The Holocene Great Belt connection to the southern Kattegat, Scandinavia: Ancylus Lake drainage and Early Littorina Sea transgression

Carina Bendixen; Jørn B. Jensen; Lars O. Boldreel; Ole R. Clausen; Ole Bennike; Marit-Solveig Seidenkrantz; Johan Nyberg; Christian Hübscher

doi:10.1111/bor.12154

Holocene Spatiotemporal Redox Variations in the Southern Baltic Sea

Frontiers in Earth Science ◽

10.3389/feart.2021.671401 ◽

2021 ◽

Vol 9 ◽

Author(s):

Dalton S. Hardisty ◽

Natascha Riedinger ◽

Noah J. Planavsky ◽

Dan Asael ◽

Steven M. Bates ◽

...

Keyword(s):

Baltic Sea ◽

Solid Phase ◽

Bornholm Basin ◽

The Holocene ◽

Isotope Data ◽

Fe Speciation ◽

Baltic Proper ◽

Southern Baltic ◽

The Baltic ◽

Ancylus Lake

Low oxygen conditions in the modern Baltic Sea are exacerbated by human activities; however, anoxic conditions also prevailed naturally over the Holocene. Few studies have characterized the specific paleoredox conditions (manganous, ferruginous, euxinic) and their frequency in southern Baltic sub-basins during these ancient events. Here, we apply a suite of isotope systems (Fe, Mo, S) and associated elemental proxies (e.g., Fe speciation, Mn) to specifically define water column redox regimes through the Baltic Holocene in a sill-proximal to sill-distal transect (Lille Belt, Bornholm Basin, Landsort Deep) using samples collected during the Integrated Ocean Drilling Program Expedition 347. At the sill-proximal Lille Belt, there is evidence for anoxic manganous/ferruginous conditions for most of the cored interval following the transition from the Ancylus Lake to Littorina Sea but with no clear excursion to more reducing or euxinic conditions associated with the Holocene Thermal Maximum (HTM) or Medieval Climate Anomaly (MCA) events. At the sill-distal southern sub-basin, Bornholm Basin, a combination of Fe speciation, pore water Fe, and solid phase Mo concentration and isotope data point to manganous/ferruginous conditions during the Ancylus Lake-to-Littorina Sea transition and HTM but with only brief excursions to intermittently or weakly euxinic conditions during this interval. At the western Baltic Proper sub-basin, Landsort Deep, new Fe and S isotope data bolster previous Mo isotope records and Fe speciation evidence for two distinct anoxic periods but also suggest that sulfide accumulation beyond transient levels was largely restricted to the sediment-water interface. Ultimately, the combined data from all three locations indicate that Fe enrichments typically indicative of euxinia may be best explained by Fe deposition as oxides following events likely analogous to the periodic incursions of oxygenated North Sea waters observed today, with subsequent pyrite formation in sulfidic pore waters. Additionally, the Mo isotope data from multiple Baltic Sea southern basins argue against restricted and widespread euxinic conditions, as has been demonstrated in the Baltic Proper and Bothnian Sea during the HTM or MCA. Instead, similar to today, each past Baltic anoxic event is characterized by redox conditions that become progressively more reducing with increasing distance from the sill.

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Late Quaternary history of the Mackenzie–Beaufort region, Arctic Canada, from modelling of permafrost temperatures. 2. The Mackenzie Delta–Tuktoyaktuk Coastlands

Canadian Journal of Earth Sciences ◽

10.1139/e96-007 ◽

1996 ◽

Vol 33 (1) ◽

pp. 62-71 ◽

Cited By ~ 34

Author(s):

Alan E. Taylor ◽

Scott R. Dallimore ◽

Alan S. Judge

Keyword(s):

Late Quaternary ◽

Mackenzie Delta ◽

Delta Front ◽

The Holocene ◽

Ground Temperatures ◽

Delta Plain ◽

Hydrocarbon Fields ◽

History Of ◽

Lake Drainage ◽

A Site

In the Mackenzie–Beaufort region, maximum permafrost thickness is 750 m in the Pleistocene Tuktoyaktuk Coastlands, less than 100 m in the Holocene Mackenzie Delta, and 500 m and anomalously warm in the Big Lake Delta Plain between the two areas. Numerical modelling has been used to derive surface temperature histories that fit ground temperatures and permafrost conditions at 12 wells in the Unipkat, Kumak, and Taglu hydrocarbon fields. The models indicate that the present Holocene Mackenzie Delta was built by fluvial processes into a submarine trough. The delta front passed a site presently some 20 km from the coast about 4.5 ka, and subsequently 58 m of ice-bonded permafrost has aggraded. In contrast, the Big Lake Delta Plain was a subaerial platform for much of the Wisconsinan. It experienced several thousand years of inundation in the Holocene, probably due to widespread development of thermokarst lakes. At sites 8–12 km from the coast, the present subaerial conditions were established 0.5–1.5 ka through lake drainage and fluvial–deltaic deposition.

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Early Holocene estuary development of the Hesselø Bay area, southern Kattegat, Denmark and its implication for Ancylus Lake drainage

Geo-Marine Letters ◽

10.1007/s00367-017-0513-7 ◽

2017 ◽

Vol 37 (6) ◽

pp. 579-591

Author(s):

Carina Bendixen ◽

Lars Ole Boldreel ◽

Jørn Bo Jensen ◽

Ole Bennike ◽

Christian Hübscher ◽

...

Keyword(s):

Early Holocene ◽

Bay Area ◽

Lake Drainage ◽

Ancylus Lake

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The Holocene sedimentary record of cyanobacterial glycolipids in the Baltic Sea: an evaluation of their application as tracers of past nitrogen fixation

Biogeosciences ◽

10.5194/bg-14-5789-2017 ◽

2017 ◽

Vol 14 (24) ◽

pp. 5789-5804 ◽

Cited By ~ 8

Author(s):

Martina Sollai ◽

Ellen C. Hopmans ◽

Nicole J. Bale ◽

Anchelique Mets ◽

Lisa Warden ◽

...

Keyword(s):

Baltic Sea ◽

Cyanobacterial Blooms ◽

The Baltic Sea ◽

The Holocene ◽

Heterocystous Cyanobacteria ◽

Cyanobacterial Species ◽

The Baltic ◽

Abundance And Distribution ◽

Yoldia Sea ◽

Ancylus Lake

Abstract. Heterocyst glycolipids (HGs) are lipids exclusively produced by heterocystous dinitrogen-fixing cyanobacteria. The Baltic Sea is an ideal environment to study the distribution of HGs and test their potential as biomarkers because of its recurring summer phytoplankton blooms, dominated by a few heterocystous cyanobacterial species of the genera Nodularia and Aphanizomenon. A multi-core and a gravity core from the Gotland Basin were analyzed to determine the abundance and distribution of a suite of selected HGs at a high resolution to investigate the changes in past cyanobacterial communities during the Holocene. The HG distribution of the sediments deposited during the Modern Warm Period (MoWP) was compared with those of cultivated heterocystous cyanobacteria, including those isolated from Baltic Sea waters, revealing high similarity. However, the abundance of HGs dropped substantially with depth, and this may be caused by either a decrease in the occurrence of the cyanobacterial blooms or diagenesis, resulting in partial destruction of the HGs. The record also shows that the HG distribution has remained stable since the Baltic turned into a brackish semi-enclosed basin ∼ 7200 cal. yr BP. This suggests that the heterocystous cyanobacterial species composition remained relatively stable as well. During the earlier freshwater phase of the Baltic (i.e., the Ancylus Lake and Yoldia Sea phases), the distribution of the HGs varied much more than in the subsequent brackish phase, and the absolute abundance of HGs was much lower than during the brackish phase. This suggests that the cyanobacterial community adjusted to the different environmental conditions in the basin. Our results confirm the potential of HGs as a specific biomarker of heterocystous cyanobacteria in paleo-environmental studies.

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The Holocene sedimentary record of cyanobacterial glycolipids in the Baltic Sea: Evaluation of their application as tracers of past nitrogen fixation

10.5194/bg-2017-324 ◽

2017 ◽

Author(s):

Martina Sollai ◽

Ellen C. Hopmans ◽

Nicole J. Bale ◽

Anchelique Mets ◽

Matthias Moros ◽

...

Keyword(s):

Baltic Sea ◽

Cyanobacterial Blooms ◽

The Baltic Sea ◽

The Holocene ◽

Heterocystous Cyanobacteria ◽

Cyanobacterial Species ◽

The Baltic ◽

Abundance And Distribution ◽

Ancylus Lake ◽

Partial Destruction

Abstract. Heterocyst glycolipids (HGs) are lipids exclusively produced by heterocystous dinitrogen-fixing cyanobacteria. The Baltic Sea is an ideal environment to study the distribution of HGs and test their potential as biomarkers because of its recurring summer phytoplankton blooms, dominated by a few heterocystous cyanobacterial species. A multicore and a gravity core from the Gotland basin were analyzed to determine the abundance and distribution of HGs at high resolution to investigate the changes in past cyanobacterial communities during the Holocene. The HG distribution of the sediments deposited during the Modern Warm Period (MoWP) was compared with those of cultivated heterocystous cyanobacteria, revealing high similarity. However, the abundance of HGs dropped substantially with depth and this may be caused by either a decrease of the cyanobacterial blooms or diagenesis, resulting in partial destruction of the HGs. The record also shows that the HGs distribution has remained stable since the Baltic has turned into a brackish semi-enclosed basin ~ 7200 yrs BP. This suggests that the heterocystous cyanobacterial species composition remained relatively stable as well. During the earlier freshwater phase of the Baltic (i.e. the Ancylus Lake phase) the distribution of the HGs varied much more than in the subsequent brackish phase and the absolute abundance of HGs was much lower than during the brackish phase. This suggests that the cyanobacterial community adjusted to the different environmental conditions in the basin. Our results confirm the potential of HGs as specific biomarker of heterocystous cyanobacteria in paleo-environmental studies.

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