Alluvial record of an early Eocene hyperthermal within the Castissent Formation, the Pyrenees, Spain

The late Palaeocene to the middle Eocene (57.5 to 46.5 Ma) recorded a total of 39 hyperthermals – periods of rapid global warming documented by prominent negative carbon isotope excursions (CIEs) as well as peaks in iron content – have been recognized in marine cores. Documenting how the Earth system responded to rapid climatic shifts during hyperthermals provides fundamental information to constrain climatic models. However, while hyperthermals have been well documented in the marine sedimentary record, only a few have been recognized and described in continental deposits, thereby limiting our ability to understand the effect and record of global warming on terrestrial systems. Hyperthermals in the continental record could be a powerful correlation tool to help connect marine and continental deposits, addressing issues of environmental signal propagation from land to sea. In this study, we generate new stable carbon isotope data (δ13C values) across the well-exposed and time-constrained fluvial sedimentary succession of the early Eocene Castissent Formation in the south central Pyrenees (Spain). The δ13C values of pedogenic carbonate reveal – similarly to the global records – stepped CIEs, culminating in a minimum δ13C value that we correlate with the hyperthermal event “U” at ca. 50 Ma. This general trend towards more negative values is most probably linked to higher primary productivity leading to an overall higher respiration of soil organic matter during these climatic events. The relative enrichment in immobile elements (Zr, Ti, Al) and higher estimates of mean annual precipitation together with the occurrence of small iron oxide and iron hydroxide nodules during the CIEs suggest intensification of chemical weathering and/or longer exposure of soils in a highly seasonal climate. The results show that even relatively small-scale hyperthermals compared with their prominent counterparts, such as PETM, ETM2, and ETM3, can leave a recognizable signature in the terrestrial stratigraphic record, providing insights into the dynamics of the carbon cycle in continental environments during these events

Origin and propagation of sedimentary sequences throughout the Escanilla fluvial routing system (South Pyrenean foreland basin)

EGU2020: Sharing Geoscience Online, 4-8 may 2020During middle Eocene, the Escanilla fluvial system transported and deposited material from East to West in the southern Pyrenees foreland basin. The paleogeography and sedimentology of the source to sink system is well established. The temporal framework is made of scattered low resolution magnetostratigraphies, and a robust temporal framework in the most distal (Olson) and most proximal (Sis) parts of the system. We built a new high resolution magnetostratigraphy from the middle part of the system, the Lascuarre section. The correlation of Lascuarre with the high resolution magnetostratigraphies and the integration of these data with other available chronological constraints results into a robust complete temporal framework from source to sink. Sedimentological analyses of the Lascuarre section allow recognizing a set of sedimentary sequences throughout the record. Here we present the result of the analyses, and discuss the relative weight of the different forcing. Particularly, we elucidate the role of tectonics in relation to subsidence distribution patterns, and also the distinct expression of climate. Eventually, we identify and explore the signal propagation mechanisms of climate aberrations and of quasi-regular orbital variations along the routing system

Magnetostratigraphy and stable isotopes record of Paleogene global climate events in a 30Myr expanded foreland basin succession, Isabena river, Southern Pyrenees, Spain

Past sedimentary archives provide invaluable comparative insights to understand Earth¿s surface reaction to climate shifts and perturbations. Foreland basins are particularly interesting settings for investigating the sedimentary record of ancient climate perturbations because their high-accommodation and high-sedimentation rates favour protracted and expanded records that complement more distal oceanic records. In addition, due to their proximity to source areas, they provide direct information on the land surface response to the regional impacts of global climate shifts. However, besides climate signals, the stratigraphic record of foreland basins is subject to a broad range of other factors that make its interpretation challenging. Indeed, foreland basins are naturally sensitive to the influence of tectonics on sediment production and accommodation, either associated with the long-term tectonic evolution of the orogen-basin system, or with the more local and regional shorter-term structural dynamics and geodynamic perturbations. Moreover, if connected to oceanic domains, eustatic sea-level oscillations can also combine with the above factors in determining final stratigraphic patterns. Over the last two decades, a large body of paleoclimate work has produced new and crucial data on global climate events that have affected our planet. In particular, a suite of global climate perturbations (warming, cooling) have been identified in the Paleogene, thanks to stable isotope of C and O, with some major global warming events such as the PETM, ETM2&3, the EECO, the MECO and others that have fundamental implications for the current global climate crisis. This well-established climatic template provides a unique opportunity to test the impact of climate on surface systems in deep time, particularly during the Paleogene hothouse. Therefore, we here present our work on the Isabena section in the South Pyrenean Foreland basin, which is a uniquely continuous and well exposed succession encompassing from the upper Cretaceous to the upper Eocene. We sampled continuously at 1-10 meters intervals over the 4 km-thick succession, from the lower Eocene to the upper Eocene. This sampling results in a new and continuous magnetostratigraphy covering almost 30 Myr of stratigraphic evolution, and a new high-resolution stable isotope record of carbon and oxygen over the Paleogene. These results combined with sedimentological descriptions and stratigraphic analyses reveal the links between important sedimentation changes and global climate events. Preliminary results suggest that hyperthermal events are often associated with enhanced sediment transport and clastic deposition in the basin, while intervals comparatively cooler seem to be more prone to enhanced carbonate accumulation

Repolarization of tumor infiltrating macrophages and increased survival in mouse primary CNS lymphomas after XPO1 and BTK inhibition

Altres ajuts: This work was supported by research funding from the Instituto de Salud Carlos III, Fondo de Investigaciones Sanitarias cofinanced by the European Regional Development Fund (ERDF); Fundación Asociación Española Contra el Cáncer (M.C. and P.A.) and Gilead Fellowships (GLD16/00144, GLD18/00047, F.B). M.C. holds a contract from Ministerio de Ciencia, Innovación y Universidades. S.B. is the recipient of a postdoctoral fellowship from Fundación Alfonso Martin Escudero.Patients diagnosed with primary central nervous system lymphoma (PCNSL) often face dismal outcomes due to the limited availability of therapeutic options. PCNSL cells frequently have deregulated B-cell receptor (BCR) signaling, but clinical responses to its inhibition using ibrutinib have been brief. In this regard, blocking nuclear export by using selinexor, which covalently binds to XPO1, can also inhibit BCR signaling. Selinexor crosses the blood-brain barrier and was recently shown to have clinical activity in a patient with refractory diffuse large B-cell lymphoma in the CNS. We studied selinexor alone or in combination with ibrutinib in pre-clinical mouse models of PCNSL. Orthotopic xenograft models were established by injecting lymphoma cells into the brain parenchyma of athymic mice. Tumor growth was monitored by bioluminescence. Malignant cells and macrophages were studied by immunohistochemistry and flow cytometry. Selinexor blocked tumor growth and prolonged survival in a bioluminescent mouse model, while its combination with ibrutinib further increased survival. CNS lymphoma in mice was infiltrated by tumor-promoting M2-like macrophages expressing PD-1 and SIRPα. Interestingly, treatment with selinexor and ibrutinib favored an anti-tumoral immune response by shifting polarization toward inflammatory M1-like and diminishing PD-1 and SIRPα expression in the remaining tumor-promoting M2-like macrophages. These data highlight the pathogenic role of the innate immune microenvironment in PCNSL and provide pre-clinical evidence for the development of selinexor and ibrutinib as a new promising therapeutic option with cytotoxic and immunomodulatory potential. The online version of this article (10.1007/s11060-020-03580-y) contains supplementary material, which is available to authorized users

Intra‐clinothem variability in sedimentary texture and process regime recorded down slope profiles

Shelf‐margin clinothem successions can archive process interactions at the shelf to slope transition, and their architecture provides constraints on the interplay of factors that control basin‐margin evolution. However, detailed textural analysis and facies distributions from shelf to slope transitions remain poorly documented. This study uses quantitative grain‐size and sorting data from coeval shelf and slope deposits of a single clinothem that crops out along a 5 km long, dip‐parallel transect of the Eocene Sobrarbe Deltaic Complex (Ainsa Basin, south‐central Pyrenees, Spain). Systematic sampling of sandstone beds tied to measured sections has captured vertical and basinward changes in sedimentary texture and facies distributions at an intra‐clinothem scale. Two types of hyperpycnal flow‐related slope deposits, both rich in mica and terrestrial organic matter, are differentiated according to grain size, sorting and bed geometry: (i) sustained hyperpycnal flow deposits, which are physically linked to coarse channelized sediments in the shelf setting and which deposit sand down the complete slope profile; (ii) episodic hyperpycnal flow deposits, which are disconnected from, and incise into, shelf sands and which are associated with sediment bypass of the proximal slope and coarse‐grained sand deposition on the medial and distal slope. Both types of hyperpycnites are interbedded with relatively homogenous, organic‐free and mica‐free, well‐sorted, very fine‐grained sandstones, which are interpreted to be remobilized from wave‐dominated shelf environments; these wave‐dominated deposits are found only on the proximal and medial slope. Coarse‐grained sediment bypass into the deeper‐water slope settings is therefore dominated by episodic hyperpycnal flows, whilst sustained hyperpycnal flows and turbidity currents remobilizing wave‐dominated shelf deposits are responsible for the full range of grain sizes in the proximal and medial slope, thus facilitating clinoform progradation. This novel dataset highlights previously undocumented intra‐clinothem variability related to updip changes in the shelf process‐regime, which is therefore a key factor controlling downdip architecture and resulting sedimentary texture

Depositional environments and sediment partitioning during early stage foreland basin thrusting: The Late Ilerdian-Early Cuisian Roda Sequence, South Pyrenean Foreland Basin (Spain).

The Late Ilerdian-Early Cuisian Roda Sequence spans approximately 3 Ma and formed in the South Pyrenean Foreland Basin (Spain). It is mapped in detail across the present-day Tremp-Graus, Ager and Ainsa sub-basins, and across the Boltaña Anticline into the Jaca sub-basin. The South Pyrenean Foreland Basin basin formed during the early stage of oblique collision of the Iberian Plate with the Eurasian Plate, and was bounded to the north by the Pyrenean chain and to the south by the Sierras Marginales. Within the basin, a time-sequenced series of curved thrusts developed (controlled by the location of inverted Mesozoic extensional faults) of which the Montsec thrust was decisive for the development of the Roda Sequence. This thrust sheet was displaced in a mostly southward direction and has an E-W orientation; it carried the Ilerdian-Cuisian sediments of the present-day Tremp-Graus and Ainsa sub-basins. It is well-expressed at the surface as well as partly buried by younger sediments. The Montsec thrust sheet is bounded east and west by the corresponding lateral ramps oriented SW-NW (Segre line), and SE-NW (La Fueba thrust system). Beyond the SE-NW oriented lateral ramp, the present-day Ainsa and Jaca sub-basins are located. The thrust had a significant influence on sediment dispersal patterns and the nature and location of depositional environments during the development of the Roda Sequence.Applied Geolog

Detecting eustatic and tectonic signals with carbon isotopes in deep-marine strata, Eocene Ainsa Basin, Spanish Pyrenees

We explore the potential of high-resolution carbon isotope stratig- raphy to provide an independent record of global sea-level changes in a 1600-m-thick succession representing ~5 m.y. of slope sedimentation in the Eocene Ainsa Basin of Spain. The restricted physiographic setting of the basin results in a bulk δ13Ccarb signal that accurately correlates with the coeval eustatic curve from the New Jersey (USA) passive mar- gin. We show that much of the deep-water sediment gravity ow (SGF) deposits are emplaced during eustatic lowstands and ne-grained marly intervals between SGFs correlate with rising and highstand sea levels. However, we also detect a substantial interval of SGF deposi- tion during a sea-level highstand, con rming the nonuniqueness of the controls on clastic deposition. This approach provides a new way to assess the origin of depositional sequences and improve stratigraphic predictions in basins with limited chronostratigraphic control

Do upstream factors control fluvial stratigraphic architecture? Insights through quantitative paleohydrology

International audienceStudies have long recognised the role of upstream factors such as sediment flux and water discharge variations in determining the equilibrium river profile. This approach has, however, not been tested in the stratigraphic record of ancient fluvial systems. Here we test the hypothesis that upstream factors control fluvial architecture through changes in water discharge and sediment flux. For this purpose, we utilise the Escanilla sediment routing system, an extensively documented source-to-sink river system in the southern Pyrenees, Spain, and of middle-upper Eocene age (ca. 40 Ma). Our focus is on the locality of Olson, at the distal part of the system, where the gullied landscape allows detailed documentation of fluvial stratigraphic architecture. We describe several fining-upward sequences of 35–40-metre thicknesses with a laterally extensive, amalgamated base overlain by a floodplain-dominated interval containing isolated channel bodies. For each amalgamated and non-amalgamated interval, data pertaining to grain size distributions and flow depths were collected. These data sets were used to perform quantitative palaeohydrological analysis based on paleoslope reconstruction, and from this, we estimated palaeoflow velocity, unit and total discharge, and bedload sediment fluxes. We find that the river slope is lower in the amalgamated intervals as discharge and sediment flux increases, while river slope increases in the non-amalgamated interval as the discharge and flux decreases. Given the available magnetostratigraphic constraints, the studied interval is compared to an astronomical reference curve. The depositional sequences reflecting variations in discharge are likely paced by the major component (413 000 yrs) of the Earth orbital eccentricity variations and thus point to climatic effect on sediment production and transport as the main driver of the fluvial sequences rather than autogenic shifts of the distributive fluvial system, or base-level changes

Do upstream factors control fluvial stratigraphic architecture? Insights through quantitative paleohydrology

International audienceStudies have long recognised the role of upstream factors such as sediment flux and water discharge variations in determining the equilibrium river profile. This approach has, however, not been tested in the stratigraphic record of ancient fluvial systems. Here we test the hypothesis that upstream factors control fluvial architecture through changes in water discharge and sediment flux. For this purpose, we utilise the Escanilla sediment routing system, an extensively documented source-to-sink river system in the southern Pyrenees, Spain, and of middle-upper Eocene age (ca. 40 Ma). Our focus is on the locality of Olson, at the distal part of the system, where the gullied landscape allows detailed documentation of fluvial stratigraphic architecture. We describe several fining-upward sequences of 35–40-metre thicknesses with a laterally extensive, amalgamated base overlain by a floodplain-dominated interval containing isolated channel bodies. For each amalgamated and non-amalgamated interval, data pertaining to grain size distributions and flow depths were collected. These data sets were used to perform quantitative palaeohydrological analysis based on paleoslope reconstruction, and from this, we estimated palaeoflow velocity, unit and total discharge, and bedload sediment fluxes. We find that the river slope is lower in the amalgamated intervals as discharge and sediment flux increases, while river slope increases in the non-amalgamated interval as the discharge and flux decreases. Given the available magnetostratigraphic constraints, the studied interval is compared to an astronomical reference curve. The depositional sequences reflecting variations in discharge are likely paced by the major component (413 000 yrs) of the Earth orbital eccentricity variations and thus point to climatic effect on sediment production and transport as the main driver of the fluvial sequences rather than autogenic shifts of the distributive fluvial system, or base-level changes