@article {2815, title = {The distribution and utility of sea-level indicators in Eurasian sub-Arctic salt marshes (White Sea, Russia)}, journal = {Boreas}, volume = {46}, year = {2017}, month = {Jan-07-2017}, pages = {562 - 584}, abstract = {In support of efforts to reconstruct relative sea level (RSL), we investigated the utility of foraminifera, diatoms and bulk-sediment geochemistry (δ13C, C:N and parameters measured by Rock-Eval pyrolysis) as sea-level indicators in Eurasian sub-Arctic salt marshes. At three salt marshes (<15 km apart) in Dvina Bay (White Sea, Russia), we collected surface sediment samples along transects from subtidal to Taiga forest environments. Foraminifera at all sites formed bipartite assemblages, where elevations below mean high higher water (MHHW) were dominated by Miliammina spp. and elevations between MHHW and the highest occurrence of foraminifera were dominated by Jadammina macrescens and Balticammina pseudomacrescens. Five high-diversity groups of diatoms were identified and they displayed pronounced variability amongst the study sites. Bulk-sediment geochemistry recognized two groups (clastic-dominated environments below MHHW and organic-rich environments above MHHW). As one group included subtidal elevations and the other included supratidal elevations, we conclude that the measured geochemical parameters are not stand-alone sea-level indicators. Core JT2012 captured a regressive sediment succession of clastic, tidal-flat sediment overlain by salt-marsh organic silt and freshwater peat. The salt-marsh sediment accumulated at 2804{\textpm}52 years before present and preserved foraminifera (Jadammina macrescens and Balticammina pseudomacrescens) with good analogy to modern assemblages indicating that RSL was +2.60{\textpm}0.47 m at this time. Diatoms confirm that marine influence decreased through time, but the lack of analogy between modern and core assemblages limited their utility as sea-level indicators. Geochemical parameters also indicate a reduction in marine influence through time. We conclude that RSL reconstructions derived from salt-marsh sediment preserved beneath Eurasian sub-Arctic peatlands can provide valuable insight into the spatio-temporal evolution of the Fennoscandian and Eurasian ice sheets.}, doi = {10.1111/bor.2017.46.issue-310.1111/bor.12233}, url = {https://onlinelibrary.wiley.com/doi/10.1111/bor.12233}, author = {Kemp, Andrew C. and Horton, Benjamin P. and Nikitina, Daria and Vane, Christopher H. and Potapova, Marina and Weber-Bruya, Elizabeth and Culver, Stephen J. and Repkina, Tatyana and Hill, David F.} } @article {2489, title = {Relative sea-level change in northeastern Florida (USA) during the last \~{}8.0~ka}, journal = {Quaternary Science Reviews}, volume = {142}, year = {2016}, month = {Jan-06-2016}, pages = {90 - 101}, abstract = {An existing database of relative sea-level (RSL) reconstructions from the U.S. Atlantic coast lacked valid sea-level index points from Georgia and Florida. This region lies on the edge of the collapsing forebulge of the former Laurentide Ice Sheet making it an important location for understanding glacio-isostatic adjustment and the history of ice-sheet melt. To address the paucity of data, we reconstruct RSL in northeastern Florida (St. Marys) over the last \~{}8.0 ka from samples of basal salt-marsh sediment that minimize the influence of compaction. The analogy between modern salt-marsh foraminifera and their fossil counterparts preserved in the sedimentary record was used to estimate paleomarsh surface elevation. Sample ages were determined by radiocarbon dating of identifiable and in-situ plant macrofossils. This approach yielded 25 new sea-level index points that constrain a \~{}5.7 m rise in RSL during the last \~{}8.0 ka. The record shows that no highstand in sea level occurred in this region over the period of the reconstruction. We compared the new reconstruction to Earth-ice models ICE 6G-C VM5a and ICE 6G-C VM6. There is good fit in the later part of the Holocene with VM5a and for a brief time in the earlier Holocene with VM6. However, there are discrepancies in model-reconstruction fit in the early to mid Holocene in northeastern Florida and elsewhere along the Atlantic coast at locations with early Holocene RSL reconstructions. The most pronounced feature of the new reconstruction is a slow down in the rate of RSL rise from approximately 5.0 to 3.0 ka. This trend may reflect a significant contribution from local-scale processes such as tidal-range change and/or change in base flow of the St. Marys River in response to paleoclimate changes. However, the spatial expression (local vs. regional) of this slow down is undetermined and corroborative records are needed to establish its geographical extent.}, keywords = {Foraminifera, Georgia, Holocene, Salt marsh, St. Marys River}, issn = {02773791}, doi = {10.1016/j.quascirev.2016.04.016}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0277379116301275http://api.elsevier.com/content/article/PII:S0277379116301275?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:S0277379116301275?httpAccept=text/plain}, author = {Hawkes, Andrea D. and Kemp, Andrew C. and Donnelly, Jeffrey P. and Horton, Benjamin P. and Peltier, W. Richard and Cahill, Niamh and Hill, David F. and Ashe, Erica and Alexander, Clark R.} }