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The carbon isotopic signature inherited from soil/epikarst processes may be modified by degassing and prior calcite precipitation (PCP) before its imprint on speleothem calcite. Despite laboratory demonstration of PCP effects on carbon isotopes and increasingly sophisticated models of the governing processes, to date, there has been limited effort to deconvolve the dual PCP and soil/epikarst components in measured speleothem isotopic time series. In this contribution, we explore the feasibility, advantages, and disadvantages of using trace element ratios and δ44Ca to remove the overprinting effect of PCP on measured δ13C to infer the temporal variations in the initial δ13C of dripwater. In 8 examined stalagmites, the most widely utilized PCP indicators Mg/Ca and δ44Ca covary as expected. However, Sr/Ca does not show consistent relationships with δ44Ca so PCP is not universally the dominant control on Sr/Ca. From δ44Ca and Mg/Ca, our calculation of PCP as fCa, fraction of initial Ca remaining at the deposition of the stalagmite layer, yields multiple viable solutions depending on the assumed δ44Ca fractionation factor and inferred variation in DMg. Uncertainty in the effective fractionation of δ13C during degassing and precipitation contributes to uncertainty in the absolute value of estimated initial δ13C. Nonetheless, the trends in initial δ13C are less sensitive to these uncertainties. In coeval stalagmites from the same cave spanning 94 to 82 ka interval, trends in calculated initial δ13C are more similar than those in measured δ13C, and reveal a common positive anomaly initial δ13C during a stadial cooling event. During deglaciations, the trend of greater respiration rates and higher soil CO2 is captured in the calculated initial δ13C, despite the tendency of higher interglacial dripwater situation to favor more extensive PCP.

The Asian summer monsoon (ASM) is a vast climate system, whose variability is critical to the livelihoods of billions of people across the Asian continent. During the past half-century, much progress has been made in understanding variations on a wide range of timescales, yet several significant issues remain unresolved. Of note are two long-standing problems concerning orbital-scale variations of the ASM. (1) Chinese loess magnetic susceptibility records show a persistent glacial-interglacial dominated ~100 kyr (thousand years) periodicity, while the cave oxygen-isotope (δ18O) records reveal periodicity in an almost pure precession band (~20 kyr periodicity)—the “Chinese 100 kyr problem”. (2) ASM records from the Arabian Sea and other oceans surrounding the Asian continent show a significant lag of 8–10 kyr to Northern Hemisphere summer insolation (NHSI), whereas the Asian cave δ18O records follow NHSI without a significant lag—a discrepancy termed the “sea-land precession-phase paradox”. How can we reconcile these differences? Recent and more refined model simulations now provide spatial patterns of rainfall and wind across the precession cycle, revealing distinct regional divergences in the ASM domain, which can well explain a large portion of the disparities between the loess, marine, and cave proxy records. Overall, we also find that the loess, marine, and cave records are indeed complementary rather than incompatible, with each record preferentially describing a certain aspect of ASM dynamics. Our study provides new insight into the understanding of different hydroclimatic proxies and largely reconciles the “Chinese 100 kyr problem“ and “sea-land precession-phase paradox”.

This study examines the first precisely dated and temporally highly resolved speleothem record from Iberia that reconstructs the Oldest Dryas (OD). The onset of cold conditions in the study area, contemporary with the beginning of Heinrich Stadial 1, is recorded at 18.13 ± 0.08 ka, with a pronounced drop of 6.1‰ in δ13C in 250 years. Henceforth, stadial conditions depict a period of instability in the Atlantic Meridional Overturning Circulation, peaking in freshwater input from iceberg melting during Heinrich Event 1. Anomalies in the δ18O of the stalagmite attributed to such a freshwater event are found from 16.17 to 15.89 ka. Such absolute dates given to the onset of the OD in Iberia and to the main iceberg discharges are reliable anchor points for non-absolute chronologies. Two periods are identified in the OD: OD-a (18.13–16.17 ka) is characterized by wet conditions and a faster growth rate, and OD-b (15.89–14.81 ka) exhibits relative dryness and a slower growth rate. The sudden release of fresh water is considered to be the reason for the disruption of rainfall patterns in eastern Iberia. The present study also highlights the existence of heterogeneous and complex hydrological conditions during the OD in Iberia when both Atlantic and Mediterranean realms are considered.

In karst coastal areas, speleothems preserved in karst caves were widely used to date the seashore emersion, as well as to infer its uplifting rate. Likewise, speleothems would be also used to approach rates of coastal subsidence. Landscape evolution and tectonic driving of Southern Spain is being investigated by relief GIS-analysis, geomorphological indicators, fault analysis and geochronology in the framework of the Spain-funded project titled “Morphomed” (PID2019-107138RB-I00). In the Westernmost Mediterranean Sea, Granada coast shows carbonate cliffs interrupted by bays and inlets filled by delta, alluvial fan and other deposits. Alluvial sediments were deposited on marine terraces located below sea level according to previous gravity and seismic studies. Cliffs barely preserve sediments such as landslides, alluvial fan deposits and karst deposits within fracture caves. Karst deposits comprise speleothems and cave detrital infills, containing fossils of continental gastropods (probably genus Iberus). A total of fifteen speleothems collected in a transect from sea level to 220 m altitude, were dated by the 238U-230Th method in Jiaotong University (China). The dating revealed ages older than 650 ka for speleothems located throughout the transect from the cliff bottom to the higher altitude areas. Field observations and datations points out the occurrence of a Chibanian karst in Granada cliff coast, but with a lack of any documented uplifting evidence (e.g., Upper Pleistocene-Holocene speleothems / raised marine deposits). This fact clashes with the occurrence of well-developed marine terraces and clear emerged Quaternary marine deposits reported in nearby shore areas sited to the West (Malaga coast) and to the East (Almeria coast) of the study area. Altogether, preliminary results suggest the relative subsidence of Granada coast since at least the Chibanian, which agrees the occurrence of submerged marine terraces and the tectonic setting defined by previous works.

We present the first results of the MORPHOMED project, in order to deepen the chronology, uplifting rate, and tectonic forcing of different sectors of the Betic Cordillera since the Pliocene. Our initial morphotectonic analysis in the Western Betics, at the active termination of the Betic dextral STEP fault, highlights the location of active orogen-parallel normal faults cutting Pliocene marine sediments, uplifted above 600 masl, and Quaternary alluvial fans. The morphometric study we carried out includes normalized river steepness (ksn) and other geomorphic indices calculated in GIS using our own code designed in python. The fieldwork developed comprises the identification of uplifted Pliocene marine deposits, faulted alluvial fans and remnants of uplifted planation surfaces. The alluvial fans are related to travertine deposits older than 350 ka, which would be associated with hot springs. Geochronological studies involve previous and new U-Th dating on travertines and speleothems from caves in the high areas. The preliminary morphometric analyses reveal the occurrence of knickpoints that coincide with normal faults affecting marine Pliocene deposits and alluvial fans. These fans show vertical displacement of more than 20 m and their age remains unknown albeit the associated travertines are being dated. These results support previous works concerning of active tectonics in the Central and Western Betic Cordillera and they will serve to define new active faults, driving tectonic uplift of the Western Betics, which are the key to understand the landscape evolution forced probably by deep mantle rooted tectonics like slab tearing and edge delamination.

We provide first insights into the speleogenesis of Ejulve cave (Teruel province, Iberian Range, NE Spain) by studying cave morphologies and cave deposits, combined with regional geomorphological and hydrothermal observations. Three main hydrogeomorphic evolutionary stages can be distinguised to explain the origin and evolution of the Ejulve endokarstic system. Cave pattern and cave solutional features (calcite vein fillings, tubes with rising ceiling cupolas, pendants and cusps, spongework and micro-corrosion features) suggest that the cave generated in a phreatic environment by ascending water. Cave morphologies and regional hydrothermal springs in this region suggest, but not prove, the involvement of thermal waters and related convection and condensation-corrosion mechanisms in the origin of the cave. Subsequently, the cave underwent a change to epigenic conditions driven by denudation, as a result of regional uplift. Once the karstic system was exhumated, carbonate speleothems formed in a vadose environment. Mineralogical, petrographic, isotopic and chronological (U-series dating) analyses of carbonate speleothems (i.e. stalagmites, flowstones, botryoids, spars, acicular crystals and farmed carbonate) are provided. Calcite, high-Mg calcite and aragonite are the most common minerals, whereas columnar, dendritic, micrite, mosaics and fans are the main fabrics. Mean δO values of − 7.3‰ and δC values of − 9.1‰ indicate carbonate precipitation from meteoric waters without a hydrothermal origin. Carbonate deposits formed at least since 650 ka BP. Our study suggests that hydrothermal fluid flow may explain, although the evidences are not fully conclusive, the speleogenesis of this cave., We acknowledge the predoctoral research Grant from the Government of Aragón (B158/13) and CTM2013-48639-C2-2-R (OPERA) and CGL2016-77479-R (SPYRIT) projects for funding. Fernando Gázquez was financially supported by the “HIPATIA” research program of the University of Almeria.

The last deglaciation (from ≈19 kyr BP to the onset of the Holocene) is a time interval characterized by major and abrupt climate changes mostly caused by the Atlantic Meridional Overturning Circulation (AMOC) which is responsible for redistributing heat on a planetary scale, including the Iberian Peninsula. This study is focused in the Western Pyrenees, northern Spain, a southern European region key to understand Northern Hemisphere climate teleconnections associated to several warming and cooling events that took place abruptly. It is especially important to know when precisely these events occurred and what their amplitude was to better understand their causes and impacts on the regional environment.The climatic events mentioned above are recorded in lake and marine sediments in the central and southern Europe denoting the importance of these records in the transitional zone between the Atlantic and the Mediterranean climatic realms. The glacial-interglacial transition was also identified in isotopic values of speleothems at this latitude, where differences and similarities with the patterns identified in the Greenland record during the last deglaciation are analysed. Even so, there is still no continental record of temperature reconstruction during part of the last deglaciation in the Iberian Peninsula that can be compared with the latest record of fluid inclusions in speleothems in central Europe (Affolter et al., 2019).In this new study, three stalagmites from Ostolo Cave in the Western Pyrenees were analysed to identify and characterize the timing of the climate variability along the abrupt changes that punctuated the last deglaciation and subsequently generate a reconstruction of the past temperature with the help of fluid inclusion water isotopes. The samples were dated at high precision and cover almost continuously the same period (16.5-10 kyr BP) with a high degree of replication. The speleothem δ18O and fluid inclusion water isotopes (δD) records follow closely the well-known changes from high latitudes showing more negative values during GS-1 and H1, related to colder climates, while more positive values were reached during GI-1 and the Early Holocene, pointing towards warmer temperatures. Our Ostolo Cave fluid inclusion temperature record resembles Greenland and Mediterranean sea surface temperature trends and allows for the first time and from a continental record, a continuous reconstruction of temperature throughout the last deglaciation in southern Europe.

This article presents for the first time a large dataset of rainfall isotopic measurements (d18Op and d2Hp) sampled every day or every two days from seven sites in a west-to-east transect across northern Spain for 2010–2017. The main aim of this study is to: (1) characterize rainfall isotopic variability in northern Spain at daily and monthly time scales, and (2) assess the principal influencing factors determining rainfall isotopic variability. This comprehensive spatio-temporal approach allows exploring the role of air mass source in determining the isotopic composition of rainfall in northern Iberia by using back-trajectories; Atlantic fronts are found to be the dominant source of northern Iberia rain events studied. The relative role of air temperature and rainfall amount in determining the stable isotope composition of precipitation changes along the west-to-east transect. Air temperature appears to be the most significant influence on d18Op at daily and monthly time scales with the highest air temperature-d18Op dependency found for the Pyrenean station while a few sites in the transect show a significant negative correlation with precipitation amount. Distance from the coast, site elevation, and moisture source region (Atlantic versus Mediterranean) also significantly modulate the d18Op values and ranges but the type of precipitation (convective vs frontal rainfall) plays a key control, with convective rainfall associated with higher d18Op values. This dataset of the rainfall isotopic composition represents another step forward towards developing a more detailed, mechanistic framework for interpreting stable isotopes in rainfall as a palaeoclimate and hydrological tracer.

The Younger Dryas (YD), arguably the most widely studied millennialscale extreme climate event, was characterized by diverse hydroclimate shifts globally and severe cooling at high northern latitudes that abruptly punctuated the warming trend from the last glacial to the present interglacial. To date, a precise understanding of its trigger, propagation, and termination remains elusive. Here, we present speleothem oxygen-isotope data that, in concert with other proxy records, allow us to quantify the timing of the YD onset and termination at an unprecedented subcentennial temporal precision across the North Atlantic, Asian Monsoon-Westerlies, and South American Monsoon regions. Our analysis suggests that the onsets of YD in the North Atlantic (12,870 ± 30 B.P.) and the Asian Monsoon- Westerlies region are essentially synchronous within a few decades and lead the onset in Antarctica, implying a north-to-south climate signal propagation via both atmospheric (decadal-time scale) and oceanic (centennial-time scale) processes, similar to the Dansgaard- Oeschger events during the last glacial period. In contrast, the YD termination may have started first in Antarctica at ~11,900 B.P., or perhaps even earlier in the western tropical Pacific, followed by the North Atlantic between ~11,700 ± 40 and 11,610 ± 40 B.P. These observations suggest that the initial YD termination might have originated in the Southern Hemisphere and/or the tropical Pacific, indicating a Southern Hemisphere/tropics to North Atlantic-Asian Monsoon-Westerlies directionality of climatic recovery., This work was supported by grants from National Nature Science Foundation of China (NSFC 41888101 and 41731174 to H.C.) and US NSF Grant (1702816 to R.L.E. and H.C.)

Mountain glaciers have generally experienced an accelerated retreat over the last three decades as a rapid response to current global warming. However, the response to previous warm periods in the Holocene is not well-described for glaciers of the of southern Europe mountain ranges, such as the Pyrenees. The situation during the Medieval Climate Anomaly (900–1300 CE) is particularly relevant since it is not certain whether the glaciers just experienced significant ice loss or whether they actually disappeared. We present here the first chronological study of a glacier located in the Central Pyrenees (N Spain), the Monte Perdido Glacier (MPG), carried out by different radiochronological techniques and their comparison with geochemical proxies with neighboring paleoclimate records. The result of the chronological model proves that the glacier endured during the Roman Period and the Medieval Climate Anomaly. The lack of ice from last 600 years indicates that the ice formed during the Little Ice Age has melted away. The analyses of the content of several metals of anthropogenic origin, such as Zn, Se, Cd, Hg, Pb, appear in low amounts in MPG ice, which further supports our age model in which the record from the industrial period is lost. This study confirms the exceptional warming of the last decades in the context of last two millennia. We demonstrate that we are facing an unprecedented retreat of the Pyrenean glaciers which survival is compromised beyond a few decades.

New speleothem records from northeastern Iberian caves provide data to explore the climatic patterns during the Holocene. We present δ13C and Mg/Ca from three speleothems from two different caves located in the Iberian Range allowing replication of the climatic signal for several millennia. Through the integration of those stalagmites covering since the Holocene onset to 2 ka, the early Holocene (11.7–8.5 ka) appears as the wettest interval. A marked change towards aridity is observed during the middle Holocene (8.5–4.8 ka) and an increase of humidity afterwards (4.8–2 ka). This three-part pattern, contrasting with other Iberian sequences, seems to be associated with the different role that seasonality has played in the response of different proxies (or records) to changes in water availability. Interpreting our speleothem records as changes in winter-spring precipitation along the Holocene allows reconciling previous data on hydrological variability from the western Mediterranean borderlands.

In glaciated areas, the environmental evolution before MIS 2 is usually poorly constrained mainly due to the later glacial erosion during the global Last Glacial Maximum (LGM). However, in carbonate areas, karst caves can preserve records of pre-LGM paleoenvironment. We studied a cave (1350 m altitude) to establish the paleoenvironmental evolution of a glaciated karst area in Picos de Europa (SW Europe). For this objective, a glacial reconstruction, cave sedimentology analyses, and macro- and micromammal remains are com bined with ten U-Th, OSL and AMS C-14 ages. The paleo-glacial reconstruction indicates glaciers descended down to 810-1040 m of altitude covering an area of 36.18 km(2) in the surroundings of Covadonga Lakes during the glacial local maximum, with the equilibrium line altitude located at 1524 +/- 36 m. The geomorphological study of the cave and the U-Th and OSL dates reveal the presence of three allochthonous alluvial sediment sequences at 132-135, 98-60 and ca. 36 ka. These last two sequences would come from the erosion of fluvioglacial sediments including teeth fragments of Pliomys coronensis (=P. lenki), an unusual species in high areas of NW Spain during the Upper Pleistocene. In addition, remains of chamois (Rupicapra pyrenaica) dated in 37-33 cal ka BP constitutes the oldest evidence of chamois above 800 m asl in the region. All the presented data indicate the development of alpine glacier-free areas covered by fluvioglacial sediments at ca. 1450 m altitude at 98-60 and 37-33 ka, corresponding to glacial retreat stages. (C) 2020 Elsevier Ltd. All rights reserved., GRUPIN6IDI/2018/000184 project (FICIY, Gobierno del Principado de Asturias, Spain, and European Union) and FUO-300-17 project (Consorcio Interauton~omico del Parque Nacional de los Picos de Europa, Spain). In addition, LRR is grant holder (Reference ACA-17-19) of the post-doctoral Clarin-COFUND Program, financed jointly by the 7th WP of the European UnioneMarie Curie Actions and Gobierno del Principado de Asturias (Spain). We thank to the grateful assistance of the National Park staff and the speleologists from Grupo Espeleol~ogico Polifemo (Oviedo), GES Monta~neiros Celtas (Vigo), Grupo de Espeleologia Dia~nu Burl~on (Corvera de Asturias), and Esp~eleo Club Aradelas (Vigo). We appreciate the work of Jo de Waele, Rafael L~opez-Martinez and other reviewer.

Western Europe is the region with the highest density of published speleothem δ18O (δ18Ospel) records worldwide. Here, we review these records in light of the recent publication of the Speleothem Isotopes Synthesis and AnaLysis (SISAL) database. We investigate how representative the spatial and temporal distribution of the available records is for climate in Western Europe and review potential sites and strategies for future studies. We show that spatial trends in precipitation δ18O are mirrored in the speleothems, providing means to better constrain the factors influencing δ18Ospel at a specific location. Coherent regional δ18Ospel trends are found over stadial-interstadial transitions of the last glacial, especially in high altitude Alpine records, where this has been attributed to a strong temperature control of δ18Ospel. During the Holocene, regional trends are less clearly expressed, due to lower signal-to-noise ratios in δ18Ospel, but can potentially be extracted with the use of statistical methods. This first assessment highlights the potential of the European region for speleothem palaeoclimate reconstruction, while underpinning the importance of knowing local factors for a correct interpretation of δ18Ospel., F.A.L. acknowledges funding by the Swiss National Science Foundation (SNSF) grant P2EZP2_172213. S.A.-M. and L.C.-B. acknowledge funding from the Geological Survey Ireland (Short Call 2017; grant number 2017-SC-056) and from the ERC-funded project GC2.0 (Global Change 2.0: Unlocking the past for a clearer future, grant number 694481). C.P.-M. acknowledges funding by the Government of Aragón predoctoral research grant B158/13 and CGL2016-77479-R (SPYRIT) project. K.R. acknowledges financial support by the German Research Foundation (DFG) grant RE3994-1/1.

Speleothem records from NE Asia are essential to understand the spatial patterns of the Asian Summer Monsoon (ASM) variability. In this paper, we present a new high-resolution and chronologically well-resolved speleothem record from Liu-li (LL) cave, NE China, through δ18O, δ13C and Sr/Ca ratio characterizing a dynamic ASM history over the past 6680 years. The LL δ18O record shows a long-term trend to higher values, following the North Hemisphere summer insolation (NHSI), with the exception of the last 2 kyr characterized by a negative δ18O excursion. The ‘2-kyr shift’ is evident in NE Asia over the past 2 kyr, originally inferred from the speleothem δ18O negative excursion in South China, as well as in many other proxy records from East China, but it merely manifests a flat trend in most of the western East Asian Summer Monsoon (EASM) and Indian Summer Monsoon (ISM) regions, rather than a negative excursion. On multi-centennial to millennial timescales, the intensification of the Tsushima Warm Current (TWC) can amplify rainfall on both sides of the Japan Sea. A close comparison between the monsoon reconstruction and the cultural changes in NE Asia suggests contemporary climatic and cultural regime-shifts, implying an important role of the ASM weakening in the collapse of Neolithic and Early Bronze cultures in this region.

The oxygen isotope composition of speleothems is a widely used proxy for past climate change. Robust use of this proxy depends on understanding the relationship between precipitation and cave drip water δ18O. Here, we present the first global analysis, based on data from 163 drip sites, from 39 caves on five continents, showing that drip water δ18O is most similar to the amount-weighted precipitation δ18O where mean annual temperature (MAT) is 10 °C and, δ18O of speleothems are a widely used paleoclimate proxy. Here, the authors conduct a global analysis of cave drip water δ18O compositions and find that drip waters from warmer climates have a seasonal bias toward precipitation δ18O of recharge periods, unlike in cooler climates where drip waters match well with recharge-weighted δ18O.

The climate during the last glacial cycle was characterized by abrupt millennial-scale changes superimposed on long-term orbital control. This study examines this climate variability for northeast Iberia for the time interval 118.9 to 36.9 kyr using a multi-proxy approach (δ18O, δ13C and Mg/Ca) applied to a stalagmite that covers this period continuously. During Marine Isotope Stage (MIS) 5 and 4, δ18O is controlled by orbital pacing, whereby more humid conditions prevailed during minima in boreal summer precession. In contrast, during MIS 3 δ18O lags precession and co-varies with δ13C (ρ = 0.53, p-value

La economía es uno de los factores explicativos más importantes para entender nuestro mundo actual. Asimismo está íntimamente relacionado con la sociedad y la política, y deja una impronta visible sobre el territorio organizándolo según sus lógicas. Las actividades económicas de mayor entidad se concentran en los distritos financieros tomando unas características propias que permiten clasificarlos fundamentalmente en dos modelos: norteamericano y europeo. En estos distritos se toman decisiones que pueden tener efectos sobre la economía de lugares muy lejanos, y en muchas ocasiones, este efecto puede ser devastador. Esto propicia que sean un tema controvertido, tanto por los que piensan que sustentan el sistema capitalista y son el máximo exponente del mismo, como por los que están en contra precisamente por el modelo que representan. Economy is one of the most important facts to understand our world. Also it’s connected with society and politics, and makes a deep footprint in territory with a self-logical order. Financial districts get together the financial activities with an own properties that classify it in two different models: American and European. In this district is being producing important decisions on the economy of so far places, and so much time these effects can be devastating. This is a controversial topic; somebody thinks that financial districts holds capitalism and is the most important exponent of it, and the other is against the model that it represents. Grupo Interdisciplinario de Estudios Críticos y de América Latina (GIECRYAL)