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The paper presents the chronology of the Holocene evolution of the Baltic Sea based on the optically stimulated luminescence (OSL) and radiocarbon dating methods applied to a core taken from the Arkona Basin. The dating results were supplemented by grain size and geochemical analysis. The obtained results of OSL and radiocarbon dating enabled the construction of an age-depth model and confirmed the continuous sedimentation since 9900 cal yrs BP. One of the most interesting findings of this study is a clear relationship between the rate of sedimentation and fluctuations in the energy of depositional environment. The analyzed sediment core revealed two sections of different accumulation rates. The bottom section was deposited until 2700 cal yrs BP when the Ancylus Lake and the Littorina Sea were present, characterized by the accumulation rate estimated at around 0.46 mm year-1 and the dynamic sedimentation environment confirmed by grain size parameters. The accumulation rate at the top section deposited during the Post-Littorina Sea stage was estimated at around 1 mm year-1. This stage, characterized by more stable deposition and lower-energy environment conditions, was confirmed by small grain size, symmetric skewness and increasing content of organic matter. [ABSTRACT FROM AUTHOR]

In this paper, a detailed overview of the Holocene evolution of the North Dvina river (ND) delta (southern White Sea) is presented; it is based on radiocarbon dating, geomorphological and other field surveys, and plant macrofossil and palynological data. We have identified three main stages of the delta evolution: estuary erosional (Allerød - 5700 cal BC), lagoon or tidal-marsh (5700 cal BC - 3700 cal BC) and fan-delta accumulative (3700 cal BC - present). These stages are correlated with local climatic curves, sea level changes, glacioisostatic raise curve and Baltic Sea stages. A variety of landforms has been identified and dated within the delta. These results help to explain the spatial and temporal patterns in the prehistoric human occupation of this area. [ABSTRACT FROM AUTHOR]

A study is focused on the Palaeo--Nemunas delta morphogenesis and development during Late Glacial and Holocene time span. Geomorphometry and morphological features of the submerged delta were recognized for the first time on the submarine Curonian (Kuršių Plateau in 1986-1992. This paper presents a pilot study applied in 2006-2008 and is based on multi-beam echo sounder and side-scan sonar images data. Two geological sections across the Palaeo--Nemunas delta are compiled from the data of core studies. Geo-morphologic, sedimentological, biostratigraphical and radiocarbon AMS14C and IR-OSL analyses suggest that Palaeo-Nemunas'delta begun to develop in the palaeotopography of this area during Preboreal time and ended at the second half of Boreal. The basal residual level of the Ancylus (A2) regression phase was identified in the delta trunks at a depth of 41.3-39.9 m and dated 9.31-8.87 ka BP (8300-8000 14C kyr BP). This residual layer is overlapped by marine depositional Litorina (L1-2-3)--Post-Litorina complexes up 2 m thick and supported by 7.40&plusm0.5 ka BP; 6.80±0.5 ka BP (IR-OSL, RLQG 1881-118, 1882-118); 6.87±45 ka BP (6030±2514C kyr BP); 4.66±110 ka BP (4100±25 14C kyr BP, UGAMS #03138, 03139). [ABSTRACT FROM AUTHOR]

ABSTRACT Tõnisson, H.; Suursaar, Ü.; Kont, A.; Muru, M.; Rivis, R.; Rosentau, A.; Tamura, T., and Vilumaa, K., 2018. Rhythmic patterns of coastal formations as signs of past climate fluctuations on uplifting coasts of Estonia, the Baltic Sea. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 611–615. Coconut Creek (Florida), ISSN 0749-0208. On uplifting and tideless Baltic Sea Coasts in Estonia, a number of elevated mid to late Holocene beach ridge systems with rhythmic patterns are identified. Such uplifted coastal formations serve as archives of past variations in sea level and climate, as well as extreme events. Luminescence dating and interpretation of airborne LiDAR elevation data were used to identify the main formation mechanisms of such beach ridge systems. More extensive (up to 100–150 ridges) and clearer ridge patterns were found on faster emerging (uplift rates around 3 mm/yr) and well-exposed western and northern coasts, where they were located on the heights of up to 18 m. The average temporal periodicity (30–40 years) in such ridge systems is in good agreement with 25–40 year cyclicity, which is detectable in Estonian tide-gauge records, wave hindcasts, regional storminess and the NAO indices. However, typical average ridge spacing was 2–3 times longer in the study areas with lower (0.5–2 mm/yr) uplift rates. It suggests that the cyclicity in ridges depends on uplift rate and is additionally enhanced or modified by decadal-scale variations in forcing conditions that is locally available. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyze resting spores of Chaetoceros spp. preserved in Middle and Late Holocene sediments of the three parts of the Gulf of Gdańsk, southern Baltic Sea. The material studied consists of ten cores retrieved from Kuźnica Deep (Puck Lagoon), as well as the shallower and deeper parts of the Outer Puck Bay region. Our results indicate that the abundance of Chaetoceros resting spores in diatom taphocoenoses corresponded to regional and local paleoecological changes registered in Mastogloia, Littorina and Post-Littorina sediments, and that they also reflect human impact in the last hundred years. [ABSTRACT FROM AUTHOR]