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This research explores the Messinian record in a western Mediterranean basin at the eastern end of the Betic Cordillera (the Garruchal section, southern sector of the Bajo Segura basin). Sedimentary facies development and foraminiferal assemblages were used as palaeoenvironmental proxies to characterize the palaeoceanographic evolution of the basin’s progressive restriction. Therefore, a succession of palaeoenvironmental phases can be established as follows. The “start phase” (until ~ 6.72 Ma) records the first ecological evidence of the restriction, evidenced by the sudden appearance of common benthic stress markers. The “amplification phase” of the restriction (up to ~ 6.35 Ma) marks a progressive increase in low bottom oxygen levels related to water-mass stratification in the evolution from upper epibathyal to outer shelf environments. The “consolidation phase” (until the intra-Messinian discontinuity ~ shortly after 6.03 Ma) records basin shallowing (from outer to inner shelf environments) in a context of a restricted basin. And lastly, the “climax phase” (until the end-Messinian discontinuity) records coastal sedimentation (marine coastal lagoon and sandy beaches). The findings of this research reveal that the Garruchal section is a good illustration of the sedimentary and palaeoenvironmental response of the peripheral basins to the progressive restriction of the Mediterranean before the Messinian Salinity Crisis. Finally, since it is widely accepted that the Mediterranean marine restriction has been developed in a stepwise mode, we here propose to establish the following terms for implementation at Mediterranean regional level: “start,” “amplification,” and “consolidation” phases, which finally led to the “climax” phase, that is, the Messinian Salinity Crisis stricto sensu. This paper was written in the context of the Paleoenvironmental Changes research group (vigrob-167) and partially supported by project GV/2018//109 (Generalitat Valenciana).

The Lorca and Fortuna basins are two intramontane Neogene basins located in the eastern Betic Cordillera (SE Spain). During the Late Tortonian—Early Messinian, marine and continental evaporites precipitated in these basins as a consequence of increased marine restriction and isolation. Here we show a stratigraphic correlation between the evaporite records of these basins based on geochemical indicators. We use SO4 isotope compositions and Sr isotopic ratios in gypsum, and halite Br contents to characterize these units and to identify the marine or continental source of the waters feeding the evaporite basins. In addition, we review the available chronological information used to date these evaporites in Lorca (La Serrata Fm), including a thick saline deposit, that we correlate with the First Evaporitic Group in Fortuna (Los Baños Fm). This correlation is also supported by micropalaeontological data, giving a Late Tortonian age for this sequence. The Second Evaporitic Group, (Chicamo Fm), and the Third Evaporitic Group (Rambla Salada Fm) developed only in Fortuna during the Messinian. According to the palaeogeographical scheme presented here, the evaporites of the Lorca and Fortuna basins were formed during the Late Tortonian—Early Messinian, close to the Betic Seaway closure. Sulphate isotope compositions and Sr isotopic ratios of the Ribera Gypsum Mb, at the base of the Rambla Salada Fm (Fortuna basin), match those of the Late Messinian selenite gypsum beds in San Miguel de Salinas, in the near Bajo Segura basin (40 km to the East), and other Messinian Salinity Crisis gypsum deposits in the Mediterranean. According to these geochemical indicators and the uncertainty of the chronology of this unit, the assignment of the Rambla Salada Fm to the MSC cannot be ruled out. Funding was provided by Spanish Government grants CGL‐2013‐42,689 and CGL‐2016‐79458, and by the Catalan Government action 217‐SGR‐829.

15 pages, 5 figures, The Middle Pleistocene Transition (MPT, ~641–920 ka) represents a period of the Quaternary climate when, in the absence of substantial changes in orbital forcing, the climate progressively shifted to the 100 ka asymmetrical glacial–interglacial cyclicity characterizing the current climate. The causes of this change remain still uncertain but several lines of evidence suggested the carbon storage of the deep ocean played a relevant role. Here we evaluate the contribution of the eastern deep tropical Pacific to the global ocean carbon sequestration and storage between 760 and 1,040 ka. We present multi‐proxy records for export production and the redox environment at the seabed from Ocean Drilling Program Site 1242 located in the deep East Equatorial Pacific. Our data indicate the development of suboxic bottom waters during early marine isotopic stage (MIS) 23 and glacial MIS 22, suggesting the capture and storage of respired carbon. Redox‐sensitive elements suggest the progressive oxygenation of the deep ocean initiated at the end of the glacial MIS 22, continued across deglaciation and ended with the accomplishment of full interglacial MIS 21. We describe this pattern as a “less complete deglacial ventilation” in that it differs from the mid‐late Pleistocene Pacific deep ocean ventilation pattern which occurs during deglaciations. The ventilation of the deep Pacific Ocean extending beyond deglaciation might have contributed to a persistent deep ocean carbon sequestration, which might have resulted in lowered atmospheric CO2 values that could have influenced the internal response of the climate system contributing to the development of the 100 ka climate variability, The laboratory technical assistance of Victor González Guitián to perform elemental analysis was funded by Xunta de Galicia through the program GRC‐ED431C 2017/55. This study was funded by the project CGL2016‐79878‐R (Spanish Ministerio de Economía, Industria y Competividad within the state program Investigación Desarrollo e Innovación Orientada a los Retos de la Sociedad)

Coastal scenery value was evaluated at 56 locations along the 244 km long coast of Alicante (western Mediterranean) according to the methodology of Ergin et al. Area 36(4):367–386, (2004) based on the evaluation of 26 physical and anthropogenic parameters. Selected areas covered remote (10), rural (9), village (15) and urban (22) bathing areas. The scenery Decision Value parameter (D), allowed to classify the investigated sites into 5 classes, from Class I (extremely attractive/natural sites) to Class V (very unattractive/urbanized sites): 2 sites belonged to Class I, 6 to Class II, 14 to Class III, 20 to Class IV and 14 to Class V. Litter presence was assessed at the same sites using the EA/NALG (2000) methodology, which allowed to classify each site in four grades: A: very good (40 sites); B: good (14); C: fair (1) and D: poor (1). In urban sites litter was composed by small items related to land-based sources and beach use while litter in natural sites was related to marine-based sources, essentially fishing. The sector analysis methodology highlighted as most sites (33 out of 56) showed contradictory characteristics for litter/scenic grades/beach awards presence. To improve scenic value, different actions have to be carried out according to the site typology. At many urban sites, actuations should be focused to the removing or reducing of beach utilities and unnecessary infrastructures. At rural and remote areas, is mandatory to carry out specific litter management plans to reduce litter presence. This research was partially supported by the project GRE14-05 (University of Alicante). This work is a contribution to the Andalusia PAI Research Group RNM-328 and to the RED PROPLAYAS network.

The historical quarry of the Nueva Tabarca fortress (Mediterranean Sea, SE of Spain) was developed in a complex sedimentary Miocene deposit. Five lithostratigraphic units have been defined, including different lithologies such as breccias and microconglomerates (Unit 1), massive and laminated lithoarenites (Units 1, 3 and 5), calcarenites and biocalcirudites (Units 2 and 4). A complete stratigraphic description of this sequence has been carried out, as well as the petrophysical characterization of the most significant lithologies including the analysis of rock durability as well as hydraulic and mechanical properties. Regarding durability, the softest rocks correspond to those from the Unit 4, whilst samples from Units 2 and 5 are the most durable. Three weathering patterns were observed during the artificial ageing test according to both the velocity and intensity of the sample decay. Each pattern is explained according to water-circulation possibility through the rock, its porous system, and the mechanical strength. Rock weathering in monuments of Nueva Tabarca is quantified and discussed according to the results found in the laboratory. Several decay forms are observed in the building stones (mainly differential erosion, alveolization, and rounding forms). Both 3D photogrammetric and 3D geological model of the historical quarry were elaborated in order to quantify the extracted volume of building stones, differentiating the specific quarried percentage of each lithology. Correlation between the results obtained in the volumetric analysis of the historical quarry and the building stones used in the monuments has been carried out. 3D models were also used for determining the remaining rock volume in the current outcrops. Finally, a set of recommendations for future conservation works of the architectural heritage are proposed after the current availability of the different rock varieties and their petrophysical behaviour., Departamento de Ciencias de la Tierra y del Medio Ambiente, Universidad de Alicante, España, Instituto Geológico y Minero de España, España

This work presents the singular case of Nueva Tabarca island (SE Spain), which is an excellent example where stone-built monuments and historical quarries greatly enhance the geoheritage interest of this site. This small western Mediterranean island brings together a rich, diverse geological record and a baroque architectural heritage represented by a fortified village. The geoheritage constitutes the bedrock of the historical and architectural monuments. In addition, though, the building stones can be used to interpret the litho- and bio-facies, which provide significant geological knowledge to better understand the island’s geosedimentary history. Furthermore, the diverse settings of the building stones allow a didactic and integrated reading of the erosional processes that can affect these stones. In short, architectural heritage becomes an alternative tool to study geology and promote geoheritage. The characterization and inventory of the local geoheritage has allowed us to propose a geotourism route of ten sites of special interest. The sites were selected due to their relevance showing the geological context, the building stones used in the architectural heritage, and the conservation state and the weathering processes that affect rocks. This paper evidences that geosites can be of special significance, particularly in geotourism, precisely due to their huge potential to connect heritages of varied natures. The closer the links between geology, history, and architecture, the more people will be interested in and concerned about geoheritage. This research was supported by projects GRE12-03, GRE14-05 (University of Alicante) and GV/2018//109 (Generalitat Valenciana).

The recognition of event beds is of paramount importance to reconstruct palaeoenvironments and to determine palaeoecological parameters. Tortonian and Tyrrhenian deposits have been studied in the Cabo de la Huerta section (Alicante, Southeastern Spain), where both open-platform and coastal deposits crop out. In the absence of sedimentary structures, we carried out ichnological, taphonomic, and palaeoecological analyses to determine the main processes involved in the material’s sedimentation. The Tortonian beds are made up of interbedded fine-grained and coarse-grained calcarenites. Event beds are mainly signalled by the presence of Ophiomorpha nodosa in coarse-grained calcarenites, typically produced by opportunistic crustaceans just after sedimentation. Background sedimentation is represented by fine-grained calcarenites without well-preserved burrows due to the soupy consistency of the substrate. The alternance of burrow-rich and burrow-poor beds reveals a decreasing-upward frequency of storm events pointing out a deepening-upward trend. The Tyrrhenian material records a regression from a sandy beach environment to a continental backshore. A thick skeletal concentration of resedimented shells from different habitats and with different residence times on the substrate was found between the beach and backshore deposits. Its features make it recognizable as a major storm deposit where a census assemblage is mixed together with a time-averaged one. Integrated palaeontological analysis is shown to be an excellent tool in diverse environmental settings in order to differentiate event beds, in particular where clear sedimentological criteria are not available. This research was supported by the project CGL2015-66835-P, financed by the Spanish Ministry of Education and Science (MINECO, Government of Spain).

The Bajo Segura basin (eastern Betic Cordillera) has one of the most complete late Miocene–early Pliocene marine records of the western Mediterranean. An updated planktonic foraminifer zonal scheme based on recent astronomically tuned biozones is presented for this interval, documenting a complete succession of biostratigraphic markers, from biozone MMi9 (earliest Tortonian) to MPl3 (latest early Pliocene), of likely significance for regional-scale correlation throughout the Mediterranean. The findings reveal a series of intrazonal events (some unreported until now in the Mediterranean Neogene basin), including the particularly interesting two influxes of the Globorotalia miotumida group during the Tortonian. These biostratigraphic findings are the basis for a framework of the major allostratigraphic units in the basin based on planktonic foraminifer event-stratigraphy: synthems Tortonian I, Tortonian II, Tortonian-Messinian I, Messinian II, and Pliocene. In addition, the timing of the main tectono-sedimentary and palaeogeographic events throughout the basin's evolution has been further constrained. Our results suggest that, at least in the Bajo Segura basin, the late-Messinian barren interval (non-distinctive zone) can be considered an ecobiostratigraphic zone (cenozone) characterized by dwarf fauna of planktonic foraminifera. Consequently, the Bajo Segura composite section can be regarded as a biostratigraphic reference section for Neogene basins in the Betic Cordillera and hence also in the Western Mediterranean. This paper was written in the context of the Paleoenvironmental Changes research group (University of Alicante, VIGROB-167) and supported by project GRE14-05 (University of Alicante).

A composite stratigraphic section ranging from the Messinian to the Pliocene, recording the most important phases of the Messinian Salinity Crisis, is represented in the San Miguel de Salinas area (Bajo Segura basin, SE Spain). Detailed magnetostratigraphic and facies analyses and foraminifer and nannoplankton assemblage studies were carried out. Integration of the results has allowed the characterization of the pre-evaporitic (synthem Messinian I), syn-evaporitic (synthem Messinian II), and post-evaporitic phases (synthem Pliocene) from a paleoenvironmental and chronostratigraphic standpoint. The pre-evaporitic phase is late Messinian and records a shallowing-upward trend. The syn-evaporitic phase took place in chron C3r and is characterized by laminated marls with intercalated selenitic gypsum beds and sandstones. Variations in foraminifer and nannoplankton assemblages together with episodic gypsum precipitation record major changes in water salinity in a stressed marine environment. The pre- and syn-evaporitic phases are separated by the intra-Messinian unconformity, represented by an erosional surface related with a sea-level fall. After the evaporitic phase, a sea-level fall generates the end-Messinian unconformity, whose strongly erosional nature is evidenced by the deeply carved paleovalley of San Miguel de Salinas. The post-evaporitic phase begins in the earliest Pliocene and records the re-establishment of normal marine conditions in the basin. Since the San Miguel de Salinas composite section can be considered as a benchmark for the study of the evolution of marginal Mediterranean basins during the Messinian Salinity Crisis, the detailed characterization of these different phases is of great importance in understanding this event. This paper was written in the context of the Paleoenvironmental Changes research group vigrob–167 (University of Alicante) and supported by project GRE14-05 (University of Alicante).

The Messinian coral reef of Santa Pola, one of the most relevant geosites in the geological heritage of the western Mediterranean, is quantitatively assessed in terms of geoscience and features of potential use. Two different methodologies are used, one developed by the Geological and Mining Institute of Spain (IGME) for the Spanish Geosite Inventory (IELIG) and the other prepared by the Paleontological Museum of Elche (MUPE) for the Fossils and Heritage Project of Alicante (FOPALI). Santa Pola scores very high with both methods, which is a clear indication that this exceptionally relevant scientific geosite (included in the Spanish Geosite Inventory) also has a high didactic and tourism-recreational potential. In addition, the paper compares and discusses the two different methodologies, concluding that the selection of a model depends on the purpose of the evaluation (representativeness of the geosite in the Spanish territory associated to the Spanish Geological Inventory (IELIG) and a comparison of palaeontological and geological features (FOPALI) between different geosites). This work is a starting point to develop a specially designed management plan and geoconservation strategy for this exceptional geosite of the western Mediterranean. This paper was written in the context of project GRE14-05 (University of Alicante).

Se ha analizado el registro sedimentario Messiniense y Plioceno de la Cuenca del Bajo Segura a través del análisis multivariante de correspondencia sin tendencia (DCA). Los resultados obtenidos permiten examinar de forma integral y sintética los ambientes sedimentarios y sintemas representados, atendiendo a la distribución de foraminíferos bentónicos y planctónicos (grupos ecológicos) registrados en seis secciones representativas de la cuenca, tres en el borde norte (Colmenar, Torrellano y Elche), y otras tres en el borde sur (Garruchal, La Pedrera y El Canal). Del análisis estadístico, contrastado con las fuentes bibliográficas disponibles, se puede concluir que: a) el sector sur presenta en comparación con el sector norte, una mayor diversidad de ambientes marinos; y b) los tres sintemas analizados presentan unas características propias, en términos de variedad y representación de los ambientes sedimentarios registrados. The Messinian and Pliocene record of the Bajo Segura Basin has been analysed by multivariate detendred correspondence analysis (DCA). The obtained results enables a comprehensive and synthetic examination of the sedimentary record, considering the distribution of benthic and planktic foraminifera (ecological groups) recorded in six representative sections of the basin, three on the northern sector (Colmenar, Torrellano and Elche) and three on the southern part (Garruchal, La Pedrera and El Canal). From the statistical analysis, contrasted with thebibliographical sources available, it can be concluded that: a) the southern sector presents, in comparison with the northern sector, a greater diversity of marine environments; and b) the three analysed synthems have their own characteristics in terms of variety and representation of their registered sedimentary environments. Este trabajo se ha realizado en el marco del grupo de investigación Cambios Paleoambientales de la Universidad de Alicante (vigrob-167) y los proyectos GRE14-05 (Universidad de Alicante) y CGL2016-79878-R (Ministerio de Economía y Competitividad de España).

A detailed taphonomic analysis was carried out on the lower Albian deposits of the Sierra Helada section (Alicante, Betic Cordillera, southeastern Spain). Ten taphonomic characters were studied and ten skeletal concentrations were defined on the basis of taphonomic features and the dominant taxa. Cluster analysis was performed on the dataset represented by the abundance of the taphonomic characters in each skeletal concentration. This enabled the definition of four different taphonomic categories: 1) skeletal concentrations characterized by the presence of fossils preserved in life position, 2) skeletal concentrations showing very little physical reworking, 3) skeletal concentrations related to high-energy background conditions, and 4) skeletal concentrations produced by medium- to high-energy events. Four taphofacies were defined on the basis of the main sedimentological features and the most representative skeletal concentrations. Taphofacies A represents the low energy outer platform, rich in skeletal concentrations with echinoids in life position and only slightly reworked. The second taphofacies (taphofacies B) is very rich in reworked echinoid tests and calcarenitic beds and records the transition to shallower areas, while taphofacies C shows abundant thick-bedded calcarenites and skeletal concentrations produced by sediment transport and rapid deposition. Finally, cross-bedded grainstone beds, which are rich in fine-grained fragmented, locally reoriented bioclasts (taphofacies D), record the existence of shifting sandy dunes in the shallow inner part of the platform. The research has been supported by Research Group VIGROB-167 (University of Alicante).

Benidorm Island is one of the most relevant protected marine areas in the Province of Alicante (south-eastern Iberian Peninsula). Its bathymetric gradient and the structural complexity of the seabed make it an ideal place to analyse foraminifer assemblages considering depth and sediment type (particle size distribution). For this purpose, seven sampling sites representing the variety of littoral/sublittoral bottoms present have been sampled. The seabed sediment is composed mainly of gravelly sand with a high bioclastic content, abundant echinoderm fragments, sponge spicules, and bivalve and gastropod shell debris. We have documented a highly diverse community of benthic foraminifera dominated by epiphytic species. This work also examines the relation between depth (or open marine influence) and the planktonic foraminifer ratio, discussing the implications in the geological marine record. The distribution of some benthic foraminifer key species has been evaluated in this regard. The scuba dives performed also reveal possible environmental deterioration due to increased marine recreational activities, mostly scuba diving and boating. Finally, the littoral bottoms surrounding Benidorm Island would be an excellent area for future research using foraminifera as bio-indicators for monitoring environmental impacts on coastal regions. This paper was written as part of the work of the Paleoenvironmental Changes research group (University of Alicante) and supported by project GRE14-05 (University of Alicante).

The marine stratigraphic record of the Granada Basin (central Betic Cordillera, Spain) is composed of three Late Miocene genetic units deposited in different sea-level contexts (from base to top): Unit I (sea-level rise), Unit II (high sea-level), and Unit III (low sea-level). The latter mainly consists of evaporites precipitated in a shallow-basin setting. Biostratigraphic analyses based on planktonic foraminifera and calcareous nannoplankton indicate four late Tortonian bioevents (PF1-CN1, PF2, PF3, and PF4), which can be correlated with astronomically-dated events in other sections of the Mediterranean. PF1-CN1 (7.89 Ma) is characterized by the influx of the Globorotalia conomiozea group (including typical forms of Globorotalia mediterranea) and by the first common occurrence of Discoaster surculus; PF2 (7.84 Ma) is marked by the first common occurrence of Globorotalia suterae; PF3 (7.69 Ma) is typified by the influx of dextral Neogloboquadrina acostaensis; and PF4 (7.37 Ma) is defined by the influx of the Globorotalia menardii group II (dextral forms). The PF1 event occurred in the upper part of Unit I, whereas PF2 to PF4 events occurred successively within Unit II. The age of Unit III (evaporites) can only be estimated in its lower part based on the presence of dextral Globorotalia scitula, which, together with the absence of the first common occurrence of the G. conomiozea group (7.24 Ma), points to the latest Tortonian. Comparisons with data from the other Betic basins indicate that the evaporitic phase of the Granada Basin (7.37–7.24 Ma) is not synchronous with those from the Lorca Basin (7.80 Ma) and the Fortuna Basin (7.6 Ma). In the Bajo Segura Basin (easternmost Betic Cordillera), no evaporite deposition occurred during the late Tortonian. The evaporitic unit of the Granada Basin (central Betics) records the late Tortonian restriction of the Betic seaway (the marine connection between the Atlantic and Mediterranean). The diachrony in the restriction of the Betic seaway is related to differing tectonic movements in the central and eastern sectors of the Betic Cordillera. Financial aid was provided by Research Projects CGL2007-65832 MEC, CGL2009-07830 MCI, GV04B-629 (Generalitat Valenciana) and the “Paleoenvironmental Changes” Group (UA).

A representative outcrop of the Messinian stromatolites belonging to the Terminal Carbonate Complex unit, from the northern sector of the Bajo Segura basin (Caja de Ahorros del Mediterraneo section, Sierra del Colmenar, SE Spain) has been studied. Here, we present a detailed analysis of the architecture, external morphology, and internal morphology in order to reconstruct the environmental and palaeoecological conditions for their growth. The stromatolites macrostructure consists of a continuously doming type morphology (build up and sheets areas).These developed close to the coast and acted as a palaeogeographic barrier, reducing physical stress, channeling the erosive effect of water and favoring restricted conditions. This stromatolitic macrostructure exhibits variations in its internal morphology, giving rise to seven subfacies, which are a product of the environmental changes experienced during the growth of the microbial mats. Although broadly suggesting a coastal environment, restricted and shallow during formation, the variation in internal morphology (mesostructure and microstructure) is evidence of minor changes in the physical environment that indicate a progressive shallowing. Fil: Villafañe, Patricio Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina Fil: Corbí, Hugo. Universidad de Alicante; España Fil: Cónsole Gonella, Carlos Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; Argentina Fil: Ruiz Sánchez, Francisco Javier. Universidad de Valencia; España Fil: Soria, Jesús Miguel. Universidad de Valencia; España

Along many Mediterranean coasts, the detached seagrass material of Posidonia oceanica creates seagrass berms that control the structure and morphodynamics of sandy beaches. Here, we show how Terrestrial Laser Scanner remote sensing data allows analyzing the 3-D morphologic change of beaches where this characteristic geomorphic structure is present. We propose a methodology for estimating accretion/erosion (almost &minus, 200 m3 in our study) by considering the sand dominated and seagrass berms as two independent elements. For this purpose, two different sampling dates (named scenarios A and B, before and after an erosive heavy storms period, respectively) recorded in a microtidal pocket-beach (300 m2) with these characteristic geomorphic structures have been modeled in 3-D. The present approach constitutes a cost-efficient, accurate, and quick tool to survey the sand volume in natural and artificial replenished beaches. The innovative approach, which can be considered as a conceptual and methodological starting point, can be useful to examine long-term and high-precision data sets in future studies of the morphodynamic evolution of these characteristic Mediterranean beaches.

The Fortuna Basin is an example of a marginal Mediterranean basin with evaporitic sedimentation during the Late Tortonian and Messinian. This basin shows an early restriction event before the main Messinian Salinity Crisis (MSC) that allows the Tortonian Salinity Crisis (TSC) to be proposed as a tectonic uplift event isolating the eastern Betic basins. Four evaporitic events are present in the central part of the Fortuna Basin, from bottom to top: Los Baños Marls Formation (composed by Fenazar Conglomerate Bed, Lower Gypsum Member [Mb] and Sanel Mb), Tale Gypsum Formation (Fm), Chicamo Diatomites and Gypsum Cycles Fm, and Rambla Salada Gypsum Fm. The present work documents the first biostratigraphic dating based on calcareous nannoplankton of these events. The lowest occurrence (LO) of Amaurolithus primus is registered at the upper part of the Sanel Mb, below the Tale Gypsum Fm. The LOs of Amaurolithus delicatus and Reticulofenestra rotaria, which mark the base of the Messinian, occur in the lower part of the Chicamo Cycles Fm, above the Tale Gypsum Fm, the Triquetrorhabdulus rugosus-Nicklithus amplificus integrate form and the LO of Nicklithus cf. amplificus in the upper part of the Chicamo Cycles Fm. Taking into account these results, a new calibration of the available magnetostratigraphic data is presented: the Chicamo Cycles Fm were formed during the reverse chron C3Ar and the Tortonian-Messinian boundary should be found within the Tale Gypsum Fm or near the top of the Sanel Mb. The onset of the TSC, the first restriction phase of the Fortuna Basin, is represented by the Fenazar Conglomerate Bed, bottom of the Los Baños Fm, and not by the Tale Gypsum Fm, as previously considered. Le bassin de Fortuna est un exemple de bassin méditerranéen marginal avec sédimentation évaporitique pendant le Tortonien supérieur et le Messinien. Il présente l’enregistrement d’événements de restriction avant la Crise de Salinité Messinienne (CSM), ce qui a permis de mettre en évidence une Crise de Salinité Tortonienne (CST) induite par un soulèvement tectonique qui a isolé le bassin. Dans la partie centrale du bassin, on peut reconnaître quatre ensembles évaporitiques, avec de bas en haut, la Formation Los Baños (Couche Conglomératique de Fenazar, Membre [Mb] du Gypse Inférieur, Mb des Marnes de Sanel), la Formation (Fm) Gypse de Tale, la Fm Cycles de Diatomites et Gypse de Chicamo et la Fm Gypse de Rambla Salada. Ici, pour la première fois, nous datons ces ensembles sur la base d’une analyse biostratigraphique du nannoplancton calcaire. La première occurrence d’Amaurolithus primus est enregistrée dans la partie supérieure du Mb Sanel, au-dessous de la Fm Gypse de Tale. Les premières occurrences d’Amaurolithus delicatus et de Reticulofenestra rotaria, qui marquent la base du Messinien, sont localisées dans la partie inférieure de la Fm Cycles de Chicamo, au-dessus de la Fm Gypse de Tale. Finalement, la transition Triquetrorhabdulus rugosus-Nicklithus amplificus et la première occurrence de Nicklithus cf. amplificus sont enregistrées dans la partie supérieure de la Fm Cycles de Chicamo. Sur la base de ces résultats, nous proposons un nouveau calibrage des données magnétostratigraphiques disponibles. La Fm Cycles de Chicamo s’est déposée durant le Chrone C3Ar. La limite tortonienne/messinienne est localisée près du toit du Mb Sanel ou dans la partie inférieure de la Fm Gypse de Tale. L’initiation de la CST, la première phase de restriction du bassin de Fortuna, est représentée par le Conglomérat de Fenazar, au bas de la Fm Los Baños et non pas par la Fm Gypse de Tale comme préalablement suggéré dans la littérature. This work have been supported by the projects CGL2006-08848, CGL2007-65832/BTE, CGL2006-10593, and GV06/093, and the research group GRUPOS03/085 (Generalitat Valenciana).

The analysis of the Messinian and Pliocene stratigraphy of the southern Bajo Segura Basin (Betic Cordillera, Spain) has revealed three highstand sedimentary phases (Messinian I, Messinian II, and Pliocene) bounded by two lowstand erosional surfaces (intra-Messinian and end-Messinian unconformities). The Messinian I highstand phase is characterized by the progradation of coastal and shallow marine sandstones (La Virgen Fm) over slope and pelagic-basin marls (Torremendo Fm). After this first phase, a fall in sea level brought about the intra-Messinian unconformity, a subaerial erosional surface with local accumulations of karstic breccias and caliche-like carbonate crusts. The Messinian II highstand phase is represented by sandy beaches and muddy lagoons (Garruchal Fm) correlative with shallow marine evaporites (San Miguel Fm); this second phase records the intra-Messinian reflooding of the basin, which characterizes the salinity crisis in the marginal basins of the Mediterranean. A new sea-level fall resulted in the end-Messinian unconformity, of which the most significant feature is the presence of a broad palaeovalley, c. 200 m deep, which, along its course, completely eroded the deposits of the Messinian II phase and part of the deposits of the Messinian I phase. The Pliocene highstand phase begins with coastal and shallow marine conglomerates and sandstones (La Pedrera Fm) which fill the deep part of the above-mentioned palaeovalley. These bottom deposits evolved gradually upwards towards pelagic marls (Hurchillo Fm), over which shallow marine and coastal sandstones prograded (Rojales Fm). This third phase records the flooding of the basin at the beginning of the Pliocene, when the salinity crisis ended in the marginal basins of the Mediterranean. The combination of calcareous nannoplankton biostratigraphy and magnetostratigraphy has confirmed that both the end of the sedimentation of the Messinian I phase, as well as the two lowstand erosional surfaces (intra- and end-Messinian unconformities) and also the onset of the Pliocene phase occurred in the chron C3r (c. 5.9–5.2 Ma). Under the assumption of the classical model of a desiccated deep basin, either of the two aforementioned erosional surfaces, or even both, could be correlative with the evaporites deposited in the abyssal parts of the Mediterranean. Financial aid was provided by Research Projects BTE2003-05047, CGL2005-06224/BTE, CGL2007-65832/BTE MEC, and GV04B-629 (Generalitat Valenciana) and the “Paleoenvironmental Changes” Group (UA).

A detailed sedimentological and paleontological analysis of the uppermost Miocene (Messinian)–Pliocene boundary at the northern border of the Bajo Segura Basin, southeastern Spain, was carried out in order to describe the evolution of the regional paleocoastline during the Pliocene reflooding of the Mediterranean immediately after the sea-level fall related to the Messinian Salinity Crisis. Multiple trace fossils typical of firm- and hardgrounds were recognized, allowing identification of Glossifungites (two different types), Entobia, and Gnathichnus ichnofacies. Trace-fossil analysis showed that lithology and media consistency exerted considerable control on the development of the different ichnocoenoses and that there was a clear decrease in hydrodynamic energy from a coastal to a shallow-water shelf environment related to progressive sea-level rise. Ichnological and sedimentological data provide evidence that the definitive flooding of the Mediterranean was rapid and synchronous throughout the northern margin of the Bajo Segura Basin. The following model for the Pliocene transgression in the study area is therefore proposed: (1) the marine ingression penetrated along the incised paleovalleys carved as a consequence of the fall in sea level, where the first two Pliocene systems were deposited (P0–P1); (2) during the maximum flooding surface of the transgression, the sea overflowed the margins of the paleovalleys and extended throughout the entire northern margin of the basin; and (3) the third Pliocene system was deposited, forming the lower part of a highstand systems tract (P2). This paper was written in the context of the Paleoenvironmental Changes research group (Universidad de Alicante), and with the financial aid of research projects BTE2003-05047, CGL2007-65832/BTE MEC, CGL2009-07830/BTE, and GV04B-629.

The sedimentary record of delta-front to prodelta transition that developed during the early Pliocene (Bajo Segura Basin, peri-Mediterranean Betic Cordillera Basin) represents an unusual infilling of an incised valley cutting downwards into late Messinian pelagic marls. The complete delta succession, less than 65 m thick, consists of four upwardly fining and thinning sequences several metres thick. Each sequence consists of basal conglomeratic and coarse-grained sandstone beds (delta-front deposits) evolving upwards to alternating sandstones and silty-marl beds (prodelta deposits). The retrogradational stratal succession pattern is interpreted as having been deposited during an overall sea-level rise. Facies association is characterised by quasi- to planar-laminated sandstones and pebbly sandstones alternating with clast-supported boulders to pebbles, sheet-like climbing cross-laminated sandstones with abundant plant remains, and epsilon cross-stratified and channelized gravels and sandstones. These are interpreted as having been deposited by highly concentrated flows interpreted as hyperpycnal turbidity flows from high (cohesionless debris flows and sinuous submarine channels) to moderate (sheet-like climbing cross-laminated sandstones) discharge river-flood events. Slabs of sediment from unstable banks, outsized clasts which roll onto thin beds from channel mouths, slumps and intraformational breccias in delta front are other signatures (including a lack of bored clasts) which indicate high-energy and rapid deposition at the river mouth, encouraging the delta-front gravitational instability failures. Major changes in the discharge of the river-fed delta could have been caused by brief catastrophic, heavy-precipitation events coupled with quasi-stationary convective orographic rainfall typical of the modern Mediterranean. This research was supported by projects CGL2009-07830/BTE, CGL2009-05768-E/BTE, CGL2007-65832/BTE and CGL2005-06224/BTE and financed by the Spanish Ministry of Education and Science (MEC), the European Found of Regional Development (FEDER), and Research Groups RNM-200 and RNM-369 of the Junta de Andalucía.