Water Column Chemistry of Late Holocene Lake Bafa, Eastern Coast of the Aegean Sea (Turkey)

Thermaikos Gulf, located in the Northwestern Aegean Sea (Greece), is a marine ecosystem of major importance, not only environmentally (as an area of the deep water formation with contribution to the renewal of the North Aegean deep waters), but also due to the various socioeconomic activities associated with the area. Observational and simulated data are used to investigate the evolution of eutrophication events during the last two years in order to evaluate the current (2017-2019) quality state of the seawater in the Gulf. The quality of the marine environment of Thermaikos Gulf was appraised by measuring physical, chemical and biological parameters. Specific physical-chemical characteristics (temperature, salinity, density along with pH and dissolved oxygen) and biological parameters (chl-a and phytoplankton biomass) throughout the water column were evaluated by conducting in situ measurements during the sampling campaigns. Current fields, derived from a high-resolution 3-D ocean model, together with ADCP measurements, are used to describe the major circulation patterns, the river plume dynamics and the renewal pathways of the Gulf. The obtained results are discussed with regards to seasonal and spatial variability, and the water column stratification. Satellite ocean color data were also used to discuss the in-situ findings and confirm &#8220;Dirty&#8221; Sea and Red Tide phenomena, that were detected and analyzed based on the physical dynamics and especially the renewal patterns of the Gulf. Moreover, we compare these recent findings to respective observations from a previous period (1997 to 2007) to evaluate potential changes in the quality state of the Gulf with respect to meteorological and river discharge conditions.&#160;&#160;&#160; &#160;

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Multiple Submerged Tidal Notches: A Witness of Sequences of Coseismic Subsidence in the Aegean Sea, Greece

Journal of Marine Science and Engineering ◽

10.3390/jmse9040426 ◽

2021 ◽

Vol 9 (4) ◽

pp. 426

Author(s):

Anna Karkani ◽

Niki Evelpidou

Keyword(s):

Sea Level ◽

Late Holocene ◽

Aegean Sea ◽

Sea Level Changes ◽

Short Term ◽

Aegean Region ◽

Return Times ◽

Average Return ◽

Coseismic Subsidence

In some islands of the Aegean, there is evidence of the occurrence of repeated rapid subsidences during the Late Holocene. In this paper, the shape of tidal notches that may be well-preserved underwater is recalled in order to reconstruct sequences of coseismic subsidences and other relative sea-level changes, which occurred during, at least, the last few millennia. A reanalysis of the published measurements of submerged tidal notches in several islands reveals that subsidence trends in many areas of the Aegean are not continuous with gradual movement but, also, are the result of repeated coseismic vertical subsidences of some decimetres at each time. The estimated average return times are of the order of approximately some centuries to one millennium. Although the results cannot be used for short-term predictions of earthquakes, they may provide useful indications on the long-term tectonic trends that are active in the Aegean region.

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Human history and palaeoenvironmental change at Site 17, Freshwater Beach, Lizard Island, northeast Queensland, Australia

Queensland Archaeological Research ◽

10.25120/qar.16.2013.227 ◽

2013 ◽

Vol 16 ◽

pp. 141 ◽

Cited By ~ 9

Author(s):

Carol J. Lentfer ◽

Matthew W. Felgate ◽

Robynne A. Mills ◽

Jim Specht

Keyword(s):

Intertidal Zone ◽

Late Holocene ◽

The Other ◽

Eastern Coast ◽

Human History ◽

Palaeoenvironmental Change ◽

Lizard Island ◽

Reef Islands ◽

The Relationship

Late Holocene patterns of change in occupation and use of islands along the eastern coast of Queensland have long been debated in terms of various drivers, though much of this discussion relates to regions south of Cairns, with comparatively little study of the far northern Great Barrier Reef islands. The numerous middens, stone arrangements and art sites on Lizard Island suggest long-term use by Indigenous people, but recent discoveries of pottery give tantalising glimpses of a prehistoric past that may have included a prehistoric economy involving pottery. Here we review previous archaeological surveys and studies on Lizard Island and report on new archaeological and palaeoenvironmental studies from the Site 17 midden at Freshwater Beach, with an oldest date of 3815–3571 cal BP. We identify two major changes in the archaeological and palaeoenvironmental records, one associated with more recent European influences and the other at c.2000 cal BP. Pottery from the intertidal zone is as yet undated. When dates become available the relationship between the Site 17 results reported here and the use of pottery on the island may be clarified.

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GEOMORPHIC EVOLUTION OF THE PALAMARI BAY (NORTHEASTERN SKYROS ISLAND) DURING LATE HOLOCENE

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.16907 ◽

2018 ◽

Vol 36 (2) ◽

pp. 1044

Author(s):

Κ. Παυλόπουλος ◽

Ε. Καρύμπαλης ◽

Π. Καρκάνας ◽

Λ. Παρλαμά ◽

Ι. Μάνος ◽

...

Keyword(s):

Radiocarbon Dating ◽

Late Holocene ◽

Depositional Environment ◽

Aegean Sea ◽

Archaeological Site ◽

Palynological Analysis ◽

Geomorphic Evolution ◽

Geomorphological Mapping ◽

Sedimentary Sequences ◽

Palynological Study

Palamari bay is loceted on the northeastern coast of Skyros island (Sporades islands, Aegean sea). The area is of fundamental archaeological interest because of a prehistoric archaeological site, located at the northern part of the bay. In order to investigate the geomorphic evolution of the broader area a detailed geomorphological mapping of the coastal and submarine area of the bay at a scale 1:5000 was carried out. Additionally the stratigraphy of the late Holocene sediments was studied and micropaleontological and palynological study of collected samples from the deposits of the coastal alluvial plain as well as radiocarbon dating of selected layers rich in organic material were done. The main morphological features of the coastal zone are two beachrock formations with the first one extending along the coastline reaching a depth of-1.70 m and the second one occupying the southern part of the bay lying between -1.90 and -2.90 m below sea level. Microfaunal and palynological analysis of collected samples identified two main sedimentary sequences. The uppermost sedimentary unit represents a terrestrial depositional environment dominated by aeolian wellsorted sands and fluvial sediments. The underlying sequence showed a lagoonal depositional environment, implying a protected lagoon connected to the sea, which was periodically supplied with fresh water. This lagoon existed between 3700 years BP and 700 years BP as radiocarbon dating showed. The existence of this lagoon after that period is possible.

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A new Miocene detachment from Antiparos Island (Cyclades, Greece)

10.5194/egusphere-egu2020-19863 ◽

2020 ◽

Author(s):

Dimitrios Baroutsos ◽

Konstantinos Soukis ◽

Erich Draganits ◽

David A Schneider ◽

Bernhard Grasemann ◽

...

Keyword(s):

Late Miocene ◽

Hanging Wall ◽

Normal Fault ◽

Aegean Sea ◽

Axial Plane ◽

Amphibolite Facies ◽

Eastern Coast ◽

Lower Grade ◽

Mylonitic Foliation ◽

Metamorphic Core Complexes

Numerous studies throughout the world have focused on the structure and evolution of metamorphic core complexes and the exhumation of subducted rocks in back-arc areas of orogenic belts. The Cycladic Islands (central Aegean Sea, Greece) are key areas for studying mechanisms of high-pressure rock exhumation. In that domain, the highly attenuated upper plate is preserved only as sparse extensional allochthons in the hanging wall of crustal-scale detachments. Several detachment systems have been identified on a number of islands indicating overall bivergent extension during the late Oligocene&#8211;Miocene. The island of Antiparos is situated at the center of the Cyclades, SW of the larger Paros Island where the top-to-N Paros-Naxos Detachment has exhumed pre-Alpine basement and metamorphosed Permian-Mesozoic rocks of the Cycladic Blueschist Unit (CBU). The tectonostratigraphic relationship of an enigmatic element, the Dryos Unit, remains unclear.Detailed mapping in Antiparos revealed the existence of a sub-horizontal normal fault along the eastern coast of the island. This fault juxtaposes CBU in the footwall against the Dryos Unit and scarce (?)late Miocene clastic sediments in the hanging wall.The CBU occupies most of the island and consists of marble alternating with schists and gneiss layers. The earlier HP assemblages are totally overprinted by mainly amphibolite facies metamorphism. An axial plane foliation to NE-SW isoclinal folds is accompanied by NE-SW stretching lineation. As indicated by recrystallization of feldspars and high-grade deformation mechanisms these structures formed under amphibolite facies conditions. Towards the detachment the foliation is reworked by a brittle-ductile mylonitic foliation and a brittle-ductile S -C&#8217; fabric can be observed.Numerous kinematic indicators such as &#963;- and &#948;-clasts, Riedel shears, flanking structures S-C&#8217; fabric, observed within the ultramylonitic rocks of the footwall and the mylonites/cataclasites of the hanging wall indicate top-to-NE sense of shear, comparable to the sense of shear in the Paros-Naxos detachment.The Dryos Unit is observed only along the central eastern coast of Antiparos, above the low-angle detachment and comprises lower grade (greenschist facies) metabasite, calc-phyllite and pink marble. Deformation in the structurally upper part is characterized by intense refolding and a steep axial plane foliation. At the structurally lower part a strong mylonitic foliation prevails, overprinted by intense cataclastic deformation. The stretching lineation is mostly NW-SE but in the lower part and towards the detachment it rotates to NE-SW. The late Miocene sediments are found adjacent to the Dryos rocks in two localities, comprising mainly sandstone, mudstone and conglomerate in which, large blueschist clasts are abundant.The new data presented in this study combined with existing data from Paros Island substantially add to the continuation and structure of the complex Paros-Naxos detachment system, domed at an island scale. Furthermore, it suggests that most probably the Dryos Unit is not an upper part of the Cycladic Blueschist Unit but belongs to a different unit, possibly of Pelagonian origin.

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