scholarly journals Plio-Quaternary history of the Turkish coastal zone of the Enez-Evros Delta: NE Aegean Sea

2001 ◽  
Vol 2 (2) ◽  
pp. 95 ◽  
Author(s):  
B. ALPAR
Keyword(s):  
Late Pleistocene ◽  
Sand Dunes ◽  
Aegean Sea ◽  
Interglacial Period ◽  
Shelf Area ◽  
Sea Level Changes ◽  
Seismic Profiles ◽  
Alluvial Deposits ◽  
History Of ◽  
Quaternary History

The Enez-Evros Delta, NE Aegean Sea, is located in one the most important wetlands in the world with its sandy offshore islands, abandoned channel mouths, sand-dunes, shoals, marshlands, saline lagoons and saltpans. It comprises very well developed sedimentary units and a prodelta lying on an older submarine delta. The present day elevations of the middle-late Pleistocene marine terraces indicate a regional tectonic uplift in the area. Due to lack of geophysical and bore hole data and partly due to its strategic position, the structural and stratigraphic features of the submarine extension of the delta are not known in detail. In this paper, Plio-Quaternary history of this delta and its submarine part on the Turkish shelf was explored by using high-resolution shallow reflection seismic profiles. The delta is formed by the alluvial deposits of the Enez-Evros River and shaped by their interaction with the sea. It takes place in front of a large and protected ancient bay which was filled rapidly over millennia. The sediments in the plateau off the river are principally pro-deltaic with muddy areas near the river mouths changing to muddy sand further out. The sea-level changes in Plio-Quaternary were characterised by three different seismic stratigraphic units on the folded Miocene limestone basement. In the late Pleistocene, the shelf area over an Upper Miocene basement was flooded during the Riss-Würm interglacial period, exposed in the Würm glacial stage, and flooded once again during the Holocene transgression.

scholarly journals Detection and Characterisation of Eemian Marine Tephra Layers within the Sapropel S5 Sediments of the Aegean and Levantine Seas

Quaternary ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 6
Author(s):  
Christopher Satow ◽  
Katharine M. Grant ◽  
Sabine Wulf ◽  
Hartmut Schulz ◽  
Addison Mallon ◽  
...  
Keyword(s):  
Major Element ◽  
Eastern Mediterranean ◽  
Aegean Sea ◽  
Interglacial Period ◽  
Last Interglacial ◽  
Proxy Records ◽  
Last Interglacial Period ◽  
Levantine Basin ◽  
History Of ◽  
Tephra Layers

The Eemian was the last interglacial period (~130 to 115 ka BP) to precede the current interglacial. In Eastern Mediterranean marine sediments, it is marked by a well-developed and organic-rich “sapropel” layer (S5), which is thought to reflect an intensification and northward migration of the African monsoon rain belt over orbital timescales. However, despite the importance of these sediments, very little proxy-independent stratigraphic information is available to enable rigorous correlation of these sediments across the region. This paper presents the first detailed study of visible and non-visible (cryptotephra) layers found within these sediments at three marine coring sites: ODP Site 967B (Levantine Basin), KL51 (South East of Crete) and LC21 (Southern Aegean Sea). Major element analyses of the glass component were used to distinguish four distinct tephra events of Santorini (e.g., Vourvoulos eruption) and possible Anatolian provenance occurring during the formation of S5. Interpolation of core chronologies provides provisional eruption ages for the uppermost tephra (unknown Santorini, 121.8 ± 2.9 ka) and lowermost tephra (Anatolia or Kos/Yali/Nisyros, 126.4 ± 2.9 ka). These newly characterised tephra deposits have also been set into the regional tephrostratigraphy to illustrate the potential to precisely synchronise marine proxy records with their terrestrial counterparts, and also contribute to the establishment of a more detailed volcanic history of the Eastern Mediterranean.

Late Pleistocene and Holocene Sea Level Changes in the Hisarönü Gulf, Southeast Aegean Sea

2012 ◽  
Vol 27 (3) ◽  
pp. 220-236 ◽  
Author(s):  
Nilhan Kızıldağ ◽  
A. Harun Özdas ◽  
Atilla Uluğ
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Aegean Sea ◽  
Sea Level Changes ◽  
Holocene Sea Level

Retracing the Quaternary history of sea-level changes in the Spanish Mediterranean–Atlantic coasts: Geomorphological and sedimentological approach

Geomorphology ◽  
2013 ◽  
Vol 196 ◽  
pp. 36-49 ◽  
Author(s):  
C. Zazo ◽  
J.L. Goy ◽  
C.J. Dabrio ◽  
J. Lario ◽  
J.A. González-Delgado ◽  
...  
Keyword(s):  
Sea Level ◽  
Sea Level Changes ◽  
History Of ◽  
Quaternary History

Eolian sand and loess deposits indicate west-northwest paleowinds during the Late Pleistocene in western Wisconsin, USA

2017 ◽  
Vol 89 (3) ◽  
pp. 769-785 ◽  
Author(s):  
Randall J. Schaetzl ◽  
Phillip H. Larson ◽  
Douglas J. Faulkner ◽  
Garry L. Running ◽  
Harry M. Jol ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
River Valley ◽  
River Sand ◽  
Eolian Sand ◽  
Westerly Winds ◽  
History Of ◽  
Quaternary History ◽  
Loess Deposits

AbstractOur study adds to the Quaternary history of eolian systems and deposits in western Wisconsin, USA, primarily within the lower Chippewa River valley. Thickness and textural patterns of loess deposits in the region indicate transport by west-northwesterly and westerly winds. Loess is thickest and coarsest on the southeastern flanks of large bedrock ridges and uplands, similar in some ways to shadow dunes. In many areas, sand was transported up and onto the western flanks of bedrock ridges as sand ramps, presumably as loess was deposited in their lee. Long, linear dunes, common on the sandy lowlands of the Chippewa valley, also trend to the east-southeast. Small depressional blowouts are widespread here as well and often lie immediately upwind of small parabolic dunes. Finally, in areas where sediment was being exposed by erosion along cutbanks of the Chippewa River, sand appears to have been transported up and onto the terrace treads, forming cliff-top dunes. Luminescence data indicate that this activity has continued throughout the latest Pleistocene and into the mid-Holocene. Together, these landforms and sediments paint a picture of a locally destabilized landscape with widespread eolian activity throughout much of the postglacial period.

Late Pleistocene Sea Level History of Bermuda

1978 ◽  
Vol 9 (2) ◽  
pp. 205-218 ◽  
Author(s):  
Russell S. Harmon ◽  
Henry P. Schwarcz ◽  
Derek C. Ford
Keyword(s):  
Sea Level ◽  
Interglacial Period ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
The Bahamas ◽  
Sea Level Fluctuations ◽  
Vertical Range ◽  
Level Data ◽  
Last Interglacial Period ◽  
History Of

The timing of eustatic sea level fluctuations over the vertical range + 15 to −11 m has been deduced from 230Th/234U dating of Bermudan corals and speleothems. On this tectonically stable carbonate island, interglacial periods are characterized by platform submergence, development of patch reefs, and the deposition of littoral and eolian carbonates, whereas glacial periods are times of platform emergence, carbonate diagenesis, soil development, and the deposition of speleothems in caves extending below present sea level. Interglacial periods are observed at about 200,000, 130,000 to 90,000, and 10,000 yr BP to present. The sea level history of the last interglacial period (130,000 to 90,000 yr BP) is complex, consisting of at least two short, distinct episodes of high sea stand (at 125,000 and 97,000 yr BP) superimposed on a longer period of general platform submergence. The sea level data derived from this study are compatible with those from other stable areas such as the Bahamas, but in addition suggest that eustatic sea level changes can be rapid, on the order of 5 to 10 m/1000 yr.

Timing and development of sand dunes in the Golestan Province, northern Iran—Implications for the Late-Pleistocene history of the Caspian Sea

2019 ◽  
Vol 41 ◽  
pp. 100538 ◽  
Author(s):  
Neda Rahimzadeh ◽  
Farhad Khormali ◽  
Natacha Gribenski ◽  
Sumiko Tsukamoto ◽  
Martin Kehl ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Caspian Sea ◽  
Sand Dunes ◽  
The Caspian Sea ◽  
Northern Iran ◽  
History Of ◽  
Golestan Province

scholarly journals Late Pleistocene sea-level changes recorded in tidal and fluvial deposits from Itaubal Formation, onshore portion of the Foz do Amazonas Basin, Brazil

2015 ◽  
Vol 45 (suppl 1) ◽  
pp. 63-78 ◽  
Author(s):  
Isaac Salém Alves Azevedo Bezerra ◽  
Afonso César Rodrigues Nogueira ◽  
José Tasso Felix Guimarães ◽  
Werner Truckenbrodt
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Sea Level Changes ◽  
Fluvial Deposits ◽  
Base Level ◽  
Lower Unit ◽  
Basement Rocks ◽  
History Of ◽  
Floodplain Deposits ◽  
The Last Glacial

ABSTRACTThe Pleistocene deposits exposed in the Amapá Coastal Plain (onshore portion of the Foz do Amazonas Basin, northeastern South America) were previously interpreted as Miocene in age. In this work, they were named as "Itaubal Formation" and were included in the quaternary coastal history of Amazonia. The study, through facies and stratigraphic analyses in combination with optically stimulated luminescence (single and multiple aliquot regeneration), allowed interpreting this unit as Late Pleistocene tidal and fluvial deposits. The Itaubal Formation, which unconformably overlies strongly weathered basement rocks of the Guianas Shield, was subdivided into two progradational units, separated by an unconformity related to sea-level fall, here named as Lower and Upper Units. The Lower Unit yielded ages between 120,600 (± 12,000) and 70,850 (± 6,700) years BP and consists of subtidal flat, tide-influenced meandering stream and floodplain deposits, during highstand conditions. The Upper Unit spans between 69,150 (± 7,200) and 58,150 (± 6,800) years BP and is characterized by braided fluvial deposits incised in the Lower Unit, related to base-level fall; lowstand conditions remained until 23,500 (± 3,000) years BP. The studied region was likely exposed during the Last Glacial Maximum and then during Holocene, covered by tidal deposits influenced by the Amazon River.

Late Quaternary lacustrine and deltaic sedimentation near Banff, Alberta

1983 ◽  
Vol 20 (12) ◽  
pp. 1834-1842 ◽  
Author(s):  
R. A. Kostaschuk ◽  
D. G. Smith
Keyword(s):  
Surface Morphology ◽  
Late Pleistocene ◽  
Final Stage ◽  
Late Quaternary ◽  
Low Energy ◽  
The West ◽  
Deltaic Sedimentation ◽  
History Of ◽  
Organic Clay ◽  
Quaternary History

Evidence provided by surface morphology, exposures, cores, and the stratigraphic positions of Mazama (6600 years BP) and Bridge River (2500 years BP) ashes was used to interpret the origin and late Quaternary history of lacustrine and deltaic sediments in the Bow River valley near Banff, Alberta.There were three distinct stages of Lake Vermilion occupying the study area from Late Pleistocene to mid-Holocene times. The earliest stage was ice dammed, deposited beach gravel and nearshore sand, and drained along the present course of the Cascade River to the east. The second, proglacial stage is associated with thick subsurface deposits of non-organic clay and drained to the east along the course of the modern Bow River. The final stage is suggested by point bar and aeolian beach dune sediments.With the stabilization of the final stage of Lake Vermilion the low-energy, river-dominated Bow Delta prograded into the lake from the west. Progradation of the delta through three depositional zones produced the present Vermilion Lakes.

scholarly journals Origin and Paleoenvironmental Significance of the Old Red Sand Along the Southeast Coast of China

2021 ◽  
Vol 9 ◽  
Author(s):  
Qingbin Fan ◽  
Jie Liao ◽  
Yan Li ◽  
Wei Ye ◽  
Tao Wang ◽  
...  
Keyword(s):  
Grain Size ◽  
Climate Changes ◽  
Sand Dunes ◽  
Interglacial Period ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Aeolian Sand ◽  
Southeast Coast ◽  
Last Interglacial Period ◽  
Grain Surface

The “Old Red Sand” (ORS) along the southeast coast of China is of significant paleoclimatic and paleoenvironmental significance. However, its provenance remains controversial. In this study, grain size characteristics and quartz grain surface microtextures were analyzed to study the origin and paleoenvironmental significance of the ORS, the results show that the grain size of the ORS show typical aeolian features, the quartz grain surface microtextures of the ORS show both aeolian features and subaqueous environments characteristics. Combined with the latest OSL dating data, we suggest that the ORS was coastal aeolian sand dunes developed since the last interglacial period. The formation of the ORS was restricted jointly by climate changes of the coastal area and the distance from the shoreline that resulted from sea level changes.

Late Quaternary sedimentation in central Flemish Pass

1992 ◽  
Vol 29 (3) ◽  
pp. 535-550 ◽  
Author(s):  
David J. W. Piper ◽  
Christopher P. G. Pereira
Keyword(s):  
Late Quaternary ◽  
Ice Sheets ◽  
Seismic Profiles ◽  
Grand Banks ◽  
The Past ◽  
Labrador Current ◽  
Lithostratigraphic Units ◽  
History Of ◽  
Quaternary History ◽  
Late Wisconsinan

Flemish Pass is a basin in 1000 m water depth on the continental slope off the Grand Banks of Newfoundland and has a Quaternary fill principally of turbidites. The late Quaternary history of the pass has been investigated using mid-range side-scan sonargraphs, high-resolution seismic profiles, and cores dated using C-14. The sequence of facies in the cores reveals six lithostratigraphic units deposited in the past 40 ka. At 15–19 ka and ?25–30 ka, sedimentation was dominated by debris-flow and turbidite deposits, together with hemipelagic deposits of similar clay-size mineralogy, derived from the Grand Banks. At other times, ice-rafting and hemipelagic sedimentation, principally of carbonate-rich sediment transported by the Labrador Current, predominated. A late Quaternary regional unconformity on the slope may reflect the effects of ice sheets reaching the shelf break, probably in the Early Wisconsinan. Late Wisconsinan resedimentation was not related to ice-marginal processes and probably resulted from iceberg impacts.

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