NW Sardinia Research Articles

Checklist of the marine malacofauna of Culuccia Peninsula (NW Sardinia, Italy), with notes on relevant species.

Culuccia is a small peninsula of about 3 km2 placed in north-western Sardinia (Italy) at the margin of the Maddalena Archipelago. The marine area surrounding this Peninsula is a Special Area of Conservation, included in the European Natura 2000 Ecological Network of protected areas, but until now, no information on biodiversity of this area is available. In 2021, a research project to study both terrestrial and marine biodiversity of Culuccia has started in order to fill this gap of knowledge. This work provides the first inventory of the marine malacofauna of the coast of Culuccia. Fifteen sites were sampled seasonally for one-year by using different sampling methods and the present study shows the results from approximately 50 scientific SCUBA and free dive surveys, carried out in all main marine habitats of the studied area. In total, 259 species of molluscs were recorded along the coasts of the Culuccia Peninsula (0-25 m depth), belonging to the classes Bivalvia, Gastropoda, Polyplacophora and Scaphopoda. Amongst the four classes recorded, gastropods were the most represented (66.90%; 173 species), followed by bivalves (28.10%; 73 species), polyplacophorans (4.60%; 12 species) and scapophods (0.40%; 1 species). Notes about distribution, conservation status and ecology for some valuable species are provided, together with images of representative species, consisting mainly of in situ photographs. Additionally, the present investigation recorded the presence of four alien species, whose Mediterranean distribution was extended to north-western Sardinia.

Bone histology of the Late Pleistocene Prolagus sardus (Lagomorpha: Mammalia) provides further insights into life-history strategy of insular giant small mammals

Abstract Fossils provide an excellent opportunity to study and understand the evolution of insular environments free of human-made perturbations. Here, we evaluated the life-history traits and strategy of the extinct insular giant Prolagus sardus (Mammalia: Lagomorpha) by examining microscopically its fossilized bone tissues (osteohistology, skeletochronology, and quantitative geometry). For this task, a complete ontogenetic series of femora retrieved from the Late Pleistocene Grotta della Medusa (NW Sardinia, Italy) were analysed. Our results reveal that: (i) P. sardus’ pups were weaned at large size; (ii) the species’ maturation was delayed in its life cycle; and (iii) P. sardus lived longer than expected for its size. Hence, the giant P. sardus should have a slow pace of life triggered by the low levels of extrinsic mortality of the insular habitat. On the other hand, bone tissue differences between P. sardus and Ochotona were found in the vascularization, slow- growing bone presence, and cortical and medullary growth trajectories. The results obtained in this study concur with the eco-evolutionary responses described to date in extinct insular lagomorphs, as well as provide new empirical evidence about the phenomenon known as ‘insular gigantism’ as a pattern of evolution of small-sized mammals in genuine insular ecosystems.

A shallow-water dunefield in a microtidal, wind-dominated strait (Stintino, NW Sardinia, Italy)

Abstract This study focuses on the recent evolution of a shallow-water dunefield system off La Pelosa Beach, located in the wind-dominated, microtidal, asymmetrical Asinelli Strait (Stintino, NW Sardinia, Italy). The system comprises four zones defined by a gradual decrease in current strength from the strait centre to more distal parts that form different bedforms. The strait centre (Zone A) is a substrate-carved channel passing downcurrent to a vast sandy shoal characterized by a subaqueous dunefield (Zone B) that is surrounded by a sandwave–ripple carpet (Zone C). The strait margin (Zone D) is dominated by a sandy cusp, the so-called La Pelosa Beach system. The extensive seagrass meadow located on the SE side of the strait-end zone feeds the system with bioclastic-rich sands. This carbonate sedimentary load is ensured by natural seagrass meadow retreats that are possibly boosted by human impact. The sediment transport is modulated by the interaction between two opposite currents triggered by the east-incoming Greco/Levante and NW-incoming Mistral winds. These currents experience a great variability due to multi-annual fluctuations (4–6 years) of the prevailing wind activities. Such cyclicity is responsible for periodic dune migration and and transport from La Pelosa Beach out of the system below the active part of the submerged beach (depth of closure). Bedform formations (ripples, dunes and sandwaves) and migrations within the strait are the result of complex physical processes observed in modern environments but rarely described in rock formations. The presented conceptual model can be used to recognize sediment ‘spillover’ processes on other modern, microtidal, wind-dominated straits, as well as proposing the main criteria for recognizing this strait sedimentary succession in the geological record.

Effects of Field Simulated Marine Heatwaves on Sedimentary Organic Matter Quantity, Biochemical Composition, and Degradation Rates.

Simple SummaryMarine heatwaves (MHWs) are intensifying due to global warming. Based on their effects on biochemical reactions, they are also likely to affect coastal biogeochemistry. We investigated organic matter quantity, composition and degradation rates in nearshore sediments affected by simulated MHWs, with 1.5 and 5.0 °C anomalies, before and after 3 and 11 weeks from the release of an artificial warm water plume. MHWs enhanced organic loads (by >100%), with larger effects in the short-term under the highest temperature anomaly. Phytopigment contents increased (by 50–90%) in the short term but decreased to initial values in the longer one. The autotrophic and lipid contents decreased with time (by 15–50% 53–79%, respectively), suggesting a drop in the nutritional quality of organic matter, along with a slowdown of its turnover. We contend that MHWs’ intensification will affect not only species and communities but will also alter sediment biogeochemistry and, possibly, the energy transfer towards higher trophic levels.Since rising temperature (T) will enhance biochemical reactions and coastal marine sediments are hotspots of carbon cycling, marine heatwaves’ (MHWs’) intensification caused by climate change will affect coastal biogeochemistry. We investigated the effects of MHWs on sediment organic matter (OM) in a nearshore locality (NW Sardinia, Mediterranean Sea) receiving an artificial warm water plume generating T anomalies of 1.5–5.0 °C. Sediments were collected before and after 3 and 11 weeks from the initial plume release. Both MHWs influenced sedimentary OM quantity, composition, and degradation rates, with major effects associated with the highest T anomaly after 3 weeks. Both MHWs enhanced sedimentary OM contents, with larger effects associated with the highest T anomaly. Phytopigment contents increased in the short term but dropped to initial levels after 11 weeks, suggesting the occurrence of thermal adaptation or stress of microphytobenthos. In the longer term we observed a decrease in the nutritional quality of OM and a slowdown of its turnover mediated by extracellular enzymes, suggestive of a decreased ecosystem functioning. We anticipate that intensification of MHWs will affect benthic communities not only through direct effects on species tolerance but also by altering benthic biogeochemistry and the efficiency of energy transfer towards higher trophic levels.

Gradients of salinity and plant community richness and diversity in two different Mediterranean coastal ecosystems in NW Sardinia.

This study aimed to test if differences in soil salinity, plant richness and diversity were significantly affected by habitat, site and distance from the seashore at three sandy and three rocky coastal sites in north-western Sardinia.Each site has been divided into three belts placed at an equal distance of 50 m from the shoreline. We measured soil salinity using a probe and vascular plants richness and diversity using linear transects at all sites. Average soil salinity varied from 0.115 g/l to 0.180 g/l; it was higher in the rocky habitats than in the sandy ones. A total of 21 species were found per transect/site at the rocky sites and 30 species per transect/site at the sandy sites, with an average of Shannon and Weaver's Diversity Index of 1.8 per each belt at each site. These data confirm that, also in the Mediterranean islands, there are coastal gradients of soil salinity from the seashore to inland areas and that also vascular plant richness and diversity are influenced by the distance from the sea. Soil salinity was strongly affected by the type of habitat, being average at the rocky coasts and negligible at the sandy shores. The site effect was not significant for both soil salinity and plant richness and diversity.

Sant\u2019Imbenia (Alghero): further archaeometric evidence for an Iron Age market square

Lead isotope compositions were determined for 18 metal objects from the archaeological site of Sant’Imbenia, NW Sardinia, dating to the end of the ninth century BCE onwards. The provenance of some objects is unambiguously traced to SW Sardinia; other objects could derive either from central Sardinia or the Iberian coastal ranges. The variety of the provenances attests to a wide trade network that spanned the entire island of Sardinia and extended to the Iberian sites.

Weathering Products of a Dismantled Variscan Basement. Minero-Chemical Proxies to Insight on Cretaceous Palaeogeography and Late Neogene Palaeoclimate of Sardinia (Italy)

This study compares, for the first time, the mineralogy and geochemistry of two residual-clay deposits in NW Sardinia (Nurra district) that formed at different times in tropical and sub-tropical climates. Both deposits represent palaeosols with deep-weathered residual profiles and overlie Mesozoic carbonate rocks that were deposited on the south European palaeomargin. The older alterite is Cenomanian–Turonian in age and grades upward into a horizon of karstic bauxite, whereas the younger unit occurs within alluvial deposits of Late Neogene age. The Cretaceous palaeosol represents the precursor of the overlying bauxite and formed from unknown sedimentary parent rocks. In contrast, the Messinian weathering products formed by alluvium that was sourced from the Variscan metamorphic basement. Chemical Index of Alteration values, REE fractionation index values, and the results of R-mode factorial analysis suggest a common initial weathering path and a common precursor for the deposits. However, the latter stages of weathering of the Cretaceous palaeosols resulted in lateritic alteration and bauxite production, whereas weathering of the Late Neogene, palaeosols produced 2:1 clay minerals under less extreme conditions. Comparison of these residual products constrains the parental material and weathering trends and allows insight into the relationship between palaeoclimate and regional/local palaeogeography of southern Europe during Upper Cretaceous and during Messinian.

Tetrapod tracks from the Middle Triassic of NW Sardinia (Nurra region, Italy)

We report here on the first tetrapod tracks from the Triassic of the Nurra region (north-western Sardinia, Italy). The specimens were found on sandstone blocks used to build a fence limiting a seasonal camping, in the coastal area north of Capo Caccia promontory. Lithologic and petrographic features allowed an assignment of the track-bearing blocks to the middle-upper portion of the Anisian (Middle Triassic) Arenarie di Cala Viola (Buntsandstein). Footprints are attributed to the ichnotaxa Rhynchosauroides and Rotodactylus, two common ichnotaxa of late Early Triassic and Middle Triassic ichnofaunas of Europe and United States, commonly referred in the literature to neodiapsid and archosaur producers, respectively.

Assessing seawater intrusion in arid and semi-arid Mediterranean coastal aquifers using geochemical approaches

The Plio-Quaternary aquifer of Jerba Island (Tunisia), the Upper Miocene-Pliocene-Quaternary aquifer of Tripoli (Libya), the Plio-Quaternary aquifer of Nador plain (Algeria), the Bou Areg Plio-Quaternary aquifer (Morocco), the Miocene carbonate aquifer of Porto Torres (NW Sardinia, Italy) and the Pleistocene oolitic aquifer of the Baghoush area (Egypt), are essential contributor sources of drinking water and irrigation water for agricultural needs. They are increasingly being degraded by salinization processes, essentially allied with groundwater over-exploitation. In this study, a hydrogeochemical investigation, by interpretations of conservative dissolved ions was used to probe the main mechanisms controlling groundwater salinization and to characterize the associated hydrogeochemical processes occurring in Mediterranean coastal aquifers. Groundwaters of the different aquifers are of meteoric origin and they mostly flow toward the coast. Based on EC and ionic ratios, a hydro-chemical zonation of water types (ranging from Ca-HCO3, Na-HCO3, Ca-Mg-Cl-SO4, Ca-Cl to Na-Cl) from recharge areas toward the coast is revealed. This zonation is mainly controlled by migration and mixing of saline waters with regional groundwaters. The behaviour of the major ions, the adherence of the majority of ion/Cl ratios and molar ratios characterising salinity in function of [Cl−] indicate that besides mixture with seawater, groundwater chemistry of the six aquifers is also influenced by evaporation, weathering of silicates, cation exchange and anthropogenic pollutants. The study provides insights into the hydrodynamic and geochemical relationships between freshwater and seawater at different Mediterranean coastal aquifers and provides regional authorities with a basic tools for sustainable water management aiming to limit seawater intrusion.

New Estimation of the Post Little Ice Age Relative Sea Level Rise

The study area is located in NW Sardinia Island (Italy), Mediterranean Sea. Sardinia is considered stable since the late Pliocene with a negligible subsidence of about 0.01 mm/y. It is therefore normally used to reconstruct the Pleistocene and Holocene sea level curves. Our research focusses on the sea-facing city of Alghero that from 1353 to 1720 was under the Spanish government. During this time, the city was renovated and new buildings edified. Dimension stones were quarried all around Alghero both in the nearby inland and along the coast. Coastal quarries were considered the most suitable for both rock quality and the easiest way to transport the quarried material by boat. The quarried rocks are late Pleistocene dune and beach sandstones deposited from the 132 ka (Marine Isotopic Stage—MIS5) to about 65 ka (MIS4). Sandstones crop out from few cm to 3 m above the present sea level and underwent several consolidation processes related to loading and marine weathering. This latter favoured dissolution and circulation of calcium carbonate which cemented the rocks. It is reported that the Spanish were looking for these “marine” sandstones for their high geotechnical characteristics. Different rules were adopted through time for the size of the dimension stones and this has allowed us to establish a quarry exploitation chronology. For example, “40 × 60 × 20” cm was the size of the dimension stones used for the Alghero Cathedral dated at 1505–1593. Nowadays most of the coastal Spanish quarry floors are 30 centimetres below mean sea level (tidal range is 30 cm). Accordingly, we infer that relative sea level from 1830 AD (and of the Little Ice Age) rose in about 200 years to the present level at the rate of about 1.4 mm/y. Considering that relative sea level rise during the Medieval warm period was of 0.6 mm/y over a period of about 400 years, we may deduce that human influence was strong enough to lead to a relative sea-level rise faster and in shorter time.

Shallow geophysics of the Asinara Island Marine Reserve Area (NW Sardinia, Italy)

ABSTRACT We present a high-resolution swath bathymetric and backscatter map of the entire sector of the Marine Reserve Area (MRA) of the Asinara Island, along with a geological and sediment thickness map derived from the interpretation of a large set of high-resolution seismic profiles, and an airborne-derived hyperspectral image of the Asinara Island. Acquired data show that most of the eastern marine sector of the Asinara Island is characterized by quite gentle bathymetric gradients, whereas the western coastline appears to be very indented, with an articulated and rough morphology of the seafloor, which deepens sharply towards the open sea. The maps presented in this study at the 1:50.000 scale do not only provide the first, high-resolution bathymetry of the MRA of the Asinara Island but also may furnish the base for the creation of a benthic habitat map and a more comprehensive maritime spatial planning of this protected area.

A new elephant fossil from the late Pleistocene of Alghero: The puzzling question of Sardinian dwarf elephants

Endemic elephants, variously reduced in size, have been reported from a number of Mediterranean islands. Most of these originated from the mainland species Palaeoloxodon antiquus. A few dwarf mammoth remains are recorded from Crete and Sardinia. In Sardinia, a largely incomplete skeleton and a few mammoth teeth have been reported from localities believed to range in age from the late middle to the late Pleistocene. The chronology of colonisation by the ancestral species, the actual persistence through time of Mammuthus lamarmorai on the island, and the morphological and dimensional range of the species are, however, poorly known. This research aims to describe a distal portion of a left tibia of a dwarf elephant found in the Alghero area (NW Sardinia), showing some morphological traits and dimensions consistent with those of the endemic Sardinian mammoth (Mammuthus lamarmorai). The main unanswered questions about chronology, colonisation and population dynamics of endemic Sardinian elephants are highlighted and briefly discussed.

Post-IR IRSL290 dating of K-rich feldspar sand grains in a wind-dominated system on Sardinia

The reliability of a post-IR elevated temperature IRSL (290 °C; pIRIR290) is tested on wind-blown, sand-sized (180–250 μm) K-rich feldspar grains. The pIRIR290 ages were compared with quartz SAR-OSL data, other independent age controls and historical information. Three study areas along the coast of Sardinia (Italy) were selected: the south Alghero coast, the Bue Marino cave (E Sardinia) and the Alghero bay (NW Sardinia). Along the south Alghero coastline a thick dunefield system is widely recognised in the literature to represent the beginning of the last glacial phase (post 80 ka). From a single block sand-sized grains for quartz SAR-OSL and K-feldspar pIRIR dating were collected. The natural quartz SAR-OSL sample lies below the saturation limit of the dose response curve (De < 2xD0) giving a reliable age of 76 ± 6 ka. The fading-uncorrected pIRIR290 age of 73 ± 5 ka is in good agreement with the quartz result. A further test on older samples was carried out on the sedimentary succession at Bue Marino cave, which includes a sandy wind-blown unit, enclosed between two calcareous crusts. U-series dates of crusts constrain the aeolianite formation between ∼130 and ∼86 ka. The quartz SAR-OSL signals for aeolianite samples lies close to saturation and the resulting ages underestimate the independent age control. Instead, uncorrected pIRIR290 ages on K-feldspar extracts point to a formation of the wind-blown unit between ∼100 and ∼80 ka, in good agreement with the U-series data. The bleachability of the pIRIR290 signal was further investigated using samples from a modern coastal barrier system backing the Alghero bay. The dunefield was stabilized by plantation during the 1950s. The quartz SAR-OSL ages span from 2450 ± 170 years to 60 ± 13 years ago, consistent with the known coastal barrier stabilization. The pIRIR290 ages indicate an offset up to ∼1000 years. We can conclude that the pIRIR290 method on sand-sized K-feldspar grains shows great promise for samples at or beyond the quartz OSL age limit but should not be applied to Late Holocene or modern deposits.

The late Pleistocene to Holocene palaeogeographic evolution of the Porto Conte area: Clues for a better understanding of human colonization of Sardinia and faunal dynamics during the last 30 ka

The timing of the colonization of Sardinia by mammalian fauna and anatomically modern humans (AMH) is currently under debate. The understanding of the geological and palaeoclimatological conditions that characterized the Late Pleistocene and the Holocene is essential to investigate colonization processes and requires an integrated multidisciplinary approach. In this research we combine for the first time new radiometric dating, field evidence of relative sea-level changes (RSL), sea-level and glacial-isostatic adjustment modelling, stratigraphical, palaeontological, palaeoecological and isotope analyses that were performed on sites and finds from the Porto Conte and Capo Caccia area (Alghero, NW Sardinia). The most important Late Pleistocene fossiliferous deposits in Sardinia have been discovered in this part of the island. Modelled palaeogeographical reconstructions of the Porto Conte area combined with the inferred environmental context and chronology of Late Pleistocene faunal assemblages from Medusa-Dragonara Cave suggest that Homo sapiens did not inhabit this area before the Holocene. Our results support the hypothesis that human presence in Sardinia during the Last Glacial Maximum was at best sporadic.

Geomorphology of four wave-dominated microtidal Mediterranean beach systems with Posidonia oceanica meadow: a case study of the Northern Sardinia coast

ABSTRACTThe results of this geomorphological study, which focuses on four Mediterranean embayed microtidal wave-dominated beach systems and the related inner shelf, are reported on a detailed geomorphological map (1:12,000 scale). The study area is located between Punta di Li Francesi and Lu Poltiddolu in NW Sardinia, W of the Strait of Bonifacio. The Main Map presents geomorphological, sedimentological, hydrodynamical and ecological (underwater vegetation) features indicated in nine sections of the map legend. Integrative maps (1:40,000 scale) of side-scan sonar surveys, sedimentary facies, survey routes and sampling point locations are also represented on the Main Map. This work summarizes 25 years of historical geomorphological datasets and can be considered as a reference for future comparisons of the study area as indicated by current European legislation. In addition to the scientific value of this study, the proposed map can be an important tool for coastal, beach and inner shelf management.

3D hydrogeological modelling supported by geochemical mapping as an innovative approach for management of aquifers applied to the Nurra district (Sardinia, Italy)

A hydrogeological 3D modelling, supported by hydrogeochemical mapping and integrated interpretation of available data, was performed. The proposed methodology was applied to the strategic aquifer of the Nurra district (NW Sardinia, Italy). The finding of this work highlighted that structural history of the Nurra district exerts a relevant control on the hydrogeology and hydrochemistry of groundwater. The local connection of Triassic and Jurassic aquifers was proposed. The knowledge-base system will provide a suitable and effective tool for understanding and monitoring pollutants transfer dynamics into groundwater to better manage water resources and mitigate desertification processes.

Occurrence, relative abundance and spatial distribution of microplastics and zooplankton NW of Sardinia in the Pelagos Sanctuary Protected Area, Mediterranean Sea

Environmental context Plastic materials are accumulating in the marine environment where they can now be found in the remotest areas of the world's oceans. Microplastics (plastic particles ≤5mm), abundant in marine surface waters, are also found in neritic and pelagic waters of Mediterranean marine protected areas. Microplastics can accumulate along marine food chains, having noxious effects on marine organisms at different trophic levels and creating a serious threat to marine ecosystems. Abstract Floating plastic debris tends to fragment into smaller pieces, termed microplastics, which may increase the likelihood of ingestion of plastics by marine organisms entering the food web. This study analyses the amount and spatial distribution of microplastics and zooplankton in an area near Asinara National Park (NW Sardinia) and overlapping the Pelagos Sanctuary (Mediterranean Sea). Analysis showed microplastics in 81% of the 27 samples analysed, with a mean value of 0.17±0.32 items m–3. From geographic information system processing of the data, microplastics appeared more abundant (by a factor of four) in the pelagic than in the neritic environment, and showed a size range of the same order as major zooplanktonic taxa determined in the area. These findings suggest a potential risk of mesozooplankton and species preying on plankton mistaking microplastics for food. Further functional and toxicological studies are therefore necessary to assess the hazard associated with microplastics in the marine food web.

Buried palaeosols of NW Sardinia (Italy) as archives of the Late Quaternary climatic fluctuations

A multi-disciplinary approach was performed to investigate two compound geosols included between wind-blown deposits at the top, and interglacial (MIS 5) beach sediments at the bottom, located along the Alghero coast (North-western Sardinia, Italy). A sedimentological and morphological study was carried out on the profile in the field, and samples collected on the main pedomembers were subjected to several laboratory analyses, consisting of physical and chemical determinations on bulk samples, mineralogy (XRD), micromorphology on undisturbed samples (thin Section, SEM), and EDAX-micro probe analyses. Dating was performed by means of Optically Stimulated Luminescence (OSL). The studied geosols show the evidence of a complex pedosedimentary evolution. Around 80 to 70ka the lower geosol underwent weathering and clay illuviation (wet and warm conditions), followed by calcification-recalcification processes (dry-contrasted), and finally by strong bioturbation. Around 70ka the onset of the glacial period (MIS 4) is marked by the deposition of a sand dune, capping the lower geosol. These results indicate that the coastal area of the central Mediterranean kept the relatively warm conditions typical of the interglacial climate for most of the Early Würm and reached cold conditions only at about 70ka, possibly in relation to the rapid cooling of the Heinrich event H7. The upper geosol developed on colluvial material including abundant pedorelicts and reddish earth material, deposited around 50ka. Before being buried by aeolian sand around 43ka, this deposit underwent pedogenesis phases possibly associated to Middle Würm interstadial events, indicating that in the study area these events were intense enough to influence pedogenesis.

Sustainable management of an intercropped Mediterranean vineyard

In the Mediterranean area, the use of cover crops in vineyards is still debated and the results of the few scientific experiments considering the influence of cover crop on grapevine are often conflicting. This work aims at providing useful indications on sustainable management for irrigated vineyards growing in a hot and dry region. A five year study was carried out in NW Sardinia, Italy, in a 8 year old vineyard cv. Carignano. To evaluate interactions between grapevine and cover crop as well as the economic impact of intercropping, soil tillage (T1) was compared with 4 inter-row treatments: natural covering (T2), complex commercial grass–legume mixture (T3), simple experimental grass–legume mixture (T4) and perennial grass Dactilys glomerata cv Currie (T5).During the five years of the experiment, the mixtures have ensured a higher level of soil covering compared to the other treatments. Moreover, the covering and the contribution to the dry matter yield for every component of the mixtures changed drastically with an increased presence of D. glomerata. Compared to the soil tillage, the cover crops reduce the vigor but does not affect yield. Regarding fruit quality, only the perennial grass influenced positively the amount of total anthocyanins. The cost analysis has not evidenced strong differences among treatments or limiting factors for growers related to the use of cover crop in vineyards.

Middle Pleistocene to Holocene coastal evolution of NW Sardinia (Mediterranean Sea, Italy)

The Middle Pleistocene–Holocene Sardinian stratigraphy has been revised to identify the roles played by sea and climate changes in controlling sedimentation. The succession, dated through Optically Stimulated Luminescence (quartz, K-feldspar) and 14C (the most recent) was grouped into eight major stratigraphic units mainly represented by coastal dunes, shallow marine, and alluvial systems. These units range in age from MIS 8 (300 ka) to MIS1 (6 ka).Little information is available for the period between MIS 8 and 6. The available data, however, allow some comments on climate changes over the last 125 ka. The last interglacial (MIS 5) is subdivided into five substages (e–a). MIS5e (Eemian) is considered the climate optimum of this interglacial, sea level was 4–6 m higher than today, and climate conditions were warmer and more humid. MIS 5c is the second high stand peak. Sea level was about 1.5 m above the modern level, and paleoclimatic and paleogeographic conditions were similar to the present. During MIS 4, at the beginning of the glacial phase, a climatic deterioration occurred. Temperatures dropped by 6C° relative to MIS 5e in about 5 ka, and sea level fell about 60 m. This led to a progressive disruption of inland vegetation cover and to repeated valley slope denudation. The sea-level fall created the accommodation space for fan development in sheltered and cliffed areas, where debris flows developed and filled almost completely the terminal parts of the narrow coastal valleys/coves. In wider areas, however, coastal dune fields developed. Contemporaneous presence of alluvial fan and dune systems is associated with the local morphology that could mitigate or amplify moist conditions within a generally arid environment.During MIS 3, several climate fluctuations occurred (wet/arid, D/O-H events). However, the shallow Sardinian shelf was continuously sufficiently exposed to become the source area of bioclastic sands. These sands were blown inland, and formed extensive dunefield systems. Dunes dominated the west coasts of Sardinia under cold and relatively dry conditions. In some areas, these dunefield systems were eventually almost completely dismantled and reworked into water-flow dominated alluvial fans by catastrophic rainfall events. Thus, the local climate quickly switched from arid to humid conditions. No record of the last Glacial Maximum deposits, MIS 2, was observed along the NW Sardinian coast. During the Holocene transgression (MIS1) coastal dune systems developed and progressively migrated inland, and temperature rose to reach the present-day condition.