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(left) Map of the Eastern Mediterranean Sea. Red square indicates the study area. (right) Bathymetric map with the location of the three studied cores MP50‐MP39‐MP37PC at 775‐, 1,359‐, and 1,908‐m water depths, respectively. Information contained here has been derived from data that are made available under the European Marine Observation Data Network Seabed Habitats project (http://www.emodnet‐seabedhabitats.eu/), funded by the European Commission's Directorate‐General for Maritime Affairs and Fisheries. Black, red, and blue lines and arrows depict surface, (Levantine) intermediate, and deep water circulation pattern, respectively.
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Eastern Mediterranean thermohaline circulation is directly influenced by middle‐ and low‐latitude climate systems. The dramatic paleoclimate changes during the last African Humid Period (~10–6 ka BP) were captured in Mediterranean sediments as the distinctly organic‐rich unit sapropel S1. Here, deepwater formation variability during S1 deposition i...
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A multiproxy study of the sediment cores taken from the Snorri Drift, formed under the influence of the Iceland–Scotland bottom contour current, and from the Gloria Drift, located southward Greenland at the boundary of Irminger and Labrador Seas, was performed. This area undergoes a variable mixing of polar waters with the warm North Atlantic curre...
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... The total organic carbon (TOC) contents in three selected cores (C1, C4, C8) are correlated to the relative variations of the regional sea level (Paskoff and Sanlaville 1983) linked to the last postglacial phase (Fig. 5). TOC peak occurs simultaneously with the high sea level peak, validating an extension of organic-rich facies to the whole Mediterranean Sea, from eastern deep-sea domains to western littoral areas (Filippidi and De Lange 2019;Hennekam et al. 2014;Zirks et al. 2019). ...
... Therefore, we can consider the F3 facies, overcoming the euxinic layer (Fig. 4a, b) and containing high magnesium minerals, as biotic proxies that can indicate density stratification in the water column. This creates anoxic conditions on the bottom, such as in the Black Sea, the Mediterranean Sea, and the Nile Delta (Olausson 1991;Stanford et al. 2011;Filippidi and De Lange 2019;Zirks et al. 2019;Hennekam et al. 2014). The sapropel S1 of the Eastern Mediterranean was deposited at great depth (700-1700 m). ...
... The sapropel S1 of the Eastern Mediterranean was deposited at great depth (700-1700 m). It started near about 9000 years BP (Sapropel S1a) and finished around 7000 years BP (only the Sapropel S1b) (Filippidi and De Lange 2019;Rohling et al. 1997). On the west Mediterranean coast, the last similar phase corresponding to the top of the sapropel S1 was formed and is linked to the Holocene marine transgression and should be homologated to the sapropel S1 (Achikawa et al. 2015). ...
On the southeast Tunisian coast, organic-rich facies were formed at the middle Holocene in a confined Boujmel lagoon bottom (currently Sebkha Boujmel) during the last deglaciation. Sedimentological and organic geochemistry are used to analyze samples from respectively eight and three cores. The total organic carbon (TOC) and humic compounds analysis highlighted the setting of anoxia around 6800 years before present (BP) and its breakdown at about 4000 years BP. Biotic and abiotic anoxic proxies constitute waterproofing of a high degree of confinement occurring under water column stratification. The well-preserved organic-rich material of mixed origin (continental and marine) constitutes a biotic proxy and the abiotic ones are made of polyhalite and magnesian minerals that layer just above the euxinic facies close-fitting water column stratification. The TOC peak registered in the euxinic facies of the Sebkha Boujmel correlates with the highest Holocene sea level change during the transgression of the Mediterranean Sea. Such correlation and the time of the anoxic phase launch the relationship between the Mediterranean sapropel S1 and the euxinic facies of Sabkha Boujmel. It seems that anoxia began early around 9000 years BP in the deepest areas of the Mediterranean Sea and progressively reached its edges around 6000–7000 years BP, recording a diachronism in the installation of the organic-rich facies, which agrees with the marine intrusion highlighted in the Sebkha Boujmel.
... The distributions Mn/Al and Mo/Al ratios (Fig. 4C) were typical of redox-sensitive elements. They exhibit well-defined peaks above the sapropel (~15-17 cm) indicating the oxidation front of the sapropel, consistent with patterns reported for the Sapropel S1 in a nearby station of the same basin (Filippidi and De Lange, 2019). ...
... In the sediment core EA, sapropel S1 is characterized by high C org concentrations (Fig. 4A) which result from OM preservation owing to oxygen-depleted conditions in the bottom waters and high primary production in surface water of the Ionian sea (e.g., Filippidi and De Lange, 2019;Murat and Got, 2000). The high primary production behind the formation of S1 is thought to be due to an increased discharge of freshwater into the Mediterranean following a change to a warmer and wetter climate during the African Humid Period (Ariztegui et al., 2000). ...
... Below the 1.5 cm, (i.e., before the Industrial Era), the obtained linear SRs were 2.2 ± 1.0 cm ka − 1 , in agreement with previously published SRs in that area (e. g., Rutten et al., 2000;De Lange et al., 2008). At the bottom of the core, linear SR increased in the Sapropel S1, up to ~4.3 cm ka − 1 consistently with reported values for the eastern Mediterranean Sea (De Lange et al., 2008;Filippidi and De Lange, 2019). ...
... The upper Mn/Al peak (start at ~6.1. ka BP; Fig. 3d) is thought to mark the time of re-introduction of oxygenated bottom waters at the end of S1, as a response to the resumption of DW formation (Filippidi and de Lange et al., 2019). The BWO index is thought to largely withstand post-depositional diagenesis (Jorissen et al., 2007). ...
The eastern Mediterranean Sea (EMS) sedimentary record is periodically interspersed with organic-rich ‘sapropel’ layers. Sapropels are characteristic of basin-wide anoxic events, triggered by precession-forced insolation maxima. Relatively subdued insolation maxima, however, are not always expressed as distinct sapropel events. The EMS sedimentary record is thus useful to investigate feedbacks between marine anoxia and the nitrogen (N)
cycle and offers an analogue for modern deoxygenation and past oceanic anoxic events. To this end, we investigated a ~68 kyr sedimentary record from the EMS containing the well-established sapropel S1 (deposited in two phases: S1a [~10.5–8.5 ka BP] and S1b [~7.8–6.1 ka BP]) and sediments timed to the ambiguous S2
sapropel (~53 ka BP). We used lipid biomarkers of microorganisms to reconstruct key N-cycle components: (1) anaerobic ammonium oxidation (anammox) using ladderanes and a stereoisomer of bacteriohopanetetrol (BHTx), (2) dinitrogen gas (N2) fixation using heterocyte glycolipids, and (3) nitrification by Thaumarchaeota using
crenarchaeol. Additionally, benthic foraminifera and trace metals (U, Mo, Mn) were used to reconstruct redox conditions. During S1a, abundances of Thaumarchaeota increased, likely promoted by elevated high-nutrient freshwater discharge. At this time, a combination of phosphorus supply and intensified loss of bioavailable N via water column anammox, may have reinforced anoxia by favoring diatom-diazotroph associations. During
S1b, anammox is equally intense. Yet, no positive feedback on N2-fixation is observed, likely because diazotrophs were phosphorus limited. Instead, anammox may have provided negative feedback on anoxia by quenching primary production. Ladderanes suggest additional episodes of anammox between ~69 to 39 cal ka BP, corresponding to brief periods of water column deoxygenation. Anoxia likely occurred at the sediment–water interface
in S2-timed sediments (53–51 cal ka BP). During these episodes, ladderanes co-occur with the later eluting BHT-34R stereoisomer. δ13CBHT-34R indicate an anammox source, potentially synthesized by marine sedimentary anammox bacteria. No corresponding increase in diatom-diazotroph associations is observed, likely due to the oligotrophic conditions and the limited effect of sedimentary anammox on N-availability in the euphotic zone. Our results highlight various modes of operation of the N-cycle at different degrees of deoxygenation, which depend amongst others on nutrient-availability and the niche-segregation of N-loss and N2-fixating
microorganisms.
... Cardiff University Ray Zammit silica standards. The following ratios were calculated to act as palaeoproxies: Ti/Al and Zr/Al for aeolian flux (Krom et al., 1999;Govin et al., 2012;Hennekam et al., 2015;Martín-Puertas et al., 2010;Martinez-Ruiz et al., 2015) , Sr/Ca for sea-level controlled export of shelf carbonate material (Bialik et al., 2020), K/Al for chemical weathering (Clift et al., 2014), and Si/Ti for biogenic silica production (Brown et al., 2007;Kylander et al., 2011 (Passier & de Lange, 1998;Wei et al., 2009;Filippidi & Lange, 2019). All X-ray fluorescence data are semi-quantitative. ...
The Miocene represents a key interval in the transition to our modern bipolar icehouse world. The early Miocene climate (23.0 Ma to 19.2 Ma) was typified by a cool-arid climate with large swings in global benthic δ18O records. This climate regime changed to a gradually warming trend (19.2 Ma to 17.0 Ma) until it was replaced by the relative warmth of the Miocene Climatic Optimum from 17.0 Ma to 14.7 Ma. Climate subsequently cooled in a step-wise manner, with a major expansion of the Antarctic ice sheet occurring at 13.8 Ma. In addition to these climatic shifts, a major change in oceanic circulation also occurred during the Miocene. This was due to the restriction of water flow through the Mesopotamian Seaway that connected the Mediterranean with the Indian Ocean. This flow restriction occurred in two steps, one during the early Miocene (19.0 to 20.2 Ma) and the second and complete disconnection between 13.8 Ma and 13.6 Ma. The Miocene deposits of Malta are temporally and spatially ideally situated to investigate local and global paleoenvironmental changes during the Miocene.
Lithological and geochemical changes from the Early Miocene il-Blata section outcropping in Malta indicate a regional shift from a cold arid climate to a warm humid climate following the first Miocene restriction of the Mesopotamian Seaway. A marked shift in sedimentation rate at ~19.1 Ma coincident with a change to organic-rich clays and changes in bulk CaCO3, Sr/Ca, K/Al, Ti/Al, Zr/Al and Si/Ti support this interpretation. The closure of the Mesopotamian Seaway and consequent diversion of warm intermediate waters into the Atlantic Ocean is a plausible mechanism for the intensification of the hydrological cycle over North Africa. This transition to a humid regime and associated influence of terrigenous sediment delivery likely helped in the termination of the extensive Early Miocene phosphorites of Malta.
Planktic and benthic foraminiferal geochemical records from the Ras il-Pellegrin section (Malta) indicate changes in regional hydroclimate following the Middle Miocene expansion of the Antarctic ice sheet at 13.82 Ma. Foraminiferal Mg/Ca was used to generate temperature records, which enabled the generation of surface and bottom seawater δ18O, and in turn an estimate of sea surface salinity variability. These records show that a significant input of freshwater occurred following the Middle Miocene expansion of the Antarctic icesheet and the closure of the Mesopotamian Seaway. The input of freshwater is precession and obliquity driven and indicates that a strong seasonal, monsoonal type climate was emplaced over North Africa.
A new planktic foraminiferal B/Ca record was used with previously published δ13C records from the composite Marsalforn (Gozo Island) and Ras il-Pellegrin sections to investigate carbon cycle dynamics in the Central Mediterranean from 14.4 Ma to 12.8 Ma. The vertical seawater δ13C gradient coupled with B/Ca, Mn/Ca, and calculated [B(OH)]4^-]/[DIC], indicates a highly active biological pump following the Antarctic ice sheet expansion at 13.82 Ma and coinciding with the global CM-6 δ13C excursion. These records also cast doubt on the interpretation of the pCO2 records from Malta published in Badger et al. (2013), and suggests that low latitude shallow water zones are particularly important in carbon cycle dynamics as zones of enhanced carbon burial.
Overall, this thesis highlights the importance of the tectonic closure of the Mesopotamian Seaway on regional climate, with possible effects on global climate and cryospheric feedbacks. It confirms the Maltese Islands as a natural laboratory for investigating the Miocene climate. This thesis also underlines the importance of considering the Miocene as a geological time suitable for investigating global environments and climate feedbacks at near-future pCO2 levels.
https://orca.cardiff.ac.uk/id/eprint/160007/
... Variations in these taxa and the overall Impagidinium species point to a warming trend that was broken by a pre-Holocene cool period about 11 ka BP. Early Holocene pollen evidence of a relatively high Nile flow and the organic-rich S1 sapropel are consistent with the AHP (Filippidi & De Lange, 2019). The episode that dated around 9.5-6.27 ...
The Quaternary sediments in Egypt record the interplay of several factors, the most important of which are marine, fluvial, terrestrial and climatic factors. According to the strength of each factor, the Egyptian territories are subdivided into several basins reflecting the potential depositional environments. The present review promotes the Quaternary sediments of the Nile Delta, the North Western coast, the Western Desert and the Red Sea and Gulf of Aqaba coasts as proxies for Quaternary paleoclimate. The Quaternary Nile Delta sediments clearly reflect the African monsoons and the associated Nile floods correlated with the Eastern Mediterranean and global marine isotope stratigraphy. The fossil records of both planktonic and benthonic foraminifera (Pl/Be) and their δ18O represent potential references to Marine Isotope Stages (MIS) and sea level changes. Pollen and spores, δ13C, C3 and C4 plants record paleovegetation cover, and thus paleoenvironments and paleoclimate. It has been globally agreed that the primary control of climate changes and the region’s hydrological cycle are the insolation-driven changes in the strength and shifting of the Intertropical Convergence Zone (ITCZ), and therefore the intensity and northward extent of the African Humid Period (AHP), non-excluding the Atlantic westerlies (NAO). Such conditions induced intervals of heavy rainfall in Egypt as well as the Nile Headwaters. In Egyptian Sahara, such heavy rains charged the groundwater and dissolved the Paleocene–Eocene carbonate leaving deposits of lacustrine and freshwater carbonate and other karstic landforms. These terrestrial deposits supported with the calibrated age dating are used as proxies for paleoclimate along the Sahara. At the Red Sea coast, the growth of coral reefs and deposition of thick fluvial gravels are used as proxies for climate and sea level changes, while the aeolianites and paleosols are the available proxies at the NW Mediterranean coast of Egypt. On the other hand, the increase in outflow of the River Nile led to stagnation of freshwater over the marine water and formation of sapropel layers in Eastern Mediterranean. The oxygen isotopes and age determination of the above-mentioned materials allow correlation with global climate conditions; however, such correlation is not always isochronic. The offsets are explained by the presence of regional driving forces overriding the global influences.KeywordsQuaternary geologyNile Delta sedimentsNW calcarenite ridgesRed sea coastEgyptian SaharaIsotope stratigraphyPaleoclimate
... The following ratios were calculated to act as paleoproxies: Ti/Al and Zr/Al for aeolian flux (Krom et al., 1999;Govin et al., 2012;Hennekam et al., 2015;Martín-Puertas et al., 2010;Martinez-Ruiz et al., 2015) , Sr/Ca for sea-level controlled export of shelf carbonate material (Bialik et al., 2020), K/Al for chemical weathering (Clift et al., 2014), and Si/Ti for biogenic silica production (Brown et al., 2007;Kylander et al., 2011). The bulk [Ca] was used to indicate the marine carbonate component while the bulk [S] indicates redox conditions (Passier & de Lange, 1998;Wei et al., 2009;Filippidi & Lange, 2019). All X-ray fluorescence data are semiquantitative. ...
During the Miocene (23.0–5.3 Ma) North Africa experienced both humid and arid intervals, but the underlying cause of these transitions is unknown. Earth's climate was characterized by a unipolar icehouse with a dynamic Antarctic ice sheet, which may have influenced regional hydrology through atmospheric teleconnections. However, the Miocene also witnessed the restriction of the Mesopotamian Seaway, which may have had significant climatic impacts. The Maltese il‐Blata section (Central Mediterranean) comprises Late Oligocene to Early Miocene marine deposits previously used to constrain the timing of the Mesopotamian Seaway restriction using the εNd tracer. The location of this section also makes it sensitive to climatic changes in the North African region, and biogeochemical changes in the central Mediterranean. Here, we present lithological and geochemical records of the il‐Blata section. We find a marked shift in lithology and an increase in sedimentation rate coeval with the Early Miocene (∼19–20 Ma) restriction of the Mesopotamian Seaway. Concomitant changes in bulk sediment CaCO3, Sr/Ca, K/Al, Ti/Al, Zr/Al, and Si/Ti support a major humid climate transition and associated intensification of river systems over western North Africa. We propose that these changes in North African hydroclimate reflect either a tipping point effect in a gradually warming global climate, or are the result of the initial restriction of the Mesopotamian Seaway, perhaps through consequent changes in Atlantic Meridional Overturning Circulation and the West African Monsoon. We also suggest the restriction of the Mesopotamian Seaway inhibited phosphorite deposition at low latitudes.
... The Sapropel S1 time interval is punctuated by three re-ventilation events at 9.2, 8.2 and 7.2 ka (Incarbona and Sprovieri, 2020) connected with African monsoon weakening and intermittent intermediate and deep water formation (Abu-Zied et al., 2008;Casford et al., 2003;Filippidi et al., 2016;Filippidi and De Lange, 2019;Incarbona et al., 2019a;Incarbona and Di Stefano, 2019;Le Houedec et al., 2020;Zirks et al., 2019). In the benthic record, these events correspond to slight increases in BFAR and, in particular, of the oxyphillic U. mediterranea which in the eastern Mediterranean was related to deep water reoxygenation during the S1 (Casford et al., 2003) (Fig. 9). ...
Here we present a high-resolution record of benthic foraminiferal assemblages for the last 74 kyr from the Sicily Channel Ocean Drilling Program Leg 160 Site 963. Benthic foraminiferal results are compared with geochemical (benthic and planktic δ¹⁸O and δ¹³C) and calcareous plankton data, previously acquired on the same marine core sediments. Within the succession, three benthic foraminifera compositional zones were defined. Temporal changes in the assemblages are interpreted in the context of the modification of subtropical and temperate climate systems that affected the Mediterranean thermohaline circulation.
A close connection between bottom conditions in the Sicily Channel and eastern Mediterranean Sea is evidenced by two intervals, characterized in the ODP Site 963 by reduced oxygen conditions. The first one, around 53–51 ka, is tentatively attributed to the ‘missing’ sapropel S2 while the second, between 35 and 29 ka, is marked by short and recurrent episodes of bottom-water oxygen decrease. Both are related to a weakening of the intermediate circulation in the Sicily Channel connected with relatively high northern hemisphere summer insolation and increase in Nile River discharge, which inhibited vertical mixing and intermediate water ventilation in Eastern Mediterranean Sea.
Over the last deglaciation, the African humid period (AHP) and the sea level rise, also influenced the water mass structure in the Sicily Channel and a reduction of the bottom ventilation is suggested by a strong reduction of deep-water Miliolids. Decreased bottom oxygen levels, which testifies for a weakening of intermediate circulation in Sicily Strait, also characterized the interval corresponding to S1 deposition. Yet, the strong decrease of benthic foraminiferal abundance related to a low surface water trophic level, appears to be conditioned by the reduction of trophic levels in the western Mediterranean. The very high relative abundance of U. mediterranea recorded during this interval is explained by the availability of organic matter during a limited short year period and/or the availability of more degraded organic matter from river runoff. In general, compositional data analysis highlighted a quite complex response of benthic foraminifera to paleoclimatic changes. However, changes in the benthic foraminiferal assemblages recorded during the last glacial are coherent with surface paleoproductivity dynamics connected with D-O oscillation, and support oligotrophic, meso-eutrophic and oligo-mesotrophic conditions during the early interstadials, late interstadials and stadials, respectively.
... This could also explain why the ORL1 demise shows a slightly diachronic pattern that could reflect differences in the SRs and depths, among other factors. A similar pattern has been described for sapropel S1 demise over the Holocene in the eastern Mediterranean Sea (Filippidi and De Lange, 2019). ...
We present a high-resolution analysis of seven marine sediment records from the western Mediterranean in a transect from the Algero-Balearic basin to the Alboran Sea, spanning the last 20 ka, to decipher the paleoenvironmental and paleoceanographic evolution of the Western Mediterranean Sea. To do so, diverse elemental ratios have been used for reconstructing sediment input variations and paleo-oxygen conditions. In particular, the Ti/Ca ratio has been used to reconstruct variations in the terrigenous and carbonate fractions. However, the specific sedimentary processes controlling this ratio are still poorly understood thus, we also provide new insights for appropriate interpretations, in the studied zone. Our results suggest that the Ti/Ca ratio at the suborbital scale is mostly controlled by bottom current intensity, and less influenced by marine productivity, sea level variations, and the fluvial and eolian inputs. Comparison of diverse records within the western Mediterranean reveals that the Ti/Ca ratio depicted a similar trend in both regions, except during the Heinrich Stadial 1 (HS1) and the Middle Holocene. The HS1 is recorded as a single-phase event in the Algero-Balearic basin, whereas three phases are recognized in the Alboran Sea basin, with a relative minimum in the Ti/Ca ratio. Conversely, during the Middle Holocene, an increase in the Ti/Ca ratio is recorded in the Alboran Sea and the Atlantic Iberian margin, but not in the Algero-Balearic basin, which could be related to the establishment of the Alboran gyres. Redox sensitive proxies, in particular the Mo/Al, U/Al and Mn/Al ratios, point to different phases within the Organic Rich Layer 1 (ORL1): the ORL1a (15-11.7 ka cal BP), characterized by more reducing conditions in the Alboran Sea sediments, and the ORL1b (11.7- ~9 ka cal BP) characterized by suboxic-ferruginous conditions. The sea level transgression, the enhanced fluvial input and the shelf flooding played a key role during the ORL1 onset and demise, increasing the sedimentation rate in the basin and preventing the organic matter oxidation. During the last 2 ka cal BP, an unprecedented common response is recognized in all the studied regions, showing an overall increase in the Ti/Ca ratio, which may be related to intensified human activity in the Mediterranean area, promoting a greater terrigenous input.
... This finding may suggest a weakening or temporary interruption of stratification, consistent with the increased abundance of plankton foraminifera G. glutinata and G. siphonifera that represent winter conditions of relatively mixed water masses (Checa et al., 2020). Our conclusion partially confirms the data of Filippidi and De Lange (2019), that studying three sites at the same area, reported anoxic conditions only during the first part of S1 (S1a) at intermediate depth (775 m), whereas deeper sites (1359 and 1908 m) were anoxic (sulfidic) throughout the S1 interval. This scenario can be reconciled with episodic dense-water formation in the northern basins but constrained to shallower depths (< 2000 m deep), where anoxia only developed in 'blankets' draped over the sea floor (Grimm et al., 2015). ...
A high resolution study of calcareous nannofossils has been performed on samples from the Sapropel S1interval deposited in the North Ionian Sea, with the aim to assess the paleoenvironmental changes in the photic zone during this crucial interval in Mediterranean circulation. Calcareous nannofossil data have been integrated with planktonic foraminiferal data recently published from which the paleoclimatic curve has been constructed.
Placoliths (namely Emiliania huxleyi) and Florisphaera profunda distributions, along with that of planktonic foraminifer Globigerinoides ruber white, evidence that, after a progressive weakening of surface water mixing, a deep chlorophyll maximum developed just prior to the sapropel deposition. We suggest that these changes took place as a response to enhanced precipitation conditions and riverine discharge as testified by increasing trend of reworked coccoliths and the occurrence of lower salinity taxon Braarudosphaera bigelowii. Calcareous nannofossils also point out that the oceanographic (water column stratification, reduced bottom water ventilation) and biogeochemical (increased primary production) processes that occurred during the S1 formation were particularly dominant during the earliest part of the older S1 warm phase (S1a). Our results support than some re-ventilation events of the shallow depth of studied site (665 m) occurred to some extent, particularly during the final phases of S1a.
The distribution of holococcoliths, more abundant during the cold interruption phase S1i, seems confirm that the preservation of these tiny and delicate coccoliths, highly susceptible to dissolution, is enhanced under seafloor re-ventilation conditions.
Finally, we tentatively suggest that preservation also plays a significant role in the distribution of the warm upper photic zone taxa, particularly during the warm S1b interval.
... In fact, it is well-established that around 10-9 ka, during the Holocene maximum insolation, the rivers around Mediterranean Sea records a maximum flooding. This is well recorded in the eastern basin with the Nile River (Weldeab et al., 2014) as well as in the rivers of the northern Mediterranean borderlands (Magny et al., 2012;Filippidi and Lange, 2019;Wagner et al., 2019). Our data confirm than the Var river system also counts for the northern Mediterranean borderlands' river systems showing a flow peak during the Holocene insolation maximum. ...
The sedimentary archives of the Mediterranean Sea record periodic deposits of organic-rich deposits, called sapropels in the eastern basin and organic-rich layers (ORL) in the western basin. Changes in both the Mediterranean circulation and inputs of fresh water through borderlands rivers under more humid climate, are important mechanisms to explain those events. The last ORL and sapropel S1 have different timing, respectively from ~14.5 to 9 Ka and from ~10 to 6 Ka, presumably due to different forcing factors in the western basin (i.e., melting of Alps ices). Here we present a high-resolution study of a marine sediment core located off the mouth of the Var River, one of the most dynamic river system of the northern borderland of the western Mediterranean Sea. We applied a multi-proxy approach based on benthic foraminiferal assemblages, foraminiferal δ¹⁸O and δ¹³C, grain size analyses, organic carbon content and XRF elemental data to decipher the regional climate signals from the basin-scale intermediate circulation signature. Our results do not show large river inputs at the timing of the last ORL deposit. On the opposite, foraminiferal and geochemical evidence indicate that the 11–6 kyr period, concomitant to Sapropel S1 event in the Eastern Mediterranean, was characterised by high river activity and low ventilated bottom waters at the studied location. Additionally, our results characterized the last 6 ka with large scale episodes of more active bottom water ventilation due perhaps to enhanced wind activity under an overall cooler climate.
Time series analyses were computed from stable isotopes, Ca/Ti XRF ratio and foraminifera abundances. They show common frequencies peaks (2.2–3, 1.1–1.2, 0.9–1.0, and 0.4–0.5 kyr) most likely related to the solar activity. Also, a specific frequency band (1.5–1.6 kyr) was only recorded in benthic foraminiferal abundance and stable isotopic records. This was preferentially attributed to an oceanic-driven internal forcing.
