Sedimentary archives of climate and sea-level changes during the Holocene in the Rhône prodelta (NW Mediterranean Sea)

Abstract. A 7.38 m long sediment core was collected from the eastern section of the Rhône prodelta (NW Mediterranean) at 67 m water depth. A multi-proxy study (including sedimentary facies, benthic foraminifera, ostracods, and clay mineralogy) provides a multi-decadal to century-scale record of climate and sea-level changes during the Holocene. The early Holocene is marked by alternative silt and clay layers interpreted as distal tempestites deposited in a context of rising sea level. This interval contains shallow infra-littoral benthic meiofauna (e.g., Pontocythere elongata, Elphidium spp., Quinqueloculina lata) and formed between ca. 20 and 50 m water depth. The middle Holocene (ca. 8.3 to 4.5 ka cal. BP) is characterized, at the core site, by a period of sediment starvation (accumulation rate of ca. 0.01 cm yr−1) resulting from the maximum landward shift of the shoreline and the Rhône outlet(s). From a sequence stratigraphic point of view, this condensed section, about 35 cm thick, can be identified on seismic profiles as a maximum flooding surface that marks the transition between delta retrogradation and delta progradation. The transition between the early Holocene deposits and the middle Holocene condensed section is marked by a gradual change in all proxy records. Following the stabilization of sea level at a global scale, the late Holocene is marked by the establishment of prodeltaic conditions at the core site, as shown by the lithofacies and by the presence of benthic meiofauna typical of the modern Rhône prodelta (e.g., Valvulineria bradyana, Cassidulina carinata, Bulimina marginata). Several periods of increased fluvial discharge are also emphasized by the presence of species commonly found in brackish and shallow-water environments (e.g., Leptocythere spp.). Some of these periods correspond to the multi-decadal to centennial late Holocene humid periods recognized in Europe (i.e., the 2.8 ka event and the Little Ice Age). Two other periods of increased runoffs at ca. 1.3 and 1.1 ka cal. BP are recognized, which are likely to reflect periods of regional climate deterioration that are observed in the Rhône watershed. Conversely, the Migration Period Cooling (ca. 1.4 ka cal. BP) and the Medieval Climate Anomaly (ca. AD 950–1250) correspond locally to periods of increased dryness.

Download Full-text

Sedimentary archives of climate and sea-level changes during the Holocene in the Rhone prodelta (NW Mediterranean Sea)

10.5194/cp-2016-57 ◽

2016 ◽

Author(s):

Anne-Sophie Fanget ◽

Maria-Angela Bassetti ◽

Christophe Fontanier ◽

Alina Tudryn ◽

Serge Berné

Keyword(s):

Sea Level ◽

Water Depth ◽

Late Holocene ◽

Ice Age ◽

Sea Level Changes ◽

The Holocene ◽

The Core ◽

Core Site ◽

Nw Mediterranean ◽

And Sea Level

Abstract. A 7.38 m-long sediment core was collected from the eastern part of the Rhone prodelta (NW Mediterranean) at 67 m water depth. A multi-proxy study (sedimentary facies, benthic foraminifera and ostracods, clay mineralogy, and major elements from XRF) provides a multi-decadal to century-scale record of climate and sea-level changes during the Holocene. The early Holocene is marked by alternative silt and clay layers interpreted as distal tempestites deposited in a context of rising sea level. This interval contains shallow infra-littoral benthic meiofauna (e.g. Pontocythere elongata, Elphidium spp., Quinqueloculina lata) and formed between ca. 20 and 50 m water depth. The middle Holocene (ca. 8.3 to 4.5 ka cal. BP), is characterized, at the core site, by a period of sediment starvation (accumulation rate of ca. 0.01 cm yr−1) resulting from the maximum landward shift of the shoreline and the Rhone outlet(s). From a sequence stratigraphic point of view, this condensed interval, about 35 cm-thick, is a Maximum Flooding Surface that can be identified on seismic profiles as the transition between delta retrogradation and delta progradation. It is marked by very distinct changes in all proxy records. Following the stabilization of the global sea level, the late Holocene is marked by the establishment of prodeltaic conditions at the core site, as shown by the lithofacies and by the presence of benthic meiofauna typical of the modern Rhone prodelta (e.g. Valvulineria bradyana, Cassidulina carinata, Bulimina marginata). Several periods of increased fluvial discharge are also emphasized by the presence of species commonly found in brackish and shallow water environments (e.g. Leptocythere). Some of these periods correspond to the multi-decadal to centennial late Holocene humid periods recognized in Europe (i.e. the 2.8 ka event and the Little Ice Age). Two other periods of increased runoffs at ca. 1.3 and 1.1 ka cal. BP are recognized, and are likely to reflect periods of regional climate deterioration that are observed in the Rhone watershed.

Download Full-text

The Norse in Greenland and late Holocene sea-level change

Polar Record ◽

10.1017/s0032247407006948 ◽

2008 ◽

Vol 44 (1) ◽

pp. 45-50 ◽

Cited By ~ 17

Author(s):

Naja Mikkelsen ◽

Antoon Kuijpers ◽

Jette Arneborg

Keyword(s):

Sea Level ◽

Little Ice Age ◽

Late Holocene ◽

Ice Age ◽

Documentary Evidence ◽

Sea Level Changes ◽

Middle Holocene ◽

Level Change ◽

Farming Community ◽

Holocene Sea Level

ABSTRACTNorse immigrants from Europe settled in southern Greenland in around AD 985 and managed to create a farming community during the Medieval Warm Period. The Norse vanished after approximately 500 years of existence in Greenland leaving no documentary evidence concerning why their culture foundered. The flooding of fertile grassland caused by late Holocene sea-level changes may be one of the factors that affected the Norse community. Holocene sea-level changes in Greenland are closely connected with the isostatic response of the Earth's crust to the behaviour of the Greenlandic ice sheet. An early Holocene regressive phase in south and west Greenland was reversed during the middle Holocene, and evidence is found for transgression and drowning of early-middle Holocene coast lines. This drowning started between 8 and 7ka BP in southern Greenland and continued during the Norse era to the present. An average late Holocene sea level rise in the order of 2–3 m/1000 years may be one of the factors that negatively affected the life of the Norse Greenlanders, and combined with other both socio-economic and environmental problems, such as increasing wind and sea ice expansion at the transition to the Little Ice Age, may eventually have led to the end of the Norse culture in Greenland.

Download Full-text

Post-glacial Foraminifera of the incised Yangtze paleo-valley and paleoenvironmental implications

Journal of Paleontology ◽

10.1017/jpa.2017.66 ◽

2017 ◽

Vol 91 (6) ◽

pp. 1102-1122 ◽

Cited By ~ 2

Author(s):

Xue Ke ◽

Baohua Li ◽

Zongyan Zhang ◽

Yi Wei ◽

Fei Hu ◽

...

Keyword(s):

Sea Level ◽

Middle Part ◽

The Other ◽

Glacial Deposit ◽

Benthic Foraminifers ◽

The Holocene ◽

Middle Holocene ◽

Sea Level Fluctuations ◽

The Core ◽

Abundance And Diversity

AbstractThree gravity cores (LZK1, ZKA4, and CSJA6) from the incised Yangtze paleo-valley comprise a thick sequence of the post-glacial deposit. Nineteen genera (26 species) of the benthic foraminifers are described from these cores, with detailed down-core foraminiferal variations to investigate their paleoenvironmental implications. Three foraminiferal assemblages are recognized for the lower, middle, and upper parts of the cores respectively. The lower part is dominated byAmmonia beccariivar. andFlorilus decoruswith lower abundance and diversity. In the middle part, the foraminifers are abundant and diverse, dominated by bothAmmonia beccariivar. andElphidium advenum.Cavarotalia annectens,Pararotalia nipponica, and porcellaneous benthic foraminiferal forms are always present, sometimes abundant. The upper part is characterized by theAmmonia beccarii-Elphidium magellanicumassemblage, except for the Core ZKA4, which is barren of foraminifers in this interval. AMS14C dates and foraminiferal assemblages both confirm that the transgression-regression sequence in these cores belongs to the “Ammoniatransgression” during the Holocene. In addition to documenting the post-glacial sea-level fluctuations, the benthic foraminifers also reflect a warmer climate during the early–middle Holocene. The foraminiferal differences among the three cores can be used to interpret the influence of seawater during the post-glacial sea-level fluctuations. The area in the vicinity of Core ZKA4 was affected by marine water only during the middle Holocene, which was much shorter than the areas of the other cores.

Download Full-text

Crustal subsidence inferred from reconstruction of the Pleistocene–Holocene palaeogeography in the northern Lake Inba area, central Japan

Quaternary Research ◽

10.1017/qua.2019.69 ◽

2019 ◽

Vol 94 ◽

pp. 61-79

Author(s):

Takashi Chiba ◽

Shigeo Sugihara ◽

Yoshiaki Matsushima ◽

Yusuke Arai ◽

Kunihiko Endo

Keyword(s):

Sea Level ◽

Late Holocene ◽

Environmental Changes ◽

Sea Level Changes ◽

Diatom Assemblages ◽

Central Japan ◽

Lower Salinity ◽

The Holocene ◽

Holocene Transgression

ABSTRACTTo help characterise the palaeogeographic and lacustrine environmental changes that resulted from the Holocene transgression and residual subsidence in the eastern Kanto Plain of central Japan, we analysed four drill cores and reviewed other core data from the southern part of the Lake Inba area. Fossil diatom assemblages yielded evidence of centennial-scale palaeogeographic and salinity responses to sea-level changes since the late Pleistocene. We determined that the seawater incursion into the Lake Inba area during the Holocene transgression occurred at approximately 9000 yr. We also recognised a late Holocene regression event corresponding to the Yayoi regression, considered to have occurred from ca. 3000 to ca. 2000 yr, and a subsequent transgression. Our data clarify some of the palaeogeographic changes that occurred in the Lake Inba area and document an overall trend toward lower salinity in the lake during the regression. In particular, the environment in Lake Inba changed from brackish to freshwater no later than 1000 yr. From the detailed palaeogeographic and palaeo-sea-level reconstruction, we recognised that residual subsidence occurred during the Holocene in this area. Thus, comparison of sea-level reconstructions based on modelling and fossil diatom assemblages is effective in interpreting Holocene long-term subsidence.

Download Full-text

Middle to Late Holocene relative sea-level changes recorded on the coast of Apulia (Italy) / Variations relatives du niveau marin pendant l'Holocène moyen et supérieur le long des côtes méridionales des Pouilles (Italie)

Géomorphologie relief processus environnement ◽

10.3406/morfo.2004.1196 ◽

2004 ◽

Vol 10 (1) ◽

pp. 19-33 ◽

Cited By ~ 16

Author(s):

Rita Auriemma ◽

Giuseppe Mastronuzzi ◽

Paolo Sansò

Keyword(s):

Sea Level ◽

Late Holocene ◽

Sea Level Changes ◽

Relative Sea Level

Download Full-text

CORRELATION OF THE BLACK, MARMARA AND AEGEAN SEAS DURING THE HOLOCENE

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.21610/conferencearticle_58b4315c686d6 ◽

2017 ◽

Author(s):

Nikolay Esin ◽

Vladimir Ocherednik ◽

Vladimir Ocherednik

Keyword(s):

Mathematical Model ◽

Sea Level ◽

Black Sea ◽

Aegean Sea ◽

The Black Sea ◽

Sea Level Changes ◽

The Holocene

A mathematical model describing the change in the Black Sea level depending on the Aegean Sea level changes is presented in the article. Calculations have shown that the level of the Black Sea has been repeating the course of the Aegean Sea level for the last at least 6,000 years. And the level of the Black Sea above the Aegean Sea level in the tens of centimeters for this period of time.

Download Full-text

GROUNDWORK: Late Holocene relative land- and sea-level changes: Providing information for stakeholders

GSA Today ◽

10.1130/gsatg50gw.1 ◽

2009 ◽

pp. 52-53 ◽

Cited By ~ 28

Author(s):

Ian Shennan

Keyword(s):

Sea Level ◽

Late Holocene ◽

Sea Level Changes ◽

And Sea Level

Download Full-text

BIOINDICATORS OF SEA-LEVEL FLUCTUATIONS IN SOUTHEASTERN BRAZIL: NEW DATA AND METHODOLOGICAL REVIEW

Radiocarbon ◽

10.1017/rdc.2021.50 ◽

2021 ◽

pp. 1-15

Author(s):

Julia Caon Araujo ◽

Kita Chaves Damasio Macario ◽

Vinícius Nunes Moreira ◽

Anderson dos Santos Passos ◽

Perla Baptista de Jesus ◽

...

Keyword(s):

Sea Level ◽

Late Holocene ◽

Data Interpretation ◽

Progressive Increase ◽

Southeastern Brazil ◽

Recrystallization Process ◽

Sea Level Changes ◽

Sea Level Fluctuations ◽

Data Gap ◽

Current Zero

ABSTRACT The vermetidae fossils of Petaloconchus varians, formed by calcium carbonate, associated with their radiocarbon ages, are the most accurate indicators of paleo sea level due to their restricted occupation in the intertidal zone in the rocky shore. However, the recrystallization of minerals can affect these age calculations and, consequently, the interpretation of the data. The aim of this study is to present new indicators of paleo sea-level changes in Southeast Brazil for the last 6000 years contributing to fill the data gap for the late Holocene. The influence of the recrystallization process was successfully resolved using the CarDS protocol, enabling the separation of the original aragonite fraction by density, prior to radiocarbon dating. This avoids the rejuvenation of ages and ensures greater efficiency for data interpretation. Paleo sea-level indicators were able to show a progressive increase in sea level up to the transgressive maximum of 4.15 m in 3700 BP years, followed by a regression to the current zero. This regression seems to have in addition, here we reinforce the reliability of the use of fossil vermetids as indicators of sea-level fluctuations.

Download Full-text