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New luminescence ages reveal early to Middle Weichselian deposits in central Latvia

Lamsters, Kristaps; Kalinska-Nartisa, Edyta LU ; Zelčs, Vitālijs and Alexanderson, Helena LU (2017) In Geological Quarterly 61(2). p.480-490
Abstract

New optically stimulated luminescence (OSL) ages show that sandy deposits overlain by Late Weichselian subglacial till in central Latvia are of Early to Middle Weichselian age. The finer chronological resolution of unconsolidated sediment deposition in the Central Latvian Lowland (CLL) remains relatively unstudied, and here we provide a first characterisation of the deposits with respect to their age. Three OSL ages ranging between 84 ± 9 ka and 112 ± 11 ka suggest that the deposits studied in the CLL are of Early Weichselian age (MIS 5). We found no Middle Weichselian deposits in the CLL, and assume that any such younger sediments might have been eroded during the advance of the Zemgale Lobe in the Late Weichselian. One site, in the... (More)

New optically stimulated luminescence (OSL) ages show that sandy deposits overlain by Late Weichselian subglacial till in central Latvia are of Early to Middle Weichselian age. The finer chronological resolution of unconsolidated sediment deposition in the Central Latvian Lowland (CLL) remains relatively unstudied, and here we provide a first characterisation of the deposits with respect to their age. Three OSL ages ranging between 84 ± 9 ka and 112 ± 11 ka suggest that the deposits studied in the CLL are of Early Weichselian age (MIS 5). We found no Middle Weichselian deposits in the CLL, and assume that any such younger sediments might have been eroded during the advance of the Zemgale Lobe in the Late Weichselian. One site, in the ice-marginal zone adjacent to the interlobate area, has nevertheless deposits dated to 44 ± 10 ka corresponding to the Middle Weichselian (MIS 3). Our results are compatible with existing ESR ages on three sets of Portlandia arctica shells from the central part of the lowland; the shells had been incorporated into glacial deposits during later glacial advances. Finally, our findings largely support ice-free conditions during the Early and Middle Weichselian in the middle and southern part of central Latvia.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Central latvia, Early weichselian, Middle weichselian, Optically stimulated luminescence (OSL) dating, Subglacial bedforms
in
Geological Quarterly
volume
61
issue
2
pages
11 pages
publisher
Polish Geological Institute
external identifiers
  • scopus:85018518347
  • wos:000402850300016
ISSN
1641-7291
DOI
10.7306/gq.1349
language
English
LU publication?
yes
id
68c37e0e-fe86-437c-9ef4-df909f5914e8
date added to LUP
2017-05-22 10:05:50
date last changed
2017-09-18 11:36:34
@article{68c37e0e-fe86-437c-9ef4-df909f5914e8,
  abstract     = {<p>New optically stimulated luminescence (OSL) ages show that sandy deposits overlain by Late Weichselian subglacial till in central Latvia are of Early to Middle Weichselian age. The finer chronological resolution of unconsolidated sediment deposition in the Central Latvian Lowland (CLL) remains relatively unstudied, and here we provide a first characterisation of the deposits with respect to their age. Three OSL ages ranging between 84 ± 9 ka and 112 ± 11 ka suggest that the deposits studied in the CLL are of Early Weichselian age (MIS 5). We found no Middle Weichselian deposits in the CLL, and assume that any such younger sediments might have been eroded during the advance of the Zemgale Lobe in the Late Weichselian. One site, in the ice-marginal zone adjacent to the interlobate area, has nevertheless deposits dated to 44 ± 10 ka corresponding to the Middle Weichselian (MIS 3). Our results are compatible with existing ESR ages on three sets of Portlandia arctica shells from the central part of the lowland; the shells had been incorporated into glacial deposits during later glacial advances. Finally, our findings largely support ice-free conditions during the Early and Middle Weichselian in the middle and southern part of central Latvia.</p>},
  author       = {Lamsters, Kristaps and Kalinska-Nartisa, Edyta and Zelčs, Vitālijs and Alexanderson, Helena},
  issn         = {1641-7291},
  keyword      = {Central latvia,Early weichselian,Middle weichselian,Optically stimulated luminescence (OSL) dating,Subglacial bedforms},
  language     = {eng},
  month        = {03},
  number       = {2},
  pages        = {480--490},
  publisher    = {Polish Geological Institute},
  series       = {Geological Quarterly},
  title        = {New luminescence ages reveal early to Middle Weichselian deposits in central Latvia},
  url          = {http://dx.doi.org/10.7306/gq.1349},
  volume       = {61},
  year         = {2017},
}