Publication : Late Pleistocene and Holocene groundwater flow history in the Baltic Artesian Basin : a synthesis of numerical models and hydrogeochemical data
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Date
2021-06-20
Auteurs
Pärn, Joonas
Raidla, Valle
Ivask, Jüri
Kaup, Enn
Aeschbach, Werner
Gerber, Christoph
Purtscher, Roland
Direction de publication
Direction de recherche
Titre de la revue
ISSN de la revue
Titre du volume
Éditeur
Tallinn Estonian Academy Publishers
Résumé
We review our current understanding of groundwater flow history in the northern part of the Baltic Artesian Basin (BAB) from the end of the Late Pleistocene to current conditions based on the hydrogeological studies carried out in 2012–2020 by the Department of Geology, Tallinn University of Technology and its partners. Hydrogeochemical data and various numerical models are combined in order to understand the link between glaciations and groundwater flow. The results of our earlier research and published literature on groundwater flow history in the BAB are also taken into account. The reconstruction of groundwater flow history is based on the database of the isotopic, chemical and dissolved gas composition of groundwater. The database contains data on 1155 groundwater samples collected during 1974–2017. We find that groundwater in the BAB is controlled by the mixing of three distinct water masses: interglacial/modern meteoric water (δ18O ≈ –11‰), glacial meltwater (δ18O ≤ –18‰) and an older syngenetic endmember (δ18O ≥–4.5‰). The numerical modelling has suggested that the preservation of meltwater in the northern part of the BAB is controlled by confining layers and the proximity to the outcrop areas of aquifers. Aquifers containing groundwater of glacial origin are in a transient state with respect to modern topographicallydriven groundwater flow conditions. The most important topics for future research that can address gaps in our current knowledge are also reviewed.
Description
Revue
Estonian Journal of Earth Sciences, Vol. 70 (3), 152-164 (2021)
DOI
10.3176/earth.2021.11
URL vers la version publiée
Mots-clés
Baltic Artesian Basin , Groundwater flow , Environmental tracers , Nnumerical modelling , Palaeohydrology
Citation
Type de document
article de recherche