El registro sedimentario de las transgresión del Albiense-Cenomaniense en la Serranía de Cuenca (Cordillera Ibérica, España) : evolución paleogeográfica y paleoflora

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Geológicas, leída el 07-11-2022This Ph.D. thesis presents a high‐resolution palaeogeographical study of the onset and evolution of the largest ever recorded marine transgression, the “mid” Cretaceous transgression, in an exceptional setting located in the Western Tethys, at the eastern margin of Iberia: the Cuenca Basin (Spain). The study of the Cuenca Basin allows the accurate reconstruction of the time‐space evolution of the transgressive event due to:(1) The Albian to early Cenomanian sedimentary succession represents the sedimentary record of that major transgressive event. This succession is composed of the siliciclastic deposits of the Utrillas Gr, interpreted as an arid braidplain system, and the mixed shallow marine deposits of the La Bicuerca Mb (Aras de Alpuente Fm).(2) The basin is located at the interface between those areas entirely dominated by marine sedimentation during the “mid” and Late Cretaceous, and the areas that were dominated mainly by continental sedimentation until the transgression reached its climax during the Cenomanian‐Turonian boundary. Additionally, the Albian to early Cenomanian time in Iberia was characterised by: (a) representing the transition from the Late Jurassic‐Early Cretaceous syn‐rift stage to the Late Cretaceous post‐rift stage, and (b) being an extremely prolific time span regarding the deposit of amber‐bearing successions...Esta tesis doctoral presenta un estudio de alta resolución sobre el comienzo y evolución de la mayor transgresión marina del Mesozoico, la transgresión del Cretácico “medio”, en un contexto privilegiado, localizado al oeste del Océano del Tethys, en el margen este de Iberia: La Serranía de Cuenca (España). El estudio de esta cuenca sedimentaria ha permitido realizar una reconstrucción espacio‐temporal precisa y pormenorizada del registro geológico de la transgresión debido a dos factores:(1) La sucesión sedimentaria Albiense ‐ Cenomaniense inferior representa el registro de la transgresión del Cretácico “medio”. Esta sucesión comprende un cambio lateral de facies entre los depósitos siliciclásticos del Gr. Utrillas, interpretados como una llanura alluvial de tipo braided, y los mixtos del Mb. La Bicuerca (Fm. Aras de Alpuente), interpretados como depositados en un ambiente marino somero.(2) La cuenca sedimentaria está localizada en una zona de transición entre las areas dominadas por sedimentación marina durante el Cretácico “medio” y Superior (hacia el SE de la zona de estudio), y la sáreas que estuvieron dominadas por sedimentación continental (localizadas al NO de la zona estudiada)hasta que tuvo lugar el máximo de la transgresión durante el límite Cenomaniense‐Turoniense. Además, cabe destacar que el intervalo Albiense ‐ Cenomaniense inferior en Iberia estuvo caracterizado por: (a) registrar la transición de la etapa sin‐rift del Jurásico Superior ‐ Cretácico Inferior a la etapa postrift del Cretácico Superior, y (b) ser un periodo en cuyos depósitos se han descubierto numerosos yacimientos ambarígenos...Fac. de Ciencias GeológicasTRUEunpu

Biodiversity of ecosystems in an arid setting: The late Albian plant communities and associated biota from eastern Iberia

Deserts are stressful environments where the living beings must acquire different strategies to survive due to the water stress conditions. From the late Albian to the early Cenomanian, the northern and eastern parts of Iberia were the location of the desert system represented by deposits assigned to the Utrillas Group, which bear abundant amber with numerous bioinclusions, including diverse arthropods and vertebrate remains. In the Maestrazgo Basin (E Spain), the late Albian to early Cenomanian sedimentary succession represents the most distal part of the desert system (fore-erg) that was characterised by an alternation of aeolian and shallow marine sedimentary environments in the proximity of the Western Tethys palaeo-coast, with rare to frequent dinoflagellate cysts. The terrestrial ecosystems from this area were biodiverse, and comprised plant communities whose fossils are associated with sedimentological indicators of aridity. The palynoflora dominated by wind-transported conifer pollen is interpreted to reflect various types of xerophytic woodlands from the hinterlands and the coastal settings. Therefore, fern and angiosperm communities abundantly grew in wet interdunes and coastal wetlands (temporary to semi-permanent freshwater/salt marshes and water bodies). In addition, the occurrence of low-diversity megafloral assemblages reflects the existence of coastal salt-influenced settings. The palaeobotanical study carried out in this paper which is an integrative work on palynology and palaeobotany, does not only allow the reconstruction of the vegetation that developed in the mid-Cretaceous fore-erg from the eastern Iberia, in addition, provides new biostratigraphic and palaeogeographic data considering the context of angiosperm radiation as well as the biota inferred in the amber-bearing outcrops of San Just, Arroyo de la Pascueta and La Hoya (within Cortes de Arenoso succesion). Importantly, the studied assemblages include Afropollis, Dichastopollenites, Cretacaeiporites together with pollen produced by Ephedraceae (known for its tolerance to arid conditions). The presence of these pollen grains, typical for northern Gondwana, associates the Iberian ecosystems with those characterising the mentioned region.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEMinisterio de Ciencia, Innovacio ́n y UniversidadesIGME-CSICSecretaria d’Universitats i Recerca de la Generalitat de CataloniaEuropean Social Fundpu

Taphonomy and palaeoenvironmental interpretation of a new amber-bearing outcrop from the mid-Cretaceous of the Maestrazgo Basin (E Iberian Peninsula)

Cretaceous amber-bearing outcrops are numerous and mainly distributed along the Northern Hemisphere. They have been related to extensive resin mass production occurring from the Barremian to the Campanian presumably due to interrelated abiotic and biotic factors. Amber outcrops are also abundant in the Iberian Peninsula, and they are mostly dated as Albian. Here, we present a new amber-bearing outcrop from the Cretaceous of the Maestrazgo Basin called La Dehesa (Estercuel, Aragón, Spain). This locality is assigned to the Boundary Marls Unit and is known for its rich and diverse palaeobotanical record. The dating of the amber-bearing bed is late Albian-early Cenomanian, based on palynomorphs and ostracods. Amber characteristics are compatible with a medium to long-distance transport before resin deposition, i.e., allochthonous origin. Organism-resin interactions have been identified, such as hyphae of resinicolous fungus in the cortex of the amber, a pholadid boring determined as Teredolites clavatus, and an oyster shell that grew on the solidified resin surface. No bioinclusions have been found so far. The study of the microfossils, some of them containing pyrite aggregates or crystals, found in the amber-bearing bed (palynomorphs, plant remains, foraminifers, echinoid spines, ostracods, and vertebrate remains) points to a coastal to inner mixed platform environment.Los yacimientos de ámbar del Cretácico son numerosos y están distribuidos principalmente por el hemisferio norte. Se han relacionado con una producción en masa de resina que ocurrió desde el Barremiense hasta el Campaniense posiblemente debido a la interrelación de factores abióticos y bióticos. Los yacimientos de ámbar también son abundantes en la península ibérica, y son en su mayoría atribuidos al Albiense. Aquí presentamos un nuevo yacimiento de ámbar del Cretácico de la Cuenca del Maestrazgo denominado La Dehesa (Estercuel, Aragón, España). Esta localidad se incluye en la Unidad Margas de Transición y es conocida por su rico y diverso registro paleobotánico. La datación del nivel con ámbar indica una edad Albiense superior-Cenomaniense inferior, a partir de palinomorfos y ostrácodos. Las características del ámbar son compatibles con un transporte de media-larga distancia antes del depósito de la resina, es decir, con un origen alóctono. Se han identificado interacciones organismos-resina tales como hifas de hongo resinícola en la corteza del ámbar, una perforación de foládido identificada como Teredolites clavatus y una concha de ostreido que creció en la superficie de resina solidificada. Por el momento no se han hallado bioinclusiones. El estudio de los microfósiles, algunos de ellos con agregados o cristales de pirita, encontrados en el nivel con ámbar (palinomorfos, restos de plantas, foraminíferos, espinas de erizo, ostrácodos y restos de vertebrados) indica un ambiente marino costero o de plataforma interna mixta

Amber and the Cretaceous Resinous Interval

Amber is fossilized resin that preserves biological remains in exceptional detail, study of which has revolutionized understanding of past terrestrial organisms and habitats from the Early Cretaceous to the present day. Cretaceous amber outcrops are more abundant in the Northern Hemisphere and during an interval of about 54 million years, from the Barremian to the Campanian. The extensive resin production that generated this remarkable amber record may be attributed to the biology of coniferous resin producers, the growth of resiniferous forests in proximity to transitional sedimentary environments, and the dynamics of climate during the Cretaceous. Here we discuss the set of interrelated abiotic and biotic factors potentially involved in resin production during that time. We name this period of mass resin production by conifers during the late Mesozoic, fundamental as an archive of terrestrial life, the `Cretaceous Resinous Interval (CREI).This work was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades [research agreement CRE CGL2017-84419 AEI/FEDER, UE] and by the Consejería de Industria, Turismo, Innovación, Transporte y Comercio of the Gobierno de Cantabria through the public enterprise EL SOPLAO S.L. [research agreement #20963 with University of Barcelona and research contract Ref. VAPC 20225428 to CN-IGME CSIC, both 2022–2025]; the Conselho Nacional de Pesquisa (Brazil) [research grand PQ 304529/19–2]; National Geographic Global Exploration Fund Northern Europa [research agreement GEFNE 127-14]; Deutsche Forschungsgemeinschaft (DFG) [research agreement SO 894/6-1]; VolkswagenStiftung [research agreement 90946]; the Secretary of Universities and Research (Government of Catalonia) and by the Horizon 2020 program of research and innovation of the European Union under the Marie-Curie [research contract no. 801370, Beatriu de Pinós]; the Secretary of Universities and Research (Government of Catalonia) and the European Social Fund [research contract 2021FI_B2 00003]; this work is a contribution to the grant RYC2021-032907-I, funded by the MCIN/AEI/10.13039/501100011033 and by the European Union «NextGenerationEU»/PRTR; and the National Agency for Research and Development (ANID) Scholarship Program [BECAS CHILE 2020-Folio 72210321].Abstract Keywords 1. Introduction 2. Definition of the Cretaceous Resinous Interval 3. Conditional factors on resin production and preservation 3.1. Abiotic factors 3.1.1. Atmospheric gas composition, temperature, and wildfires 3.1.2. Volcanism and changes in sea level 3.1.3. Oceanic physicochemical properties and hurricanes 3.1.4. Climatic overview throughout the CREI 3.2. Biotic factors 4. Present limitations and future directions 5. Conclusions Funding Author contributions Declaration of Competing Interest Acknowledgements Appendix A. Supplementary data Data availability Reference

Dinosaur bonebed amber from an original swamp forest soil

Dinosaur bonebeds with amber content, yet scarce, offer a superior wealth and quality of data on ancient terrestrial ecosystems. However, the preserved palaeodiversity and/or taphonomic characteristics of these exceptional localities had hitherto limited their palaeobiological potential. Here, we describe the amber from the Lower Cretaceous dinosaur bonebed of Ariño (Teruel, Spain) using a multidisciplinary approach. Amber is found in both a root layer with amber strictly in situ and a litter layer mainly composed of aerial pieces unusually rich in bioinclusions, encompassing 11 insect orders, arachnids, and a few plant and vertebrate remains, including a feather. Additional palaeontological data—charophytes, palynomorphs, ostracods— are provided. Ariño arguably represents the most prolific and palaeobiologically diverse locality in which fossiliferous amber and a dinosaur bonebed have been found in association, and the only one known where the vast majority of the palaeontological assemblage suffered no or low-grade pre-burial transport. This has unlocked unprecedentedly complete and reliable palaeoecological data out of two complementary windows of preservation—the bonebed and the amber—from the same site.European Regional Development Fund (FEDER)Ministerio de Ciencia e Innovación (MICINN)/FEDERMinisterio de Economía y Competitividad (MINECO)/FEDERGeneralitat de CatalunyaGeneralitat de Catalunya/FEDERMMinisterio de Ciencia e Innovación (MICINN)Oxford UniversityAustrian Academy of SciencesUniversité de TunisGeneralitat ValencianaDepto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Dinosaur bonebed amber from an original swamp forest soil

[EN] Dinosaur bonebeds with amber content, yet scarce, offer a superior wealth and quality of data on ancient terrestrial ecosystems. However, the preserved palaeodiversity and/or taphonomic characteristics of these exceptional localities had hitherto limited their palaeobiological potential. Here, we describe the amber from the Lower Cretaceous dinosaur bonebed of Ariño (Teruel, Spain) using a multidisciplinary approach. Amber is found in both a root layer with amber strictly in situ and a litter layer mainly composed of aerial pieces unusually rich in bioinclusions, encompassing 11 insect orders, arachnids, and a few plant and vertebrate remains, including a feather. Additional palaeontological data-charophytes, palynomorphs, ostracods- are provided. Ariño arguably represents the most prolific and palaeobiologically diverse locality in which fossiliferous amber and a dinosaur bonebed have been found in association, and the only one known where the vast majority of the palaeontological assemblage suffered no or low-grade pre-burial transport. This has unlocked unprecedentedly complete and reliable palaeoecological data out of two complementary windows of preservation-the bonebed and the amber-from the same site.Funding Ministerio de Ciencia, Innovación y Universidades: CGL2017-84419 (Eduardo Barrón, Xavier Delclòs); Ministerio de Ciencia, Innovación y Universidades: PGC2018-094034-B-C22 (Luis Alcalá) ; Ministerio de Economía y Competitividad: CGL2015-69805-P (Carles Martín-Closas) ; Generalitat de Catalunya: 2017SGR-824 (Carles Martín-Closas, Xavier Delclòs) ; Generalitat de Catalunya: 2020FI_B1 00002 (Sergio Álvarez-Parra) ; Oxford University Museum: Research Fellowship (Ricardo Pérez-de la Fuente) ; Ministerio de Ciencia, Innovación y Universidades: BES-2016-076469 (Jordi Pérez-Cano) ; Austrian Academy of Sciences: Project 661 (Khaled Trabelsi) ; Université de Tunis: LR18 ES07 (Khaled Trabelsi) ; Generalitat Valenciana: APOSTD2019 (Alba Sánchez-García) ; European Regional Development Fund: IGME13-4E-1518 (Rafael P Lozano)Peer reviewe

Desarrollo de dunas eólicas en un sistema de braidplainárido costero de edad Albienseen la Serranía de Cuenca (Cuenca Ibérica, España)

The Utrillas Sandstone Group is an Albian to Cenomanian clasticsuccession which is widely spread along most areas in the Iberian Basin. Inthe Southwestern sector (Serranía de Cuenca) an arid braidplain wasdeveloped and connected to the Tethys towards SE, thus some faciesassociations present tidal features. Aeolian dune development within thearid braidplain system was possible, although as a minor feature. This paperaims: 1) to describe the facies associations of the arid braidplain regardingtheir different origin, and 2) to study and interpret aeolian duneaccumulations based on the granulometric study of 5 samples and on theoutcrop study of the geometry and surfaces hierarchyEl Grupo Utrillas es una sucesión clástica Albiense-Cenomaniense la cualse encuentra ampliamente extendida en todo el contexto de la Cuenca Ibérica.En el sector Suroccidental (Serranía de Cuenca) un sistema de braidplain áridofue el principal paleoambiente. Este sistema de braidplain árido estuvo conec-tado con el Tethys hacia el SE. El desarrollo de dunas eólicas en el sistema debraidplain fue posible aunque no son una facies muy abundante. Este artículotiene como objetivo: 1) describir las asociaciones de facies del sistema braidedárido, y 2) estudiar e interpretar las dunas eólicas sobre la base del analisis gra-nulométrico de 5 muestras y del estudio de la arquitectura estratigráfica delafloramient

Estudio palinológico de los yacimientos con ámbar del norte de la Península Ibérica

Congreso realizado en Valencia del 4 al 7 de octubre de 2023.Peer reviewe

Along-strike sedimentological variability and architectural patterns of the transgression of a “mid”-Cretaceous braidplain system (Iberian Basin, eastern Spain): A tool for depicting eustatic and tectonic signatures within the framework of a global transgression

The mid-Albian to lower Cenomanian Utrillas Group is interpreted as an arid braidplain system in the Serranía de Cuenca region (Iberian Basin, Spain). In its proximal locations, it consists of an interaction of alluvial facies and subordinate aeolian deposits, with the occurrence of tidally-influenced deposits that reflect a general transgressive trend to the top of the succession. However, the distal areas of this braidplain system, where there was a more intense interaction with the Tethys Ocean, have remained understudied to date. We present a sedimentological study of two outcrops (Pajaroncillo and Reíllo) located at the distal sector of the braidplain system and 12 km apart, defining an along-strike relative position. Both outcrops differ notably regarding the arrangement and distribution of the facies associations identified despite their relative closeness. Based on the sedimentological analysis, the main transgressive and regressive trends of the succession have been identified, along with several correlatable stratigraphic surfaces. This has permitted us to distinguish five stages (T1–T5), which reflect the overall transgressive evolution of the succession: a continental aggradational stage (T1), dominated by alluvial deposition; an initial transgression stage (T2) dominated by an open coast setting in Reíllo and a restricted mudflat system in Pajaroncillo; a regressive stage (T3), during which continental alluvial to supratidal environments deposited; a resumption in transgression (T4), characterised by an array of inter- to subtidal environments; and a deepening stage (T5), when the transgression advanced landward, giving rise to the most distal deposits of the studied succession. The studied outcrops, located at the basin edge, have been integrated within the regional sequence stratigraphy framework, which was originally devised for more central areas of the Iberian Basin (Valencia Domain) and the Prebetic. This regional approach has allowed us to interpret the studied deposits as third-order depositional sequences. Besides, the supra-regional implications of this research are discussed within the broader context of Iberia and the subtleties of its tectono-sedimentary evolution during the Albian to Cenomanian times