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The São Francisco delta in eastern Brazil is considered a classical example of a wave-dominated delta constructed in a glacial isostatic adjustment (GIA) far-field region. Although this delta is widely mentioned in the international literature, few details about its sedimentary architecture have been published. In this paper, we use a new dataset consisting of 15 boreholes and 26 radiocarbon datings to discuss the 3D architecture of the delta and the role played by GIA far-field effects in delta construction. The delta plain consists of a 10–12 m thick littoral sand sheet that progrades over a muddy subaqueous clinoform, forming a compound clinoform. Delta construction began between 8.4 and 7.2 ka BP and included a stage of normal regression that lasted until 5.7 ka BP, followed by a stage of forced regression. The transition between these two stages is marked by the highest position of the sand–mud transition in the boreholes. This forced regression is due to a 3–4-m drop in relative sea level since the mid-Holocene, which is characteristic of GIA far-field regions. Additionally, as a consequence of this drop in relative sea level, there is a progressive increase in the altitude of the beach-ridge deposits continentward, which combined with the development of extensive dune fields in the later stages of delta construction, contributes to the increased resilience of the delta to ongoing sea-level rise. The 3D architecture of the delta was strongly influenced by antecedent topography. The delta was built on a bathymetric depression on the shelf that almost entirely traps the sediment load of the São Francisco River. The uneven relief inside this bathymetric depression ultimately controlled lateral variations in the total thickness of the delta edifice. • Two-stage delta construction in GIA far-field regions: normal and forced regression. • Drop in sea level since mid-Holocene in GIA far-field regions increases delta resilience to ongoing sea-level rise. • Antecedent topography strongly controlled the delta 3D architecture. • 3D architecture of the São Francisco wave-dominated delta is presented for the first time. [ABSTRACT FROM AUTHOR]

Sedimentological characteristics, sedimentary environment and see-level change of the middle Cretaceous oolitic ironstones of one hydrocarbon field in central Persian Gulf were analyzed in this study. The analyses include petrography, XRD and size analysis using laser particle sizing. Core analysis of the sequence shows that it is composed of shaly limestone, limy shale, carbonate cemented sandstones, shale and oolitic ironstones from bottom to top. The dominant minerals of these deposits at the upper part are goethite, phosphate, calcite, clay minerals and siderite. These analyses showed that the studied ooids were deposited in a shallow marine environment with bidirectional currents and occasional storms. Lack of limestone relics, the presence of marine ooids, change in iron minerals from siderite to goethite in sediment sequence from bottom to top and high roundness and symmetry of grains confirms such environment. Deposition of a shale layer just above this complex has protected them from considerable diagenetic changes with creating two impermeable layers around this unit. The sea-level falls toward the oolitic ironstone layer and rises again after the deposition of this layer. If this sequence be present at the other parts of the Persian Gulf, it could be used as a key bed in stratigraphic studies and correlations in Persian Gulf area.

The fluvial systems of Saurashtra, Gujarat, India have archived signatures of sea-level stands for the Late Quaternary Period. Based on geomorphology, sedimentology and optical dating, the lower reaches of Noli river in southwestern Saurashtra reveal the presence of marine, fluvially reworked and aeolian forms of miliolite. Optical chronology permits us to extend the age range of fluvially reworked miliolites from 75 (as previously believed) to 114 ka. The fluvial sequence of southwestern Saurashtra has responded to sea-level changes through meandering. Presence of aeolian miliolites dated to 23 ka suggests regional aridity during the time of their deposition and preservation. Marine notches in Diu mark Middle Holocene high sea-level stand and their preservation implies active tectonism in the region. [ABSTRACT FROM AUTHOR]

The East China Sea Shelf Basin was a back‐arc basin located at the active continental margin of the western Philippine Sea Plate. This study explores facies and architectural changes from tide‐influenced deltas to tide‐dominated estuaries in transgressive–regressive cycles, as well as their controlling factors. Cores, wireline well‐logs and seismic data allow the sedimentary architectures and models of the depositional systems to be reconstructed. In the Xihu Depression of the East China Sea Shelf Basin, the stratigraphic sequences of the Eocene Pinghu Formation are interpreted to be dominated by repeated phases of deltaic progradation, but with intervening transgressive phases only thinly developed as bioturbated, open‐marine shelf deposits. The sequences of the overlying Oligocene Huagang Formation, in contrast, are interpreted as stacked, tide‐dominated estuary units, alternating with only poorly preserved regressive half‐cycles because of repeated, strong estuary down‐cutting. The intervening unconformity in the succession corresponds to the Yuquan tectonic movements, which triggered a change from extensional to compressional settings in the Xihu Depression. In the Late Eocene, extension of the Xihu Depression led to moderately high rates of subsidence (163 m Ma−1), and short‐term sea‐level falls led to multiple phases of deltaic progradations. After the Yuquan Movement, Early Oligocene compression brought overall lower rates of subsidence (110 m Ma−1), as well as sea‐level rise and stacked estuary development with significant tidal influence in the infill. The interaction of tectonics, sea‐level change and sediment supply determined the nature of the depositional systems on the shelf during the entire period, whereas the sedimentary processes were key to reworking and shaping the facies distribution, geomorphology and architectures in the back‐arc basin. This research provides an insight into spatial and temporal characterization of deltaic and estuarine systems, contributing to a better understanding of the mechanisms controlling a change in dominant coastline type, despite continued strong tidal influence. [ABSTRACT FROM AUTHOR]

The Albian series have been deposited on both sides of a major E-W paleogeographic fault, which was inherited in the early stages of the Tethyan-rifting phase. To the south of this fault, a shallow platform domain (footwall block or horst) occurred and is relayed northward by a slope-deep shelf setting (hanging wall block or graben). The platform to basin transition was analyzed northward of this fault nearby M’rhila Mountains. A detailed sedimentological study, coupled with a tectonic analysis, indicates that the Albian sedimentary deposits consist of four third-order depositional sequences. The three lower ones are only present in the deep-shelf setting and include substantial carbonate accumulations. The latter deposits are generally arranged into alternating mud-rich-bedded limestone and conglomeratic levels. Most of this material was exported from the adjacent shallow platform by mass flow and suspension transport processes. In the studied series, the maximum carbonate accumulation is recorded in the deep shelf during the moderate transgressive increasing and the late highstand decreasing rates of sea-level rise. However, the minimum carbonate sedimentation is thought to be linked to both the minimum lowstand and the maximum transgressive sea-level rise. The uppermost depositional sequence—which occurs on both sides of the major fault, is different from the three lower ones as it includes only scarce thin re-sedimented limestone beds. The youngest sequence is related to an important interplay between a pulse of tectonic subsidence and the major see level rise that happened during the upper Albian (100-98.9 Ma), resulting in a regional collapse of the substratum and the drowning of the carbonate factory situated southward. Therefore, the uppermost sequence is considered as a tectonically originated depositional sequence rather than a “pure” eustatic one. The organic-rich deposits associated to this sequence south and north of the major fault correlate well with the global anoxic events. The present study case represents a good example illustrating the role of local tectonics and global eustatic fluctuations in controlling not only the facies and thickness distribution but also the carbonate production and accumulation. [ABSTRACT FROM AUTHOR]

Abstract On Xisha Islands, located in the South China Sea, the Neogene succession includes the unconformity-bounded Huangliu Formation that is 210.5 m thick in well CK-2 and formed almost entirely of dolostones. The diverse biota in the Huangliu Formation, which includes corals, algae, bivalves and foraminifera, indicates that the original carbonate sediments accumulated in water that was <30 m deep. The dolostones are formed of various mixtures of low- and high‑calcium calcian dolomite with limpid dolomite lining the walls of many cavities. The 18O and 13C stable isotopes suggest that dolomitization was mediated by slightly modified seawater. The 87Sr/86Sr ratios from the dolostones suggest that dolomitization took place ~9.4 and 2.3 Ma ago, with the age of dolomitization becoming progressively younger towards the top of the formation. "Island dolostones" like these, found on many islands throughout the Pacific Ocean and the Caribbean Sea, have commonly been linked to eustatic changes in sea-level with dolomitization taking place during lowstands, highstands, or transgressive phases. Data from the Huangliu Formation in well CK-2 suggests that dolomitization was associated with (semi-)continuous transgressive conditions that were controlled by the interaction of tectonic subsidence and eustatic changes in sea level. Highlights • Dolostones in the Huagliu Formation (Miocene) on the Xisha Islands are similar to island dolostones found on other isolated oceanic islands, including the Cayman Islands. • Dolomitization of the Miocene limestones on Xisha Islands, which took place ~9.4 to 2.3 Ma, appears to have been a (semi-)continuous time-transgressive process. • Critically, the similarity in the style and pattern of dolomitization on the Xisha Islands and other islands (e.g. Grand Cayman, Cayman Brac, Kita-daito-jima, Little Bahama Bank, San Salvador) suggests that the process of dolomitization may have been related to a worldwide phenomenon. • Available evidence indicates that dolomitization on the Xisha Islands influenced by eustatic changes in sea-level and tectonic subsidence of the Xisha Platform. [ABSTRACT FROM AUTHOR]

Abstract We have assembled a database of Relative Sea Level (RSL) data points from the eastern coast of Canada from Hudson Bay to the border with the USA. In compiling this database we have critically reviewed 1092 radiocarbon dated samples from raised beaches, isolation basins, intertidal and marine deposits, and archaeological indicators to produce 405 sea-level index points and 687 sea-level limiting points. Our comprehensive, systematic, and quality-controlled RSL database allowed for the reconstruction of the postglacial evolution of 34 regions of eastern Canada providing new basin-scale insights into the processes driving RSL changes in the last ∼16 ka. The combination of a database of sea-level index points with an innovative empirical-Bayesian spatio-temporal statistical model provided new insights into rates and magnitude of the spatially-variable glacial isostatic adjustment (GIA), which dominated the postglacial RSL evolution in this sector of North America. A continuous postglacial RSL fall is observed at latitudes ≥ ∼50° N with higher rates (up to 35 mm a−1) recorded in southeastern Hudson Bay. At lower latitudes, the evolution is non-monotonic with RSL that dropped to a spatially variable early-Holocene lowstand, followed by a mid-Holocene highstand and, eventually, a gradual drop to present RSL. This pattern is particularly evident in the St Lawrence corridor. Along the majority of the Newfoundland, New Brunswick and western Nova Scotia coasts, a late-Pleistocene/early-Holocene RSL lowstand was followed by a continuous rise through the Holocene. At the margin of the former ice-sheet (i.e. eastern Nova Scotia), our data identify a continuous RSL rise through the Holocene. These records are characterized by decreasing rates of RSL rise through time, commencing with a rapid rise during the early Holocene (up to ∼17 mm a−1), a slowdown in the mid-Holocene (average rates ≤ ∼9 mm a−1), and a further reduction in the late Holocene (average rates < 2 mm a−1). Finally, our database allowed the identification of regions, including the Labrador coast and part of the St Lawrence corridor, where further investigations are required to better constrain the RSL evolution and improve our ability to assess the variability of RSL histories. Highlights • A database of Relative Sea Level data from the eastern Canada. • We produced 405 sea-level index points and 687 sea-level limiting points. • New insights into the RSL changes in eastern Canada. • A continuous postglacial RSL fall is observed above ∼50° N. • Highest falling rates recorded in SE Hudson Bay. [ABSTRACT FROM AUTHOR]

Advances in digital spatial analysis and 3D photorealistic modeling offer the potential to create virtual interpretations of the now inundated landscapes of NW Australia. While this provides a useful template for potential late Pleistocene and early Holocene coastal occupation on the shelf, we stress the importance of understanding sediment dynamics as a primary control for terrain modelling, particularly at the scale of human ecosystem dynamics. We briefly review six major drivers of change upon tropical and semi‐tropical continental shelves and coastlines, and some of the typical coastal geomorphologies associated with each. We then hypothesize how these drivers might have varied on the NW Shelf of Australia since 65 ka, and then apply the logic to the Barrow Island region, to form some "end‐member" visualizations of coastal change in the early Holocene. The visualizations indicate a high degree of variability in coastal morphology, particularly through the post‐glacial period, which is likely to have radically changed the capacity of the coastline to provide resources for human use during that period. Hence, rather than considering any single visualization as being absolute, end‐member visualizations should be used to generate testable hypotheses that are reviewed repeatedly in the light of new physical, environmental, and archaeological information. [ABSTRACT FROM AUTHOR]

Abstract A detailed geomorphological survey using Light Detection and Ranging (LiDAR) was carried out along the western part of the Assu River valley, NE, Brazil. The study was complemented by the investigation of sedimentological, mineralogical, and sediment benthic foraminifera indicators within the 14C geochronological framework. The integration of data sets permitted the reconstruction of the main phases in the evolution of this area during the Holocene. The shallow embayment, which is now completely infilled, acquired its present form within the limits of antecedent morphology developed since the last interglacial period. The main forcing factors responsible for repositioning the shoreline, which ran along the strike-slip Afonso Bezerra fault at an angle of approximately 35° to the present coast in the Early/Mid Holocene, were as follows: (1) tectonic activity along the strike-slip Afonso Bezerra fault, (2) fast inundation of the shallow paleo-valley embayment during the last pulse of Holocene transgression ca. 8000 cal yr BP, (3) advance of the Assu river mouth through accretion of fluvial bay head delta and costal drift sediments and (4) sheltering of embayment by barrier islands which permitted a widespread development of mangrove forest during the last 3 millennia. The estimated rate of progradation of the Assu estuary that led to the present stage of terminal infilling is in the order of 3–4 m/yr. Highlights • This study presents the late Quaternary evolution of an estuary in Brazil. • Fast inundation occurred in the paleo-valley during the Holocene at ~7500 cal BP. • The valley was drowned by the Holocene highstand at ~5000 cal yr BP. • The progradation rate of the estuary that led to the infilling was 3–4 m/yr. • The Holocene estuary limit is the late Pleistocene morphology. • A fault escarp marks the Holocene-Pleistocene boundary in the W part of the estuary. [ABSTRACT FROM AUTHOR]

Among blue carbon ecosystems, mangroves are very efficient in storing carbon in their sediments over decadal to millennial time scales. However, this ability varies with numerous parameters, including climate and sea-level variations. In New Caledonia, mangrove ecosystems develop in semi-arid conditions with a typical zonation: Rhizophora spp. colonize the seaward side of the intertidal area, while Avicennia marina develops at higher elevations, just below the salt-flat. Within this context, we determined both the quantity (organic carbon content and carbon stocks) and the characteristics (carbon over nitrogen ratios (C/N), stable carbon and nitrogen isotopes, radiocarbon age) of the organic matter stored beneath each mangrove stands. Carbon stocks were determined down to different limits with depth: approximate extension of the root systems, one-meter depth, and the hard substrate. Within the extension of the root systems, the sediment carbon stock was lower than 100 MgC ha −1 regardless of the mangrove species. This low value resulted directly from the dry climate that limits mangrove productivity. At depth beneath every zone, a buried layer enriched in mangrove-derived organic matter, with C/N values around 40 and δ 13 C values around −26‰ was observed. This layer likely resulted from a sea-level high stand during the late Holocene that allowed a long period of stability of the mangrove, slowly accumulating organic matter within the sediment. In this buried layer, the carbon stock was higher than in the upper sediment and reached up to 665, 255 and 300 MgC ha −1 in the salt-flat zone, the A. marina stand and the R. spp. stand, respectively. The highest stock, determined beneath the salt-flat, was suggested to be related to a period of sea-level stability that lasted ~3000 years, whereas beneath the other zones, which are at lower elevations, mangrove colonization was more recent and the sea-level was continuously decreasing till recently. Sea-level variations, and, specifically current sea-level rise, may strongly influence mangrove development due to their migration along the tidal elevation gradient to maintain the biotic conditions needed for their development. [ABSTRACT FROM AUTHOR]

Abstract Submerged prehistory has emerged as a key topic within archaeology over the last decade. During this period the broader academic community has become aware of its potential for revolutionising our understanding of the past. With recent technological and scientific developments has come an opportunity to investigate larger areas and learn more than previously thought possible. When charting the future of the subject, however, it is also necessary to consider its historical trajectory. This sense of opportunity and optimism has been experienced before, but not sustained. As such, our greatest challenge lies not in adopting technological developments, but in maintaining momentum. [ABSTRACT FROM AUTHOR]

The sedimentological and micropaleontological analysis of three mechanical cores in the marshland of Almenara (Valencian Community, Spain) has allowed the reconstruction of the Holocene evolution of this wetland. The cold and dry 8.2-ka event might be represented in Almenara by a massive carbonate precipitation bed, upon which mid- and late-Holocene sediments were subsequently deposited. The direct influence of sea-level changes has been recorded in the two cores (S-4 and S-5) located near the marsh barrier, at 400-450 m from the current coastline. The maximum flood area during MIS 1 (last 11,600 years) is represented in these cores by sediments indicative of different littoral subenvironments (shoreface, foreshore, backshore). These sediments contain typically littoral marine foraminiferal species such as Ammonia beccarii, Rosalina globularis, Asterigerinata mamilla, Adelosina longirostra, Cibicidoides lobatulus, Elphidium macellum, and Bolivina pseudoplicata. The base of these littoral sedimentary materials has been dated as 5480 and 5580 cal. yr BP. At this moment, the inner area (core S-7) was occupied by a restricted oligohaline marsh subject to water-table fluctuations and with scarce individuals of brackish water foraminifera, such as Ammonia tepida, Haynesina germanica, or Cribroelphidium excavatum, that in more recent times (since at least 1700 cal. yr BP) gradually evolved to a palustrine area. [ABSTRACT FROM AUTHOR]

Barrier/lagoon systems occupy a significant part of the world's coast. They are diverse in size, morphology, geological and oceanographic setting, and morphodynamic behaviour. Understanding the behaviour of barriers at 10 1 to 10 2  year and 10 1 to 10 2  km scales (mesoscale) is an important scientific and societal goal, not least because of the preponderance of intensive coastal development in a time of global climate change. Such understanding presents significant challenges. Challenges in describing mesoscale system behaviour relate largely to the incomplete evidence base of (i) morphological change in system components, (ii) dynamic and internal forcing factors (drivers) and (iii) geological constraints. These shortcomings curtail the development of baseline datasets against which to test models. Understanding observed changes and thereby predicting future behavioural patterns demands assumptions and simplifications regarding the linkages between initial state, dynamic drivers, system feedbacks and a multiplicity of geological constraints that are often location-specific. The record of mesoscale change is improving with the acquisition of long-term morphological datasets. Advances in technology and chronological control mean that geological investigations can now provide decadal to century-scale temporal resolution of morphological change. In addition, exploratory modelling is improving understanding of the influence of various dynamic and geological factors. Straightforward linking of dynamic forcing and response is seldom able to account for observed mesoscale behaviour. Geological factors exert a significant or even dominant control on barrier behaviour at decadal to century timescales. Whereas these geological controls can be quantified to some extent by detailed investigations of contemporary barrier/lagoon morphology and constituent materials, underlying geology and topography and sediment supply, in all but a few locations, such data are absent. This sets an unavoidable constraint on efforts to quantitatively predict the future behaviour of barrier systems, which are strongly site-specific in terms of their geological setting and morphology. Geological controls exist in a network of interactions that individually and collectively influence mesoscale barrier behaviour. Dominant, first-order controls are: • Basement slope; • Basement irregularity and erodibility; • External sediment supply; • Orientation; and • Shoreline lithification (beachrock and aeolianite) An important intermediate level of geological control is exerted by shoreface morphology. Shorefaces are themselves influenced by underlying geological factors, but they are dynamic at longer timescales than barriers. Geological influences are in most cases unquantified and are usually disregarded when conceptualizing and modelling barrier evolution. Consideration of the geological influences is, however, essential in efforts to predict future behaviour at mesoscale (management) timescales. [ABSTRACT FROM AUTHOR]

Ascaridoids are among the commonest groups of zooparasitic nematodes (roundworms) and occur in the alimentary canal of all major vertebrate groups, including humans. They have an extremely high diversity and are of major socio-economic importance. However, their evolutionary history remains poorly known. Herein, we performed a comprehensive phylogenetic analysis of the Ascaridoidea. Our results divided the Ascaridoidea into six monophyletic major clades, i.e. the Heterocheilidae, Acanthocheilidae, Anisakidae, Ascarididae, Toxocaridae, and Raphidascarididae, among which the Heterocheilidae, rather than the Acanthocheilidae, represents the sister clade to the remaining ascaridoids. The phylogeny was calibrated using an approach that involves time priors from fossils of the co-evolving hosts, and dates the common ancestor of the Ascaridoidea back to the Early Carboniferous (approximately 360.47–325.27 Ma). The divergence dates and ancestral host types indicated by our study suggest that members of the Ascaridoidea first parasitized terrestrial tetrapods, and subsequently, extended their host range to elasmobranchs and teleosts. We also propose that the fundamental terrestrial-aquatic switches of these nematodes were affected by changes in sea-level during the Triassic to the Early Cretaceous. [ABSTRACT FROM AUTHOR]

The most commonly cited control on delivery of sand to deep water is the rate of relative sea-level fall. The rapid rate of accommodation loss on the shelf causes sedimentation to shift basinward. Field and experimental numerical modeling studies have shown that deep-water sand delivery can occur during any stage of relative sea level position and across a large range of values of rate of relative sea-level change. However, these studies did not investigate the impact of sediment transport efficiency on the relationship between rate of relative sea-level change and deep-water sand delivery rate. We explore this relationship using a deterministic nonlinear diffusion-based numerical stratigraphic forward model. We vary across three orders of magnitude the diffusion coefficient value for marine settings, which controls sediment transport efficiency. We find that the rate of relative sea-level change can explain no more than 1% of the variability in deep-water sand delivery rates, regardless of sediment transport efficiency. Model results show a better correlation with relative sea level, with up to 55% of the variability in deep water sand delivery rates explained. The results presented here are consistent with studies of natural settings which suggest stochastic processes such as avulsion and slope failure, and interactions among such processes, may explain the remaining variance. Relative sea level is a better predictor of deep-water sand delivery than rate of relative sea-level change because it is the sea-level fall itself which promotes sand delivery, not the rate of the fall. We conclude that the poor relationship between sea level and sand delivery is not an artifact of the modeling parameters but is instead due to the inadequacy of relative sea level and the rate of relative sea-level change to fully describe the dimensional space in which depositional systems reside. Subsequently, sea level itself is unable to account for the interaction of multiple processes that contribute to sand delivery to deep water. [ABSTRACT FROM AUTHOR]

A multiproxy record comprising pollen, charcoal, loss on ignition and particle size analyses from two radiocarbon dated sediment cores from Klong Kone subdistrict on the western coast of the Gulf of Thailand provides insights on mangrove dynamics, environmental changes and human activities during the last 800 years. The mangroves were dominated by Rhizophora which indicates that the area has been influenced by the sea level from at least 820 cal BP until 720 cal BP. An intertidal area may have formed that supported mangrove development as part of an old shoreline during 820-720 cal BP. After 720 cal BP, mangroves decreased and were replaced by grasses, suggesting that a lower sea level caused the mangroves to grow closer to the sea until around 140 cal BP. Cereal pollen increased from 720 cal BP suggesting probable use of the shoreline for intensive cultivation. The mangroves were characterised by Avicennia, which increased toward the top of the 2 cores, suggesting that the mangroves then grew further inland, probably due to recent sea-level rise. Intensive human activity is recorded during the 20th century, as indicated by increased particle size, charcoal and carbonate content. At present, human activity in the area includes dams and construction as well as aquaculture. [ABSTRACT FROM AUTHOR]

Following the pioneering work of Schmiedt et al. (1972) on establishing the level of the Tyrrhenian Sea in Antiquity, a number of studies have examined this evidence from Roman Period fish tanks but with significantly different outcomes due primarily to different interpretations of the functional level of these pools at the time of their construction. As part of a longer term project to understand the causes of sea-level change around the Italian coast, we have reexamined and resurveyed 12 well-documented fish tanks, all based on the same construction principles, from the Tyrrhenian coast (between Formia and Orbetello) for which it can be established that they were in open contact with the sea at the time of operation. The structural features that tidally control the exchange of water used to define the ancient local sea level are identified as the channel thresholds, the sluice gate and sliding post positions, and the lowest level crepido. These are consistent for all the tanks examined, permitting the local sea-level change over the past 2000 years to be established at each location with a precision of ± 20 cm and against which other coastal archaeological features can be calibrated. We conclude that published local sea levels that are based on the present-day elevations of the foundations of protective walls constructed around the tanks and lie ~ 50 cm above our inferred levels are inconsistent with the successful functioning of the water exchange and have to be rejected. In one case, for Santa Liberata, we have been able to calibrate our interpretation against sedimentary evidence from the nearby Orbetello Lagoon that confirm our interpretation of the functional control level of the tanks and we conclude that the accuracy of our local sea levels is also ± 20 cm. The causes of sea-level change along this section of the coast are several, including land motion driven by tectonic and glacio-isostatic processes and any change in ocean volume. The individual estimates for the observed local sea levels range from − 0.9 to − 1.5 m with a mean value of − 1.22 ± 0.20 m. These values show that the spatial variability of the local levels is small and consistent with model-inferences of the glacio-isostatic process that indicate near-constant contributions for this section of coast and with tectonic inference from the elevations of the Last Interglacial shoreline. [ABSTRACT FROM AUTHOR]

Cambrian carbonates with abundant fossils of agnostoid trilobites deposited on the southern slope (Jiangnan slope belt) of the Yangtze Platform and in the Jiangnan deepwater basin are well exposed in the Wangcun Section of western Hunan, South China, and in the Duibian A Section of western Zhejiang, southeastern China, respectively. To better understand the response of carbon-isotope excursions to depositional environment changes, mass extinctions and eustatic events, we collected 530 carbonate samples in fresh roadcut exposures of the two measured sections for analysis of carbon and oxygen isotopic compositions. Data of δ13C from the Wangcun Section, western Hunan, South China, demonstrate that the Cambrian carbon-isotope profile includes three remarkable positive excursions CPEwc-1, 2, 3 in the Upper Series 2, in the Lower and in the Middle Furongian Series. Three distinctive negative excursions CNEwc-1, 2, 3 were separately tested in the Lower Terreneuvian Series, Lower Series 3 and in the Upper Furongian Series. Similarly, in the corresponding horizons in the Duibian A Section, Zhejiang Province, southeastern China, three positive excursions CPEdb-1, 2, 3 and three negative excursions CNEdb-1, 2, 3 also have been discovered. We interpret these significant carbon-isotope excursions as being associated with enhanced biogenic productivity, mass extinctions and eustatic events. [ABSTRACT FROM AUTHOR]

Abstract: In north‐central Alberta and adjacent British Columbia, clastic strata of the middle to late Albian Peace River and Shaftesbury formations were deposited in alluvial to shallow‐marine environments across the foredeep of the Western Canada Foreland Basin. A high‐resolution, log and core‐based allostratigraphic framework for the Paddy Member of the Peace River Formation established nine allomembers, PA to PI, bounded by flooding surfaces and apparently equivalent non‐marine surfaces. Within the estimated 2 Myr. duration of the Paddy, allomembers allow the evolving palaeogeography and changing relationship between accommodation and sedimentation rates to be analysed on time‐steps on the order of 105 years. Paddy strata fill an arcuate depocentre ca 300 km wide, across which the rocks thin eastward from 125 m to ca 5 to 10 m. The northern part of the basin is occupied by muddy, offshore marine deposits that pass abruptly southward into a linear, WSW‐ENE‐trending body of sandstone deposited in a wave‐dominated barrier‐strandplain, at least 350 km long. Extending >200 km to the south of the strandplain was a region of shallow brackish to freshwater lagoons and lakes that graded to the SW into alluvial facies. Within the lagoon region, few‐m thick, elongate and patchy sandstones represent river‐dominated deltas. In allomembers PA to PG, these sandstones are concentrated in the west and south, implying supply from the western Cordillera. In allomembers PH and PI, sandstones are mainly in the east and have a distinctive, quartz‐rich composition. They can be correlated eastward into the coeval Pelican Formation, and were sourced probably from the Canadian Shield on the opposite side of the basin. In the western foredeep, alluvial rocks comprise aggradational, unconfined floodplain deposits with ribbon sandstones, dissected, on at least nine separate levels, by palaeovalleys that are confined to the proximal foredeep. Valleys are 10 to 30 m deep, few km wide, and filled with multi‐storey channel‐bars of pebbly coarse sandstone or conglomerate. Valleys cut down from well‐developed interfluve palaeosols that record a falling and then rising water table. Alternating aggradation and degradation, and advance and retreat of the alluvial gravel front is attributed to cycles of varying rainfall intensity, rather than tectonism or eustasy. Apparently, coeval transgressive‐regressive successions in the lagoon and marine regions are attributed to few‐m scale eustatic changes. On the NE margin of the basin, tidal sandstone fills a northward‐opening estuary cut on the basal Paddy unconformity. This sandstone contains the first well‐documented specimens of Gnesioceramus comancheanus (Cragin), proving contemporaneity with at least part of the marine Joli Fou Formation to the east. Paddy allomembers change shape upward from short blunt wedges, through more acutely tapered wedges, to sheets. This change reflects initially rapid flexural subsidence, attributed to active thickening of the adjacent orogenic wedge. A waning rate of deformation permitted wider dispersal of sediment across the basin, driving broad isostatic subsidence beneath increasingly sheet‐like rock bodies. A major hiatal surface, VE3, records non‐deposition or subtle erosion attributed to erosional unloading and uplift of the adjacent orogen. A subsequent marine transgression is attributed to renewed thickening of the tectonic wedge that triggered deposition of marine mudstone that thickens westward from 0 to >110 m over 300 km. A postulated Milankovitch‐band climatic control on both local gravel supply (via fluctuating rainfall), and shoreline movement (via ?Antarctic glacio‐eustasy or groundwater storage), might account for cycles of alternating incision and aggradation in the alluvial realm. The same mechanism may also explain why shallow‐marine units such as the Cretaceous Viking and Cardium formations contain abundant conglomerate in lowstand shoreface deposits (higher river discharge), yet have highstand shorelines dominated by sandstone (lower river discharge). [ABSTRACT FROM AUTHOR]

The late Pliensbachian–early Toarcian (Early Jurassic) was a time of major environmental changes that culminated with the Early Toarcian Oceanic Anoxic Event (T-OAE, ca. ~183 Ma). This period is marked by significant disturbances in the carbon cycle and rapid climatic changes. To improve the understanding of the expression of these events in westernmost Tethyan domains, this study provides new belemnite and bulk carbonate C and O stable isotope records of a ~5 Myr upper Pliensbachian to middle Toarcian marine succession of the Balearic Basin (Es Cosconar section, Majorca). Time resolution has been improved by combination of biostratigraphic (ammonoids and brachiopods) and geochronologic ( 87 Sr/ 86 Sr) methods. Seawater paleotemperatures derived from δ 18 O belemnite records reveal cooler paleotemperatures in the upper part of the Spinatum Zone. The uppermost Spinatum Zone is characterized by the onset of a warming event that crosses the Pliensbachian-Toarcian boundary, culminating with the warmer temperatures (up to ~10 °C of warming) for the Serpentinum Zone of the lower Toarcian. This warming event has been detected contemporaneously in many other European and Tethyan basins and is interpreted to represent generalized raised seawater temperatures linked to the T-OAE. Four significant δ 13 C events have been recorded in belemnite and bulk carbonate records. The first is a negative carbon isotope excursion (CIE) around the Pliensbachian-Toarcian boundary, which is best represented in the belemnite record. Soon after, the bulk‑carbonate record shows a positive shift in the lower Tenuicostatum Zone concomitant with a return to background values in the belemnite record, suggesting strong water stratification or decoupling probably related with export of neritic carbonate to the basin. The third is a negative CIE represented in bulk carbonate across the Tenuicostatum - Serpentinum zonal transition, which could be correlated with the negative excursion characterizing the onset of the T-OAE in other sections. The position of this excursion corresponds with a gap in the belemnite record. Finally, in the lower Toarcian, both the bulk carbonate and belemnite carbon isotope records show pronounced positive CIEs in the lower-middle part of the Serpentinum Zone. These CIEs testify the impact of the T-OAE in the Balearic basin. [ABSTRACT FROM AUTHOR]

Ongoing glacial isostatic adjustment (GIA) due to surface loading (ice and water) variations during the last glacial cycle has been contributing to sea-level changes globally throughout the Holocene, especially in regions like Canada that were heavily glaciated during the Last Glacial Maximum (LGM). The spatial and temporal distribution of GIA, as manifested in relative sea-level (RSL) change, are sensitive to the ice history and the rheological structure of the solid Earth, both of which are uncertain. It has been shown that RSL curves near the center of previously glaciated regions with no ongoing surface loading follow an exponential-like form, with the postglacial decay times associated with that form having a weak sensitivity to the details of the ice loading history. Postglacial decay time estimates thus provide a powerful datum for constraining the Earth's viscous structure and improving GIA predictions. We explore spatial patterns of postglacial decay time predictions in Hudson Bay by decomposing numerically modeled RSL changes into contributions from water and ice loading effects, and computing their relative impact on the decay times. We demonstrate that ice loading can contribute a strong geographic trend on the decay time estimates if the time window used to compute decay times includes periods that are temporally close to (i.e. contemporaneous with, or soon after) periods of active loading. This variability can be avoided by choosing a suitable starting point for the decay time window. However, more surprisingly, we show that across any adopted time window, water loading effects associated with inundation into, and postglacial flux out of, Hudson Bay and James Bay will impart significant geographic variability onto decay time estimates. We emphasize this issue by considering both maps of predicted decay times across the region and site-specific estimates, and we conclude that variability in observed decay times (whether based on existing or future data sets) may reflect this water loading signal. [ABSTRACT FROM AUTHOR]

Diverse paleoceanographic proxies from three sediment cores (GC12ex, JPC35, and JPC30) collected from the Chukchi Shelf north of the Bering Strait elucidate the Holocene paleoceanographic changes (surface water productivity and sediment transport) caused by the Bering Strait throughflow from the Bering Sea into the Chukchi Sea. Lithology of three sediment cores identified the same three units. Based on comparison and correlation to adjacent agedated cores as well as AMS 14C dates of core GC12ex, the boundary between Unit 1 and Unit 2a is dated about 8500 cal. yr BP, and the boundary between Unit 2a and Unit 2b is also dated about 4500 cal. yr BP. Consistent down-core profiles of the geochemical and isotopic properties among the three cores differentiate the paleoceanographic conditions corresponding to lithologic units. Based on the biogenic opal, total organic carbon, and δ13C values, Unit 1 is characterized by low surface water marine productivity under relatively shallow water with weak transport of Bering Strait throughflow. Unit 2a shows a mixture of terrestrial and marine contributions, indicating the onset of increased marine surface water productivity after the main flooding (~11,500 cal. yr BP) of the Bering Strait by the Holocene sea-level rise. Unit 2b exhibits stable and enhanced marine biogenic opal production similar to the presentday oceanographic conditions. Such paleoceanographic changes were confirmed by the clay minerals (smectite, illite, kaolinite, and chlorite) and detrital isotopes (εNd and 87Sr/86Sr). Thus, the Bering Strait throughflow played an important role on surface water productivity and sediment deposition in the Chukchi Shelf in response to Holocene sea-level rise after the opening of the Bering Strait. [ABSTRACT FROM AUTHOR]

ABSTRACT Jeong, E.J.; Woo, H.J.; Kang, J.; Lee, J.-H., and Choi, J.U., 2018. Study of Holocene paleo-environmental evolution using cores from the downstream area of the Nakdong River Delta, Korea. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 626–630. Coconut Creek (Florida), ISSN 0749-0208. The Nakdong River Delta in Korea consists of wide and thick sediments, which are excellent for undertaking highresolution investigations of paleo-environmental evolution. This study describes the horizontal evolution of the sediment environment during the Late Quaternary based on the KND-3 and ND-3 cores obtained from the downstream area of the Nakdong River Delta. The lowest sediments in these cores differ markedly, with KND-3 mainly being composed of olive gray coarse, sandy sediments with pebbles of c. 2-cm diameter, which are interpreted as representing a paleo-channel environment, and ND-3 mainly consisting of red silty sediments (paleosol), which are interpreted as representing alluvial deposits that were exposed to the atmosphere. By contrast, the upper sediments above 40.00 m in both cores were deposited when the sea level rose to a similar level as seen today, at which time both cores evolved through a succession of environments from estuary complex, through to shallow-marine, prodelta, delta front, and the present-day delta plain. [ABSTRACT FROM AUTHOR]

Abstract: This reports on a project that combined evidence gleaned from aerial photographs, place‐names, interviews, topography, LIDAR data, and sonar bathymetry to locate stone tidal fish weirs in the Molène Archipelago. The results were verified by diver and pedestrian visual surveys. Models of Holocene sea‐level change allowed a group of possibly Late Mesolithic–Early Neolithic weirs to be recognized, with a second group broadly dated to the later Neolithic–Early Bronze Age. The construction of these long megalithic structures is compared to the funerary monuments for which the Molène Archipelago is well known, in terms of technique, cost, and societal organization. [ABSTRACT FROM AUTHOR]

We present a history of late Quaternary coastal evolution based on the study of a 41.9-m-long sediment core from the Oujiang Delta. Multiple analytical methods are employed, including sedimentary facies analysis, radiocarbon dating, and the investigations of grain size, elemental, microfossil and pollen compositions. Two transgression-regression sequences, separated by a paleosol layer, are identified. Several lines of evidence indicate that the lower sequence was deposited during the mid-early MIS 3 stage, under a relatively warm and wet climate. An elevated MIS 3 highstand sea level (higher than − 24 m) is observed. The upper sequence was created after the paleosol was flooded during a marine transgression at ~ 9.5 cal kyr BP. Seven weak East Asian Summer Monsoon (EASM) events are identified with central years of ~ 8.4, 7.7, 6.3, 5.7, 4.7, 2.8 and 1.8 cal kyr BP. These coincide with those from the ECS sediment cores and the Dongge Cave δ 18 O record, indicating that EASM precipitation is a major controlling factor of sedimentation rates in the region. The Oujiang Delta is also subject to typhoon impacts and East Asian winter monsoon (EAWM)-induced coastal currents. Active typhoons and a relatively enhanced EAWM occurred during the weak EASM period between 4.9 and 6.4 cal kyr BP, producing high sedimentation rates in the middle Holocene. We emphasize the high sensitivity of small Asian river deltas as archives of the EASM, EAWM and typhoons. Such environments merit further as a means to understand past changes as well as future responses to projected climatic and sea-level change. [ABSTRACT FROM AUTHOR]

The widely quarried and commercially exploited Gonioclymenia Limestone of the western and southern Tafilalt Platform (Anti-Atlas, SE Morocco) represents a transgressive but strongly condensed and shallowing upwards unit that overlies conformably or unconformably Famennian to Lower Devonian deposits. It is characterized by abundant, giant-sized Gonioclymenia speciosa, which characterizes the Famennian V-B, and rare Leviclymenia ramula sp. nov. Associated conodont faunas fall in the Bispathodus costatus Subzone of the B. aculeatus aculeatus (= Middle expansa) Zone. A rare outcrop at Jebel Ihrs West proved that Kalloclymenia and conodont faunas of the B. ultimus ultimus (= Upper expansa) Zone occur in a separate, overlying unit of the lower part of Famennian VI. Consequently, joint occurrences of Gonioclymenia and Kalloclymenia on large limestone slabs that are on offer in rock shops are artificial assemblages; there is no evidence for a regional co-occurrence of both genera. This is supported by correlation into thicker sections of the adjacent Maider and Tafilalt Basins. The Tafilalt Gonioclymenia Transgression may represent the regional expression of a eustatic pulse in the B. costatus Subzone that is known on the Ardennes Shelf as the transgressive Epinette Event. The conodont faunas yielded Neopolygnathus fibula sp. nov., Pseudopolygnathus primus tafilensis ssp. nov., new morphotypes of B. spinulicostatus and Pseudopolygnathus primus primus, the oldest Siphonodella (Eosiphonodella) and variable 'siphonodelloids' that are currently left in open nomenclature. [ABSTRACT FROM AUTHOR]

This study assesses the use of the Tescan Integrated Mineral Analyser (TIMA) platform, which integrates scanning electron microscopy—energy dispersive spectroscopy (SEM-EDS) chemical analysis with mineral identification software, to quantitatively determine the mineralogical composition of sediments in archaeological research. Ten samples, spanning 50,000 years of sedimentation, were examined from archaeological excavation profiles in the Boodie Cave, Barrow Island, Western Australia. TIMA mineral abundance data show a gradual change from a polymineralogic quartz-rich assemblage from ~50–12 ka to a more simple carbonate-dominate assemblage from the terminal Pleistocene. This trend is consistent with a decreasing contribution of reworked terrestrial siliciclastic sediments derived from the mainland and an increase in carbonate sediments of marine derivation, as the exposed coastal plain become submerged during post-glacial sea-level rise. SEM-EDS analysis has also provided empirical data on cultural materials, mainly bone and shell fragments that similarly reflect the increasing contribution of marine fauna into the Holocene sediments. Particularly useful is the ability of mineral mapping function of the TIMA outputs to help distinguish 16 sub-units representing sections of the main nine stratigraphic units, including at least three contiguous midden events. The SEM-EDS data indicate that the redeposited sediments were derived from the overlying midden unit, with layering reflecting differential settling of mineral phases. This study demonstrates that automated mineralogy studies using TIMA can clearly aid the identification of provenance and processes within archaeological sediments and soils. [ABSTRACT FROM AUTHOR]

The Manawatu incised-valley estuary was rapidly infilled between 12,000–4700 cal. yr BP. A combination of empirical measurements of sedimentation rates, a reconstruction of relative sea-level (RSL) change, and digital elevation models of key surfaces within the Holocene sedimentary fill of the valley were integrated to produce a numerical model to investigate the influence of the system controls of sea-level change, sediment flux, and accommodation space on the rapid infilling history of the palaeo-estuary. The numerical model indicates that sediment flux into the palaeo-estuary was greatest during the Holocene marine transgression between 12,000–8000 years BP. The average rate of sediment deposition in the estuary during this period was ~ 1.0 M m 3 yr − 1 . This rapid rate of sedimentation was controlled by the rate of accommodation space creation, as regulated by the rate of sea-level rise and the antecedent configuration of the valley. By the time sea levels stabilised c. 7500 cal. yr BP, the palaeo-estuary had been substantively infilled. Limited accommodation space resulted in rapid infilling of the central basin, though sediment flux into the estuary between 7100 and 4500 cal. yr BP was at a lower rate of 234,000 m 3 yr − 1 . The limited accommodation space also influenced hydrodynamic conditions in the estuarine central basin, driving export of fine-grained sediment from the estuary. Once the accommodation space of the estuarine basin was infilled sediment bypassed the system, with a consequent reduction in the sedimentation rate in the valley. More accurate partitioning of the sources of sediment driving the infilling is necessary to quantify sediment bypassing. Post-depositional lowering of RSL index points from the valley is driven by neotectonics and sediment compaction. [ABSTRACT FROM AUTHOR]

Future changes in sea-level are projected to have significant environmental and social impacts, but we have limited understanding of comparable rates of change in the past. Using comprehensive palaeoenvironmental and archaeological datasets, we report the first quantitative model of the timing, spatial extent and pace of sea-level change in the Sahul region between 35-8 ka, and explore its effects on hunter-gatherer populations. Results show that the continental landmass (excluding New Guinea) increased to 9.80 million km 2 during the Last Glacial Maximum (LGM), before a reduction of 2.12 million km 2 (or ∼21.6%) to the early Holocene (8 ka). Almost 90% of this inundation occurs during and immediately following Meltwater Pulse (MWP) 1a between 14.6 and 8 ka. The location of coastlines changed on average by 139 km between the LGM and early Holocene, with some areas >300 km, and at a rate of up to 23.7 m per year (∼0.6 km land lost every 25-year generation). Spatially, inundation was highly variable, with greatest impacts across the northern half of Australia, while large parts of the east, south and west coastal margins were relatively unaffected. Hunter-gatherer populations remained low throughout (<30,000), but following MWP1a, increasing archaeological use of the landscape, comparable to a four-fold increase in populations, and indicative of large-scale migration away from inundated regions (notably the Bass Strait) are evident. Increasing population density resulting from MWP1a (from 1/655 km 2 to 1/71 km 2 ) may be implicated in the development of large and complex societies later in the Holocene. Our data support the hypothesis that late Pleistocene coastal populations were low, with use of coastal resources embedded in broad-ranging foraging strategies, and which would have been severely disrupted in some regions and at some time periods by sea-level change outpacing tolerances of mangals and other near-shore ecological communities. [ABSTRACT FROM AUTHOR]

The Neoproterozoic Cryogenian (‘Marinoan’) Ghaub Formation of northwestern Namibia represents an important founding pillar of the Snowball Earth hypothesis and its derivative, the Panglacial Earth hypothesis. These hypotheses assume oceans and continents covered by thick ice, even in the tropics, which caused a very distinct drop in eustatic sea-level. Over time, strongly increased CO 2 contents of the atmosphere led to sudden ice melting, very substantial sea-level rise, and strong weathering on the continents associated with the deposition of cap carbonates in the newly ice-free oceans. The ongoing controversy about Snowball-type glaciations in Namibia and elsewhere is reviewed, and other hypotheses (Slushball Earth, Waterbelt Earth, Jormungand state of the Earth, Thin Ice state of the Earth, Zipper-Rift Earth, High-Obliquity Earth) are discussed. We prefer the term ‘Waterbelt Earth’ instead of the originally proposed ‘Waterbelt state’ because of the clearer contrast with ‘Snowball Earth’. Because a great deal of information related to Cryogenian glaciations comes from the Ghaub Formation of northwestern Namibia, these hypotheses should be tested independently based on a time-equivalent depositional system. This analogue was found in the carbonate-dominated successions of the Otavi Mountainland (OML), northeastern Namibia, and is highly comparable with the successions in the well-investigated northwest of the country. An extreme eustatic sea-level drop caused by a global glaciation of oceans and continents and imposed on a carbonate platform or ramp such as the one in the OML would have led either to glacial cover or widespread subaerial exposure and extensive erosion, including deeply incised valleys. The presence of such features would strongly support the Snowball Earth hypotheses if tectonic effects did not play a major role. During the postglacial transgression, distinct reworking of the carbonate platform/ramp surface would have occurred, leaving behind lag deposits, as well as infills of incised valleys with fluvial, reworked glacial, and marine deposits. The main objective of our research was to weigh and investigate the strengths and weaknesses of the proposed Snowball Earth model of glacially induced large-amplitude sea-level changes during Ghaub time, and to compare different models to obtain a rough estimate of the amount of glaciation. The study area in the OML includes two different, age-equivalent facies realms: platform sedimentation in the Southern area without diamictites, and slope deposits, including Ghaub diamictites, in the Northern area. The southern, continuously shallow-marine area shows a shallowing-upward succession from the pre-glacial lower Auros Formation, often varve-like laminated shales formed below wave base, to metre-high columnar stromatolites and microbial mat-related carbonates with intervals of vertical tubes (degassing features) of the upper Auros Formation, overlain by cap carbonates of the Maieberg Formation. The columnar stromatolites and the microbial tubestone lithotypes were clearly deposited in the euphotic zone. Indications for tidal conditions or subaerial exposure were not recorded in this platform succession without unconformities. Neither dropstones, nor incised channels, nor transgressive lag deposits were observed. The facies changes from below storm wave base to the photic zone and finally a shallow subtidal zone is explained by a prolonged, modest sea-level fall, partly counterbalanced by subsidence, followed by a slow transgression. In contrast, coarse-grained sedimentary rocks (e.g., oolites, debrites) characterise the time-equivalent successions in the Northern area. Starting with laminated shales at the base, similar to the Southern area, the overlying redeposited oolites and breccias of the Auros Formation show distinct lateral and vertical inhomogeneities and thickness changes, which indicate long-lasting synsedimentary tectonism. The same phenomenon is observed in the overlying diamictites of the Ghaub Formation. Their variable clast content indicates erosion of a strongly uplifted local source area formerly covered by a thick carbonate succession, which was downstripped to the crystalline basement. The prograding diamictite succession with repeatedly intercalated silt-stringers is interpreted as periglacial debris flows into a marine environment. Sparse striated clasts in the diamictites and very rare dropstones (much less common than in northwestern Namibia) are indicators of glaciations somewhere in the area. However, compared with other glacial sequences, e.g. Quaternary periglacial sediments at the forefront of continental ice, dropstones and striated clasts would be expected to be much more common and more uniformly distributed if the entire area was covered by melting continental ice, as proposed in the Snowball/Panglacial Earth scenario. In the Southern area, dropstones would be expected to occur on the flooded platforms/ramps as well, even when diamictites are absent. Both the relatively moderate sea-level change and the less common, irregular distribution of locally concentrated glacial rainouts provide strong evidence against the presence of a thick, laterally continuous ice cover over oceans and continents extending to equatorial areas. The oceans possibly corresponded to the scenario of a Waterbelt Earth or High-Obliquity Earth; evidence of open oceanic water exists, which would have enabled the continued evolution of biota. Glacial ice was present on tropical continents, but its occurrences may have been regional in patches, sourced from mountainous areas, and ice streams would have reached the oceans only locally, unrelated to a thick continental ice cover. [ABSTRACT FROM AUTHOR]

The rate of relative sea-level (RSL) rise at Sandy Hook, NJ (4.0 ± 0.5 mm/yr) was higher than The Battery, NY (3.0 ± 0.3 mm/yr) from 1900 to 2012 despite being separated by just 26 km. The difference cannot be explained by differential glacial isostatic adjustment (GIA; 1.4 ± 0.4 and 1.3 ± 0.4 mm/yr RSL rise, respectively) alone. We estimate the contribution of sediment compaction to subsidence at Sandy Hook using high-resolution grain size, percent organic matter, and porosity data from three upper Quaternary (≤13,350 cal yr) cores. The organic matter content (<2%) is too low to contribute to local subsidence. However, numerical modeling of the grain size-depth-age-porosity relationship indicates that compaction of deglacial silts likely reduced the column thickness by 10–20% over the past 13,350 cal yrs. While compaction rates were high immediately after the main silt deposition (13,350–13,150 cal yrs BP), rates decreased exponentially after deposition to an average 20th century rate of 0.16 mm/yr (90% Confidence Interval (C.I.), 0.06–0.32 mm/yr). The remaining ∼0.7 mm/yr (90% C.I. 0.3–1.2 mm/yr) difference in subsidence between Sandy Hook and The Battery is likely due to anthropogenic groundwater withdrawal. Historical data from Fort Hancock wells (2 km to the southeast of the Sandy Hook tide gauge) and previous regional work show that local and regional water extraction lowered the water levels in the aquifers underlying Sandy Hook. We suggest that the modern order of contribution to subsidence (highest to lowest) appears to be GIA, local/regional groundwater extraction, and compaction of thick Quaternary silts. [ABSTRACT FROM AUTHOR]

The timing and choice of initial settlement location are examined on the small island of Tavua in Fiji's Mamanuca Group. The mid- to late-Holocene sealevel retreat influenced the island's coastal landforms through the acceleration of coastal progradation and the production of habitable land. Archaeological, sedimentological, and chronological data are integrated to better understand the island's settlement and geomorphological history. These datasets are then compared with regional and modeled sea-level curves for Fiji in order to constrain the time period for the onset of coastal regression. The results indicate that Tavua was initially settled around 3000 years ago, within a few centuries of the formation of the coastal plain. Integrating archaeological, sedimentological, and sea-level datasets helps produce a more precise understanding of the relationship between sea-level change and the timing of settlement on small islands in Oceania. [ABSTRACT FROM AUTHOR]

The Penmarc’h granitic coastal domain, SW Brittany (Western France), offers the opportunity to address the little investigated issue of erosional processes in a granitic coastal context. From land to sea, the granitic coast is composed of 1) an aerial marine terrace ( <4 km), 2) a large shore platform ( <800 m), 3) an extensive submarine rocky platform ( <7 km), corresponding to the inner shelf, and 4) an outer shelf. Our geomorphological study, further completed by cosmogenic nuclide ( 10 Be) analyses, supplies new constraints on the weathering and denudation processes recorded by the Penmarc’h platform in Quaternary times. The role of at least two denudation events is emphasized: (i) a >1.8 m-thick level of granitic material is assumed to have been removed by erosion during the MIS5 sea-level highstand, both in the offshore domain and in the low part of the marine terrace; (ii) an additional 0.6 m-thick level of the granitic substratum was later removed during the last Holocene transgression, mainly in the marine domain. The lack of any morphological step between the subaerial marine terrace and the shore platform is here attributed to the combined effect of multiple factors, including (i) a Quaternary tectonic quiescence, (ii) a major eustatic transgression (MIS5) shaping both the shore platform and the low part of the marine terrace, (iii) the mechanically strong behaviour of the granitic basement with regard to erosion, and (iv) the moderate influence of the Holocene sea-level stillstand (since 6 ka) on the shore platform. Thanks to 10 Be content analysis, a range of vertical erosion rates of ca. 3–6 m⋅Ma −1 is obtained for the onshore domain, showing no discernable difference between the intertidal and aerial erosion rates. From that result, it is thus determined that the long-term development of the Penmarc’h granitic shore platform was mainly driven by marine erosive processes during the MIS5 and Holocene marine transgressions, whereas subaerial erosive processes prevailed after the MIS5 event. [ABSTRACT FROM AUTHOR]

At many times during the Quaternary, when the global sea level was much lower than today (at least 30 m), the Thai-Malay Peninsula was connected by land to the Indonesian archipelago. This now submerged region is known as Sundaland and played a key role in the expansion of flora, fauna, and humans during the Quaternary. However, information regarding past environmental conditions is sparse as post-glacial sea-level rise submerged and eroded most sedimentary archives. In this study, a combination of geomorphological mapping, investigating sedimentary features, and optically stimulated luminescence dating is used to decipher the evolution of sand ridges found in the coastal zone of the Nakhon Si Thammarat Province, southern Thailand. The two main ridges (eastern and western) are composed of moderately to poorly sorted medium to coarse, structureless massive sands. The eastern ridge deposited between ca. 8.3 ka and 0.16 ka and formed by coastal processes related to sea-level change and storm surge during the Holocene. Surprisingly, the western ridge yields a minimum depositional age of ca. 82 ka, and further deposition dates to different periods of the Late Pleistocene. We suggest that the initial formation of the western ridge possibly occurred during the Last Interglacial (Marine Isotope Stage 5e). During periods of low global sea level, when the region was far away from the coast, the ridge accumulated further sand, most likely due to aeolian activity. This would imply a rather limited vegetation cover in the interior of Sundaland and support previous assumptions of savannah-like conditions during global-scale glacial periods. • Holocene ridges deposited in association with sea-level changes and storm surges. • Pleistocene ridges older than 82 ka, probably dating to MIS 5e. • During Sundaland exposure, ridges were modified by aeolian processes. • Aeolian deposits likely reflect savannah ecosystem in interior Sundaland during Late Pleistocene. [ABSTRACT FROM AUTHOR]

The Cretaceous–Paleogene (K–Pg) boundary interval at Gabal Aras, Qena region (part of the southern Tethyan margin) was investigated in detail for calcareous nannofossil and foraminiferal (planktonic and benthonic) assemblages to characterize the surface and bottom sea water conditions. The K–Pg boundary is marked by a minor hiatus expressed by the absence of the lowermost Danian P0 and Pα planktonic foraminiferal zones. Benthonic foraminifera assemblages indicate moderately oxygenated bottom sea waters associated with oligo-mesotrophic conditions during early late Maastrichtian, and mesotrophic conditions during the latest Maastrichtian. The benthonic foraminiferal assemblage reflects a decrease in the food supply in the bottom sea water during the early Danian, while well-oxygenated and oligotrophic conditions dominated during late Danian. The late Maastrichtian surface water witnessed a general cooling trend that was interrupted by a warming episode that could correspond to the Late Maastrichtian Warming Event (LMWE). Acme of Thoracosphaera associated with increased abundance of Neobiscutum romeinii were observed within the upper part of NP1 Zone indicating stressful surface water conditions. The increase of the epifaunal foraminiferal taxa and the occurrence of Cruciplacolithus primus throughout NP2 and NP3 zones reflect a progressive return to normal marine conditions. In the framework of sequence stratigraphy, two third-order depositional sequences covering the K–Pg boundary interval were identified, interpreted, and correlated. The obtained sea-level curve was evaluated to assess whether it was controlled by the eustatic sea-level changes, regional tectonics, or both these factors. • One stratigraphic section encompasses the K-Pg boundary interval examined in detail. • The Bottom water did not experience significant environmental perturbation. • Late Maastrichtian Warming Event was recorded. • Two third-order depositional sequences (SQ1-SQ2) were recorded. • The sea-level is controlled by eustasy and tectonic events. [ABSTRACT FROM AUTHOR]

The southeastern China coast is a region of special interest in the study of past and present relative sea-level change, given its distal location from giant ice sheets (far-field regions). During the past decades, a large number of biological, geological, and archaeological sea-level indicators have been retrieved from the Fujian coastal region which allows for recalibration and recalculation of sea-level index points (SLIPs). This study constructs a database of Holocene relative sea-level (RSL) observations for the Fujian coast, southeastern China. The database contains 59 quality-controlled SLIPs which show that RSL for the Fujian coast did not exceed present (0 m) during the Holocene, except potentially during 7.5–5.5 cal. kyr BP and 1.8–0.7 cal. kyr BP. Rates of RSL change were highest during the early Holocene and have decreased over time, due to the diminishing response of the Earth's mantle to glacial isostatic adjustment (GIA) and reduction of meltwater input. A series of sea-level oscillations were recorded in our SLIPs-based reconstructions which might correspond to global climate warming or cooling events. We assessed the spatial variability of RSL histories and compared these with the ICE-6G_C and ANU-ICE GIA model predictions. Substantial misfits between GIA predictions and regional RSL reconstructions were recognized: (1) the deceleration of the early-Holocene sea-level rise ended about one millennia earlier in the ICE-6G_C model than in the SLIPs-based reconstructions; (2) GIA model predictions show a mid-Holocene sea-level highstand of 1–3 m which is absent from our SLIPs-based reconstructions; and (3) all GIA model predicted a gradual RSL fall to 0 m since the middle Holocene, while our reconstruction displays significant RSL oscillations. It is presently unknown whether these misfits are caused by uncertainties in regional tectonic movement estimation or parameters used in the GIA models. Future applications of spatiotemporal statistical techniques are required to better quantify the gradient of the isostatic contribution and to provide improved context for the assessment of the ongoing acceleration of sea-level rise. • Holocene sea level index points (SLIPs) for the Fujian coast have been standardized. • SLIPs-based relative sea level (RSL) reconstructions are compared to model predictions. • Early-Holocene rapid RSL rise terminates earlier in models than in reconstructions. • Mid-Holocene highstands are captured in models but not obvious in the reconstruction. • Local tectonic and modelling parameter selection might have resulted in the misfits. [ABSTRACT FROM AUTHOR]