The Mediterranean calcareous red alga Lithophyllum byssoides forms thick bioconstructions in the intertidal zone, developing in a very narrow vertical range (ca. 20 cm), making it an exceptionally precise indicator of past sea-level positions. This high sensitivity to even minimal sea-level fluctuations enables the detection of high-frequency, low-amplitude changes that occurred over the last 1000 years. The Late-Holocene relative sea-level curve presented here, is based on L. byssoides rims extensively encrusting the swell-exposed rocky shores of the Mesozoic limestone cliffs of northwestern Sardinia (NW Mediterranean). The rim accretion structures reveal the in situ superposition of multiple generations of L. byssoides thalli, which bind sand-sized clasts. Combined AMS radiocarbon dating identifies four main growth phases, each bounded by distinct erosional surfaces. These phases correlate with stages of relative sea-level rise and coincide with the warmest periods of the last millenium. In contrast, erosional surfaces frequently draped by a reddish muddy matrix indicate sea-level drops associated with the coldest phases of the Little Ice Age. Our findings indicate decimetric relative sea-level fluctuations on sub-centennial timescales, which significantly exceed the average magnitude of sea-level change documented over the last millenium, implying major shifts in coastal dynamics and ecosystems. These results support a strong link between sub-centennial climate variability and sea-level fluctuations and underscore the value of L. byssoides rims as high-resolution archives of past sea-level oscillations.

The El Jable plain (Lanzarote, Canary Islands) preserves an exceptional stratigraphic archive of Late Quaternary environmental change in a semi-arid island setting. Through an integrated sedimentological and chronological approach combining facies analysis, post-IR IRSL and radiocarbon dating, we reconstruct the alternation of aeolian, colluvial, and ephemeral-stream dynamics over the past similar to 140 ka. Results document major shifts in sedimentary regimes linked to Marine Isotope Stages (MIS): intensified dune formation during MIS 6 and MIS 4, slope-derived colluvial-alluvial phases under MIS 5e humidity, and variable hydrological activity during MIS 3. MIS 2 to early Holocene records oscillating dry-wet phases, with Last Glacial Maximum aeolian activation followed by Late Glacial to Holocene fluvial reactivation and humid pulses. Comparison with previous work across the Canaries and Northwest Africa highlights both archipelago-wide signals (aeolian activation during glacial lowstands) and local responses to precipitation variability. Our findings demonstrate that El Jable represents a uniquely sensitive archive of climate forcing in oceanic semi-arid environments and provides a valuable analogue for arid-margin basins worldwide.

Aeolianite and colluvial deposits at coastal outcrops located at the base of an energetic and structurally complex coastal slope have been examined in northwestern Mallorca (Balearic Islands, Western Mediterranean). A chronological framework has been established using Optically Stimulated Luminescence (OSL) dating. Due to the intensive weathering and bioturbation of the aeolianites, OSL dates have been obtained from the fine-grained polyminerals found in the colluvial paleosoils interbedded between the aeolianite layers. This limitation does not stem from the scarcity of quartz, but rather from the fact that the available quartz grains have been reworked from underlying strata and are, therefore, not chronologically reliable. The outcrop reveals a complex interaction between aeolian and colluvial deposition, and both dating and facies analysis have identified four episodes of aeolian activity during Marine Isotope Stages 5 to2 (MIS5 to MIS2). The data suggest that aeolian transport and dune formation were particularly intense during global colder climatic intervals, coinciding with low sea levels, while colluvial deposits correspond to more humid conditions. Given that the outcrop architecture and its elevation relative to present sea level (i.e., the altitude at which it is situated in relation to the modern shoreline) are comparable to those of other outcrops in structurally stable areas of the island, it is inferred that the northwestern side of the Tramuntana Range has remained relatively stable since MIS 5.

Geophysical surveys and multiproxy analyses of sediment cores have been used to reconstruct the palaeoenvironmental evolution of the Santa Giusta coastal lagoon (SGL), along the western coast of Sardinia. This area served as a natural harbour mainly during the Punic and Roman Republican periods (6th-2nd century bc). The inlet of the SGL is connected to the adjacent mouth of the River Tirso and lies on the incised valley of an ancient tributary that once fed into the Tirso during the last sea-level lowstand. The SGL formed after the sea level rose following the LGM, resulting in the inundation of the incised valleys, which were subsequently filled with estuarine sediments. About 6000 years ago, the area that is now occupied by the mouth of the river and the SGL was protected by a sandy barrier enclosing an open lagoon. About 4500 years ago, the deposition of alluvial sediments marked the beginning of the progradation of the river mouth, leading to the gradual enclosure of the SGL. Before 2100 years ago, the SGL was a suitable location for a sheltered harbour, as evidenced by archaeological indicators, both pottery and wooden structures, found within the lagoon sediments. By this time, the progressive narrowing of the inlet had reduced the accessibility of the site from the sea and the harbour lost its functionality.

In the Mediterranean Sea, restoration of marine habitats has mostly focused on the endemic seagrass Posidonia oceanica. Despite several transplanting experiments, large-scale projects are rare, and their success is poorly known. The present work describes a restoration project of a large, degraded area in northern Sardinia (Italy) using cuttings harvested from a donor meadow that was destined for destruction due to harbor expansion. The receiving site was selected through a multidisciplinary study including acoustic mapping, ROV surveys, sediment assessment, and analyses of satellite images across ten years to evaluate the site suitability. Plants were manually uprooted from the donor meadow and cuttings were selected and transplanted within 24 h by environmental engineering techniques. The cuttings were transplanted onto degradable mats of natural coconut nets coupled with a double-twist steel mesh and anchored to the bottom. Overall, 7000 patches, each containing 20 cuttings, were transplanted in three periods: June–July 2022, October–November 2022, and February–March 2023. One year after the restoration, all the patches were in situ, with an overall cutting survival of 59%. The results are comparable to those of previous small-scale projects using the same technique and also endorse its suitability for the restoration of large, degraded areas.

The Geomorphologycal map of the continental shelf of the northeaster sector of the Sardinian coast has allowed the recognition of several seafloor features. These have been related to the geology and climate history of the area from the Last Glacial Maximum (LGM) to the early Holocene. During the LGM sea level was about 130 below the present and cuspate deltas fed by rivers crossing the continental shelf formed. The post LGM sea level rise caused submersion of the exposed continental shelf and changed the dominant sedimentary processes. The rise was not continuous but punctuated by stillstands during which suites of beach ridges developed. The mapped ridges (BRS1, BRS2 and BRS3) are correlated to specific post-LGM sea level stillstands. These fit pretty well with the cold phases that punctuated the post LGM warming phase; that is, the Older Dryas (17-15 ka), Younger Dryas (12.9-11.6 ka) and the 8.2-kiloyear event (8.7-8.2 ka).

The age determination is crucial to unravel the evolution and to provide a framework of the geological, paleo-anthropological, and cultural conditions of a specific region of interest. The lack of chronological information makes difficult to correlate the site of interest with other temporal attributes provided by stratigraphy and paleoclimatology. Luminescence is a well-established dating technique for determining the absolute age of formation (or most recent reworking event) of geological deposits/sediments and archaeological finds on Earth, with a time range that spans from the last few decades up to one million years. The most common geological targets are dust, silt, sand, cobbles, and rock outcrops originating from different environments: aeolian, fluvial, alluvial, lacustrine, marine, glaciogenic, slope deposits, karstic, soils, tectonic activity. In the archaeological field, this technique is applied not only to the geological sediments in excavation sites but also directly to artifacts of interest, especially when they are made of pottery or stone.A miniaturized luminescence dating prototype for in-situ examination has been designed by Alma Sistemi S.r.l., Guidonia, Italy, and validated by University of Sassari, Sassari, Italy, under European Union H2020-MSCA-RISE-2018 research programme (G.A. n.823934). The instrument is equipped with an infrared and blue optical stimulation subsystem to perform both optically and infrared-stimulated luminescence (OSL, IRSL) and is able to measure both paleo-dose and dose rate. An X-ray generator (XRG) irradiates the sample, while the response luminescence signal is obtained through a photon counting photomultiplier tube (PMT). A thermal subsystem consisting of a heater and air-cooling pumps allows the instrument to heat during SAR (single-aliquot regenerative-dose) procedure and to perform thermally stimulated luminescence. Remote control for data analysis application and a battery power supply are implemented on the instrument for usage on the field.The development of this portable instrument is of great relevance since it finds practical use in geological and archaeological Earth's field applications. In fact, compared to current luminescence dating technologies and considering its reduced dimensions (11x11x18 cm excluding electronic box and cover) and weight (currently

Coastal landscapes are the most sensitive system to abrupt climate changes and important archives of past changes and can be used to reconstruct possible future scenarios potentially undergoing recurrent extreme climatic events. Evidence of this change can be observed in the study area of this paper, Punta de s'Avan & ccedil;ada in Pollen & ccedil;a, Mallorca (Balearic Islands, Spain). The stratigraphic record from the Punta de s'Avan & ccedil;ada outcrop in North Mallorca provides valuable insights into the paleoenvironmental changes driven by Heinrich (HE) and Dansgaard-Oeschger (DO) events during the late Pleistocene. Detailed analysis of six distinct sedimentary units (U1-U6) reveals the significant impact of abrupt climatic shifts on sediment supply, depositional environments, and sea-level fluctuations. The cold, arid conditions during HE events, particularly H4 and H5, promoted extensive dune formation in Units U4 and U6, while the warmer, wetter conditions during DO events facilitated alluvial and colluvial deposition in Units U1 and U5. By integrating OSL dating with climatic oscillations, this study demonstrates the influence of millennial-scale HE and DO events on sedimentary processes in coastal landscapes of the western Mediterranean. The results show ages between 34 and 91 ka, suggesting a time interval between MIS 3 and MIS 5a. The findings underline the dynamic interplay between climate, sea level, and sedimentation in shaping Pleistocene coastal environments, contributing to a deeper understanding of the region response to glacial cycles and abrupt climate events.

Determining the age of precise sea level markers such as marine terraces is often difficult because of the inherent limitation of traditional dating methods. A novel method based on Optical Stimulated Luminescence applicable to rock surfaces has been showing great promise in dating boulder and cobble surfaces from various environments. We performed Optically Stimulated Luminescence Rock Surface Dating (OSL RSD) on five cobbles from a basal transgressive lag deposit sealing a marine terrace referred to as the Last Interglacial (Marine Isotopic Stage 5e). We applied a consistent and highly selective 3-step acceptance criteria on five cobbles and obtained that only one was sufficiently well-bleached prior to burial. The resulting ages of 131 +/- 8 ka and 127 +/- 8 ka (obtained on 22 analyzed aliquots, n = 22) derived from the post-infrared infrared stimulated signal at 225(o)C (pIRIR(225)) and the preceding infrared stimulated signal at 50(o)C (pIR(50/225)), respectively, are consistent with each other as well as with the conventional luminescence age of similar to 135 ka from the same sequence and with the U/Th age of similar to 130 ka obtained from coral fragments. This work demonstrates that the RSD is a promising method for dating gravel veneer deposits overlaying marine terraces, enabling new chronologies for similar Quaternary deposits.

Aeolian sand covers a significant part of the granite peninsula Hammeren on northernmost Bornholm in the Baltic Sea. The coastline of Hammeren is rocky and apart from one relative wide and sandy pocket beach at the east coast only few, small and gravelly pocket beaches exist. The aeolian deposits form three sand covers that stretch inland from the east and northwestern facing coasts of Hammeren. The largest sand cover forms a rising sand plain that cover the granitic landscape up to 700 m inland and reaches up to 60 m above sea level. Historical sources mention aeolian sand movement around CE 1775 in the middle of the Little Ice Age, but until this study no absolute age control has been available to confirm these observations. Luminescence dating of selected sample sites indicates that aeolian sand movement took place in three episodes. The first episode was in the last part of the Younger Dryas at about 11,500 BP, the second episode was in the Danish Late Bronze Age at about 2700 BP, and the youngest episode was indeed during the Little Ice Age around 200 BP (CE 1750). These episodes with aeolian activity all fall during relatively cold climatic intervals and add support to previous studies indicating a link between cold climates an increased storminess in Northwest Europe including the southern Baltic Sea region.

The islet of Scoglio d’Affrica (Tuscany Archipelago, northern Tyrrhenian Sea) is an emerging segment of the Elba-Pianosa Ridge. This ridge is a major tectonic-structural high formed by Eocene-Early Miocene clastic succession which separates the Tuscany shelf from the Corsica Basin. The distinctive structural setting of the Scoglio d’Affrica region is a result of crustal fragmentation during the extensional tectonic regime of the Northern Tyrrhenian Sea. Along the Elba Pianosa Ridge, a complex interplay between Miocene magmatism, active submarine gas emissions and mud volcanism has been observed. Currently, the Scoglio d’Affrica region experiences active mud volcanism, accompanied by diffuse seafloor gas leakages and sporadic violent mud-water mixed eruptions, as exemplified by the most recent event in 2017.In this study, we present a comprehensive analysis of ship-borne magnetic data, swath bathymetry, single and multichannel seismic profiles of Scoglio d’Affrica region focalized to provide a comprehensive geophysical model of shallow crustal dynamics.Forward and inverse magnetic models reveal the presence of a continuous high magnetic susceptibility body running along a NNW-SSE direction, parallel to the main tectonic lineaments. This high magnetic source is interpreted as an ophiolite/high grade serpentine deposit embedded in Eocene siliciclastic layers resulting from the disrupting of the Corsica Alpine basement. This deposits are related to sedimentary gravity processes originated from peripheral highs and accumulated in intra-wedge basins subsequently deformed during the Oligocene. Our reconstruction provides previously unknown details about geometry and distribution of shallow ophiolite-like deposits thereby improving the comprehension the intricate structural evolution of Elba-Pianosa Ridge featured by a multiphase tectonic deformation and shallow manifestations of fluid/gas circulation.

Loess–palaeosol sequences serve as valuable archives of changes in climate and atmospheric mineral dust deposition. However, little work has been conducted on Holocene loess in the Arctic, despite the sensitivity of this region to climate changes. Aeolian silt/loess profiles in the ice-free region of western Greenland near Kangerlussuaq were sampled to develop a robust age framework using both luminescence and bulk organic matter radiocarbon dating. Radiocarbon ages generally show consistent age increases with depth but are likely offset to younger ages due to sediment mixing in the upper 10-20 cm of the profiles. Quartz OSL signals exhibit insensitivity, while low-temperature infrared stimulated luminescence performed at 50 °C (IR50) and the post-IR IRSL at 180 °C (pIRIR180) signals of polymineral fine grain revealed a consistent natural inherited dose of approximately 5 Gy for pIRIR180 and an unbleachable residual of around 2 Gy for IR50, with substantial fading rates in the latter. This led to a notable age overestimation when compared with bulk organic matter radiocarbon ages. To develop an appropriate dating approach, we evaluated the differential bleaching rates of feldspar IR50 and pIRIR180 signals, and corrected for modern inherited doses. Radiocarbon ages measured on the bulk organic carbon oxidised at 400°C (LT 14C) increased very consistently with depth, allowing calculation of accumulation rates. The presence of the atmospheric radiocarbon bomb signal at depth indicated down-mixing of surface material into the profile, which caused negative (younger) age offsets. The offset-corrected radiocarbon-based age-depth model could be compared to the luminescence results.We show that a combination of LT 14C with polymineral pIRIR180 dating allows the development of age models for these deposits. This multi-chronological approach reveals that loess accumulation in the region was initiated around 4 ka, probably consisting of two main phases of loess accumulation at 4-3 ka and <1 ka. The initial phase matches the proposed onset of aeolian sand activity in the wider region, but post-dates local ice retreat by c. 3 kyr. The more recent phase of accumulation also matches the timing of increased sand accumulation in the region and likely coincides with Neoglacial to Little Ice Age ice advances, or even enhanced dust activity in the last decades.

This study was conducted in the Middle Branch of Bue Marino Cave (Sardinia, Italy) to reconstruct paleoecological conditions during the Holocene through microfaunal proxies in seven surface sediment samples and a short sediment core (BMD-2018, 18 cm), all collected in 2018 and another core sampled in 2021 (BMD-2021, 28 cm). The first attempt at dating cave sediment through luminescence was conducted on BMD-2021; the derived age was 6.04 ± 0.47 ka at 18 cm depth. Although continuous sedimentation and constant rates are not probable in the cave, this indicates that the sedimentary record dates to the early times after the Holocene flooding of the cave by the sea. Benthic foraminifera and grain size were analyzed in all surface samples and core BMD-2018, while only benthic foraminifera were studied in BMD-2021. The recent foraminiferal assemblages, studied from an ecological point of view, were applied as modern analog to reconstruct the paleoecological conditions in sediment cores. Significant changes in the sedimentary environment were excluded; the two cores showed a similar foraminiferal turnover at a similar depth, from an older assemblage with prevailing indifferent Ammonia inflata to a younger one with prevailing opportunist Eggerelloides advena. This turnover was attributed to changes in the amount and/or quality of available nutrients. Based on these results, this event is likely related to possibly attributable to the effects of climate changes that occurred in the Holocene. However, more extensive studies are necessary to better understand the effects of the climatic/environmental events in the Late-Holocene in the caves. Although it represents a first attempt at paleoenvironmental reconstruction based on sediments from a Mediterranean marine cave, this study demonstrated that benthic foraminifera are refined paleoenvironmental proxies and that the integrated approach with the luminescence dating produces reliable results for studying the effects of global changes in these environments.

AbstractThe relict beach deposit of the Cala Mosca marine terrace is considered an important section of Marine Isotopic Stage (MIS) 5e (ca. 125 ka) sea-level highstands. Analysis of the stratigraphy and sediments of the deposit indicates the presence of a composite marine terrace comprising two superimposed marine units, luminescence dated to the MIS 5e (137 ± 7, 134 ± 7 ka) and MIS 5c (92 ± 6 ka) substages. The stratigraphic superimposition of the two highstands, both placed ~5 m above present sea level, agrees with other areas along the Sardinia coasts. The evident superimposition of two sea-level highstands and development of the composite terrace cannot be accounted solely by high-frequency sea-level oscillation that occurred within MIS 5 for the Mediterranean Sea. This suggests controversial, but significant, regional versus local tectonic activity occurred during the Late Pleistocene.

ABSTRACTThis paper presents the structural map of the Barrabisa Complex, an E-W ribbon-like migmatitic massif exposed in the northern part of Sardinia. The migmatites consist of metatexites and diatexites with variable melt proportion, grading in the central part of the complex to a foliated peraluminous granodiorite. Xenotime/monazite dating indicates that the foliated granodiorite pluton emplaced in upper Carboniferous times (≈307–313 Ma) within a narrow E-W ductile top-to-the east shear zone cutting through a Variscan high-grade metamorphic basement composed of orthogneisses, metasedimentary-derived migmatites and subordinate amphibolites. Field geological mapping, coupled with structural and micro-structural analysis, allowed us to distinguish the granodioritic pluton and three metamorphic units characterized by variable melt to protholith ratio, that represent a continuous transition from metatexite to diatexite with high melt concentration, to foliated granodiorite.

Mapping of coralligenous banks was carried out along the continental shelf of the northern and western margin of Sardinia Island (Italy, western Mediterranean Sea) in the context of the European Marine Strategy Framework Directive (MSFD, 2008/56/EC). Coralligenous banks are bioconstructions produced by calcareous coralline algae. Seafloor mapping was carried out through multibeam echosounder surveys and video transects, using a Remote Operating Vehicles (ROV), in areas not formerly explored. A high-resolution digital model of the seabed (DTM) was obtained from multibeam data. A total surface of 436 km2 of sparse patches of coralligenous banks was mapped in the depth range ~40-160 m. A final map of coralligenous habitat distributions along the western and northern continental shelf of Sardinia (scale 1:250,000) was produced. The base-map is formed by the shaded DTM of the seabed. Other mapped features include the edge of the continental shelf and the distribution of rocky seabed.

The Asinara Island Marine Protected Area (AMP) (Sardinia, Italy) represents one of the most uncontaminated areas of the Mediterranean Sea and, therefore, but misses of an accurate mapping of the biocenoses and associated lithologies present on the sea floor. The provided map has highlighted the presence of 21 biocenoses laying on rocky or sandy substrate if shallower or deeper respectively. The most recurring are: the Posidonia oceanica L (Delile) and the coralligenous. The good state of conservation the P. oceanica meadow characterizing the eastern part of the island, and the diffuse presence Coralligenous reefs on the western side, are indicative of the well conditions of the marine ecosystem of the Asinara Marine Protect area. Moreover, the Coralligenous reefs developed on beach rocks have allowed defining which was the paleogeography of the Asinara Island during the time interval comprised from 12.9 to 10.0 ka Before Present (BP).

Mediterranean mesophotic hard bottoms are mostly characterized by coralligenous banks. Although investigations on this habitat have increased in the last years, knowledge about its structure and spatial variability is still very limited as most studies are focused on the description of assemblages of peculiar and small locations such as biodiversity hotspots. This study aimed at i) describing coralligenous megafauna on the western Sardinian continental shelf between 80 and 120 m of depth, ii) assessing the distribution of the dominant taxa, and iii) estimating patterns of spatial variability at different scales. The coralligenous banks were studied along five sectors of the western Sardinian continental shelf by means of Remote Operated Vehicles (ROVs) and images were analyzed to identify the main taxa or morphological groups and their abundance. Results highlighted several common patterns among sectors, with assemblages dominated by the gorgonians Eunicella cavolini and Callogorgia verticillata. On the other hand, some taxa (e.g. Callogorgia verticillata, Paramuricea hirsuta, Antipathella subpinnata, Corallium rubrum Paramuricea clavata, Poecillastra compressa and Aplidium spp.) mainly contribute to segregate the coralligenous assemblages within the considered sectors of this study. A high small-scale variability was also observed. The presence of extensive and well diversified mesophotic animal forests stresses the importance to improve the conservation of the western Sardinian continental shelf.

Coralligenous reefs are the main biogenic constructions of the Mediterranean Sea and they are considered indicators of the ecological quality of coastal systems and of “seafloor integrity” by the Marine Strategy Framework Directive. The two main coralligenous morphologies are the cliffs and platforms, the former developing in shallow waters (about 20–50 m) on vertical/subvertical rocky substrate and the latter built over horizontal substrates below 50 m depth also on detritic bottoms. The present study aims at assessing whether patterns of spatial variability and ecological quality of the coralligenous cliff assemblages reflect those of platform assemblages. At this aim, six geographic areas around Sardinia (western Mediterranean, Italy) were considered and, within each area, the structure of both the coralligenous cliffs and platforms was investigated by SCUBA and ROV methods, and their ecological quality was assessed by ESCA and CBQI indices, respectively. Overall, 20 morphological groups (seven macroalgae and thirteen invertebrates) were found but differences in community structure were evident both spatially and between systems, platforms vs cliffs. In fact, spatial variability in assemblages structure changed between the two morphologies across the areas. Moreover, a different spatial pattern in the ecological quality was found between platform and cliff assemblages. The results of the present study corroborate the individual peculiarity of coralligenous platforms and cliffs, highlighting the importance of the concurrent assessment of both systems in monitoring programs..