A Holocene relative sea-level database for the Baltic Sea

Highlights: • A first standardized and publicly available Holocene relative sea-level database for the Baltic Sea is presented. • The database holds 1099 revised data points with an estimation of vertical and chronological uncertainties. • Negative RSL tendencies prevail over the positive and complex tendencies in the Baltic Sea Basin. • Mid-Holocene RSL highstand occurred around 7.5–6.5 ka BP being consistent with the end of the final melting of the LIS. • The contribution of ice loading in the eastern Baltic Sea Basin is likely overestimated in the ICE-5G and ICE-6G_C models. Abstract: We present a compilation and analysis of 1099 Holocene relative shore-level (RSL) indicators located aro…

Accumulation of metals and changes in composition of freshwater lake organic sediments during the Holocene

Abstract The distribution of metals in the strata of sediments deposited in the freshwater environment formed during the Holocene in the territory of Latvia has been studied rather insufficiently. Considering the large volume of accumulated organic matter in sediments, studies on the content of metallic elements in sediments can help to determine the peculiarities of the metal accumulation process in limnic systems and the biogeochemical cycling of metals. Lake Pilvelis, which is located in the eastern part of Latvia (the northern part of Europe), was selected as the main study site. Lake Pilvelis is a small lake of a glacial origin, and >90% of its depression is filled with organic-rich se…

Peat stratigraphy and changes in peat formation during the Holocene in Latvia

Mires represented by raised bogs, fens, and transitional mires cover approximately 10 % of Latvia. They started to form towards the end of the last glacial period and the beginning of the Holocene under varying geological and palaeoecological conditions. The aim of the study was to evaluate how the results of peat palaeobotanical investigation can reveal changes in the conditions of peat formation and allow a subdivision to be made of the Holocene according to the scheme suggested by the INTIMATE group (Walker et al. 2012). Records from 21 mires have been evaluated to find evidence of changes in mire vegetation and peat formation, and to discover whether these records define boundaries allo…

Quartz grains reveal sedimentary palaeoenvironment and past storm events: A case study from eastern Baltic

Abstract Sediment record collected from the coastal lake serves as a powerful tool for reconstructing changes in palaeoenvironment and understanding the potential signals of past storminess. In this study, we use several proxies from sediment of the Holocene Thermal Maximum at coastal Lake Lilaste, Latvia. We focus on surface texture of quartz grains from the mineral inorganic fraction as indicators of depositional environments. We then use this as a proxy for potential storm transport and combine with information on granulometry, diatom stratigraphy and chronology to answer the question whether flux of quartz grains in the lake originated from the sea or from the land. Analyses in a binocu…

STOP 12: Late-glacial and Holocene development of Lake Rāzna as recorded by biostratigraphy

Būšnieku ezera attīstība un vides apstākļu izmaiņas holocēnā

Bakalaura darbā apskatīta nepieciešamība veikt pētījumus Būšnieku ezerā, jo tas ir lagūnas tipa ezers, kuru apdraud antropogēnā ietekme. Lai labāk izprastu, kādi pasākumi nepieciešami tā aizsardzībai, ieskaitot nozīmīgo Natura 2000 teritoriju – Būšnieku ezera krasts, ir svarīgi veikt pētījumus par tā attīstību. Pētījuma lauka darbos iegūto datu analīze (urbumu apraksti), sporu - putekšņu analīžu rezultāti, nogulumu datējumi, kā arī kartogrāfiskā materiāla analīze, tai skaitā Būšnieku ezera apkārtnes karte, ģeoloģiskā karte un ezera ģeoloģiskie šķērsgriezumi ļauj secināt, ka organogēnie nogulumi Būšnieku ezerā uzkrājušies kopš preboreāla laika līdz mūsdienām bez ievērojamiem pārtraukumiem, k…