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

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.

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

2016 ◽  
Vol 12 (12) ◽  
pp. 2161-2179 ◽  
Author(s):  
Anne-Sophie Fanget ◽  
Maria-Angela Bassetti ◽  
Christophe Fontanier ◽  
Alina Tudryn ◽  
Serge Berné
Keyword(s):  
Sea Level ◽  
Water Depth ◽  
Late Holocene ◽  
Sea Level Changes ◽  
The Holocene ◽  
Middle Holocene ◽  
The Core ◽  
Condensed Section ◽  
Core Site ◽  
Nw Mediterranean

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.

scholarly journals Late Little Ice Age palaeoenvironmental records from the Anzali and Amirkola Lagoons (south Caspian Sea): Vegetation and sea level changes

2011 ◽  
Vol 302 (3-4) ◽  
pp. 415-434 ◽  
Author(s):  
S.A.G. Leroy ◽  
H.A.K. Lahijani ◽  
M. Djamali ◽  
A. Naqinezhad ◽  
M.V. Moghadam ◽  
...  
Keyword(s):  
Sea Level ◽  
Caspian Sea ◽  
Little Ice Age ◽  
Ice Age ◽  
Sea Level Changes ◽  
And Sea Level

The Norse in Greenland and late Holocene sea-level change

Polar Record ◽  
2008 ◽  
Vol 44 (1) ◽  
pp. 45-50 ◽  
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.

Paleoenvironmental Evolution of the Coastal Plain of Marathon, Greece, during the Late Holocene: Depositional Environment, Climate, and Sea Level Changes

2006 ◽  
Vol 222 ◽  
pp. 424-438 ◽  
Author(s):  
Kosmas Pavlopoulos ◽  
Panagiotis Karkanas ◽  
Maria Triantaphyllou ◽  
Efthimios Karymbalis ◽  
Theodora Tsourou ◽  
...  
Keyword(s):  
Sea Level ◽  
Coastal Plain ◽  
Late Holocene ◽  
Depositional Environment ◽  
Sea Level Changes ◽  
Paleoenvironmental Evolution ◽  
And Sea Level

Integrated biostratigraphy of the lower Silurian of the Ohesaare core, Saaremaa, Estonia

1998 ◽  
Vol 135 (6) ◽  
pp. 769-783 ◽  
Author(s):  
D. K. LOYDELL ◽  
D. KALJO ◽  
P. MÄNNIK
Keyword(s):  
Sea Level ◽  
Sea Level Changes ◽  
Precise Position ◽  
Lower Silurian ◽  
The Core ◽  
And Sea Level

Integrated graptolite, conodont and chitinozoan biostratigraphical data are presented from the lower Silurian of the Ohesaare core, Saaremaa, Estonia. A precise correlation of graptolite and conodont biozonations for much of the Telychian and Sheinwoodian is presented; this differs significantly from correlations suggested previously, which were based on inadequate graptolite data. The boundary between the celloni and amorphognathoides conodont biozones lies close to that between the spiralis and lapworthi graptolite biozones. The boundary between the bicornis and procerus conodont superzones lies mid-way through the murchisoni graptolite Biozone. The top of the procerus conodont Superzone lies at or very close to the boundary between the murchisoni and firmus graptolite biozones. The boundary between the Lower and Upper ranuliformis conodont biozones lies close to the boundary between the firmus and riccartonensis graptolite biozones. The precise position of the Llandovery–Wenlock boundary cannot be identified in the core. The newly demonstrated biozonal correlations are significant for studies of Silurian chronostratigraphy (previous estimates of the duration of the epochs and ages of the Silurian were based on inaccurate correlations) and sea-level changes. Palaeogeographically, the setting of Ohesaare is considered to be relatively deep shelf. Perhaps surprisingly, there is a major unconformity in the Llandovery of the core: much, if not all, of the Aeronian is missing, as is the lower part of the Telychian.

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