Pleistocene and Holocene aeolian sediments of different location and geological history: A new insight from rounding and frosting of quartz grains

Abstract Rounding and frosting of quartz grains in aeolian sediments of the known stratigraphic position and unique geological setting was explored in Finnish, Estonian, Latvian, and Polish localities and in Fuerteventura Island. The aim of the study is to characterize the variability of the spatial pattern of rounding and frosting of quartz grains in the sandy (0.5–0.8 mm) fraction and to evaluate the factors influencing it. The relationships between rounded and non-abraded, as well as matt- and shiny-type quartz grains were calculated for 159 samples and evaluated against the aeolian subenvironment, substratum and presumed age of the locations. The obtained relations do not confirm meridi…

Outlines of the Quaternary geology of Latvia

Sedimentary features reveal transport paths for Holocene sediments on the Kristianstad coastal plain, SE Sweden.

AbstractWe have investigated coastal and aeolian deposits on the Kristianstad plain in southernmost Sweden by a combination of methods that has yielded data on sedimentary features such as grain-size variations, shape and character of quartz grain surfaces (determined in light microscope and scanning electron microscope), and mineralogical composition. Such sedimentary techniques have been not applied to coastal deposits in this part of the Baltic Sea region before. The littoral, foredune and parabolic dune sands are sedimentologically similar, only a slight grain-size transformation by aeolian processes in the foredune was observed. Sand in straight-crested dunes, on the other hand, origin…

Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift

Abstract Geologically extremely rapid changes in altitude by glacial rebound of the Earth crust after retreat of the Scandinavian Ice Sheet at the end of the last Weichselian glaciation influenced the palaeogeography of northern Europe. The uplift of the Earth crust apparently was not gradual, but shock-wise, as the uplift was accompanied by frequent, high-magnitude earthquakes. This can be deduced from strongly deformed layers which are interpreted as seismites. Such seismites have been described from several countries around the Baltic Sea, including Sweden, Germany and Poland. Now similarly deformed layers that must also be interpreted as seismites, have been discovered also in Latvia, a…

Pleistocene Glaciations in Latvia

Abstract During the Pleistocene the territory of Latvia was repeatedly overridden by Scandinavian ice sheets, at least from the Elsterian onwards. Extent limit of all glaciations was located far outside of Latvia. Due to vigorous erosion by subsequent glaciations the Pleistocene record is incomplete. Radiocarbon, cosmogenic nuclide and radiation exposure dating methods have been mainly used only for age determination of the upper part of the Pleistocene sequence. Decay of the Late Weichselian glaciation in Latvia is marked by five major ice-marginal zones

Multiple deformed layers in Weichselian lacustrine sediments at Baltmuiža, western Latvia

STOP 1: Lower Gauja spillway valley at Sigulda

STOP 6: Morphology, internal structure and texture of inland dunes at the Smilškalni site, Middle Gauja Lowland

Injection structures and load casts in lagoon sediments (Sārnate outcrop, W Latvia)

Luminescence dating of aeolian–coastal events on the Kristianstad plain, SE Sweden

Aeolian–coastal sediments and landforms are excellent palaeoenvironmental archives, but chronological studies of coastal records are scarce in Sweden. In this study, we provide luminescence and radiocarbon ages of aeolian activity and coastal landscape evolution on the Kristianstad plain, SE Sweden, based on the investigations of two foredunes and two inland dunes at Åhus and Vittskövle. Additionally, we do a laboratory intercomparison of five young luminescence samples. The comparison shows a significant age difference most likely due to an instrumental difference. The equivalent dose cannot be determined accurately with the low irradiation times, and therefore, the results obtained from …

Late-glacial to Holocene aeolian deposition in northeastern Europe - The timing of sedimentation at the Iisaku site (NE Estonia)

Abstract The Late-glacial and Holocene aeolian inland dune complex at Iisaku (NE Estonia) has been investigated using an accurate and detailed compilation of the sedimentary properties and chronological framework. The quartz grains forming the dunes are very variable, reflecting aeolian, weathering, and periglacial conditions, both prior and after deposition. Although the morphological forms and the sedimentary record point to a dune-like environment, the transport record reflects either a short transport time or/and distance, and a contribution from neighbouring sedimentary environments. Dune development in the area was strongly controlled by the formation of the Baltic Ice Lake (BIL) in f…

An erratic dropstone of granodiorite with a water-escape structure from a Weichselian terrace along the River Gauja (NE Latvia)

Abstract A river terrace of the River Gauja (Latvia), built of Weichselian glaciolacustrine deposits, contains a large number of erratic boulders from the Fennoscandian Shield. These erratic boulders include several types of granites and granodiorites. Some of the granodiorites are so strongly weathered that they fall apart into mm-sized grains of individual minerals when it is attempted to take them out of the host sediment. This strongly weathered nature makes them physically comparable to unconsolidated sand. A consequence is that they may be subjected to soft-sediment deformation. The erratic granodiorite boulder under study here is the first described to show such a soft-sediment defor…

STOP 7: Madona-Trepe ice-marginal ridge at Smeceres sils, East-Latvian Lowland

New insights on ice dynamics from analysis of terrain of Latvia

Ledājkušanas ūdeņu baseini Ziemeļlatvijas un Vidusgaujas zemienēs Vēlā Vislas leduslaikmeta beigu posmā

Disertācijā aplūkoti ledājkušanas ūdeņu baseini, kuri eksistēja Ziemeļvidzemes un Vidusgaujas zemienēs vēlā Vislas leduslaikmeta deglaciācijas laikā. Pirmo reizi Latvijā iekšzemes ledājkušanas baseinu rekonstruēšanā ir ņemta vērā Zemes virsmas šķietamā pacelšanās, kā arī pašas rekonstrukcijas ir veiktas ĢIS vidē ar modelēšanas rīku palīdzību. Darbā ir veiktas Vidusgaujas, Smiltenes un Strenču ledāja sprostezeru rekonstrukcijas ūdens līmeņu kritumam no 125 līdz 46 m v.j.l., kuras parāda minēto sprostezeru izplatību, dziļumu, ūdens pieteces un noteces vietas, attīstību laikā un saistību ar citām tālaika ūdenstilpēm. Baseinus veidojošo un tiem sekojošo eolo procesu nogulumu datējumi ar OSL met…

Liquefaction and re-liquefaction of sediments induced by uneven loading and glacigenic earthquakes: Implications of results from the Latvian Baltic Sea coast

Abstract Seven internally-deformed layers were recognised in the shallow marine bay sediments deposited during mid Marine Isotope Stage 2 along the Latvian Baltic Sea coast bluff at Baltmuiža. Detailed sedimentological analyses of these deformed layers indicate that liquefaction was responsible for the development of soft-sediment deformation structures (SSDS) including injection structures, load casts, flame structures and pseudonodules. Traces of both initial liquefaction and re-liquefaction were recognised within at least four of the seven layers with SSDS (two different generations of pseudonodules and injection structures, clastic injection pipes, disrupted load casts). This is a uniqu…

An aeolian or a glaciolacustrine record? A case study from Mieļupīte, Middle Gauja Lowland, northeast Latvia

Abstract In the Middle Gauja Lowland, northeast Latvia, dunes are distributed over a vast glaciolacustrine plain that formed during the retreat of the Fennoscandian ice sheet. Such a direct contact between aeolian and glaciolacustrine sediments can be used to infer depositional settings and decipher to what extent these sediments bear an aeolian component. Our proxies, although preliminary, reveal a limited range of variation in grain-size parameters, a significant presence of quartz grains with silica precipitation and matt-surface grains of various rounding degrees and massive structure combined with horizontal lamination. These are indicative of periglacial-aeolian depositional condition…

STOP 13: Inland dune field near Daugavpils, East-Latvian Lowland

Sample details on OSL data for aeolian sediments in north-eastern part of European Sand Belt

A compilation of previously published and unpublished absolute age (OSL and TL) determinations of aeolian sediments from the north-eastern part of European Sand Belt. Contains age, error, sampling depth, location etc. and a reference to data source. Coordinates of sampling locations for contemporary publications are taken from field observations (GPS), but older ones - published schematic maps. Data set is created according to schema of DATED-1 database (https://doi.org/10.1594/PANGAEA.848117).