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Surface salinity and nutrient variations during the Littorina Stage in the Fårö Deep, Baltic Sea

Willumsen, Pi LU ; Filipsson, Helena LU ; Reinholdsson, Maja LU and Lenz, Conny LU (2013) In Boreas 42(1). p.210-223
Abstract
Early to late Holocene sediments from core F80, Fårö Deep, Baltic Sea, are investigated for their palynomorph composition and dinoflagellate cyst record to map variations in sea-surface-water salinity and palaeoproductivity during the past 6000 years. The F80 palynomorph assemblages are subdivided into four Assemblage Zones (AZs) named A to D. The transition from the stratigraphically oldest AZ A to B reflects a marked increase in palaeoproductivity and a gradual increase in surface-water salinity over the ~1500 years between the Initial Littorina (former Mastogloia Sea Stage) and Littorina Sea Stage. A period with maximum sea-surface salinity is recorded within the overlying AZ C from 7200 to 5200 cal. a BP, where the process length of... (More)
Early to late Holocene sediments from core F80, Fårö Deep, Baltic Sea, are investigated for their palynomorph composition and dinoflagellate cyst record to map variations in sea-surface-water salinity and palaeoproductivity during the past 6000 years. The F80 palynomorph assemblages are subdivided into four Assemblage Zones (AZs) named A to D. The transition from the stratigraphically oldest AZ A to B reflects a marked increase in palaeoproductivity and a gradual increase in surface-water salinity over the ~1500 years between the Initial Littorina (former Mastogloia Sea Stage) and Littorina Sea Stage. A period with maximum sea-surface salinity is recorded within the overlying AZ C from 7200 to 5200 cal. a BP, where the process length of Operculodinium centrocarpum indicates that average salinities were probably the highest (~15–17 versus 7.5 psu today) since the last glaciation. The change from AZ C to D correlates with a shift from laminated to non-laminated sediments, and the dinoflagellate cyst assemblages suggest that the surface- and the deep-water environment altered from c. 5250 cal. a BP, with less productivity in the surface water and more oxygenated conditions in the deep water. Here we demonstrate that by mapping overall palynomorph composition, dinoflagellate cyst assemblages and variations in the process length of O. centrocarpum in relation to periods of laminated/non-laminated sedimentation have great potential to track past regional changes in surface salinity, primary productivity and deep-water oxygenation status. An understanding of past productivity changes is particularly important to better understand present-day environmental changes within the Baltic Sea region. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Palynology, dinoflagellate cysts, salinity and nutrient variations, paleoproductivity, early-late Holocene marine sediments, Baltic Sea, Fårö Deep
in
Boreas
volume
42
issue
1
pages
210 - 223
publisher
Taylor & Francis
external identifiers
  • wos:000316342600014
  • scopus:84871622773
ISSN
1502-3885
DOI
10.1111/j.1502-3885.2012.00286.x
project
BECC
language
English
LU publication?
yes
id
70619f57-383c-4df1-bff5-a8da39264b8c (old id 3131525)
date added to LUP
2012-11-02 15:13:14
date last changed
2019-06-11 01:22:56
@article{70619f57-383c-4df1-bff5-a8da39264b8c,
  abstract     = {Early to late Holocene sediments from core F80, Fårö Deep, Baltic Sea, are investigated for their palynomorph composition and dinoflagellate cyst record to map variations in sea-surface-water salinity and palaeoproductivity during the past 6000 years. The F80 palynomorph assemblages are subdivided into four Assemblage Zones (AZs) named A to D. The transition from the stratigraphically oldest AZ A to B reflects a marked increase in palaeoproductivity and a gradual increase in surface-water salinity over the ~1500 years between the Initial Littorina (former Mastogloia Sea Stage) and Littorina Sea Stage. A period with maximum sea-surface salinity is recorded within the overlying AZ C from 7200 to 5200 cal. a BP, where the process length of Operculodinium centrocarpum indicates that average salinities were probably the highest (~15–17 versus 7.5 psu today) since the last glaciation. The change from AZ C to D correlates with a shift from laminated to non-laminated sediments, and the dinoflagellate cyst assemblages suggest that the surface- and the deep-water environment altered from c. 5250 cal. a BP, with less productivity in the surface water and more oxygenated conditions in the deep water. Here we demonstrate that by mapping overall palynomorph composition, dinoflagellate cyst assemblages and variations in the process length of O. centrocarpum in relation to periods of laminated/non-laminated sedimentation have great potential to track past regional changes in surface salinity, primary productivity and deep-water oxygenation status. An understanding of past productivity changes is particularly important to better understand present-day environmental changes within the Baltic Sea region.},
  author       = {Willumsen, Pi and Filipsson, Helena and Reinholdsson, Maja and Lenz, Conny},
  issn         = {1502-3885},
  keyword      = {Palynology,dinoflagellate cysts,salinity and nutrient variations,paleoproductivity,early-late Holocene marine sediments,Baltic Sea,Fårö Deep},
  language     = {eng},
  number       = {1},
  pages        = {210--223},
  publisher    = {Taylor & Francis},
  series       = {Boreas},
  title        = {Surface salinity and nutrient variations during the Littorina Stage in the Fårö Deep, Baltic Sea},
  url          = {http://dx.doi.org/10.1111/j.1502-3885.2012.00286.x},
  volume       = {42},
  year         = {2013},
}