Mapping the Late Miocene Pyrenean forests of the la Cerdanya Basin, Spain

The Late Miocene palaeofloras of the La Cerdanya Basin represent a unique look into the Pyrenean Miocene forested areas of the Iberian Peninsula at a time when the European warm and humid climate was experiencing progressive cooling and aridification. Macrofossils (leaves, seeds, fruits and cones) and miospores from several outcrops revealed the composition and abundances of the different plant species present in the area during the Tortonian and early Messinian geological stages (ca. 11.1–5.7 Ma). These fossils were found in the sediment deposits of an ancient lake system situated in the southwestern part of the basin. Previous studies indicated the presence of highly diversified mixed mesophytic forests with broadleaved evergreen and deciduous trees and conifers. However, the spatial structure and distribution of these forest types remains unknown. In the present work, the biomization method was used to infer the different late Miocene vegetation types from the basin. The extent of these vegetation types was calculated using a methodology for mapping vegetation units from fossil and biome data. While previous attempts at mapping Miocene vegetation units had a broad geographical scale, the present work aimed to map the extent of the vegetation units at a small scale, recreating local and specific vegetation changes in an abrupt basin. Results showed similarly high scores between for four biome types, which represent the different types of vegetation that coexisted in the basin during the Tortonian and the early Messinian: warm-temperate evergreen broadleaf and mixed woodlands (WTEM biome), temperate deciduous forests (TEDE) and cool conifer forests (COMX and COEG). Their extent was depicted in two vegetation maps, which account for differences in palaeoaltitude and palaeoclimate. These forests occupied different vegetation belts, which shifted upwards and downwards with climatic variations and the progressive uplift of the Pyrenees during the late Miocene. Azonal riparian forests and wetland vegetation occupied the more humid areas in the centre of the basin. Nonetheless, dry conditions during the early Messinian and decrease in the lake area degraded the wetland environments, which were partially replaced by broadleaved evergreen mixed woodlands

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

Preliminary results on the application of the aminoacid racemization technique in the Murcia Region (SE Iberian Peninsula) and their interest in paleoseismological research

Geochronology is a critical issue in paleoseismological research. The aminoacid racemization technique shows important advantages respect to more traditional dating methods; not just for the lower costs and promptness, also because the object to analyze is relatively frequent, in this study: terrestrial gastropods. Furthermore, the costs of the analysis are by far faster and cheaper compared to other dating techniques. Racemization results allow comparing the relative age from different sedimentary units from one trench to another.Additionally, the racemization technique can also be used as a geochronological tool, provided a calibration curve has been first obtained for the particular climate for the area and, ideally, for a particular genus. In this study we show the results obtained from the analysis of 40 samples of terrestrial gastropods from 7 different trenches located in the Murcia Region (SE Spain). Making use of the D/L ratio of aspartic acid we show the coherence found between relative stratigraphic ages and the racemization age. Finally, we show a provisional conversion equation between age of racemization, obtained from Torres et al. (1997) algorithm, and the likely age of the samEl control geocronológico es una cuestión crítica en los estudios de paleosismología. La técnica de racemización de aminoácidos ofrece importantes ventajas respecto a otros métodos de datación, tanto en los costes y rapidez, como en la facilidad de encontrar el objeto de análisis; en este estudio, gasterópodos terrestres. Los resultados permiten comparar la edad relativa entre unidades sedimentarias diferentes de unas zanjas a otras. La técnica de racemización también es una herramienta geocronológica, si bien es necesario primero establecer una curva de calibración para el ambiente climático de la zona e, idealmente, para un género concreto. En este estudio se muestran los resultados obtenidos en 40 muestras de gasterópodos terrestres recogidas en 7 zanjas de investigación paleosismológica en la Región de Murcia. Haciendo uso de la relación D/L del ácido aspártico mostramos la coherencia entre las edades relativas estratigráficas y su edad de racemización. Finalmente, proponemos una relación provisional de conversión entre las edades de racemización obtenidas por el algoritmo de Torres et al. (1997) para gasterópodos de la zona central de la Península Ibérica y la edad probable de las muestra

Primeros resultados sobre la aplicación de la técnica de racemización de aminoácidos en la Región de Murcia (SE de la Península Ibérica) y su interés en estudios de paleosismología

Geochronology is a critical issue in paleoseismological research. The aminoacid racemization technique shows important advantages respect to more traditional dating methods; not just for the lower costs and promptness, also because the object to analyze is relatively frequent, in this study: terrestrial gastropods. Furthermore, the costs of the analysis are by far faster and cheaper compared to other dating techniques. Racemization results allow comparing the relative age from different sedimentary units from one trench to another.Additionally, the racemization technique can also be used as a geochronological tool, provided a calibration curve has been first obtained for the particular climate for the area and, ideally, for a particular genus. In this study we show the results obtained from the analysis of 40 samples of terrestrial gastropods from 7 different trenches located in the Murcia Region (SE Spain). Making use of the D/L ratio of aspartic acid we show the coherence found between relative stratigraphic ages and the racemization age. Finally, we show a provisional conversion equation between age of racemization, obtained from Torres et al. (1997) algorithm, and the likely age of the samples. RESUMEN: El control geocronológico es una cuestión crítica en los estudios de paleosismología. La técnica de racemización de aminoácidos ofrece importantes ventajas respecto a otros métodos de datación, tanto en los costes y rapidez, como en la facilidad de encontrar el objeto de análisis; en este estudio, gasterópodos terrestres. Los resultados permiten comparar la edad relativa entre unidades sedimentarias diferentes de unas zanjas a otras. La técnica de racemización también es una herramienta geocronológica, si bien es necesario primero establecer una curva de calibración para el ambiente climático de la zona e, idealmente, para un género concreto. En este estudio se muestran los resultados obtenidos en 40 muestras de gasterópodos terrestres recogidas en 7 zanjas de investigación paleosismológica en la Región de Murcia. Haciendo uso de la relación D/L del ácido aspártico mostramos la coherencia entre las edades relativas estratigráficas y su edad de racemización. Finalmente, proponemos una relación provisional de conversión entre las edades de racemización obtenidas por el algoritmo de Torres et al. (1997) para gasterópodos de la zona central de la Península Ibérica y la edad probable de las muestras

Palynological investigations in the Orce Archaeological Zone, Early Pleistocene of Southern Spain

Palynological investigations in the Orce Archaeological Zone (OAZ) (Guadix-Baza Basin, Granada, Spain), Venta Micena 1 (VM1), Barranco Leon (BL) and Fuente Nueva 3 (FN3) are presented. This archaeological region is con-nected with the first Homo populations in Western Eurasia during the Early Pleistocene. The VM1 pollen record is characterized by Ephedra, and to a lesser extent, Pinus, Juniperus and evergreen Quercus, occassionally accompa-nied by Olea, Genisteae, Erica, deciduous Quercus, Alnus, Castanea, Fraxinus, Salix and Phillyrea. BL is dominated by Juniperus, Olea, Pinus, Poaceae, and evergreen Quercus. FN3 is characterized by an open Mediterranean woodland dominated by evergreen Quercus, Pinus, Juniperus and Olea, accompanied by deciduous Quercus, Castanea, Populus, Salix, Ulmus, Fraxinus, Pistacia, Phillyrea, Genisteae, Erica, Cistus, and Ephedra fragilis. Relic Tertiary taxa in OAZ include Carya, Pterocarya, Eucommia, Zelkova, and Juglans. The Early Pleistocene OAZ vegetation is a mosaic of different landscapes embracing mesophytes, thermophytes, xerophytes, xerothermophytes, and Mediterra-nean elements. These finds are compared with former pollen analyses in the region and beyond within the Ibe-rian Peninsula. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).Peer reviewe

Early Pleistocene environments before, during and after the first expansion of early Homo into Southern Spain

One of the most important events in human history occurred during the Early Pleistocene: the dispersal of early hominins out of Africa and into Europe and Asia. In Western Europe, the earliest evidences of the genus Homo have been found in the Baza Basin, at the sites of Orce in the SE of the Iberian Peninsula. These sites contain fossils and lithic industry dated approximately as 1.4–1.3 Ma.While hominin remains and artifacts at Orce, as well as the accompanying fauna, have been extensively studied, the properties and evolution of the Early Pleistocene vegetation in the basin remain unknown. The general effect of climate change on the expansion of early hominins from Africa into Eurasia still remains unclear. It is not known if the Early Pleistocene climate changes and the development of glacials periods led to the extirpation of European communities, or if those communities were able to endure and persist through such adverse climatic periods. This open question highlights the need for climate and environmental analyses for the time before, during and after the first presence of Homo in Europe. This PhD thesis contributes to that need by the presentation of the first long pollen record of the Baza Basin, where the oldest hominin sites in Western Europe are found

An environmental scenario for the earliest hominins in the Iberian Peninsula: Early Pleistocene palaeovegetation and palaeoclimate

International audienceThe Early Pleistocene deposits of the Iberian Peninsula provided some of the oldest hominin fossil sites of Western Europe. Evidence also shows that early Homo thrived in the Mediterranean peninsulas during the Early Pleistocene 'interglacial' phases. To assess the role of climatic conditions on early human environments, the present work features a quantitative palaeoclimatic analysis for a number of Early Pleistocene macroflora and pollen assemblages located at different geographical locations where hominin activity has been recorded. The results picture a cyclic climate with a possible latitudinal aridity gradient. Warm and humid ('interglacial') phases would have been wetter and slightly warmer than the modern climate. During cooler and drier ('glacial') phases, temperature and precipitation were comparatively milder and more similar to modern ones. The favourable conditions during the humid phases may have allowed for the earliest hominin communities arriving in Europe to rapidly thrive during 'interglacial' periods. The present climatic quantification suggests that hominins in Iberia may have survived these mild 'glacial' Early Pleistocene stages

Miocene (Burdigalian) coastal lowland vegetation and palaeoclimate based on a palaeoenvironmental reconstruction of the Els Cardscolers site, Majorca, Spain

The early Miocene (Burdigalian) macroflora of the Els Cardscolers site (Majorca Island, Balearic Islands province, Spain) is studied here from a palaeoecological and taxonomical perspective. The study shows the presence of a palaeotropical flora with thermophilic and hygrophilic elements characteristic of a coastal wetland environment, formed by monocotyledons, Lygodium gaudinii, palms (Sabalites sp.), a predominance of shrubs with Myrica lignitum and the presence of accessory elements such as Berberis kymeana, Engelhardia orsbergensis, Ziziphus paradisiaca, Sapotacites minor and Myrica longifolia. Arboreal taxa like Lauraceae or Fagaceae and some Fabaceae species were also present. The temperature values obtained by CLAMP analysis are as follows: MAT: 17.6–19.9 °C, WMMT: 24.3–27.07 °C, and CMMT: 10.4–14.2 °C. These findings suggest a warm climate with little temperature seasonality. Precipitation values (e.g., GSP, MMGSP, Three_WET, and Three_DRY) suggest the absence of a summer-dry regime although a clear contrast in precipitation is inferred. The inferred climate is similar to that of other coeval regions of Southern Europe, although it stands out for its high values of CMMT. It is similar to the climate of the island of Evia in Greece. From a floristic point of view, the Els Cardscolers flora is similar to the Burdigalian site of Cristo Rei (Portugal), and a clear relationship with the floral complex of Ipolytarnóc-Luzern (Hungary) also can be inferred

Miocene (Burdigalian) coastal lowland vegetation and palaeoclimate based on a palaeoenvironmental reconstruction of the Els Cardscolers site, Majorca, Spain

The early Miocene (Burdigalian) macroflora of the Els Cardscolers site (Majorca Island, Balearic Islands province, Spain) is studied here from a palaeoecological and taxonomical perspective. The study shows the presence of a palaeotropical flora with thermophilic and hygrophilic elements characteristic of a coastal wetland environment, formed by monocotyledons, Lygodium gaudinii, palms (Sabalites sp.), a predominance of shrubs with Myrica lignitum and the presence of accessory elements such as Berberis kymeana, Engelhardia orsbergensis, Ziziphus paradisiaca, Sapotacites minor and Myrica longifolia. Arboreal taxa like Lauraceae or Fagaceae and some Fabaceae species were also present. The temperature values obtained by CLAMP analysis are as follows: MAT: 17.6–19.9 °C, WMMT: 24.3–27.07 °C, and CMMT: 10.4–14.2 °C. These findings suggest a warm climate with little temperature seasonality. Precipitation values (e.g., GSP, MMGSP, Three_WET, and Three_DRY) suggest the absence of a summer-dry regime although a clear contrast in precipitation is inferred. The inferred climate is similar to that of other coeval regions of Southern Europe, although it stands out for its high values of CMMT. It is similar to the climate of the island of Evia in Greece. From a floristic point of view, the Els Cardscolers flora is similar to the Burdigalian site of Cristo Rei (Portugal), and a clear relationship with the floral complex of Ipolytarnóc-Luzern (Hungary) also can be inferred.Ministerio de Ciencia e Innovación (MCIN).Agencia Estatal de InvestigaciónNECLIMEDepto. de Biodiversidad, Ecología y EvoluciónDepto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias BiológicasFac. de Ciencias GeológicasTRUEpu