Sea level reconstruction based on vertical distribution of grain-size parametri and carbonate content in beach ridge plains

Sea level reconstruction based on vertical distribution of grain-size parameters and carbonate content 
in beach ridge plains
Ionel-Bogdan STAN1*
, Alfred VESPREMEANU-STROE1,2, Luminita PREOTEASA1,2, Laurentiu TUTUIANU1
1 GEODAR Research Center for Geomorphology, Geoarchaeology and Paleo-Environments, Bucharest University, 1 N. Bălcescu, 
01004 Bucharest, Romania; 
2 Sfântu Gheorghe Marine & Fluvial Research Station, Faculty of Geography, Bucharest University, Sf. Gheorghe, Tulcea, 
Romania;
*Correspondence to: Stan Ionel Bogdan. E-mail: ionel.bogdan.stan@gmail.com
KEY WORDS: SLIP, SEA-LEVEL in Late Holocene, Western Black Sea
Accurate sea-level reconstruction is important in modelling and anticipating the effects of currently
accelerated eustatic changes and the associated landscape changes.
The methodologies that determine the paleo-sea level currently involve various level indicators - Sea 
Level Index Points (SLIP) -, such as: (a) basal peat (formed in lagoons and swamps whose substrate is 
very close to contemporaneous mean sea level), (b) biological indicators: those species that support 
very shallow depths or that live at known depths, (c) speleothems (which cannot directly quantify sea-
level, but may indicate a maximum level below which the sea surface was during their formation), (d) 
archaeological material of past sea level significance (e.g., harbour structures), (e) marine terraces. Yet, 
the uncertainty range of these SLIPs is large and new and more accurate indicatora are necessary. 
Our previous studies on the morphology and sedimentology of beach ridge plains from Danube Delta 
(Preoteasa and Vespremeanu-Stroe, 2010; Vespremeanu-Stroe et al., 2016) suggest the imprint of the
mean sea level on the vertical distribution of textural parameters of sediments in the (former) foreshore 
system, especially on the beach face and berms. In the present study, we examined the vertical 
distribution of the sedimentary parameters and inorganic carbonate content along cross-shore profiles 
on several beach ridge plains from the Danube delta to capture those changes attributed to mean sea-
level changes on a larger time scale. OSL dating of the berm sediments on successive beach ridges was 
undertaken to constrain the chronological framework of the BRP formation and sea-level variation.
Our analysis shows the content of inorganic carbonates usually increases within ca. 15-30 cm envelope 
near the mean sea level and that the sediment sorting becomes poorer in the mid and lower beach face 
zone comparative to the upper beach face and berm sediments. These results supports a new method to 
track sea-level in beach ridge plains at a comparatively better resolution. A preliminary sea-level curve 
for the last 3500 years was obtained based on new data from Danube delta strandplains which shows
clear fluctuations in sea level during different climatic periods.