Biological Indicators Reveal Small-Scale Sea-Level Variability During MIS 5e (Sur, Sultanate of Oman)

Bibliographic Data

ID7936799
AuthorsMichaela Falkenroth (0000-0003-1705-1085, RWTH Aachen University), Silja Kerstin Adolph, Adolph, Silja Kerstin Adolphs, M Cahnbley (RWTH Aachen University), H Bagci (RWTH Aachen University), Miklós Kázmér (0000-0003-1092-1316, RWTH Aachen University), Mechernich, Silke Mechernich (0000-0003-3684-040X), Gösta Hoffmann (0000-0002-2605-2672, RWTH Aachen University)
Year2020
Volume6
Publication date2020-01-13
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueOpen Quaternary (JOURNAL)
Journal identifiersISSN: 2055-298X • E-ISSN: 2055-298X
PublisherUbiquity Press, Ltd. (PUBLISHER)
DOI10.5334/oq.72
OpenAlexW3000487250
LanguageEN
Citations received3
References cited42

The harbour city Sur is located at the northeastern coastline of Oman on a Holocene barrier spit that separates a 6 km2 sized lagoon from the Gulf of Oman. Around the margins of this lagoon a paleo coastal notch occurs 3.75 m above mean sea-level (MSL). The notch contains exceptionally well preserved bioerosional features. Additionally, on several locations coastal notches without bioerosional features occur. At one location a beachrock is found cemented to the rocksurface inside the bioerosion notch. This beachrock was dated to an age of 80.000 a BP in a previous study (Mauz et al. 2015). We therefore presume that the bioerosion notch formed during the last interglacial period in MIS 5e. Given that MIS 5e was the last time with a warmer global climate and a higher eustatic sea-level than today it is of special interest to the scientific community. In this study we aim to document the bioerosional features of the notch and interpret them regarding their use as sea-level indicator. We also intend to unravel any short-term sea-level fluctuations during the last interglacial period, which are potentially documented within the coastal notches in Sur. To meet this goal all outcrops of paleo notches around SurLlagoon were investigated in regards to the faunal distribution and notch shape. Furthermore, the absolute elevation of the notches and biological markers relative to MSL were measured with a differential GPS. The results reveal that the bioerosional notch shows the same height around Sur Lagoon indicating that the area remained tectonically stable over the last 125.000 a. Given the elevation of the notch-apex MSL was 3.75 m higher than today during the last interglacial. The distribution of organisms relative to the notch shape displays five phases of short-term sea-level fluctuations subsequent to the notch formation. The interpretation of the other landforms in Sur Lagoon, namingly abrasional notches and beachrocks, shows that these landforms were formed in a more exposed setting rather than the lagoonal milieu we observe nowadays. With a MSL of 3.75 m above the current MSL Sur Lagoon does indeed not exist, as is shown by reconstructing a higher sea-level within a digital elevation model

Elevation (ballistics · Geography · Glacial period · Interglacial · Outcrop · Pangaea · Permian · Physical geography · Sea level · Sediment · Geology and Paleoclimatology Research · Marine and environmental studies · Maritime and Coastal Archaeology · Geology · Oceanography · Paleontology