Coastal interglacial deposits of the English Channel

1960 ◽  
Vol 243 (701) ◽  
pp. 95-133 ◽  
Keyword(s):  
Sea Level ◽  
Pollen Analysis ◽  
Brackish Water ◽  
High Tide ◽  
English Channel ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Marine Transgression ◽  
Plant Remains ◽  
Eemian Interglacial

Fossiliferous Late-Pleistocene deposits on the foreshore of the English Channel at Selsey (Sussex), Stone (Hampshire), and near Arromanches (Calvados), have been investigated. At each site analyses of pollen, macroscopic plant remains and Mollusca have been made and from these vegetational, faunal, environmental and climatic conditions have been reconstructed. At Selsey, it is shown that the deposits, which lie in a channel cut in Eocene rocks, are of Ipswichian (Eemian or Last) Interglacial age. Pollen analysis of the sediments of the channel filling show they were formed during zones b , c , d , e and f of this interglacial from open parkland vegetation to birch-, to pine-, to oak-dominated forests. Analysis of the macroscopic plant remains and of the molluscs suggests a rapid climatic amelioration at the beginning of the interglacial, so that by the beginning of zone f there are indications of summer warmth exceeding that of the present day in the area. In the upper part of the channel filling, estuarine deposits overlie freshwater deposits. It is shown that the marine transgression causing the change was taking place in zone f and was probably responsible later for the raised beach deposits which overlie the channel deposits and which form the cliffs at Selsey Bill. At Stone pollen analysis shows that brackish water deposits, below present high tide level, were formed in zone f of the Ipswichian Interglacial. At that time Quercus , Pinus and Acer were the chief trees forming the forest in the region. The macroscopic plant remains and the Mollusca indicate that the deposit was formed under saltmarsh conditions. As at Selsey, the raised beach gravel found overlying the interglacial deposit is related to the same marine transgression that produced the brackish water conditions. Near Arromanches, at St Côme de Fresne and Asnelles-Belle-Plage, two deposits showing a change from marine to freshwater sediments were investigated. The analysis of pollen and the Mollusca showed the prevalence of pine forest and its replacement by open steppe-like conditions as the marine regression occurred. After the regression, limon covered the freshwater deposits. The fossiliferous deposits are tentatively correlated with zone i of the Eemian Interglacial. The relative land- and sea-level changes indicated by all the deposits are considered. It is concluded that in the English Channel, during the Ipswichian (Eemian) Interglacial, sea level rose above its present height in zone f and fell below it during zone i . The Selsey-Brighton raised beach and the Normannien II raised beach are correlated with the same marine transgression. It is pointed out that if the Selsey-Brighton raised beach is to be correlated with the Monastirian II level of 7—8 m, then this level should be correlated with the Ipswichian (Eemian) Interglacial.

Interglacial deposits at Bobbitshole, Ipswich

1957 ◽  
Vol 241 (676) ◽  
pp. 1-31 ◽  
Keyword(s):  
Sea Level ◽  
Lacustrine Sediments ◽  
Interglacial Period ◽  
Lake Basin ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Marsh Vegetation ◽  
Sandy Gravel ◽  
North West ◽  
Plant Remains

The stratigraphy and palaeobotany of fresh-water interglacial deposits at Bobbitshole, Ipswich, Suffolk, have been investigated. The interglacial deposits are shown to occupy a lake basin in a valley cut in the local plateau, which is partly formed by a chalky boulder clay assigned to the Gipping ice advance. In this basin was deposited a series of lacustrine sediments, first silt (probably of aeolian origin), then clay-mud and finally clay. These interglacial sediments are sealed unconformably by sandy gravel, probably deposited under cold conditions. Pollen diagrams and macroscopic plant remains from the interglacial deposits are described. They give evidence of the vegetational and climatic history during the first half of an interglacial period. The succession of pollen zones found is similar to that described from the Eemian (Last) Interglacial in north-west Europe, with which the interglacial is correlated. The Eemian pollen zones b , c , d , e and f which show the succession from birch- to pine- to oak-dominated forest, are all present. An analysis of the very abundant macroscopic plant remains, together with the pollen results, suggests a rapid amelioration of the climate at the beginning of the interglacial period, and in zone f , the final zone represented, there are indications of a summer warmth exceeding that of the present day in the area. The interglacial flora is particularly rich in aquatic plants, and an analysis of the abundance of each species indicates a vegetational succession, as the lake filled with sediment, from open-water to reed-swamp to marsh vegetation. The palaeobotany of the deposits is briefly compared with that of other interglacial deposits in Britain and on the continent. The correlation of the interglacial deposits with the continental Eemian (Last) Interglacial provides confirmation of the correlation of the Gipping ice advance with the Saale Glaciation of northern Germany, and indicates that the covering gravels are of Last Glaciation age. The interglacial deposits are partly below sea-level, and close to the tidal Orwell estuary. The significance of this for local relative land- and sea-level changes in and after the interglacial is discussed.

WALIS - Towards a global database of Last Interglacial sea-level proxies.

2021 ◽  
Author(s):  
Alessio Rovere ◽  
Deirdre Ryan ◽  
Matteo Vacchi ◽  
Alexander Simms ◽  
Andrea Dutton ◽  
...  
Keyword(s):  
Sea Level ◽  
Research Council ◽  
Geological Data ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Global Database ◽  
The World ◽  
First Results ◽  
Data Points ◽  
The Subject

<p>The standardization of geological data, and their compilation into geodatabases, is essential to allow more coherent regional and global analyses. In sea-level studies, the compilation of databases containing details on geological paleo sea-level proxies has been the subject of decades of work. This was largely spearheaded by the community working on Holocene timescales. While several attempts were also made to compile data from older interglacials, a truly comprehensive approach was missing. Here, we present the ongoing efforts directed to create the World Atlas of Last Interglacial Shorelines (WALIS), a project spearheaded by the PALSEA (PAGES/INQUA) community and funded by the European Research Council (ERC StG 802414). The project aims at building a sea-level database centered on the Last Interglacial (Marine Isotope Stage 5e, 125 ka), a period of time considered as an "imperfect analog" for a future warmer climate. The database is composed of 17 tables embedded into a mySQL framework with a total of more than 500 single fields to describe several properties related to paleo sea-level proxies, dated samples and metadata. In this presentation, we will show the first results of the global compilation, which includes nearly 2000 data points and will discuss its relevance in answering some of the most pressing questions related to sea-level changes in past warmer worlds. </p>

A standardized database of Last Interglacial sea-level indicators in southeast Asia: Records from coral reef terraces in a tectonically complex region

2021 ◽  
Author(s):  
Kathrine Maxwell ◽  
Hildegard Westphal ◽  
Alessio Rovere
Keyword(s):  
Coral Reef ◽  
Southeast Asia ◽  
Sea Level ◽  
Tectonic Setting ◽  
Sea Level Change ◽  
The Philippines ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Level Change ◽  
Se Asia

<p>The Last Interglacial (LIG), as well as other warmer periods in the Earth’s geologic history, provides an analogue for predicted warming conditions in the near future. Analysis of sea-level indicators during this period is important in constraining regional drivers of relative sea-level change (RSL) and in modeling future trajectories of sea-level rise. In southeast Asia, several studies have been done to examine LIG sea-level indicators such as coral reef terraces and tidal notches. A synthesis of the state-of-the-art of the LIG RSL indicators in the region, meanwhile, has yet to be done. We reviewed over 50 published works on the LIG RSL indicators in southeast Asia and used the framework of the World Atlas of Last Interglacial Shorelines (WALIS) in building a standardized database of previously published LIG RSL indicators in the region. In total, we identified 38 unique RSL indicators and inserted almost 140 ages in the database. Available data from Indonesia, the Philippines, and East Timor points to variable elevation of sea-level indicators during the LIG highlighting the complex tectonic setting of this region. Variable uplift rates (from as low as 0.02 to as high as 1.1 m/ka) were reported in the study areas echoing various collision and subduction processes influencing these sites. Although several age constraints and elevation measurements have been provided by these studies, more data is still needed to shed more light on the RSL changes in the region. With this effort under the WALIS framework, we hope to identify gaps in the LIG RSL indicators literature in SE Asia and recognize potential areas that can be visited for future work. We also hope that this initiative will help us further understand the different drivers of past sea-level changes in SE Asia and will provide inputs for projections of sea-level change in the future.</p>

14C Age Offset in the Mar Piccolo Sea Basin in Taranto (Southern Italy) Estimated on Cerastoderma Glaucum (Poiret, 1789)

Radiocarbon ◽  
2019 ◽  
Vol 61 (5) ◽  
pp. 1387-1401 ◽  
Author(s):  
Gianluca Quarta ◽  
Paola Fago ◽  
Lucio Calcagnile ◽  
Giulia Cipriano ◽  
Marisa D’Elia ◽  
...  
Keyword(s):  
Sea Level ◽  
Southern Italy ◽  
Morphological Evolution ◽  
Sediment Cores ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Cerastoderma Glaucum ◽  
14C Age ◽  
Two Samples ◽  
Stratigraphic Succession

ABSTRACTThe stratigraphic succession of the Mar Piccolo basin (Gulf of Taranto, Southern Italy) is well known in the scientific literature dealing with the last interglacial since its morphological evolution is influenced by sea level changes during Late Pleistocene-Holocene. The local Holocene sea level history is well known thanks to data deriving from peat and ash layers identified in different sediment cores obtained underwater and in coastal areas. Peat sediments are frequently interlayed with muddy-sand beds rich in Cerastoderma glaucum (Poiret, 1789). In the literature of the Mediterranean basin, AMS 14C dating on C. glaucum is widely used also in paleo-environmental reconstruction because this bivalve is considered an useful marker of sea level, though in lagoonal systems, large age offsets have been reported in different areas. Due to the availability of precise chronological and geochronological markers, in order to validate the use of C. glaucum in paleo sea level reconstruction, AMS 14C dating campaign was carried out on this bivalve deriving from several cores drilled in the Mar Piccolo basin and its nearby areas. Nineteen AMS 14C dating analyses carried out on C. glaucum sampled from different sediment cores up to a maximum of 30 m from the seafloor are presented. These results show an inconsistency of the ages in relation to a sea-level rise reconstruction model. The interpretation of the data was performed after the estimation of the local age offset calculated by analyzing six live samples, collected in 2017 in Mar Piccolo and in Croatia, and two samples dated to 1968–1969. The results show that for both the classes of samples (2017 and 1960s) an age offset ranging from 600 to 800 yr can be estimated.

scholarly journals An Estimate of Increases in Storm Surge Risk to Property from Sea Level Rise in the First Half of the Twenty-First Century

2010 ◽  
Vol 2 (4) ◽  
pp. 271-293 ◽  
Author(s):  
Ross N. Hoffman ◽  
Peter Dailey ◽  
Susanna Hopsch ◽  
Rui M. Ponte ◽  
Katherine Quinn ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Storm Surge ◽  
Full Range ◽  
High Tide ◽  
World Ocean ◽  
Sea Level Changes ◽  
Global Signal ◽  
The Impact ◽  
Zip Code

Abstract Sea level is rising as the World Ocean warms and ice caps and glaciers melt. Published estimates based on data from satellite altimeters, beginning in late 1992, suggest that the global mean sea level has been rising on the order of 3 mm yr−1. Local processes, including ocean currents and land motions due to a variety of causes, modulate the global signal spatially and temporally. These local signals can be much larger than the global signal, and especially so on annual or shorter time scales. Even increases on the order of 10 cm in sea level can amplify the already devastating losses that occur when a hurricane-driven storm surge coincides with an astronomical high tide. To quantify the sensitivity of property risk to increasing sea level, changes in expected annual losses to property along the U.S. Gulf and East Coasts are calculated as follows. First, observed trends in sea level rise from tide gauges are extrapolated to the year 2030, and these changes are interpolated to all coastal locations. Then a 10 000-yr catalog of simulated hurricanes is used to define critical wind parameters for each event. These wind parameters then drive a parametric time-evolving storm surge model that accounts for bathymetry, coastal geometry, surface roughness, and the phase of the astronomical tide. The impact of the maximum storm surge height on a comprehensive inventory of commercial and residential property is then calculated, using engineering models that take into account the characteristics of the full range of construction types. Average annual losses projected to the year 2030 are presented for regions and key states and are normalized by aggregate property value on a zip code by zip code basis. Comparisons to the results of a control run reflecting the risk today quantify the change in risk per dollar of property on a percentage basis. Increases in expected losses due to the effect of sea level rise alone vary by region, with increases of 20% or more being common. Further sensitivity tests quantify the impact on the risk of sea level rise plus additional factors, such as changes in hurricane frequency and intensity as a result of rising sea surface temperatures.

Climate and Sea Level During Oxygen Isotope Stage 7b: On-Land Evidence from New Zealand

1988 ◽  
Vol 29 (2) ◽  
pp. 176-185 ◽  
Author(s):  
Brad Pillans ◽  
Geoff Holgate ◽  
Matt McGlone
Keyword(s):  
New Zealand ◽  
Oxygen Isotope ◽  
Sea Level ◽  
Northern Hemisphere ◽  
Pollen Analysis ◽  
Deep Sea ◽  
Sea Level Changes ◽  
Oxygen Isotope Stage ◽  
Oxygen Isotopic ◽  
And Sea Level

Strata at Landguard Bluff, near Wanganui, New Zealand preserve a clear record of relative sea-level changes during oxygen-isotope stage 7. Two relative high sea-level stands (during stages 7a about 210,000 yr ago and 7c about 240,000 yr ago) are separated by a relative low sea level (stage 7b) that was at least 32 m lower than present. Pollen analysis of sediment deposited during stage 7b indicates climate at the time was up to 3°C cooler than present. The climate and sea-level evidence from Landguard Bluff are consistent with oxygen-isotopic evidence from deep-sea cores indicating a marked cooling during stage 7, which is closely associated with a summer radiation minimum centered at about 230,000 yr ago in the Northern Hemisphere.

Eustatic control of late Quaternary sea-level change in the Arabian/Persian Gulf

2014 ◽  
Vol 82 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Thomas Stevens ◽  
Matthew J. Jestico ◽  
Graham Evans ◽  
Anthony Kirkham
Keyword(s):  
Sea Level ◽  
Persian Gulf ◽  
Late Quaternary ◽  
Osl Dating ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Coastal Evolution ◽  
Last Glacial ◽  
Sea Level Variations ◽  
The Last Glacial

AbstractAccurate sea-level reconstruction is critical in understanding the drivers of coastal evolution. Inliers of shallow marine limestone and aeolianite are exposed as zeugen (carbonate-capped erosional remnants) on the southern coast of the Arabian/Persian Gulf. These have generally been accepted as evidence of a eustatically driven, last-interglacial relative sea-level highstand preceded by a penultimate glacial-age lowstand. Instead, recent optically stimulated luminescence (OSL) dating suggests a last glacial age for these deposits, requiring >100 m of uplift since the last glacial maximum in order to keep pace with eustatic sea-level rise and implying the need for a wholesale revision of tectonic, stratigraphic and sea-level histories of the Gulf. These two hypotheses have radically different implications for regional neotectonics and land–sea distribution histories. Here we test these hypotheses using OSL dating of the zeugen formations. These new ages are remarkably consistent with earlier interpretations of the formations being last interglacial or older in age, showing that tectonic movements are negligible and eustatic sea-level variations are responsible for local sea-level changes in the Gulf. The cause of the large age differences between recent studies is unclear, although it appears related to large differences in the measured accumulated dose in different OSL samples.

scholarly journals Late Glacial Marine Transgression and Ecosystem Response in the Landlocked Elefsis Bay (Northern Saronikos Gulf, Greece)

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1505
Author(s):  
Katerina Kouli ◽  
Maria V. Triantaphyllou ◽  
Olga Koukousioura ◽  
Margarita D. Dimiza ◽  
Constantine Parinos ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Glacial ◽  
Ecosystem Response ◽  
Sea Level Changes ◽  
Marine Transgression ◽  
Sea Level Fluctuations ◽  
Geological Processes ◽  
Marginal Areas ◽  
Coastal Landscapes ◽  
Marine Realm

Coastal landscapes are sensitive to changes due to the interplay between surface and submarine geological processes, climate variability, and relative sea level fluctuations. The sedimentary archives of such marginal areas record in detail the complex evolution of the paleoenvironment and the diachronic biota response. The Elefsis Bay is nowadays a landlocked shallow marine basin with restricted communication to the open Saronikos Gulf. A multi-proxy investigation of a high-resolution sediment core recovered from the deepest part of the basin offered a unique opportunity to record the paleoenvironmental and aquatic ecosystem response to climate and glacioeustatic sea level changes since the Late Glacial marine transgression. The retrieved sedimentary deposits, subjected to thorough palynological (pollen, non-pollen palynomorphs, dinoflagellates), micropaleontological (benthic foraminifera, calcareous nannoplankton, ostracods), and mollusc analyses, indicates isolation of the Elefsis Bay from the Saronikos Gulf and the occurrence of a shallow freshwater paleolake since at least 13,500 cal BP, while after 11,3500 cal BP the transition towards lagoon conditions is evidenced. The marine transgression in the Elefsis Bay is dated at 7500 cal BP, marking the establishment of the modern marine realm.

Sign in / Sign up

Export Citation Format

Share Document