Early Holocene Sea-level Rise Research Articles

Calibrating Holocene human–environment interactions using ancient narratives: The example of Ngurunderi in South Australia

The essence of stories of human–environment interactions can be preserved in oral contexts for millennia, creating novel opportunities for humanizing the past. This study examines stories (knowledge-rich narratives) about the ancestral being Ngurunderi, told by Ngarrindjeri peoples of South Australia. Three elements of the Ngurunderi narrative are considered. The first recalls his journey along a 170-km long coastal barrier (Younghusband Peninsula) when this was continuous. The second discusses Ngurunderi’s encounters with what are now islands off the Fleurieu Peninsula, some of which he created, interpreted as memories of when sea level was lower and “islands” were contiguous with the mainland. The third refers to the crossing of a land connection between modern Kangaroo Island and the Fleurieu Peninsula, later submerged to form Backstairs Passage. Using paleogeographic data, the most recent times at which each narrative element could have taken place and observed by people are estimated. This research suggests that: (1) stories about Younghusband Peninsula may be >6700 years cal BP; (2) islands off the Fleurieu Peninsula were created 6800–10,400 cal BP; and (3) submergence of Backstairs Passage occurred 11,000–10,100 cal BP. Narratives are linked to the period of early Holocene sea-level rise, the rapid 8200-cal BP sea-level rise event, and stabilization of sea level 7000–6000 cal BP. These narratives humanize the past and provide information that can be interpreted as both observed coastal and seascape changes as well as past human responses to rising sea level that can inform our future encounters with coastal-landscape change.

Earliest Neolithic occupation and maritime adaptation on the West Pacific coast

Maritime adaptation plays a significant role in the dispersal of modern humans and the transition of subsistence strategies. The real timing of the worldwide intensification of maritime adaptation has been debated mainly because of the presumed inundation of archaeological sites (prior to 7000 cal yr BP) by early Holocene sea-level rise. In this study, we present a coastal shell midden submerged ∼8 m below the present sea level at the Jingtoushan site, containing robust evidence of the earliest Neolithic occupation and maritime adaptation on the West Pacific. Bayesian modelling of 15 14C dates, cultural deposits, and microfossils (pollen, phytolith, and diatom) indicated that the Jingtoushan site was an anthropogenic deposit originally accumulated on the coastline during the stable sea-level period (8000–7600 cal yr BP) and subsequently submerged by sea-level jumps. In addition to being largely dependent on marine food resources, humans also utilised the stable sea-level window of meltwater pulses and began rice cultivation. This study not only pushed back the timing of maritime adaptation to 8000 cal yr BP but also provides promise for future investigations of coastal underwater settlements, shedding new light on the understanding of the West Pacific coastal environment and cultural succession.

The Clay Mineralogy and Geochemistry of Sediments in the Beibu Gulf, South China Sea: A Record of the Holocene Sedimentary Environmental Change

In this study, we analyzed the clay mineralogy and geochemistry of surface and drill core samples from the northeastern Beibu Gulf in order to unravel the sediment provenance of, and factors controlling, the sedimentary environment. The main clay mineral assemblage in the surface sediment samples included kaolinite (27–72%), smectite (4–51%), illite (7–20%), and chlorite (8–17%). The study area comprises three major clay distribution zones (from the northeastern coastal area to central Beibu Gulf basin), i.e., the kaolinite-dominated, kaolinite–smectite, and smectite-dominated zones. The zoning of the clay mineralogy and major and trace elements indicated the mixing of coarse terrigenous sediments with distal fine sediments. Early Holocene sea level rise was documented in core B15-1, which had three sedimentary units (divided into Units 1–3 from top to bottom), as revealed by the changes in the dominant clay minerals and geochemical/oxide ratios (SiO2/Al2O3, Rb/Sr, Sr/Ba, and Ti/Ca) in Unit 2. Unit 1 and Unit 3 were likely deposited in the continental and marine environments, respectively. The low sedimentation rate and hydrodynamic disturbance may have influenced the deposition process more than climatic fluctuations.

Stratigraphic expression of the human impacts in condensed deposits of the Northern Adriatic Sea

Abstract Evaluating the history of human impacts on marine ecosystems based on sediment cores is challenging on shelves characterized by very slow sedimentation. To assess the stratigraphic expression of such impacts in the condensed deposits of an epicontinental sea, we analysed a 3 m-long core collected at 31 m water depth off the Po prodelta in the Northern Adriatic Sea by integrating geochronological ( 14 C and 210 Pb), sedimentological, geochemical and palaeontological proxies. A depositional history of the last 10 000 years is expressed in four different facies: (1) alluvial floodplain, (2) transitional, shell-poor silts, (3) a condensed 30 cm-thick shell lag, and (4) a 10 cm-thick layer of distal prodelta silts comprising the last c. 500 years. 10 000-year-old shells of Lentidium mediterraneum spread over the shell lag and prodelta sediments document onshore transport during the early Holocene sea-level rise. Varicorbula gibba shells are age-homogeneous within the subsurface shell lag, documenting decimetre-scale mixing by bioturbation in the past. However, in spite of low sedimentation rates, the organic and heavy metal enrichment, the increase in proportional abundance of benthic foraminifers preferring organic-rich sediments ( Nonionella sp.), and the increase in size of molluscs ( V. gibba ) in the upper 10 cm formed by prodelta silts still detect the eutrophication in this region during the twentieth century. These eutrophication proxies are preserved in the stratigraphic record owing to temporarily increasing sedimentation rate and decreasing mixing depth.

Tracking barrier island response to early Holocene sea-level rise: High resolution study of estuarine sediments in the Trinity River Paleovalley

Understanding how barrier islands respond to factors such as variations in sediment supply, relative sea-level rise, and accommodation is valuable for preparing coastal communities for future impacts of climate change. Increasingly, the underlying antecedent topography has been observed to have a significant control on the evolution of the barrier island system by providing increased elevation, decreased accommodation, and sediment supply for the barrier to rework and anchor upon. However, less attention has been focused on how back barrier sediments respond to this decreased accommodation, and how this may affect barrier island evolution. Additionally, the control in which the geometry of the underlying antecedent topography has on the initiation of barrier islands is poorly understood. Here we examine the stratigraphic framework of the Trinity River incised valley offshore Galveston, Texas to investigate the role of antecedent topography in the evolution of an early Holocene barrier island system. We present high-resolution imaging of the Trinity incised valley fill using over 1200 km2 of 3D seismic, ~700 km of 2D envelope and full waveform chirp data, along with 2 piston cores, 4 gravity cores, and 1 platform boring with associated grain size, foraminiferal, and radiocarbon data. We find that the geometry and elevation of the underlying antecedent topography plays a central role in the evolution of the barrier island system, promoting both initiation and stabilization. This study provides a methodology to investigate the evolution of a relict barrier island system where little to none of the barrier is preserved. With this methodology, we revise the established Holocene paleoshoreline model for the Trinity incised valley.

Holocene monsoon and sea-level variability from coastal lowlands of Kerala, SW India

The widespread Early Holocene sea-level rise observed along the global coastal realms reinvigorated the need to decipher sea-level variability on a local and regional scale, yet limited attempts were made on simultaneously addressing sea-level and climate variability. The southwest coast of India is endowed with several geomorphic features providing cues on the paleosea-level and climate variability engrossed with its sedimentary sequence in the lowlands. In view of this, the present study aims to decipher the Holocene sea-level and climate variability based on geochemical and palynological proxies supported by 10 AMS radiocarbon ages on a 32 m long sediment core (L7) raised from Upper Kuttanad Kole wetlands (Kuttoor), Kerala, Southwest India.The study demonstrated high sea-level along with warm and wet climate due to Indian summer monsoon (ISM) intensification during 9.69–7.56 ka corroborating with the Holocene Climate Optimum (HCO). However, a break in the sediment deposition is observed between 7.56 and 3.51 ka, the reason for which is yet to be fully understood. During 3.51–2.55 ka, the gradual weakening of ISM has been invoked with an intermittent monsoon spell during 3.20–3.40 ka. After 2.55 ka the sediment core records occurrence of coarser clastics indicating sediment deposition by the migrating distributary channel of the Pamba-Manimala rivers. The high sea level during HCO attests that the core location plausibly represented the southward extension of the Vembanad lagoon which transformed into part of the terrestrial system due to the gradual sea regression during the mid-late Holocene period followed by deposition of alluvial sediments from the hinterland rivers.

Environmental evidence of Valencia lagoon coastal barrier stabilization from 8500 BP to Present. Climate and eustatic variations

The Albufera de Valencia is one of the largest lagoon in the Spanish Mediterranean. Two continuous borehole cores reaching depths of 8 and 14 m in the northern part of the lagoon underwent sedimentological, micropaleontological and biological study. The organic content was also analysed, and 14C radiometric dating and amino acid racemization were performed. Study of the content of benthic foraminifera and n-alkanes and alkanoic acids in the lagoon sedimentary record identified several periods.The core records showed seven different environments: alluvial; freshwater marsh; brackish marsh; brackish lagoon; brackish lagoon with marine connection, backbarrier flat, and backshore. These environments changed due to eight phases associated with the transgression and regression of the barrier system, which caused the shift from exposed environments as the backshore with washover, to the typical low-energy lagoon and marsh deposition.The paleoenvironmental evolution described above is interpreted as a response to global climate changes. The shift from an alluvial setting to a brackish lagoon is probably related to the late of Early Holocene sea level rise ending at the Holocene Climate Optimum, when the highest sea level was reached. The persistence of the brackish lagoon, with no marine connection, is probably synchronous with dry conditions in the area (Booth et al., 2005) at the time of Bond event 3 (i.e., 4.2 ka) in the North Atlantic region (Bond et al., 2001). Finally, the arrival of large amounts of sediment triggered the accretion of the barrier, also enhancing coastal progradation until the present day. These results allow an evaluation of the impact of anthropic action on the Valencia lagoon, especially since the eighteenth century, and a short- and medium-term projection of the consequences of present-day climate change.

A Technological Assessment of the North Pacific Seafaring Hypothesis: Informed by California Channel Island Research

ABSTRACT The proposal of an initial human coastal migration into the New World during the late Pleistocene has gained considerable support in recent years. However, the methods of such a migration are not clear and the proposition that it was accompanied by seafaring around the North Pacific to access a kelp highway is still subject to debate. Recent discoveries now suggest that humans crossed Beringia into North America below the ice at least 17,000 years ago. Conversely, in southern California, people are not recorded on the ancient island of Santarosae any earlier than 13,000 years ago. In contrast, the use of seaworthy watercraft is evident only around 10,000 years ago when sea level inundation separated Santarosae into the four present-day islands of San Miguel, Santa Rosa, Santa Cruz, and Anacapa. At this time, early Holocene sea level rise appears to have stimulated watercraft technological innovations.

Early Holocene tidal flat evolution in a western embayment of East China Sea, in response to sea level rise episodes

The tidal flat in the coastal region of the East China Sea between the Yangtze estuary and Hangzhou Bay in China, interlinked with sediment transport/dispersal and sea level changes since the Last Glacial Maximum, has been a matter of rigorous research for decades. Here we focused on the evolution of the tidal flat at the westernmost extend of former marine influence in response to early Holocene sea level rise. We used sediment composition, ostracods, minerals, organic matter and carbonate contents in combination with endmember modelling analyses and principal component analysis from two sediment cores and an archaeological site close to the western boundary of former marine influence north of the Hangzhou city. The tidal flats at these sites were very sensitive to morphological changes and to sea level variation during the early Holocene. Our data show two major phases of tidal flat formation: i) an early formation stage (9.5–8.0 cal ka BP) with low sediment supply and related slow-down of the mean relative sea level rise (MRSL), followed by ii) the expansion phase with increased sediment supply, storm occurrence as well as fast depositional processes (8.0–7.5 cal ka BP) under a strong MRSL rise close to its present level. A stillstand/decline of MRSL was recorded for the last episodes (7.6–7.5 cal ka BP). The inferences match previously published local to regional sea level curves but differ from the global and modelled regional ones. We propose a connection with early Holocene unstable climatic conditions with intensified storm events and stronger variations in summer monsoon rainfall that affected river discharge and related sediment transport to the inner shelf of the East China Sea between 9.5 and 7.6 cal ka BP. Sedimentary sequences of bayhead areas in tidally-drowned coastal embayments are sensitive to sea level rise episodes and the relevant climate changes.

Hormuz River System as a micro hotspot of diversification for the aphaniid fishes in Iran

The Hormuz River System (HRS) is located in the southern coastal plain of the Zagros Mountains. Two main river drainages i.e., Mehran and Kol are known from this region, which are directly discharged to the Persian Gulf. The HRS has surprising diversity for tooth-carp fishes (family Aphaniidae). The present study aims to accentuate this notable diversity and discuss the possible cause of diversification of the tooth-carps in the HRS. To date, 15 Aphaniid species have been discovered from the Iranian drainage basins. Among them, 10 species belong to the genus Aphanius , four species belong to the genus Aphaniops , and a single species belonging to the genus Paraphanius . The HRS by having four species (22% of the Iranian tooth-carps) demonstrated the highest diversity among the other Iranian basins. Of these, one belongs to the genus Aphanius ( A. darabensis ) and three species belong to the genus Aphaniops ( A. furcatus , A. ginaonis, and A. hormuzensis ). By considering the degree of endemicity of the tooth-carps fauna relative to the territorial boundaries of drainages, the HRS has the highest endemicity, in which 31% of the Iranian endemic tooth-carp species present only in the HRS. The last connection of the Makran Basin with the HRS dates back to the late Pliocene and lower Pleistocene about 1.8 million years ago. Also, the other vicariance-based events like those events related to the last glacial maximum (21000-18000 BP), population migration during the Early Holocene sea-level rise, and the Holocene to present-day have promoted the intra- and interspecific differentiation of tooth-carps in the HRS. Also, the geological situation of the HRS provided various extreme environmental conditions, which caused a particular increase in the diversification of the tooth-carp species.

How a river submerges into the sea: a geological record of changing a fluvial to a marine paleoenvironment during early Holocene sea level rise

ABSTRACTCoastal seas, and in particular estuarine systems, were significantly affected by Quaternary sea level changes. Furthermore, the dynamics of shelf and coastal evolution have had a strong impact on coastal landscapes inhabited by humans. The postglacial evolution of the vast North Sea shelf with its huge drainage systems, e.g. the Elbe Paleovalley and its tributary system, is an excellent research target to understand how coastal shelf environments change in response to sea level rise. In this study, we investigate infill sediments of the Paleo‐Ems valley – a drowned extension of the modern Ems River and part of the Elbe Paleovalley drainage system. Radiocarbon‐dated transgression sequences provide several new observations regarding the mode and rate of the river system submerging due to the Holocene transgression. Thus, the Paleo‐Ems valley submerged within a short time span of~200 years since the river was not able to adjust its gradient to the rapid rising sea level. The fate of the Paleo‐Ems is exemplary for the rapid change of a former fluvial landscape into a coastal landscape and finally into a submarine seascape. © 2019 The Authors. Journal of Quaternary Science Published by John Wiley & Sons Ltd.

Late Quaternary meltwater pulses and sea level change

ABSTRACTAfter the Last Glacial Maximum (LGM) global mean sea level (GMSL) rise was characterized by rapid increases over short (decadal to centennial) timescales superimposed on a longer term secular rise and these have been termed meltwater pulses (MWPs). In this paper we review the timing, impact and nature of these and the effects of rapid drainage of large post‐glacial MWPs into the world's oceans. We identify nine MWPs, four of which occurred in three periods of rapid sea level rise (19.5–18.8, 14.8–13.0 and 11.5–11.1 ka BP). The rest are dated to the period during the Early Holocene sea level rise after 11 ka BP. We show that drainage of the known post‐glacial lakes in total produced less than around 1.2 m of the 125 m of GMSLR since the LGM.

The chronology of a sediment core from incised valley of the Yangtze River delta: Comparative OSL and AMS 14C dating

Optically stimulated luminescence (OSL) dating has gained increased use in dating deltatic deposits, however, its application can be hindered by the problem of incomplete bleaching. To address this limitation, we test the single-grain OSL method for the first time in the Yangtze River delta. A total of eight OSL and 14 AMS 14C samples were obtained from a 50.8m long sediment core from the incised valley of the delta. Quartz extracted from eight OSL samples from the core was first measured with small multi-grain aliquots using medium- (45–63μm) and coarse-grained (90–125μm or 150–180μm) fractions to test the internal consistency of their respective ages. The results showed that four of five medium-grained quartz samples appeared to be well bleached. In contrast, the coarse-grained quartz samples revealed poor bleaching, except for two samples from the delta front facies. Five coarse-grained quartz OSL samples were further analyzed using a single-grain OSL technique. Only 0.5–0.7% of the grains passed the rejection criteria. Single-grain OSL dating is appropriate for age determination of coarse-grained sediments which have been affected by incomplete bleaching. However, it consumes a lot of instrument time. Central and minimum age models (CAM and MAM) were used to calculate the burial age of the samples; MAM ages fit best in the stratigraphic sequence. Small aliquots are recommended as effective in identifying incomplete bleaching for medium- or coarse-grained quartz. A comparison of AMS 14C dates and OSL ages shows that 14C values are 1–3ka older than OSL ages. According to the OSL ages, core SD experienced rapid accumulation 10–8ka and in the last 2ka. The former is linked to rapid sea-level rise in early Holocene, while the latter is primarily due to the migration of depo-center towards the core site, rather than entirely increased sediment delivery caused by human activities.

Exploring Holocene palaeogeography in the ‘white ribbon’: a Mesolithic case study from the Northumberland coast

ABSTRACTMesolithic settlement sites preserved on the north‐east coast of England and in south‐east Scotland drive questions about the relationship between early human settlement and the Holocene palaeogeography of ‘Doggerland’. Palaeogeographical reconstructions before 8000 years ago have been restricted by a lack of sea‐level index points and particularly by sparse nearshore geophysical and geological datasets required for such reconstructions. This paper presents new high‐resolution geophysical survey data from Northumberland's nearshore ‘white ribbon’ which provide a foundation for more accurate palaeogeographical reconstructions within which early prehistoric settlement sites can be more readily understood. High‐resolution bathymetry data collected in the nearshore adjacent to the Mesolithic house site at Howick are integrated with coastal LiDAR, seismic, geological and archaeological datasets to underpin palaeogeographical reconstructions. The reconstructions illustrate changing coastal landscapes during Early Holocene sea‐level rise. The data and interpretations provide a ‘source‐to‐sea’ context for understanding the archaeology at important sites such as Howick and Low Hauxley. Furthermore, they provide a basis for enhancing management of at‐risk coastal prehistoric archaeology and a framework to prospect for and protect further vulnerable nearshore archaeological heritage.

Allopatric speciation in the desert: diversification of cichlids at their geographical and ecological range limit in Iran

Cichlids are textbook examples for rapid diversification and high species diversity. While in South America, several hundred and in Africa, more than 1500 species of cichlid fish have been described, only one single cichlid species, Iranocichla hormuzensis Coad 1982, was known from Iran, the easternmost range margin of the species-rich African cichlids (Cichlidae: Pseudocrenilabrinae). The aim of our paper was to assess the genetic and phenotypic diversity among populations of Iranocichla across most of its geographical range in Southern Iran. For this, we sequenced two mitochondrial genes and collected color observation of male nuptial coloration in different habitats. Besides conspicuous differences in male nuptial coloration, we found considerable genetic differentiation among Iranocichla populations pointing to the existence of at least two allopatric species, with no evidence of more than one species at one site. Diversification within Iranocichla started, based on our data, in the middle or late Pleistocene and was followed by further population differentiation and bottlenecks during isolation events in the last glacial maximum. Population dispersal leading to the population structure observed today most likely occurred in the course of the early Holocene sea-level rise.

Rapid early Holocene sea-level rise in Prydz Bay, East Antarctica

Prydz Bay is one of the largest embayments on the East Antarctic coast and it is the discharge point for approximately 16% of the East Antarctic Ice Sheet. Geological constraints on the regional ice sheet history include evidence of past relative sea-level change at three sites; the Vestfold Hills, Rauer Islands and Larsemann Hills. In this paper we compile updated regional relative sea-level data from these sites. We compare these with a suite of relative sea-level predictions derived from glacial isostatic adjustment models and discuss the significance of departures between the models and the field evidence. The compiled geological data extend the relative sea-level curve for this region to 11,258calyr BP and include new constraints based on abandoned penguin colonies, new isolation basin data in the Vestfold Hills, validation of a submarine relative sea-level constraint in the Rauer Islands and recalibrated radiocarbon ages at all sites dating from 12,728calyr BP. The field data show rapid increases in rates of relative sea level rise of 12–48mm/yr between 10,473 (or 9678) and 9411calyr BP in the Vestfold Hills and of 8.8mm/yr between 8882 and 8563calyr BP in the Larsemann Hills. The relative sea-level high stands of ≥8.8m from 9411 to after 7564calyr BP (Vestfold Hills) and ≥8m at 8563 and 7066calyr BP (Larsemann Hills) are over-predicted by some of the glacial isostatic adjustment models considered here, suggesting that assumptions relating to the magnitude and timing of regional ice loss since the Last Glacial Maximum may need revising. In the Vestfold Hills and Rauer Islands the final deglacial sea-level rise was almost exactly cancelled out by local rebound between 9411 and 5967calyr BP and this was followed by a near exponential decay in relative sea-level. In the Larsemann Hills the sea-level data suggest that the rate of ice retreat in this region was not uniform throughout the Holocene. Swath bathymetric surveys of the benthic seafloor topography show the presence of multiple offshore basins. These are a priority for further study as those that remained free of grounded ice should provide precise constraints on relative sea-level rise and ice sheet history during the most rapid phases of the last major deglaciation.

A late Quaternary multiple paleovalley system from the Adriatic coastal plain (Biferno River, Southern Italy)

A buried paleovalley system, up to 2km wide and exceeding 50m in relief, made up of multiple cross-cutting depressions incised into the Lower Pleistocene bedrock, is reported from the central Adriatic coastal plain at the mouth of Biferno River. Through a multi-proxy approach that included geomorphological, stratigraphic, sedimentological and paleontological (benthic foraminifers, ostracods and molluscs) investigations, the facies architecture of distinct, superposed valley fills is reconstructed and their relative chronology established along a transverse profile with extremely high data density (average borehole spacing 75m). Regional tectonic uplift appears as the major controlling factor of initial (Middle Pleistocene) river down-cutting and paleovalley formation. In contrast, glacio-eustatic fluctuations drove fluvial-system response over the last 120ky, when valley incision was primarily induced by the last glacial base-level lowering and climatic forcing. A fragmented record of coastal and shallow-marine deposits is available for the lower paleovalley fill, which is penetrated by a limited borehole dataset. Multiple erosion phases probably related to the post-MIS 5e sea-level fall are reconstructed from the upper paleovalley fill, where a buried fluvial terrace succession is identified a few tens of meters below the ground surface. The flat surfaces of two buried fluvial terraces suggest longer-term, stepped relative sea-level fall, and are correlated with fluvial incisions that took place possibly at the MIS 5/4 transition and at the MIS 3/2 transition, respectively. A laterally extensive gravel body developed on the valley floor during the Last Glacial Maximum. During the ensuing latest Pleistocene–early Holocene sea-level rise the Biferno paleovalley was transformed into an estuary. Upstream from the maximum shoreline ingression, the vertical succession of well-drained floodplain, poorly-drained floodplain, and swamp deposits evidences increasing marine influence in the estuary, in response to continuing sea-level rise. The interfluves were drowned around 8cal.ky BP, when brackish conditions developed in the study area. Decreasing marine influence in the uppermost 15m of the paleovalley fill suggests the onset of the modern delta: when the rate of sea-level rise was overwhelmed by sediment supply, delta progradation took place.

Origin and dynamics of the northern South American coastal savanna belt during the Holocene – the role of climate, sea-level, fire and humans

Presence of a coastal savanna belt expanding from British Guiana to northeastern Brazil cannot be explained by present-day climate. Using pollen and charcoal analyses on an 11.6 k old sediment core from a coastal depression in the savanna belt near the mouth of the Amazon River we investigated the paleoenvironmental history to shed light on this question. Results indicate that small areas of savanna accompanied by a forest type composed primarily by the genus Micropholis (Sapotaceae) that has no modern analog existed at the beginning of the Holocene. After 11,200 cal yr BP, savanna accompanied by few trees replaced the forest. In depressions swamp forest developed and by ca 10,000 cal yr BP replaced by Mauritia swamps. Between 8500 and 5600 cal yr BP gallery forest (composed mainly of Euphorbiaceae) and swamp forest succeeded the treeless savanna. The modern vegetation with alternating gallery forest and savanna developed after 5600 cal yr BP. We suggest that the early Holocene no-analog forest is a relict of previously more extensive forest under cooler and moister Lateglacial conditions. The early Holocene savanna expansion indicates a drier phase probably related to the shift of the Intertropical Convergence Zone (ITCZ) towards its northernmost position. The mid-Holocene forest expansion is probably a result of the combined influence of equatorwards shift of ITCZ joining the South Atlantic Convergence Zone (SACZ). The ecosystem variability during the last 5600 cal yr BP, formed perhaps under influence of intensified ENSO condition. High charcoal concentrations, especially during the early Holocene, indicate that natural and/or anthropogenic fires may have maintained the savanna. However, our results propose that climate change is the main driving factor for the formation of the coastal savanna in this region. Our results also show that the early Holocene sea level rise established mangroves near the study site until 7500 cal yr BP and promoted swamp formation in depressions, but did not influence the savanna vegetation.

Recognition of a drowned delta in the northern Adriatic Sea, Italy: Stratigraphic characteristics and its significance in the frame of the early Holocene sea-level rise

Seismic and core data off the Tagliamento river delta, northern Adriatic Sea, Italy, have allowed the recognition of a partially eroded sand ridge at 12 to 18 m water depth, which has been interpreted as a submerged wave-dominated delta with associated beach-ridge complexes. The ridge shows local channel fill features, interpreted as the result of the filling of tidal channels connecting the open sea with bays and lagoons placed adjacent to the ancient delta. This interpretation resembles the present day setting of the Tagliamento delta, located landwards. It is inferred that the recognized delta was drowned during the latest stage of the post-glacial sea-level rise, when the shoreline shifted near the present day position. New studies are needed to recognize other submerged deltas and barrier islands, which may allow the reconstruction of the post-glacial sea-level rise in the Mediterranean and of the position of ancient paleoshorelines.

Late Pleistocene and early Holocene exploitation of estuarine communities in northwestern Australia

This contribution synthesizes archaeological studies of human economies from the Barrow–Montebello islands and uses the area's archaeological record to determine the effects of Late Pleistocene and early Holocene sea-level rise on regional coastlines. At the height of the Last Glacial Maximum (LGM), Australia's north-western coast extended much further west than the present-day shoreline. During subsequent sea-level rise, the gently prograding continental shelf was inundated, and with it, nearly all archaeological evidence for coastal occupation. The Barrow and Montebello Islands are one of the few exceptions, as they corresponded to inland hinterland ranges during the LGM, with the coastline lying some 50 km to their west. Evidence from all late Pleistocene and Holocene occupation phases of the Barrow–Montebello Islands demonstrate that foragers continued to visit the coast and engage in the exploitation of both terrestrial and marine environments. During the late Pleistocene, when the shoreline was 10–15 km away, coastal exploitation is seen through the presence of transportable estuarine and rocky-shore gastropods. By the early Holocene, when sea-levels were within close proximity of the sites, there is a marked increase in marine fauna including reef fish, estuarine and reef shellfish, crustaceans and estuarine crocodile. Together, this suggests that the nearby muddy, procumbent coastlines were productive, as well as an important component of coastal and hinterland economies.