Late Quaternary subsidence records from the Datça graben and Cnidus ancient city (SW Turkey): sea-level changes versus tectonics

The Datça graben in southwestern Anatolia is a WNW-trending seismically active depression, with tectonic activity since Pliocene time. This tectonic activity is controlled by normal faults, which have effected ancient settlements. The Cnidus city (old and modern) –an ancient mercantile centre during the Hellenistic, Roman and Byzantine periods– is one of the places that has recorded this activity. The ancient harbour walls of Cnidus, lying 2.2-4.0m below sea level, contain important traces about sea-level changes and tectonics over the past 2.6kyr. Palaeostress analysis along boundary faults in the Datça graben yields an almost N–S oriented pure tensional regime, compatible with earthquake focal mechanism solutions located around the Datça Peninsula. Additionally, an almost E−W trending surface rupture related to a historical earthquake in modern Cnidus, which shows normal fault characteristics, gives further support to the ongoing extension along the Kızlan, Karaköy and Cnidus fault zones. Previous studies on late Quaternary sea-level changes around the Datça Peninsula suggest that 2.6kyr ago sea level was 1.0-1.25m lower than today. From the present-day depth of the Old Cnidus harbour remains and regional sea-level records, it can be inferred that tectonics has played a significant role. Our calculations show that the Datça graben is subsiding at rates of 0.36-0.46mm/yr in the central part and 1.05-1.15mm/yr in the southern part. These values match those found in other areas around the Datça Peninsula.

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Submerged Speleothems and Sea Level Reconstructions: A Global Overview and New Results from the Mediterranean Sea

10.20944/preprints202105.0100.v1 ◽

2021 ◽

Author(s):

Fabrizio Antonioli ◽

Stefano Furlani ◽

Paolo Montagna ◽

Paolo Stocchi ◽

Lucio Calcagnile ◽

...

Keyword(s):

Mediterranean Sea ◽

Sea Level ◽

Additional Data ◽

Late Quaternary ◽

Sea Level Changes ◽

Central Mediterranean ◽

Relative Sea Level ◽

Central Mediterranean Sea ◽

Regional Sea Level ◽

Sea Level Variations

This study presents a world review as well as new additional data in form of submerged speleothems that are used for paleo sea level reconstructions. Speleothems significantly contributed to the understanding of the global and regional sea level variations during the Middle and Late Quaternary. The studied speleothems cover the last 1.4 Myr and are focused mainly on Marine Isotope Stages (MIS) 1, 2, 3, 5.1, 5.3, 5.5, 7.1, 7.2, 7.3 and 7.5. Results reveal that submerged speleothems represent extraordinary archives providing detailed information on former sea level changes. We present also new results from stalactites collected in central Mediterranean sea, at Favignana and Ustica islands (Sicily, Italy), both characterized by continental, phreatic or marine layers. The study and analysis of the latter speleothems provide results of great interest for relative sea level changes over the last 1000 years.

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Morphology of the Raised Shore Platforms along the Coastline between Daghmar and Dhabab, Sultanate of Oman

Journal of Arts and Social Sciences [JASS] ◽

10.24200/jass.vol8iss2pp13-24 ◽

2017 ◽

Vol 8 (2) ◽

pp. 13 ◽

Cited By ~ 2

Author(s):

Salim Mubarak Al Hatrushi

Keyword(s):

Sea Level ◽

Late Quaternary ◽

Aerial Photographs ◽

Tectonic Activity ◽

Present Level ◽

Sea Level Changes ◽

Last Interglacial ◽

Southeastern Part ◽

Relative Level ◽

Shore Platforms

Raised shore platforms, are rocky surfaces formed by wave action and subaerial weathering during global high sea level stands. The present height of the raised shore platforms is attributed to several factors, mainly to eustatic sea level changes, isostatic changes in the relative level of land and sea, and vertical tectonic activities. The aim of this study is to investigate the detailed morphology of the raised shore platform along the rocky coastline between Daghmar and Dhabab, in the southeastern part of Muscat Governorate. The study also intends to establish a tentative chronology of the raised shore platforms development. The methodology is based on field observation and documentation, along with satellite and aerial photographs analysis. The results have shown that the study area has a sequence of five successive, well developed raised shore platforms and well preserved, except the platform at 10m altitude which is only found in isolated fragments. The formation of the raised shore platforms has been affected by a number of constructive factors including tectonic activity, and destructive factors such as fluvial action and subaerial weathering. No absolute dating has been reported or can be obtained from the study area, due to its erosional nature. However, dating from the shorelines adjacent to the study area, ranging in heights from 3 to 15m above sea level, revealed a narrow range of 26,400 to 29,600 years. This period coincides with the last glaciations when the sea level was at about 75m below the present level, and thus did not match with the altitudes of the platforms. This suggests that the platforms could be belong to the last interglacial high sea level, when the sea level stood at about 6m above the present level. Based on this scenario, the study concludes that the coastline of the study area has not experienced any significant uplift during the Late Quaternary.

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The Use of Submerged Speleothems for Sea Level Studies in the Mediterranean Sea: A New Perspective Using Glacial Isostatic Adjustment (GIA)

Geosciences ◽

10.3390/geosciences11020077 ◽

2021 ◽

Vol 11 (2) ◽

pp. 77

Author(s):

Fabrizio Antonioli ◽

Stefano Furlani ◽

Paolo Montagna ◽

Paolo Stocchi

Keyword(s):

Mediterranean Sea ◽

Sea Level ◽

Late Quaternary ◽

Accurate Information ◽

Sea Level Changes ◽

The Bahamas ◽

Isostatic Adjustment ◽

Regional Sea Level ◽

The Mediterranean ◽

New Perspective

The investigation of submerged speleothems for sea level studies has made significant contributions to the understanding of the global and regional sea level variations during the Middle and Late Quaternary. This has especially been the case for the Mediterranean Sea, where more than 300 submerged speleothems sampled in 32 caves have been analysed so far. Here, we present a comprehensive review of the results obtained from the study of submerged speleothems since 1978. The studied speleothems cover the last 1.4 Myr and are mainly focused on Marine Isotope Stages (MIS) 1, 2, 3, 5.1, 5.3, 5.5, 7.1, 7.2, 7.3, and 7.5. The results reveal that submerged speleothems represent extraordinary archives providing accurate information on former sea level changes. New results from a stalagmite collected at Palinuro (Campania, Italy) and characterized by marine overgrowth are also reported. The measured elevations of speleothems are affected by the local response to glacial and hydro-isostatic adjustment (GIA), and thus might significantly deviate from the global eustatic signal. A comparison of the ages and altitude values of the Mediterranean speleothems and flowstone from the Bahamas with local GIA provides a new scenario for MIS 5 and 7 sea level reconstructions.

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The role of late Quaternary tectonic activity and sea-level changes on sedimentary processes interaction in the Gulf of Cadiz upper and middle continental slope (SW Iberia)

Marine and Petroleum Geology ◽

10.1016/j.marpetgeo.2020.104595 ◽

2020 ◽

Vol 121 ◽

pp. 104595

Author(s):

M. García ◽

E. Llave ◽

F.J. Hernández-Molina ◽

F.J. Lobo ◽

G. Ercilla ◽

...

Keyword(s):

Sea Level ◽

Continental Slope ◽

Late Quaternary ◽

Tectonic Activity ◽

Sea Level Changes ◽

Gulf Of Cadiz ◽

Sedimentary Processes ◽

Gulf Of Cádiz ◽

And Sea Level

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Submerged Speleothems and Sea Level Reconstructions: A Global Overview and New Results from the Mediterranean Sea

Water ◽

10.3390/w13121663 ◽

2021 ◽

Vol 13 (12) ◽

pp. 1663

Author(s):

Fabrizio Antonioli ◽

Stefano Furlani ◽

Paolo Montagna ◽

Paolo Stocchi ◽

Lucio Calcagnile ◽

...

Keyword(s):

Mediterranean Sea ◽

Sea Level ◽

Late Quaternary ◽

Sea Level Changes ◽

Central Mediterranean ◽

Sea Levels ◽

Cave Deposits ◽

Regional Sea Level ◽

Sea Level Variations ◽

The Mediterranean

This study presents a global overview of the submerged speleothems used to reconstruct paleo sea levels and reports new results from two stalactites collected in the Mediterranean Sea. Coastal cave deposits significantly contributed to the understanding of global and regional sea-level variations during the Middle and Late Quaternary. The studied speleothems cover the last 1.4 Myr and focused mainly on Marine Isotope Stages (MIS) 1, 2, 3, 5.1, 5.3, 5.5, 7.1, 7.2, 7.3 and 7.5. The results indicate that submerged speleothems represent extraordinary archives that can provide detailed information on former sea-level changes. The two stalactites collected in the central Mediterranean Sea, at Favignana and Ustica islands (Sicily, Italy), are both characterized by continental, phreatic or marine layers. The U-Th and 14C ages of the new speleothems provide results of great interest for relative sea-level changes over the last 1000 years.

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