Late Holocene freshening of the Baltic Sea derived from high-resolution strontium isotope analyses of mollusk shells

Research Article| February 01, 2011 Late Holocene freshening of the Baltic Sea derived from high-resolution strontium isotope analyses of mollusk shells Anders Widerlund; Anders Widerlund * 1Division of Geosciences, Luleå University of Technology, SE-971 87 Luleå, Sweden *E-mail: Anders.Widerlund@ltu.se. Search for other works by this author on: GSW Google Scholar Per S. Andersson Per S. Andersson 2Laboratory for Isotope Geology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden Search for other works by this author on: GSW Google Scholar Author and Article Information Anders Widerlund * 1Division of Geosciences, Luleå University of Technology, SE-971 87 Luleå, Sweden Per S. Andersson 2Laboratory for Isotope Geology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden *E-mail: Anders.Widerlund@ltu.se. Publisher: Geological Society of America Received: 28 Jun 2010 Revision Received: 30 Sep 2010 Accepted: 05 Oct 2010 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2011 Geological Society of America Geology (2011) 39 (2): 187–190. https://doi.org/10.1130/G31524.1 Article history Received: 28 Jun 2010 Revision Received: 30 Sep 2010 Accepted: 05 Oct 2010 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Anders Widerlund, Per S. Andersson; Late Holocene freshening of the Baltic Sea derived from high-resolution strontium isotope analyses of mollusk shells. Geology 2011;; 39 (2): 187–190. doi: https://doi.org/10.1130/G31524.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Strontium isotopic composition (87Sr/86Sr) data from subfossil 14C-dated mollusk shells in raised beach sediments are used as a paleosalinity proxy in the brackish Baltic Sea, the precision (±5%) and accuracy (±0.7‰) of the method being judged from replicate analyses of modern shells. Paleosalinity data with an average time resolution of ∼200 yr for the period 7130–2775 calibrated 14C yr B.P. indicate maximum surface salinities of 10‰–11‰, 11‰–12‰, and 12‰–13‰ for the Bothnian Bay, Bothnian Sea, and Baltic Proper (the three major Baltic subbasins). The relative salinity differences between the basins were small (≤30%) compared to the as much as eightfold present-day relative salinity differences (Bothnian Bay 1‰–3‰; Bothnian Sea 4‰–5‰; Baltic Proper 6‰–8‰). Late Holocene freshening (ca. 3000 calibrated 14C yr B.P. to present) is most pronounced in the northernmost subbasin, the Bothnian Bay, consistent with the absence of a permanent halocline, sequestering of phosphorus in well-oxygenated bottom sediments, and phosphorus limitation of primary production in the present-day Bothnian Bay. This study suggests that paleosalinity data may be crucial to improving our understanding of the possible effects of any future, climate-induced freshening of the Baltic Sea. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.