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Camp dels Ninots is a mixed hard-soft maar-diatreme located in the Catalan Volcanic Zone (NE of Iberia), in which intra-maar lake sediments have preserved one of the most remarkable Pliocene fossil records in Europe. Geophysical surveys combined with the geological map and 11 boreholes, including two new continuous intra-crater drill cores, have enabled the construction of a 3D geological model of this maar-diatreme and its basement. The formation of this maar-diatreme started with a vent-opening phreatomagmatic explosion at the intersection between a regional fault and the Paleozoic groundwater level at a depth of 210 m. We infer and calculate the geometry, dip direction and dip angle of this regional fault. During the eruption, mixed Strombolian and phreatomagmatic episodes occurred, forming the tuff ring and filling the diatreme with minimum estimated volumes of 0.012 and 0.004 km3, respectively. The diatreme infill is composed of three main lithofacies that include tuff-breccias, welded scoriae, and mafic intrusions into the phreatomagmatic breccias. Thus, the stratigraphy of the diatreme succession suggests a progression of explosive events from deeper to shallower zones with short lateral migration of explosion vents, which control its final morphology, without evidence for significant deep enlargement of the diatreme during the later phases. This generated a wide funnel-shaped with low diatreme wall angles that differs from kimberlite pipes with great depths and sharp slope geometries. Hence, such 3D geological model helps to understand the complex architecture of maar-diatreme structures, highlighting the lack of geological modeling of this type of monogenetic system.

Ronchi et al. (in press) comment on the stratigraphic, sedimentological, mineralogical and palaeontological analyses performed in the recently described Coll de Terrers Permian–Triassic terrestrial succession from the Catalan Pyrenees by Mujal et al. (2017a). The comment debates our interpretation of a succession of red-beds as Permian (Upper Red Unit, URU). Instead, the comment infers that the analysed succession is part of the regional upper Buntsandstein facies unit (Triassic), debating the proposed stratigraphic scheme by using the tectonic evolution as the main argument. Here, we clarify and present more details on the interpretation published in Mujal et al. (2017a). Based on this clarification and taking into account the comment, we arrive to the conclusion that the interpretation and inferences presented in Mujal et al. (2017a) are sound and justified. © 2018 Elsevier B.V.

The climatic changes during the Early-Middle Pleistocene transition are a key to understand the ecosystem dynamics that involved the Homo erectus-ergaster distribution. The Aalat pedostratigraphic succession represents a continental archive in the African Rift Valley (Eritrea), where remains of Homo around 1 Ma were identified. High-resolution magnetostratigraphy dated this succession between the base of the Jaramillo subchron and the lower Brunhes chron. Despite the present arid, desert climate, the Aalat section records a persistence of water-driven, fluvio-lacustrine environments, which suggests a major tectonic control on sedimentation, although climate changes are clearly overprinted. Macro- and micromorphological, physico-chemical, mineralogical and geochemical features, up to now poorly available for Pleistocene paleosols in East Africa, depict a poor to moderate degree of development, although calcic and petrocalcic/petrogypsic horizons at different stratigraphic heights indicate phases of geomorphic stability. The concurrent alternation of these horizons with iron-stained layers suggests cyclical changes from dry to wet conditions, which fit well with aeolian dust fluxes and marine isotope stages of glacials and interglacials at higher latitudes. Stable isotope data are consistent with these climatic cycles and suggest a succession of monsoonal and non-monsoonal conditions. The Homo erectus settlement lasted apparently for a short time span, because a long, high-discharge fluvial sedimentation (and/or an aridity phase at the base of the fluvial facies) could have made the area less suitable for human settling and could have hindered preservation of fossils and artifacts. © 2018 Elsevier Ltd

The L'Espinau site is a dinosaur bonebed from the Upper Cretaceous of the South-Central Pyrenees (north-eastern Spain) that have provided hundreds of bone remains attributed to hadrosauroids, together with a rich assemblage of herpetofauna, fish and microflora. Magnetostratigraphy calibrated the site with the early late Maastrichtian, and the combined sedimentology, stable isotope geochemistry and palaeoecology revealed that this fossil site formed in a lagoon, in which a mixed freshwater-brackish palaeoenvironment was developed. This setting displays a south-north charophyte zonation from freshwater (Clavator brachycerus-dominated assemblage) to brackish or eurihaline conditions (Feistiella malladae-dominated assemblage), revealing a palaeoenvironment change towards the coast. Sedimentology and taphonomy (bidirectional arrangement of long bones, abrasion and disarticulation) indicate that the L'Espinau site is the result of a cohesive mass flow event originated very close to the sea. This process entrained and mixed fauna from both the terrestrial and the brackish/marine environment of a lagoon. An increasing of the water runoff (e.g. by intense rainfall) reworking poorly consolidated sediments is considered here as the most probable triggering mechanism. Mass flow-hosted bonebeds are commonly linked to fluvial palaeoenvironments, so our study case is a rare example of bones accumulating near the sea. This study adds evidence that hadrosauroids inhabited littoral environments during the Maastrichtian in the southern Pyrenean area. © 2017 Elsevier B.V.

The most severe biotic crisis on Earth history occurred during the Permian–Triassic (PT) transition around 252 Ma. Whereas in the marine realm such extinction event is well-constrained, in terrestrial settings it is still poorly known, mainly due to the lack of suitable complete sections. This is utterly the case along the Western Tethys region, located at Pangaea's equator, where terrestrial successions are typically build-up of red beds often characterised by a significant erosive gap at the base of the Triassic strata. Henceforth, documenting potentially complete terrestrial successions along the PT transition becomes fundamental. Here, we document the exceptional Coll de Terrers area from the Catalan Pyrenees (NE Iberian Peninsula), for which a multidisciplinary research is conducted along the PT transition. The red-bed succession, located in a long E-W extended narrow rift system known as Pyrenean Basin, resulted from a continuous sedimentary deposition evolving from meandering (lower Upper Red Unit) to playa-lake/ephemeral lacustrine (upper Upper Red Unit) and again to meandering settings (Buntsandstein facies). Sedimentary continuity is suggested by preliminary cyclostratigraphic analysis that warrants further analysis. Our combined sedimentological, mineralogical and geochemical data infer a humid-semiarid-humid climatic trend across the studied succession. The uppermost Permian strata, deposited under an orbitally controlled monsoonal regime, yields a relatively diverse ichnoassemblage mainly composed of tetrapod footprints and arthropod trace fossils. Such fossils indicate appropriate life conditions and water presence in levels that also display desiccation structures. These levels alternate with barren intervals formed under dry conditions, being thus indicative of strong seasonality. All these features are correlated with those reported elsewhere in Gondwana and Laurasia, and suggest that the Permian–Triassic boundary might be recorded somewhere around

It is shown that portable X-ray fluorescence (pXRF) is a powerful tool for the identification and geochemical characterization of prospective Cretaceous–Paleogene (K–Pg) boundary sites. Field measurements in two well-known K–Pg boundary sequences, located at Agost and Caravaca, SE Spain, have been performed. A sizable enrichment around the K–Pg horizon of several elements such as K, Ti, Fe, Ni, Cr, Cu, Zn, As or Pb, together with a strong reduction in the Ca content, is found with the pXRF instrument. These observations represent a primary geochemical signature of the K–Pg boundary in distal marine sections such as those of Agost and Caravaca. Also, the intensities of the pXRF peaks correlate well with elemental composition data obtained by inductively coupled plasma-mass spectrometry (ICP-MS) on collected samples. Hence, the pXRF field measurements are shown to provide fast and useful quantitative information about K–Pg boundary sequences.

The continental Permian–Triassic transition in southern Europe presents little paleontological evidence of the Permian mass extinction and the subsequent faunal recovery during the early stages of the Triassic. New stratigraphic, sedimentological and paleontological analyses from Middle–Upper Permian to Lower–Middle Triassic deposits of the Catalan Pyrenees (NE Iberian Peninsula) allow to better constrain the Permian–Triassic succession in the Western Tethys basins, and provide new (bio-) chronologic data. For the first time, a large vertebra attributed to a caseid synapsid from the ?Middle Permian is reported from the Iberian Peninsula—one of the few reported from western Europe. Osteological and ichnological records from the Triassic Buntsandstein facies reveal a great tetrapod ichnodiversity, dominated by small to medium archosauromorphs and lepidosauromorphs (Rhynchosauroides cf. schochardti, R. isp. 1 and 2, Prorotodactylus–Rotodactylus), an undetermined Morphotype A and to a lesser degree large archosaurians (chirotheriids), overall suggesting a late Early Triassic–early Middle Triassic age. This is in agreement with recent palynological analyses in the Buntsandstein basal beds that identify different lycopod spores and other bisaccate and taeniate pollen types of late Olenekian age (Early Triassic). The Permian caseid vertebra was found in a playa-lake setting with a low influence of fluvial water channels and related to the distal parts of alluvial fans. In contrast, the Triassic Buntsandstein facies correspond to complex alluvial fan systems, dominated by high-energy channels and crevasse splay deposits, hence a faunal and environmental turnover is observed. The Pyrenean biostratigraphical data show similarities with those of the nearby Western Tethys basins, and can be tentatively correlated with North African and European basins. The Triassic Pyrenean fossil remains might rank among the oldest continental records of the Western Tethys, providing new keys

Sedimentological, palaeontological and geochemical data provide detailed evidence of a marine-to-lagoon environmental succession around the Campanian-Maastrichtian boundary in the Ibero-Armorican domain. This regression is recorded by the succession of several environments of the south-central Pyrenees basin: open marine mixed shelf, marine restricted mixed shelf (both rudist-rich), tidal flat, lagoon and fluvial dominated. The tidal flat setting belongs to the Fumanya Member here described, which is the base of the Posa and Massana formations (Tremp Group). The Fumanya Member is 5 m thick, is built up of marly limestones and was an elongated tidal mudflat (100 km long, 25 km wide) developed in a foreland trough and was separated from the Atlantic Ocean by an island-barrier system. In the lagoon environment, marginal marine waters and continental fresh waters alternated as documented by geochemistry and fossil molluscs. The Fumanya Member is a dinosaur megatracksite, reporting the roaming activity only of sauropods in tidal flats, a likely secure area against predators. Feeding activity of these herbivores took place in the lagoonal-lacustrine environments of the Posa Formation above the Fumanya Member.

The magnetic polarity stratigraphy from a lacustrine sequence of the Baza Basin (Betic Chain, Southern Spain) has been interpreted as having a Lower Pleistocene age. Fifty-nine paleomagnetic sites have been obtained and a set of 179 specimens has been demagnetized with both thermal and alternating field procedures. Several magnetic parameters, that depend on the lithology, have been obtained. The characteristic remanent magnetization polarity has been unambiguously recovered over the whole sequence. The materials studied span chron 1r.2, located in the upper Matuyama epoch. This allows the placement of the faunas studied, ranging from the Late Villanyian to the Late Biharian, in the magnetic polarity time scale (MPTS). This work also proves that magnetostratigraphy can be established in lacustrine sediments even with extremely low magnetic intensities. © 1994.