TY - JOUR
T1 - New interglacial deposits from Copenhagen, Denmark: marine Isotope Stage 7
AU - Bennike, Ole
AU - Hedenäs, Lars
AU - High, Kirsty
AU - Korshøj, Joakim S.
AU - Lemdahl, Geoffrey
AU - Penkman, Kirsty
AU - Preece, Richard C.
AU - Rosenlund, Knud
AU - Viehberg, Finn A.
N1 - Funding Information:
Svend Funder at the Geological Museum in Copenhagen allowed us to analyse Bithynia opercula from the Free Port. Amino acid analyses were supported by the Leverhulme Trust. Sheila Taylor is thanked for technical support. We are grateful to Bernd Wagner and Jan A. Piotrowski for their comments that helped to improve the manuscript.
Funding Information:
Acknowledgements. – Svend Funder at the Geological Museum in Copenhagen allowed us to analyse Bithynia opercula from the Free Port. Amino acid analyses were supported by the Leverhulme Trust. Sheila Taylor is thanked for technical support. We are grateful to Bernd Wagner and Jan A. Piotrowski for their comments that helped to improve the manuscript.
Publisher Copyright:
© 2018 Collegium Boreas. Published by John Wiley & Sons Ltd
PY - 2019/1
Y1 - 2019/1
N2 - During a pre-site survey and construction of a new metro route and station in Copenhagen, fossiliferous organic-rich sediments were encountered. This paper reports on multidisciplinary investigations of these organic sediments, which occurred beneath a sediment succession with a lower till, glacifluvial sand and gravel, an upper till and glacifluvial sand. The organic sediments were underlain by glacifluvial sand and gravel. The organic-rich sediments, which were up to 0.5 m thick, accumulated in a low-energy environment, possibly an oxbow lake. They were rich in plant fossils, which included warmth-demanding trees and other species, such as Najas minor, indicating slightly higher summer temperatures than at present. Freshwater shells were also frequent. Bithynia opercula allowed the sediments to be put into an aminostratigraphical framework. The amino acid racemization (AAR) ratios indicate that the organic sediments formed during Marine Isotope Stage 7 (MIS 7), which is consistent with optically stimulated luminescence dating that gave ages of 206 and 248 ka from the underlying minerogenic deposit. The assemblages from Trianglen are similar to interglacial deposits from the former Free Port (1.4 km away) in Copenhagen, except that Corbicula and Pisidium clessini were not found at Trianglen. The presence of these bivalves at the Free Port and the ostracod Scottia tumida at Trianglen indicates a pre-Eemian age. AAR data from archived Bithynia opercula from the Free Port were almost identical to those from Trianglen, indicating that the two sites are contemporary. We suggest the Trianglen interglacial be used as a local name for the MIS 7 interglacial deposits in Copenhagen. MIS 7 deposits have rarely been documented from the region, but MIS 7 deposits may have been mistaken for other ages. The use of AAR ratios in Bithynia opercula has a great potential for correlation of interglacial non-marine deposits in mainland northern Europe.
AB - During a pre-site survey and construction of a new metro route and station in Copenhagen, fossiliferous organic-rich sediments were encountered. This paper reports on multidisciplinary investigations of these organic sediments, which occurred beneath a sediment succession with a lower till, glacifluvial sand and gravel, an upper till and glacifluvial sand. The organic sediments were underlain by glacifluvial sand and gravel. The organic-rich sediments, which were up to 0.5 m thick, accumulated in a low-energy environment, possibly an oxbow lake. They were rich in plant fossils, which included warmth-demanding trees and other species, such as Najas minor, indicating slightly higher summer temperatures than at present. Freshwater shells were also frequent. Bithynia opercula allowed the sediments to be put into an aminostratigraphical framework. The amino acid racemization (AAR) ratios indicate that the organic sediments formed during Marine Isotope Stage 7 (MIS 7), which is consistent with optically stimulated luminescence dating that gave ages of 206 and 248 ka from the underlying minerogenic deposit. The assemblages from Trianglen are similar to interglacial deposits from the former Free Port (1.4 km away) in Copenhagen, except that Corbicula and Pisidium clessini were not found at Trianglen. The presence of these bivalves at the Free Port and the ostracod Scottia tumida at Trianglen indicates a pre-Eemian age. AAR data from archived Bithynia opercula from the Free Port were almost identical to those from Trianglen, indicating that the two sites are contemporary. We suggest the Trianglen interglacial be used as a local name for the MIS 7 interglacial deposits in Copenhagen. MIS 7 deposits have rarely been documented from the region, but MIS 7 deposits may have been mistaken for other ages. The use of AAR ratios in Bithynia opercula has a great potential for correlation of interglacial non-marine deposits in mainland northern Europe.
UR - http://www.scopus.com/inward/record.url?scp=85053071649&partnerID=8YFLogxK
U2 - 10.1111/bor.12342
DO - 10.1111/bor.12342
M3 - Article
SN - 0300-9483
VL - 48
SP - 107
EP - 118
JO - Boreas
JF - Boreas
IS - 1
ER -