This is a repository copy of New interglacial deposits from Copenhagen, Denmark : marine Isotope Stage 7. White Rose Research Online URL for this paper: https://eprints.whiterose.ac.uk/133387/ Version: Accepted Version Article: Bennike, Ole, Hedenäs, Lars, High, Kirsty orcid.org/0000-0003-3192-4540 et al. (6 more authors) (2019) New interglacial deposits from Copenhagen, Denmark : marine Isotope Stage 7. Boreas. pp. 107-118. ISSN 0300-9483 https://doi.org/10.1111/bor.12342 Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. 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[email protected] https://eprints.whiterose.ac.uk/ Boreas New interglacial deposits from Copenhagen, Denmark: Marine Isotope Stage 7 Journal: Boreas ManuscriptFor ID BOR-013-2018.R1 Review Only Manuscript Type: Original rticle Date Submitted by the uthor: n/a Complete List of uthors: Bennike, Ole, -eological Sur.ey of Denmark and -reenland, /eden0s, Lars, 1aturhistoriska riksmuseet /igh, 2irsty, 3ni.ersity of 4ork 2orsh56, Joakim, -EO Lemdahl, -eoffrey, Linnaeus 3ni.ersity, School of 1atural Sciences 8enkman, 2irsty, 3ni.ersity of 4ork 8reece, Richard, 3ni.ersity of Cambridge, Department of 9oology Rosenlund, 2nud, 9oological Museum :iehberg, Finn, 3ni.ersity of Cologne, Institut f<r 3mweltgeologie 2eywords: Interglacial, Denmark, macrofossils, 8leistocene, MIS 7 Page 1 of 30 Boreas 1 2 3 4 New interglacial deposits from Copenhagen, Denmark: Marine Isotope Stage 7 5 6 7 OLE BENNIKE, LARS HEDENÄS, KIRSTY HIGH, JOAKIM STIEL KORSHØJ, GEOFFREY 8 9 LEMDAHL, KIRSTY PENKMAN, RICHARD C. PREECE, KNUD ROSENLUND AND FINN 10 A. VIEHBERG 11 12 13 14 Bennike, O., Galsgaard, J., Hedenäs, L., High, K., Korshøj, J.S., Lemdahl, G., Penkman, K., 15 Preece, R.C., Rosenlund, K. & Viehberg, F.A.: New interglacial deposits from Copenhagen, 16 17 Denmark: Marine Isotope Stage 7. 18 19 For Review Only 20 During a pre7site sur8ey and construction of a new metro route and station in Copenhagen, 21 22 fossiliferous organic7rich sediments were encountered. This paper reports on multidisciplinary 23 in8estigations of these organic sediments, which occurred beneath a sediment succession with of a 24 25 lower till, glacioflu8ial sand and gra8el, an upper till and glacioflu8ial sand. The organic sediments 26 27 were underlain by glacioflu8ial sand and gra8el. The organic7rich sediments, which were up to 0.5 28 m thick, accumulated in a low7energy en8ironment, possibly an oxbow lake. They were rich in 29 30 plant fossils, which included warmth7demanding trees and other species, such as Najas minor, 31 indicating slightly higher summer temperatures than at present. ,reshwater shells were also 32 33 frequent. Bithynia opercula allowed the sediments to be put into an aminostratigraphical 34 35 framework. The amino acid racemisation (AAR) ratios indicate that the organic sediments formed 36 during Marine Isotope Stage 7 (MIS 7), which is consistent with optically luminescence dating that 37 38 ga8e ages of 20A and 24C ka from the underlying minerogenic deposit. The assemblages from 39 40 Trianglen are similar to interglacial deposits from the former ,ree Port (1.4 km away) in 41 Copenhagen, except that Corbicula and Pisidium clessini were not found at Trianglen. The 42 43 presence of these bi8al8es at the ,ree Port and the ostracod Scottia tumida at Triangles indicates a 44 pre7 emian age. AAR data from archi8ed Bithynia opercula from the ,ree Port were almost 45 46 identical to those from Trianglen, indicating that the two sites are contemporary. De suggest the 47 48 Trianglen interglacial be used as a local name for the MIS 7 interglacial deposits in Copenhagen. 49 MIS 7 deposits ha8e rarely been documented from the region, but MIS 7 deposits may ha8e been 50 51 mistaken for other ages. The use of amino acid racemiEation ratios in Bithynia opercula has a great 52 53 potential for correlation of interglacial non7marine deposits in mainland northern urope. 54 55 56 57 58 59 1 60 Boreas Page 2 of 30 1 2 3 4 Ole Bennike ([email protected]), eological Survey of Denmark and reenland, $ster Voldgade 10, 5 6 D(-1350 Copenhagen (, Denmark- .oakim Stiel (orsh/, 0O, 1aglebjergvej 1, D(-2800 (gs. 7 4yngby, Denmark- 4ars 5edenäs, Swedish 1useum of Natural 5istory, Bo8 50007, S-104 05 8 9 Stockholm, Sweden- (irsty 5igh and (irsty Penkman, Department of Chemistry, University of 10 York, York, YO10 5DD, U(, eoffrey 4emdahl, 4innaeus University, SE-391 82, (almar, Sweden- 11 12 Richard C. Preece, Department of Zoology, University of Cambridge, Downing Street, Cambridge 13 14 CB2 3E., U(- (nud Rosenlund, Zoological 1useum, Universitetsparken 15, D(-2100 15 Copenhagen $, Denmark- Finn Viehberg, Anstitute of eology and 1ineralogy, University of 16 17 Cologne, ZBlpicher Str. 49A, 50D74 Cologne, ermany 18 19 For Review Only 20 Interglacial deposits occur commonly in Denmark, but most are found in the western parts of the 21 22 country where erosion by glaciers and meltwater was less intense. Only a few interglacial deposits 23 ha8e been reported from Fealand (,ig. 1). Most of these are marine deposits that ha8e been referred 24 25 to the emian or the Holsteinian, but a few non7marine deposits ha8e also been reported. 26 27 Interglacial organic sediments were found during exca8ations for the former ,ree Port in 28 Copenhagen between 1C91 and 1C93 (Rosenk3Ir 1C93, 189A). They occurred as large clasts and 29 30 floes near the base of a till, which was deposited from the north7east (Milthers 1935). Macroscopic 31 plant and animal remains were studied by Rostrup (1C95), Sarauw (1C97), Johansen (1904) and 32 33 HartE (1909) and fi8e samples were analysed for pollen by Jessen (1927). The assemblage included 34 35 warmth7demanding plants such as Euercus, Tilia, Corylus avellana, Alnus glutinosa, Cornus 36 sanguinea and Nymphoides peltata (Table 1), demonstrating that the fossils came from a temperate 37 38 stage. Sarauw (1C97) suggested that the ,ree Port deposits should be correlated with the Middle 39 40 Pleistocene Cromer ,orest Bed in ast Anglia ( ngland), whereas Johansen (1904) and Milthers 41 (1922) suggested a pre7glacial rather than interglacial age. Jessen (1927) suggested that the ,ree 42 43 Port deposit belonged to the oldest Danish interglacial (out of two recognised at that time), a 8iew 44 followed by Milthers (1935). The molluscan fauna from the ,ree Port includes the bi8al8e 45 46 Corbicula fluminalis and Pisidium clessini. Corbicula fluminalis is an extant species, which is 47 48 unknown from deposits in North7Dest urope younger than MIS 7. Pisidium clessini is extinct 49 with the last occurrences in MIS 7 depositsJ hence these species indicate a pre7 emian age. 50 51 Other non7marine interglacial occurrences on Fealand ha8e been reported from MKl28 to the 52 53 north7west of Copenhagen (Bennike et al. 2011J Middle Pleistocene) and from ,2rsle8gaard in the 54 southern part of the island (Johansen 1904). The ,2 sle8gaard fauna includes Corbicula fluminalis, 55 56 57 58 59 2 60 Page 3 of 30 Boreas 1 2 3 4 Pisidium clessini and gastropod Belgrandia marginata. The latter species is unknown from other 5 6 Luaternary deposits in Denmark, but is common in other interglacial deposits in north7western 7 urope (Preece 1990). Currently, this species is found in ,rance and Spain. 8 9 In addition to the interglacial deposit, reworked marine shells were found in the glacioflu8ial 10 gra8el between two tillsJ the fauna included MTapes aureus 8ar. eemiensisN, now Polititapes aureus 11 12 ()melin, 1791), which indicated deri8ation from deposits of emian age (Madsen et al. 190C). The 13 14 nearest in situ emian littoral deposit occurs at 3by Bro, 45 km west of Copenhagen (Madsen 15 19AC), so it is not surprising that reworked emian shells occur in the Copenhagen area. Interglacial 16 17 peat and gytt3a ha8e also been reported from a locality 11.5 km south7east of the centre of 18 Copenhagen (J2rgensen 5 ,rederiksen 2002), but no information on the palaeoecology or age was 19 For Review Only 20 pro8ided. 21 22 Pleistocene interglacial deposits in Denmark ha8e traditionally been referred to the emian, 23 Holsteinian and Cromerian (local name Harresko8ianJ Andersen 19A5), but an interglacial 24 25 occurrence in eastern Jutland has been referred to a fourth interglacial stage, and correlated with 26 27 Marine Isotope Stage (MIS) 11, although not with interglacial occurrences referred to the 28 Holsteinian (KuneO et al. 2013). Howe8er, the correlation and age of se8eral Danish interglacial 29 30 occurrences are unknown (Andersen 19A7). 31 In other parts of north7western urope it is becoming increasingly clear that the Pleistocene 32 33 successions are much more complex than pre8iously belie8ed (e.g. /rban et al. 2011J Penkman et 34 35 al. 2013). Interglacial successions in north7western urope are characterised by climatic conditions 36 similar to the Holocene (e.g. Jessen 5 Milthers 192CJ Andersen 19A5), whereas interstadial 37 38 deposits contain remains of arctic or sub7arctic species (e.g. Bennike et al. 1994, 2014). 39 40 Prior to the construction of a new metro line in Copenhagen, drilling was undertaken to 41 in8estigate the geology and the geotechnical properties of the subsurface along the line. Organic7 42 43 rich sub7till deposits were encountered in a few reconnaissance cores, in particular at Trianglen, 44 where a metro7station was planned.