-A. laxispira (middle Cuisian), and N. manfredi-N. campesinus-A. mnior (late Cuisian)

Virtualization of pliocene sites in the Huelva province: valuating the paleontological heritage in differentiate educative settings I

El patrimonio paleontológico del Plioceno de la provincia de Huelva es uno de los más importantes de España y referente europeo de moluscos de este período. Sin embargo, no existe un inventario de catalogación básica de los principales yacimientos ni de los principales grupos fósiles presentes, así como de su importancia como patrimonio natural. El presente trabajo pretende rellenar este notable vacío con una proyección tanto hacia materias preuniversitarias como universitarias, así como hacia posibles instituciones y corporaciones públicas susceptibles de utilizarlo en sus planes de ordenación. Por otro lado, se pretende que actúe como mecanismo de interconexión entre titulaciones con bajo número de alumnos de nuevo ingreso y los centros de Bachillerato, de forma que incentive una posible elección de estos Grados por los alumnos de las opciones científico-tecnológicas. También puede ser interesante para captar egresados hacia Másteres Oficiales en Patrimonio Histórico y Natural. En este sentido, se ha realizado un DVD documental sobre el patrimonio paleontológico del Plioceno de la provincia de Huelva, concretamente de las formaciones “Arenas de Huelva” y “Arenas de Bonares” desarrolladas en ambientes marinos someros y costeros durante la última etapa de evolución neógena de la cuenca. Este documental incluye una visión de conjunto de los principales yacimientos fósiles de esta edad, así como una explicación de la evolución paleogeográfica de nuestra provincia y los organismos que la han caracterizado en los últimos millones de años. Esta aportación es aplicable en el trabajo de campo de varios Grados y Posgrados universitarios y de fácil uso como material didáctico en diversas asignaturas de E.S.O. y Bachillerato. Este trabajo se ha realizado en el marco del proyecto de innovación docente (PID nº 10050) de la Universidad de Huelva.The paleontological heritage from the Neogene in the province of Huelva is one of the most important in Spain and it is considered a European reference site for the mollusk fossil record from this period. However, there are not basic inventories neither for the main sites nor the major fossil groups. Furthermore, no inventories exist about their natural heritage importance. This work aims to fill this significant gap for both pre-university and university levels, as well as to public institutions and corporations that may use it in their management plans. In addition, it is intended to act as an linking mechanism between university degrees with low number of first-year students and high school centres, in order to encourage a possible choice of these Bachelor’s degrees by scientific and technological students. It may also be interesting to catch the attention of graduates for Official Masters in Historical and Natural Heritage. In this sense, a DVD-documentary has been made about the paleontological heritage from the Pliocene in the province of Huelva, specifically from the “Arenas de Huelva” and “Arenas de Bonares” formations. These units were developed in shallow marine and coastal environments during the last stage of the Neogene evolution in the Guadalquivir Basin. This documental includes an overview of main marine fossil sites from this age and a brief explanation of the palaeogeographic evolution of the Huelva province during the last million of years. This contribution is useful for the fieldwork at Bachelor and Master Degree level and it is easy to use as teaching materials in different ESO (Obligatory Secondary Teaching) and High School subjects. This work has been support for an Innovation in Teaching Project (PID No. 10050) of the Huelva University

Virtualization of niebla formation sites (upper miocene) in the Huelva province: valuating the paleontological heritage in differentiate educative settings II

El patrimonio paleontológico del Neógeno de la provincia de Huelva es uno de los más importantes de España y referente europeo de moluscos de este período. Sin embargo, no existe un inventario de catalogación básica de los principales yacimientos ni de los principales grupos fósiles presentes, así como de su importancia como patrimonio natural. El presente trabajo pretende rellenar este notable vacío con una proyección tanto hacia materias preuniversitarias como universitarias, así como hacia posibles instituciones y corporaciones públicas susceptibles de utilizarlo en sus planes de ordenación. Por otro lado, se pretende que actúe como mecanismo de interconexión entre titulaciones con bajo número de alumnos de nuevo ingreso y los centros de Bachillerato, de forma que incentive una posible elección de estos Grados por los alumnos de las opciones científico-tecnológicas. También puede ser interesante para captar egresados hacia Másteres Oficiales en Patrimonio Histórico y Natural. En este sentido, se ha realizado un DVD documental sobre el patrimonio paleontológico del Mioceno superior de la provincia de Huelva. Este documental incluye una visión de conjunto de los principales yacimientos de fósiles marinos de la Fm. Niebla, desarrollada en un marco transgresivo bajo unas condiciones más húmedas y cálidas que las actuales. Esta aportación es aplicable al trabajo de campo de varios Grados y Posgrados universitarios y de fácil uso como material didáctico en diversas asignaturas de E.S.O. y Bachillerato. Este trabajo se ha realizado en el marco del proyecto de innovación docente (PID nº 11003) de la Universidad de Huelva.The paleontological heritage from the Neogene in the province of Huelva is one of the most important in Spain and it is considered a European reference site for the mollusk fossil record from this period. However, there are not basic inventories neither for the main sites nor the major fossil groups. Furthermore, no inventories exist about their natural heritage importance. This work aims to fill this significant gap for both pre-university and university levels, as well as to public institutions and corporations that may use it in their management plans. In addition, it is intended to act as an linking mechanism between university degrees with low number of first-year students and high school centres, in order to encourage a possible choice of these Bachelor’s degrees by scientific and technological students. It may also be interesting to catch the attention of graduates for Official Masters in Historical and Natural Heritage. In this sense, a DVD-documentary has been made about the paleontological heritage from the Upper Miocene in the province of Huelva. This documental includes an overview of the main marine fossil sites from the Niebla Formation developed in a transgressive setting under more humid and warmer conditions than today. This contribution is useful for the fieldwork at Bachelor and Master Degree level and it is easy to use as teaching materials in different ESO (Obligatory Secondary Teaching) and High School subjects. This work has been funded for an Innovation in Teaching Project (PID No. 10050) of the Huelva University

FIELD TRIP TO THE YPRESIAN/LUTETIAN BOUNDARY AT THE GORRONDATXE BEACH SECTION (BASQUE COUNTRY, W PYRENEES)

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

The early/middle Eocene transition at the Ésera valley (South-Central Pyrenees): Implications in Shallow Benthic Zones (SBZ)

An integrated study including magnetostratigraphy, larger benthic foraminifera and calcareous nannofossil biostratigraphy is presented herein. This work was performed in shallow marine siliciclastics rich in larger foraminifera, around the Ypresian/Lutetian boundary in the Ésera valley (South-Central Pyrenees). Although the calcareous nannofossil content in the studied interval is low, not allowing a precise Y/L boundary to be recognised, the taxa found are enough to support the chronostratigraphic attribution. Data obtained in the Ésera valley section has improved the knowledge of larger benthic foraminifera (Nummulites and Assilina) distribution through chron C21. SBZ 11 to SBZ 12 transition took place at the lowermost C21r, as shown in previous works. SBZ 12 assemblages extend into C21n, where the SBZ 12 to SBZ 13 boundary occurs. These data, obtained in shallow marine siliciclastic facies, with in situ fauna, results in a shift of the SBZ 12/SBZ 13 boundary to the Lower Lutetian, younger than previously believed. Accordingly, the Ypresian/Lutetian boundary occurs in SBZ 12. © A. Rodríguez-Pintó, J. Serra-Kiel, G. Bernaola, A. Barnolas, E.L. Pueyo, J. Tosquella, P. Arbués, R. Scholger, 2022 CC BY-SA

Cyclostratigraphy of the Early/Middle Eocene transition: a Pyrenean perspective

An integrated bio-, magneto- and cyclostratigraphic study of the Ypresian/Lutetian (Early/Middle Eocene) transition along the Pyrenean Otsakar section (Payros et al., 2011) resulted in the identification of the C22n/C21r chron boundary and of the calcareous nannofossil CP12a/b zonal boundary; the latter is the main correlation criterion of the Lutetian Global Stratotype Section and Point (GSSP) recently defined at Gorrondatxe (Basque Country). By counting precession-related mudstone-marl couplets of 21 ka, the time lapse between both events was calculated to be of 819 ka. This suggests that the age of the CP12a/b boundary, and hence that of the Early/Middle Eocene boundary, is 47.76 Ma, 250 ka younger than previously thought. This age agrees with, and is supported by, estimates from Gorrondatxe based on the time lapse between the Lutetian GSSP and the C21r/C21n boundary. The duration of Chron C21r is estimated at 1.326 Ma. Given that the base of the Eocene is dated at 55.8 Ma, the duration of the Early Eocene is of 8 Ma, 0.8 Ma longer than in current time scales. The Otsakar results further show that the bases of planktic foraminiferal zones E8 and P10 are younger than the CP12a/b boundary. The first occurrence of Turborotalia frontosa, being approximately 550 ka older that the CP12a/b boundary, is the planktic foraminiferal event that lies closest to the Early/Middle Eocene boundary. The larger foraminiferal SBZ12/13 boundary is located close to the CP12a/b boundary and correlates with Chron C21r, not with the C22n/C21r boundary

Marine and Transitional Middle/Upper Eocene Units of the Southeastern Pyrenean Foreland Basin (NE Spain)

The stratigraphic basis of this work has allowed the use of larger foraminifers in the biostratigraphic characterisation of the new Shallow Benthic Zones (SBZ). This part of the volume presents a description of the sedimentary cycles formed by the transgressive-regressive systems of the Lutetian and Bartonian in the southeastern sector of the Ebro Foreland Basin.Concerning the Lutetian deposits studied in the Amer-Vic and Empordà areas, four sedimentary cycles have been characterised. The first and second are found within the Tavertet/Girona Limestone Formation (Reguant,1967;Pallí,1972), while the third and fourth cycles cover the Coll de Malla Marl Formation (Clavell et al.,1970), the Bracons Formation (Gich,1969,1972), the Banyoles Marl Formation (Almela and Ríos,1943),and the Bellmunt Formation (Gich,1969,1972). In the Bartonian deposits studied in the Igualada area,two transgressive-regressive sedimentary cycles have been characterised in the Collbàs Formation (Ferrer,1971),the Igualada Formation (Ferrer,1971),and the Tossa Formation (Ferrer,1971). The Shallow Benthic Zones (SBZs)recognised within the Lutetian are the following:SBZ 13, from the Early Lutetian, in the transgressive system of the first cycle;SBZ 14,from the Middle Lutetian, in the second cycle and the lower part of the transgressive system of the third cycle; SBZ 15,from the Middle Lutetian, in the remaining parts of the third system; SBZ 16, from the Late Lutetian,throughout the fourth cycle.The association of larger foraminifers in the first and second cycles of the Bartonian in the Igualada area has been used as the basis for the definition of SBZs 17 and 18 recognised in the Bartonian of the western Tethys

Marine and Transitional Middle/Upper Eocene Units of the Southeastern Pyrenean Foreland Basin (NE spain)

The stratigraphic basis of this work has allowed the use of larger foraminifers in the biostratigraphic characterisation of the new Shallow Benthic Zones (SBZ). This part of the volume presents a description of the sedimentary cycles formed by the transgressive-regressive systems of the Lutetian and Bartonian in the southeastern sector of the Ebro Foreland Basin.Concerning the Lutetian deposits studied in the Amer-Vic and Empordà areas, four sedimentary cycles have been characterised. The first and second are found within the Tavertet/Girona Limestone Formation (Reguant,1967;Pallí,1972), while the third and fourth cycles cover the Coll de Malla Marl Formation (Clavell et al.,1970), the Bracons Formation (Gich,1969,1972), the Banyoles Marl Formation (Almela and Ríos,1943),and the Bellmunt Formation (Gich,1969,1972). In the Bartonian deposits studied in the Igualada area,two transgressive-regressive sedimentary cycles have been characterised in the Collbàs Formation (Ferrer,1971),the Igualada Formation (Ferrer,1971),and the Tossa Formation (Ferrer,1971). The Shallow Benthic Zones (SBZs)recognised within the Lutetian are the following:SBZ 13, from the Early Lutetian, in the transgressive system of the first cycle;SBZ 14,from the Middle Lutetian, in the second cycle and the lower part of the transgressive system of the third cycle; SBZ 15,from the Middle Lutetian, in the remaining parts of the third system; SBZ 16, from the Late Lutetian,throughout the fourth cycle.The association of larger foraminifers in the first and second cycles of the Bartonian in the Igualada area has been used as the basis for the definition of SBZs 17 and 18 recognised in the Bartonian of the western Tethys

An inventory of the Marine and Transitional Middle/Upper Eocene Deposits of the Southeastern Pyrenean Foreland Basin (NE spain)

In the southeastern Ebro Foreland Basin, the marine deposits of Lutetian and Bartonian age show excellent outcrop conditions, with a great lateral and horizontal continuity of lithostratigraphic units. In addition, the rich fossil record -mainly larger foraminifers-, provides iostratigraphic data of regional relevance for the whole Paleogene Pyrenean Basin, that can be used for the Middle Eocene biocorrelation of the western Tethys. This contribution is a sedimentary and biostratigraphic synthesis of the basic outcrops and sections of the Lutetian and Bartonian marine and transitional deposits in the southeastern sector of the Ebro Foreland Basin

Redefinition of the Ilerdian Stage (early Eocene)

The Ilerdian Stage was created by Hottinger and Schaub in 1960 to accommodate a significant phase in the evolution of larger foraminifera not recorded in the northern European basins, and has since been adopted by most researchers working on shallow marine early Paleogene deposits of the Tethys domain. One of the defining criteria of the stage is a major turnover of larger foraminifera, marked by the FO’s of Alveolina vredenburgi (formerly A. cucumiformis) and Nummulites fraasi. There is now conclusive evidence that this turnover was coeval with the onset of the Carbon Isotope Excursion (CIE) and, consequently, with the Paleocene-Eocene (P-E) boundary, a temporal correspondence that reinforces the usefulness of the Ilerdian as a chronostratigraphic subdivision of the early Eocene in a regional context. However, in addition to the paleontological criteria, the definition of the Ilerdian was also based on the designation of two reference sections in the southern Pyrenees: Tremp (stratotype) and Campo (parastratotype). In both sections, the base of the stage was placed at the lowest marine bed containing A. vredenburgi specimens. Using the CIE as a correlation tool we demonstrate that these two marine beds occur at different chronological levels, being older in Campo than in Tremp. Further, we show that both beds are in turn younger than the lowest strata with Ilerdian larger foraminifera at the deep-water Ermua section in the Basque Basin (western Pyrenees). Since the age of stage boundaries must be the same everywhere, the choice of these stratotype sections was misleading, since in practice it resulted in the Ilerdian being used as a facies term rather than as a chronostratigraphic unit. To eliminate that conflict, and yet be respectful with established tradition, we propose to redefine the Ilerdian Stage following a procedure similar to the one used by the International Commission on Stratigraphy to establish global chronostratigraphic standards, namely: by using a “silver spike” to be placed in the Tremp section at the base of the Claret Conglomerate, a widespread lithological unit that in the Tremp Graus Basin coincides with the onset of the CIE. The redefined regional Ilerdian Stage becomes thus directly correlatable to the lower part of the global Ypresian Stage, as currently defined by the International Commission on Stratigraphy