Southeastern Pyrenees Research Articles

Fault Gouge Dating in the Spanish Pyrenees: Fault Ages, Thrust Propagation Sequence, Wall‐Rock Provenance, and Thermal Constraints

AbstractDating brittle faults by the growth of authigenic illite in fault gouge allows for direct testing of kinematic models of orogenic evolution, such as in‐sequence versus out‐of‐sequence thrusting, and the presence of orogenic “pulses” of deformation on multiple thrusts simultaneously. We present illite gouge ages from five thrust faults along the Ter and Freser rivers in the south‐eastern Pyrenees fold‐and‐thrust belt dated by Ar‐Ar methods. The ages show in‐sequence thrusting for the south‐eastern Pyrenees fold‐thrust belt during the Eocene and early Oligocene, ranging from 49.5 + 4.4 Ma for the inboard Freser Antiformal Stack to 31.9 ± 3.9 Ma for the frontal L’Escala Thrust. Foreland progression of ages is preserved, although overlapping of ages of the frontal thrusts permits the interpretation of a period of more rapid fault displacement around 35 Ma. Shortening rates for the Ter‐Freser section range from 1.2–2.7 km/my, with strain rates ranging from 7.0 × 10−16 s−1 to 1.6 × 10−15 s−1 The latest Paleozoic ages of the cataclastically derived component inferred from the gouge dating methodology are shown to be pooled 2M1 illite/mica ages of wall rock sediments and have geological meaning. These inferred mica ages of the thrust wallrocks in the southeastern Pyrenees indicate Hercynian‐age micas were deposited in the Southern Pyrenean foreland basin as early as the late Cretaceous. Previous thermochronometer and Δ47 temperatures from syn‐faulting calcite veins constrain temperature of clay gouge formation in the Ter‐Freser section at 50–210°C, with most likely temperatures of 50–160°C, consistent with previous studies.

Glacial–interglacial cycles in the south-central and southeastern Pyrenees since ~180 ka (NE Spain–Andorra–S France)

AbstractThis study uses luminescence and 14C accelerator mass spectrometry procedures to date relevant glaciofluvial and glacial deposits from the south-central and southeastern Pyrenees (Andorra–France–Spain). We distinguish two types of end-moraine complexes: (1) those in which at least a far-flung moraine exists beyond a frequently nested end-moraine complex (the most common) and (2) those in which a close-nested end moraine encompasses at least two glacial cycles. Both types formed within six distinctive glacial intervals: (1) A penultimate glacial cycle during Marine Oxygen Isotope Stage (MIS) 6 and older glaciofluvial terraces occurred beyond the range of the luminescence dating method. (2) An early glacial advance in MIS 5d (~97 −15/+19 ka) was followed by glacial retreat during MIS 5c (< 91 ± 9 ka). (3) The last maximum ice extent (LMIE) was in early MIS 4 (~74 ± 4.5 ka). (4) Unexpectedly, glaciers thinned during the second half of MIS 3 (~39 −6/+11 ka). (5) During the MIS 3–2 transition, glaciers subsequently fluctuated behind the LMIE limits. (6) The global last glacial maximum (LGM) started as early as ~26.6 ± 0.365 ka b2k, and the corresponding end moraines were built behind the LMIE limits or merged with it, forming close-nested moraines.

Fluvial sedimentation and its reservoir potential at foreland basin margins: A case study of the Puig-reig anticline (South-eastern Pyrenees)

Fluvial fans represent one of the dominant sedimentary systems at the active margins of non-marine foreland basins. The Puig-reig anticline at the north-eastern margin of the Ebro Foreland Basin (SE Pyrenees, Spain) exposes continuous outcrops of Late Eocene-Early Oligocene fluvial deposits, from proximal to medial fluvial fan environments. The proximal deposits are found in the north limb of the anticline, especially in the northwest zone. These deposits are characterised by conglomerates with minor interbedded sandstones, with thick and wide sheet-like geometries with unscoured or variably scoured basal surfaces. These are interpreted to be the deposits of unconfined flash floods and wide-shallow channel streams. The medial deposits, covering the rest of the anticline, consist of interbedded conglomerates, sandstones and claystones. These are interpreted to have been deposited from braided to meandering channel streams and overbank areas. Distal deposits are found towards the south, beyond the anticline, and are characterised by sandstone and clay deposits of terminal lobes and lacustrine deltas. This study assesses the impact of the primary depositional characteristics, diagenesis and deformation of the most heterolithic portion of the system, with implications for increasing our understanding of folded fluvial reservoirs. Diagenetic processes, mainly mechanical compaction and calcite cementation, resulted in overall low intergranular porosity, with limited relatively high porosity developed in sandstone lithofacies in the medial deposits. Deformation associated with thrusting and fold growth resulted in the formation of abundant fractures, with relatively high fracture intensities observed in sandstone lithofacies in the anticline crest. This study shows that post-depositional processes can both improve and diminish the reservoir potential of basin proximal fluvial deposits, through the development of fracture networks and by compaction-cementation. The comparison of the Puig-reig anticline with other similar settings worldwide indicates that foreland basin margin locations may be potential areas for effective reservoirs, even in the case of low intergranular porosity.

Fracture distribution in a folded fluvial succession: The Puig-reig anticline (south-eastern Pyrenees)

Sedimentary rocks of foreland fold-and-thrust belts typically undergo intensive fracturing as folds grow. The resulting fracture networks can present significant variations depending on the distribution of sedimentary facies and the complex structural characteristics of fold-and-thrust belts. The Puig-reig anticline, located in the south-eastern Pyrenees, mainly exposes proximal fluvial deposits in the north limb and medial fluvial deposits in the rest of the anticline. Thus, this anticline constitutes an excellent case study to investigate the main controls on the distribution of fracture networks in folded fluvial deposits, in terms of structural position and lithofacies variations. Outcrops were selected to be representative of different structural positions, from the fold hinge to its limbs, and of a variety of the main lithofacies, from proximal to medial fluvial deposits. Fracture data were acquired using the linear scanline method. The results indicate that the anticline rocks have been affected by four sets of fractures. The north limb is dominated by thick conglomerate bodies with interlayered sandstones deposited from unconfined flash floods and wide-shallow channel streams in the proximal fluvial fan, and presents large fracture spacing and low fracture intensity but relatively large fracture length and aperture. The crest and the crest-limb transition zones are mainly characterised by interlayered conglomerates, sandstones, siltstones and clays, deposited from braided channel streams and overbanks in the medial fluvial fan, and present fractures with relatively high fracture intensity and variable fracture length and aperture. The south limb, composed of channel filling sandstone layers and stable overbank fine deposits in the medial fluvial fan, is characterised by low fracture intensity and small fracture length and aperture. Based on multiple linear regression analysis, fracture intensity is mainly controlled by the structural position, bedding thickness and lithological associations, with relatively more intense fracturing in thin sandstone layers with multiple interlayers of fine deposits in the anticline crest. The fracture length mainly depends on bedding thickness and is affected lithological associations. The fracture apertures are mainly controlled by lithofacies, with relatively higher apertures affecting conglomerate bodies. The results of this study are relevant for characterising similar systems in the subsurface, where data is scarce.

Reconstructing Mousterian landscapes in the southeastern Pyrenees (Roca dels Bous site, Pre-Pyrenees ranges, Spain)

AbstractLandscape evolution studies enable us to understand site formation processes affecting past hunter-gatherer settlements. This work presents a landscape reconstruction of Roca dels Bous site (RB), which is a reference site for the Late Mousterian occupation of the incised valleys of the southeastern Pyrenees. For this purpose, we combined geomorphological studies, stratigraphic descriptions, new single-grain optically stimulated luminescence datasets, statistical methods, and geophysical surveys. RB formed by gravitational processes induced by fluvial undermining of the Segre River during changing late Pleistocene climatic conditions. Geomorphological and chronological data combined with fluvial age-incision models suggest that, during Late Mousterian occupation, RB was located very near the Segre floodplain level and closer to water and raw material natural resources than at present. The accumulation of gravitational deposits associated with the archaeological levels occurred at rates of 0.16–0.44 m ka-1, between 55 and 47 ka, coinciding with Marine Oxygen Isotope Stage 3 (MIS3). More detailed comparison with available climatic curves suggests that the dated RB layers were potentially deposited during cold phases within MIS3. This work provides new landscape-based evidence to examine the paleoenvironmental context of Neanderthal presence in the southeastern Pre-Pyrenees, an important region in the debate regarding Neanderthal demise in Western Europe around 40 ka.

The backwater effect as a tool to assess formative long-term flood regimes

The Ter River drains the south-eastern Pyrenees and flows into the Mediterranean Sea. A lithological constriction affects the normal water flow in the La Plana de Vic area. As a consequence of this disturbance in the flow, the shrinkage in the bedrock activates a backwater effect. Systematic water retention during extreme events has formative consequences. The process involves the creation of a helical flow for the structural misalignment of the channel at the point of narrowness. The backwater effect transmits the secondary currents backwards, resulting in the creation of a sinuous pattern upstream from the shrinkage. A tributary, the Gurri River, flows into the main river just before the constriction, and this too has been affected by the process of water storage and channel pattern change.A two-dimensional numerical flow model (Iber) has modelled several hypothetical cases of flooding. This modelling aims to test the reach of the hydraulic influence upstream from the constriction, both in the main river and its tributary, due to the backwater effect. Moreover, it sought to find the best balance of discharge between the two streams. The upstream reach of the backwater effect was considered as its endpoint. During the flooding, the system reached hydraulic equilibrium between the constriction and the two endpoints when both were at the same water level, and the flow regime was subcritical everywhere. The hydraulic conditions that drove the water flow to the equilibrium are thought to be the ones that promoted formative processes in a sinuous pattern on a long-term basis.The water discharge values obtained from this procedure are, in general terms, 50% above those considered to be a peak flood with a recurrence time of 500 years (Q500), and they accomplish the conditions of extreme events. Thus classified, the calculated discharges can be helpful for comparison with those measured in historical and systematic records, because a water discharge like the one calculated has never been measured at the Ter River.

Contribution of isotopic research techniques to characterize high-mountain-Mediterranean karst aquifers: The Port del Comte (Eastern Pyrenees) aquifer

Water resources in high mountain karst aquifers are usually characterized by high rainfall, recharge and discharge that lead to the sustainability of the downstream ecosystems. Nevertheless, these hydrological systems are vulnerable to the global change impact. The mean transit time (MTT) is a key parameter to describe the behavior of these hydrologic systems and also to assess their vulnerability. This work is focused on estimating MTT by using environmental tracers in the framework of high-mountain karst systems with a very thick unsaturated zone (USZ). To this end, it is adapted to alpine zones a methodology that combines a semi-distributed rainfall-runoff model to estimate recharge time series, and a lumped-parameter model to obtain ΜΤΤ. The methodology has been applied to the Port del Comte Massif (PCM) hydrological system (Southeastern Pyrenees, NE Spain), a karst aquifer system with an overlying 1000 m thick USZ. Six catchment areas corresponding to most important springs of the system are considered. The obtained results show that hydrologically the behavior of the system can be described by an exponential flow model (EM), with MTT ranging between 1.9 and 2.9 years. These ΜΤΤ values are shorter than those obtained by considering a constant recharge rate along time, which is the easiest and most applied aquifer recharge hypothesis when estimating ΜΤΤ through lumped-parameter models.

Settlement patterns during the Magdalenian in the south-eastern Pyrenees, Iberian Peninsula. A territorial study based on GIS

The territorial characteristics and environmental factors involved in the selection of a specific site for establishing a settlement are key features in the analysis of hunter-gatherers' knowledge of (and dominance over) their surroundings and in the attempts to understand the survival strategies that they deployed. This paper presents a macrospatial analysis using GIS tools, which provides an objective comparison of territorial variables at several Magdalenian archaeological sites located in the south-eastern Pyrenees (NE Iberia). To establish the settlement patterns, we analyse territorial values: orientation, elevation, slope, sites aspect (caves, rock shelters or open air) and distance from rivers. With the data obtained, we create solar radiation models, construct groups of sites according to visibility, and calculate the displacement costs of mobility. The results suggest a series of different settlement patterns during the Magdalenian. The visibility of rivers from the archaeological sites and potential sunlight are characteristic features throughout the period, but the distance between rivers and settlements decreases diachronically. Comparison of the climate models indicates that settlements in the vicinity of the river were more frequent at times with evidence of low rainfall. Likewise, the costs of displacement from the surrounding territory to the archaeological sites increase; access to the Lower Magdalenian sites is easier, and access to the Upper Magdalenian sites much more difficult.

Timing of deglaciation and rock glacier origin in the southeastern Pyrenees: a review and new data

The aim of this research is to improve our current understanding of the deglaciation stages in the southeastern Pyrenees and integrate it into reconstructions of the long‐term deglaciation in the Iberian mountains since the Last Glaciation. First, we examine the existing chronological data for deglaciation in Iberian mountain ranges, mainly focusing on the Pyrenees and the results derived from cosmic ray exposure dating methods. Then, we recalculate the age of 17 samples from four different areas in the SE Pyrenees (Arànser, La Llosa and Duran valleys and Malniu‐Guils complex) based on the 36Cl isotope and applying a new age calculator. In addition, we date eight new samples from the Malniu‐Guils complex to provide a more accurate chronology for this site. The results do not clarify the timing of the maximum glacier extent, but support an extensive glacial advance followed by multiple small advances and retreats during the Last Glacial Maximum (LGM). Geomorphological and chronological data show evidence of massive deglaciation at the end of the LGM around 18 ka, and deglaciation was practically complete during the Bølling‐Allerød interstadial. There is no geomorphological evidence of glacial advances in the cirques during the Younger Dryas. Instead, cirque walls were covered with rock glaciers during the Bølling‐Allerød interstadial. The fronts of these rock glaciers stabilized at the end of this period, while their roots remained active until well into the Holocene.

Genomic diversity and geographical structure of the Pyrenean desman

The Pyrenean desman (Galemys pyrenaicus) is a small semi-aquatic mammal endemic to the Iberian Peninsula. The species has recently experienced a strong decline and some of its populations are severely threatened with extinction. To help in the preservation of this species, it is critical to understand its genetic structure and main evolutionary units, as these may have specific local adaptations and could be of great conservation value. Sequencing reduced representation libraries (ddRAD) from 26 specimens selected from across its entire range, we obtained around 45,000 loci per specimen and 1185 single nucleotide polymorphisms. Heterozygosity varied substantially among individuals from different areas. Interestingly, specimens from the southeastern Pyrenees had some of the lowest proportions of heterozygous positions inferred from genome-wide data in mammals so far. In addition, we estimated a tree reflecting genomic divergence, performed a principal component analysis, and carried out a Bayesian analysis of the population structure. Combined evidence supported the existence of five distinct genomic clusters largely coincident with the main mountain ranges where the species occurs, with few specimens presenting relevant admixture levels. There was good correspondence between these populations and the mitochondrial lineages detected in a previous study, yet substantial differences in some areas demonstrate the importance of performing genomic analysis to reveal the whole population history. Although the analysis of further specimens is necessary to better characterize the distribution of the different evolutionary units, the distinctive geographical structure of this species revealed by the genomic data should be considered in future conservation plans.

Allodaposuchus palustris sp. nov. from the upper cretaceous of Fumanya (South-Eastern Pyrenees, Iberian Peninsula): systematics, palaeoecology and palaeobiogeography of the enigmatic allodaposuchian crocodylians.

The controversial European genus Allodaposuchus is currently composed of two species (A. precedens, A. subjuniperus) and it has been traditionally considered a basal eusuchian clade of crocodylomorphs. In the present work, the new species A. palustris is erected on the base of cranial and postcranial remains from the lower Maastrichtian of the southern Pyrenees. Phylogenetic analyses here including both cranial and postcranial data support the hypothesis that Allodaposuchus is included within Crocodylia. The studied specimen suggests little change in postcranial skeleton along the evolutionary history of crocodylians, except for some bone elements such as the axis, the first caudal vertebra and the ilium. The specimen was found in an organic mudstone corresponding to a coastal wetland environment. Thus, A. palustris from Fumanya is the first Allodaposuchus reported in lacustrine-palustrine settings that expand the ecological range for this genus. The S-DIVA palaeobiogeographic reconstruction of ancestral area suggests that early members of Crocodylia rapidly widespread for the Northern Hemisphere landmasses no later than the Campanian, leading the apparition of endemic groups. In that way “Allodaposuchia” represents an endemic European clade probably originated in the Ibero-Armorican domain in the late Campanian and dispersed by the Southern European archipelago prior to the early Maastrichtian.

Maximum extent of Late Pleistocene glaciers and last deglaciation of La Cerdanya mountains, Southeastern Pyrenees

This paper examines glacial evolution in the La Pera and Malniu cirques, and Arànser, La Llosa and Duran valleys, in the Cerdanya massifs on the south-facing slopes of the eastern Pyrenees. A geomorphologic analysis and dating of moraine boulders, glacially polished bedrock and rock glacier blocks were carried out by means of cosmogenic 36Cl surface exposure dating. The maximum ice advance was contemporary with the Last Glacial Maximum at 23ka ago, and it was of greater or only slightly lesser magnitude than for previous Quaternary advances. The termini of glaciers remained close to maximum positions, with minor advances and retreats until 18–17ka when the glacial tongues disappeared from the valleys. Depending on the previous topography, these glaciers left behind a single polygenic moraine, in the case of confined valleys, or multiple moraines next to each other in the case of flat, more open areas. A final glacial advance is detected during the Oldest Dryas close to the cirque headwalls, and the glaciers finally disappeared during the Bølling interstadial. The glaciers were then replaced by rock glaciers, whose front immediately became inactive, although their activity continued near their source area until the early Holocene.

Diversified fossil plant assemblages from the Maastrichtian in Isona (southeastern Pyrenees)

At the end of the 1970s, several lower Maastrichtian localities with plant megafossil remains were reported near the village of Isona in the Tremp Syncline of the southeastern Pyrenees. These assemblages include conifers (taxodioids and cheirolepidiaceans), monocot angiosperms (Sabalites palms and likely Pandanaceans) and at least 15 types of magnoliid and eudicot angiosperm leaves. Conifers, Sabalites palms and some eudicots are shared with coeval localities in Portugal, France, Austria and Romania. In addition, Sabalites palms and at least five types of magnoliids and eudicots found here are very similar to fossil leaves reported from Upper Cretaceous localities in North America, suggesting that the Isona flora possibly share some elements with North American floras. Data from the Isona locality also indicate that eudicots dominated the floodplain plant associations in fully continental-influenced terrestrial environments.

Population genetics and conservation of the extremely narrow Pyrenean palaeoendemic Glandora oleifolia (Boraginaceae)

Background: Glandora oleifolia is one of the most narrowly restricted endemics of the Iberian Peninsula. It occurs in two locations, separated by 5 km in the south-eastern Pyrenees. The species is listed as ‘vulnerable’ in the Spanish Red List, and it is legally protected in Catalonia. Aims: To study the genetic diversity and population structure, and to review the conservation status and the threats to the survival of this species. Methods: The genetic variation of the two extant subpopulations was surveyed by means of allozymes and random amplification of polymorphic DNA (RAPD). Results: Both markers indicated depleted levels of genetic variability for G. oleifolia, in agreement with the expectation for endemic species, and low genetic divergence among the two subpopulations (below 10% with the two nuclear markers). Conclusions: The evolutionary history of this palaeoendemic species – repeated population bottlenecks and/or local extinction of populations during the glacial periods of the Quaternary – could have enhanced the loss of its genetic diversity.

Altitudinal species richness patterns of vascular plants in the south-eastern Pyrenees and nearby mountains of Catalonia

Background: Studying how species richness varies with altitude has become an important part of investigations on mechanisms explaining regional-scale plant species diversity. Altitudinal diversity patterns are poorly known in the Pyrenees and elsewhere in the main mountain massifs in Catalonia (north-eastern Iberian Peninsula). Aim: We examine the altitudinal patterns of species richness in the Catalan Pyrenees and compare them with those in other mountains in Catalonia. Altitude patterns of species richness in the Pyrenees are compared for functional and taxonomic groups of vascular plants. Methods: Data on vascular plants were obtained from the Biodiversity Data Bank of Catalonia. We used rarefaction and interpolation to quantify the altitudinal diversity patterns. Results: The interpolated and rarefied richness generally peaked in the lower part of the altitudinal gradient, but with remarkable variation depending on the taxonomic or functional groups considered. Using all species, there was little variation between the different mountains, but the altitude at which richness started to decrease varied between them. Conclusions: The pronounced differences among different taxonomic groups and life-forms indicate a strong phylogenetic and adaptive signal on the altitudinal diversity pattern in the Catalan Pyrenees. The lack of regional differences within Catalonia is probably due to small differences in the intensity of climatic gradients across mountains.

Bergacarpon viladricii gen. et sp. nov., angiosperm seeds and associated fruits from the early Maastrichtian of the eastern Pyrenees (Catalonia, Spain)

A new locality yielding angiosperm seeds and fruits is reported from the Maastrichtian of south-eastern Pyrenees. The seeds Bergacarpon viladricii gen. et sp. nov may have been produced by a monocot (probably a commelinid) based on the presence of a micropylar lid and orthotropous (atropous) development. The associated fruit is follicle-like and likely contained a single seed. The seeds form a massive accumulation in one bed in a brackish mudflat depositional setting. Size, shape and organ selection as well as the absence of other associated megafossil plant remains suggest that the seed bed originated from a paucispecific source plant community and by transport through floatation. This is one of the oldest monotypical angiosperm (probably monocot) seed accumulations found so far in the fossil record.

Pollen and non-pollen palynomorph indicators of vegetation and highland grazing activities obtained from modern surface and dung datasets in the eastern Pyrenees

This paper presents the study of modern pollen and non-pollen palynomorph assemblages carried out along an altitudinal gradient from 1242 to 2541 m a.s.l. in the south-eastern Pyrenees. This research aimed to analyse highland pollen and NPP in relation to vegetation and grazing, and to evaluate the local and regional significance of modern pollen deposition. A pilot study on modern Pyrenean dung samples was also done to evaluate the role of pollen and NPP assemblages in herbivorous excrements as indicators of local highland grazing activities. Redundancy analysis showed that grazing and altitude are the most significant variables to explain pollen and NPP variability in this high-mountain area. It also made it possible to characterise pollen and NPP indicators of types of highland vegetation and grazing pressure. This constitutes a useful tool for the interpretation of fossil records in terms of local vegetation and land-use, despite the over-representation of most pollen types in this mountain context. Results obtained from the study of dung datasets corroborate the significant role of coprophilous fungi as local indicators of herbivores in Mediterranean high-mountain areas and suggest the potential value of endo- and exoparasite remains in the identification of the local presence of domestic animals. Finally, the abundance of traditional anthropogenic pollen indicators in the modern dung samples studied has made it possible to question their regional indicator value in relation to grazing activities and to suggest the potential value of taxa with no ruderal and nitrophilous preferences as indicators of the local presence of animals in highland areas.

Assessing the sources of uncertainty associated with the calculation of rainfall kinetic energy and erosivity – application to the Upper Llobregat Basin, NE Spain

Abstract. The diverse sources of uncertainty associated with the calculation of rainfall kinetic energy and rainfall erosivity, calculated from precipitation data, were investigated at a range of temporal and spatial scales in a mountainous river basin (504 km2) in the south-eastern Pyrenees. The sources of uncertainty analysed included both methodological and local sources of uncertainty and were (i) tipping-bucket rainfall gauge instrumental errors, (ii) the efficiency of the customary equation used to derive rainfall kinetic energy from intensity, (iii) the efficiency of the regressions obtained between daily precipitation and rainfall erosivity, (iv) the temporal variability of annual rainfall erosivity values, and the spatial variability of (v) annual rainfall erosivity values and (vi) long-term erosivity values. The differentiation between systematic (accuracy) and random (precision) errors was taken into account in diverse steps of the analysis. The results showed that the uncertainty associated with the calculation of rainfall kinetic energy from rainfall intensity at the event and station scales was as high as 30%, because of insufficient information on rainfall drop size distribution. This methodological limitation must be taken into account for experimental or modelling purposes when rainfall kinetic energy is derived solely from rainfall intensity data. For longer temporal scales, the relevance of this source of uncertainty remained high if low variability in the types of rain was supposed. Temporal variability of precipitation at wider spatial scales was the main source of uncertainty when rainfall erosivity was calculated on an annual basis, whereas the uncertainty associated with long-term erosivity was rather low and less important than the uncertainty associated with other model factors such as those in the RUSLE, when operationally used for long-term soil erosion modelling.

The chronology of dinosaur oospecies in south-western Europe: Refinements from the Maastrichtian succession of the eastern Pyrenees

The Late Cretaceous deposits of the continental Tremp Formation in the Vallcebre Syncline (South-eastern Pyrenees) provide an extensive egg record of dinosaurs. The parataxonomical study and analysis of multiple eggshell samples, the precise stratigraphical control of several sections and the time calibration of the abundant egg levels enable the establishment of a robust oospecies succession. The successive occurrence of three megaloolithid oospecies ( Megaloolithus siruguei–Megaloolithus mamillare–Megaloolithus sp.) in the Early and Late Maastrichtian is well correlated with the magnetic polarity time scale throughout the chron 31. The replacement of Megaloolithus siruguei with Megaloolithus mamillare occurs around the reversal of chrons 31r–31n. A comparison with oospecies successions from Arc basin localities (France) allows the age calibration for such oospecies replacement to be confirmed. This age refinement implies that some of the stated boundaries for the proposed oospecies assemblages may change and that an in-depth revision of the age and magnetic calibration of some south European egg localities is required.

In the Kingdom of Ibex: Continuities and Discontinuities in Late Glacial Hunter-gatherer Lifeways at Guilanyà (South-Eastern Pyrenees)

In the Kingdom of Ibex: Continuities and Discontinuities in Late Glacial Hunter-gatherer Lifeways at Guilanyà (South-Eastern Pyrenees)