0000000000132273

AUTHOR

Tomas Saks

OSL dating of Middle Weichselian age shallow basin sediments in Western Latvia, Eastern Baltic

Abstract This paper presents the results of the first attempt to date the Quaternary sediments of western Latvia in the southeast Baltic region, using luminescence. The analyses have been carried out on sandy sediments of the Jurkalne Formation that are located between upper and lower Scandinavian sourced tills. Previous publications on the origin of the Quaternary sediments in the region are reviewed and it is found that there are a wide range of explanations for their processes of formation and their age of formation. It is concluded that although the sandy sediments were deposited in freshwater environment although they contain both marine and freshwater fauna and flora, a property that …

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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

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Subglacial bed deformation and dynamics of the Apriķi glacial tongue, W Latvia

Saks, T., Kalvans, A. & Zelcs, V. 2012 (January): Subglacial bed deformation and dynamics of the Apriķi glacial tongue, W Latvia. Boreas, Vol. 41, pp. 124–140. 10.1111/j.1502-3885.2011.00222.x. ISSN 0300-9483. We evaluate the glacial dynamics and subglacial processes of the Apriķi glacial tongue in western Latvia during the Northern Lithuanian (Linkuva) oscillation of the last Scandinavian glaciation. The spatial arrangement of glacial bedforms and deformation structures are used to reconstruct the ice dynamics in the study area. The relationship between geological structures at the glacier bed and the spatial distribution of drumlins and glacigenic diapirs, on the one hand, and the permeab…

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Vidus Vislas un Vēlās Vislas laika paraglaciālie un zemledāja vides apstākļi Rietumlatvijas piekrastes līdzenumos

Elektroniskā versija nesatur pielikumus

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The Devonian Stratigraphic Succession and Evolution of the Baltic Sedimentary Basin

Facies analysis, biostratigraphic and taphonomic studies, a re-evaluation of signatures of worldwide events, and a new mathematical model of the Baltic sedimentary basin (BSB) have together enabled a better understanding to be gained of the development of the Devonian basins in the Baltic area. We have established four stages of basin evolution: (a) remnant basin stage (Lochkovian); (b) shallow epeiric basin stage, with mainly siliciclastic sedimentation (Pragian–early Frasnian); (c) shallow epeiric basin stage, with mainly carbonate sedimentation (Frasnian); and (d) infilling stage of the progressively narrowing shallow epeiric basin, with mixed sedimentation (Famennian).

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Using 81Kr and Noble Gases to Characterize and Date Groundwater and Brines in the Baltic Artesian Basin on the One-Million-Year Timescale

Analyses for $^{81}$Kr and noble gases on groundwater from the deepest aquifer system of the Baltic Artesian Basin (BAB) were performed to determine groundwater ages and uncover the flow dynamics of the system on a timescale of several hundred thousand years. We find that the system is controlled by mixing of three distinct water masses: Interglacial or recent meteoric water $(\delta^{18}\text{O} \approx -10.4\unicode{x2030})$ with a poorly evolved chemical and noble gas signature, glacial meltwater $(\delta^{18}\text{O} \leq -18\unicode{x2030})$ with elevated noble gas concentrations, and an old, high-salinity brine component $(\delta^{18}\text{O} \geq -4.5\unicode{x2030}, \geq 90 \text{g …

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A comprehensive approach to the 3D geological modelling of sedimentary basins: example of Latvia, the central part of the Baltic Basin

This paper presents a semi-automatic approach adapted to the modelling of the geological structure of sedimentary basins. The modelling approach is based on developing the algorithm of the main geological processes so that the geometrical relationship is automatically defined between model elements. The algorithm is based on the assumption that sedimentary basins are formed as a result of the repeated sequence of sedimentation, faulting and erosion. This approach allows of successful modelling of the geological structure of the sedimentary basins with limited data coverage: stratigraphic intervals from well logs describing the thicknesses of sedimentary strata and a limited amount of struct…

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