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

2017 ◽  
Vol 8 (2) ◽  
pp. 13 ◽  
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. 

Eustatic control of late Quaternary sea-level change in the Arabian/Persian Gulf

2014 ◽  
Vol 82 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Thomas Stevens ◽  
Matthew J. Jestico ◽  
Graham Evans ◽  
Anthony Kirkham
Keyword(s):  
Sea Level ◽  
Persian Gulf ◽  
Late Quaternary ◽  
Osl Dating ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Coastal Evolution ◽  
Last Glacial ◽  
Sea Level Variations ◽  
The Last Glacial

AbstractAccurate sea-level reconstruction is critical in understanding the drivers of coastal evolution. Inliers of shallow marine limestone and aeolianite are exposed as zeugen (carbonate-capped erosional remnants) on the southern coast of the Arabian/Persian Gulf. These have generally been accepted as evidence of a eustatically driven, last-interglacial relative sea-level highstand preceded by a penultimate glacial-age lowstand. Instead, recent optically stimulated luminescence (OSL) dating suggests a last glacial age for these deposits, requiring >100 m of uplift since the last glacial maximum in order to keep pace with eustatic sea-level rise and implying the need for a wholesale revision of tectonic, stratigraphic and sea-level histories of the Gulf. These two hypotheses have radically different implications for regional neotectonics and land–sea distribution histories. Here we test these hypotheses using OSL dating of the zeugen formations. These new ages are remarkably consistent with earlier interpretations of the formations being last interglacial or older in age, showing that tectonic movements are negligible and eustatic sea-level variations are responsible for local sea-level changes in the Gulf. The cause of the large age differences between recent studies is unclear, although it appears related to large differences in the measured accumulated dose in different OSL samples.

Late-Quaternary Sea Level Changes, Umnak Island, Aleutians—Their Effects on Ancient Aleuts and their Causes

1974 ◽  
Vol 4 (3) ◽  
pp. 264-281 ◽  
Author(s):  
Robert F. Black
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Food Resources ◽  
Aleutian Islands ◽  
Level Curve ◽  
Present Position ◽  
Present Level ◽  
Sea Level Changes ◽  
Relative Sea Level

Late-Quaternary sea level changes in the eastern Aleutian Islands are of paramount importance in the reconstruction of the migrations and environment of the ancient Aleuts. A radiocarbon-dated ash stratigraphy provides the chronology into which geomorphic events can be fitted. These provide evidence for the sea level changes. Deployment of beach material and coastal configuration intimate that sea level was about 2–3 m above the present level about 8250 radiocarbon yr BP. Beach deposits suggest that sea level remained high until about 3000 radiocarbon y.a. when it gradually dropped to its present position. It is concluded that the ancient Aleuts that settled Anangula about 8400 y.a. used boats; all major passes in the eastern Aleutians were flooded, and did not have winter ice. Those ancient Aleuts did not have available the major year-around food resources of the present strandflats as they were cut during the high sea level stand 8250–3000 yr BP. The ancient Aleuts must have been marine oriented, for land-based food resources would have been limited.The cause of relative sea level changes on Umnak Island is considered indeterminate with present data. Eustatic, glacial isostatic, water isostatic, tectonic, and volcanic causes are considered the main possible controls in combinations such that a basic eustatic sea level curve and likely a glacial-water isostatic curve must be common to any solution. Representative solutions are given to illustrate some of the problems.

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

2021 ◽  
Vol 19 ◽  
pp. 1-14
Author(s):  
Erman Özsayın ◽  
Serkan Üner ◽  
Burcu Kahraman
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Normal Fault ◽  
Tectonic Activity ◽  
Normal Faults ◽  
Sea Level Changes ◽  
Focal Mechanism Solutions ◽  
Sw Turkey ◽  
Earthquake Focal Mechanism ◽  
Regional Sea Level

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.

Far-Field Test of the ICE-4G Model of Global Isostatic Response to Deglaciation Using Empirical and Theoretical Holocene Sea-Level Reconstructions for the Fiji Islands, Southwestern Pacific

2001 ◽  
Vol 55 (2) ◽  
pp. 203-214 ◽  
Author(s):  
Patrick D. Nunn ◽  
W. Richard Peltier
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Far Field ◽  
Present Level ◽  
Sea Level Changes ◽  
Middle Holocene ◽  
Broad Agreement ◽  
Fiji Islands ◽  
Level Data ◽  
Holocene Sea Level

AbstractHolocene paleosea-level data for Fiji, represented by 77 dates and emergence magnitudes, are presented, screened, and adjusted. Most data are from coral microatolls, potentially the most precise paleosea-level indicators in this region. Holocene sea-level changes are reconstructed for five areas within Fiji known to have had different late Quaternary tectonic histories. Resulting analysis suggests that postglacial sea level in Fiji reached its present level more than 6900 14C yr B.P. It also suggests either that a single maximum 5650–3200 14C yr B.P. (perhaps +2.19 m but more likely +1.35–1.50 m) occurred or that two maxima occurred 6100–4550 14C yr B.P. (+0.75–1.85 m) and 3590–2800 14C yr B.P. (+0.90–2.46 m). Broad agreement exists between these empirical sea-level reconstructions and those derived theoretically using the ICE-4G model (predicted maximum ∼4000 14C yr B.P.; ∼+2.1 m). This suggests that both methods of reconstructing Holocene sea-level changes are valid, as are the assumptions underpinning the ICE-4G model. The most important of these, that eustatic sea level had effectively stopped rising by late middle-Holocene time (5000–4000 yr B.P.), is confirmed by observations from Fiji.

scholarly journals Late Quaternary Landscape Dynamics at the La Spezia Gulf (NW Italy): A Multi-Proxy Approach Reveals Environmental Variability within a Rocky Embayment

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 427
Author(s):  
Veronica Rossi ◽  
Alessandro Amorosi ◽  
Marco Marchesini ◽  
Silvia Marvelli ◽  
Andrea Cocchianella ◽  
...  
Keyword(s):  
Sea Level ◽  
Environmental Variability ◽  
Late Quaternary ◽  
Landscape Dynamics ◽  
Last Interglacial ◽  
Core Depth ◽  
Coastal Bay ◽  
Nw Italy ◽  
Global Sea Level ◽  
Geomorphological Features

The Gulf of La Spezia (GLS) in Northwest Italy is a rocky embayment with low fluvial influence facing the Mediterranean Sea. Past landscape dynamics were investigated through a multi-proxy, facies-based analysis down to a core depth of 30 m. The integration of quantitative ostracod, foraminifera, and pollen analyses, supported by radiocarbon ages, proved to be a powerful tool to unravel the late Quaternary palaeoenvironmental evolution and its forcing factors. The complex interplay between relative sea-level (RSL), climatic changes, and geomorphological features of the embayment drove four main evolution phases. A barrier–lagoon system developed in response to the rising RSL of the Late Pleistocene (likely the Last Interglacial). The establishment of glacial conditions then promoted the development of an alluvial environment, with generalised erosion of the underlying succession and subsequent accumulation of fluvial strata. The Holocene transgression (dated ca. 9000 cal year BP) caused GLS inundation and the formation of a low-confined lagoon basin, which rapidly turned into a coastal bay from ca. 8000 cal year BP onwards. This latter environmental change occurred in response to the last Holocene stage of global sea-level acceleration, which submerged a morphological relief currently forming a drowned barrier-island complex in the embayment.

Palaeoecological evidences from foraminifers and ostracods on Late Quaternary sea-level changes in the Ombrone river plain (central Tyrrhenian coast, Italy)

Geobios ◽  
2002 ◽  
Vol 35 ◽  
pp. 40-50 ◽  
Author(s):  
M Gabriella Carboni ◽  
Luisa Bergamin ◽  
Letizia Di Bella ◽  
Fabrizia Iamundo ◽  
Nevio Pugliese
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Sea Level Changes ◽  
River Plain

WALIS - Towards a global database of Last Interglacial sea-level proxies.

2021 ◽  
Author(s):  
Alessio Rovere ◽  
Deirdre Ryan ◽  
Matteo Vacchi ◽  
Alexander Simms ◽  
Andrea Dutton ◽  
...  
Keyword(s):  
Sea Level ◽  
Research Council ◽  
Geological Data ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Global Database ◽  
The World ◽  
First Results ◽  
Data Points ◽  
The Subject

<p>The standardization of geological data, and their compilation into geodatabases, is essential to allow more coherent regional and global analyses. In sea-level studies, the compilation of databases containing details on geological paleo sea-level proxies has been the subject of decades of work. This was largely spearheaded by the community working on Holocene timescales. While several attempts were also made to compile data from older interglacials, a truly comprehensive approach was missing. Here, we present the ongoing efforts directed to create the World Atlas of Last Interglacial Shorelines (WALIS), a project spearheaded by the PALSEA (PAGES/INQUA) community and funded by the European Research Council (ERC StG 802414). The project aims at building a sea-level database centered on the Last Interglacial (Marine Isotope Stage 5e, 125 ka), a period of time considered as an "imperfect analog" for a future warmer climate. The database is composed of 17 tables embedded into a mySQL framework with a total of more than 500 single fields to describe several properties related to paleo sea-level proxies, dated samples and metadata. In this presentation, we will show the first results of the global compilation, which includes nearly 2000 data points and will discuss its relevance in answering some of the most pressing questions related to sea-level changes in past warmer worlds. </p>

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