RESEARCH/REVIEW ARTICLE Coastal glaciers advanced onto Jameson Land, East Greenland during the late glacialÁearly Holocene Milne Land Stade Helena Alexanderson1 & Lena Ha˚ kansson2,3 1 Department of Geology, Lund University, So¨ lvegatan 12, SE-223 62 Lund, Sweden 2 Geological Survey of Denmark and Greenland, Marine Geology and Glaciology, Østervoldgade 10, DK-1350 Copenhagen K, Denmark 3 Department of Geology and Mineral Resources Engineering, Norwegian University of Science and Technology, Sem Særlands veg 1, NO-7491 Trondheim, Norway Keywords Abstract Greenland; Jameson Land; glaciation; Milne 10 Land Stade; cosmogenic exposure dating; We report on Be and optically stimulated luminescence ages from moraines luminescence dating. and glaciolacustrine sediments on eastern Jameson Land, East Greenland. Sampled landforms and sediment are associated with advances of outlet Correspondence glaciers from the local Liverpool Land ice cap situated in the coastal Scoresby Lena Ha˚ kansson, Geological Survey of Sund region. Previous studies have tentatively correlated these advances with Denmark and Greenland, Marine Geology the Milne Land Stade moraines, which are prominent moraine sets deposited and Glaciology, Østervoldgade 10, DK-1350 Copenhagen K, Denmark. by mountain glaciers in the inner Scoresby Sund region. Recent constraints on E-mail: [email protected] the formation of the outer and inner of these moraines have suggested two advances of local glaciers, one prior to or during the Younger Dryas and another during the Preboreal. In this paper, we test the correlation of the Liverpool Land glacial advance with the Milne Land Stade. Our results show that outlet glaciers from the Liverpool Land ice cap reached ice-marginal positions marked by moraines in east-facing valleys on Jameson Land sometime during late glacialÁearly Holocene time (ca. 13Á11 Kya). This confirms the correlation of these moraines with the Milne Land Stade moraines described elsewhere in the Scoresby Sund region. Local glaciers are sensitive recorders of climate change Hall Bredning (Fig. 1). Even though these moraines are (e.g., Nesje et al. 2008; Carr et al. 2010; Leclercq & the only prominent ice-marginal features between the Oerlemans 2012) in comparison with ice sheets and ice- last glacial maximum and little ice age ice-marginal sheet margins, which may have a longer response time. positions, their age has been debated. Originally they Geological records from Greenland show that local were assigned a Younger Dryas age (Funder 1972, 1978). glaciers and ice caps advanced and retreated partly out However, subsequent studies have suggested deposition of tune with the Greenland Ice Sheet during the last during Preboreal time (Funder & Hansen 1996; Bjo¨ rck glacial/interglacial cycle (Adrielsson & Alexanderson et al. 1997). The latter alternative was favoured because 2005; Kelly & Lowell 2009). The rapid climate change it has long been thought that the Younger Dryas was too during the last termination has been of particular interest, cold and dry to accommodate glacier growth (Funder & and studies of moraines or other landforms demarcating Hansen 1996). Recent studies of the inner and outer local glacial extent during that time may provide in- Milne Land Stade moraines in the inner Scoresby Sund formation on climate factors such as precipitation and area place the outer Milne Land Stade prior to or during temperature (see Kelly & Lowell 2009). the Younger Dryas and the inner Milne Land Stade in the In East Greenland, one such feature is the promi- Preboreal, based on relative sea-level data and exposure nent Milne Land Stade moraines, originally described by ages of moraines (Hall et al. 2008; Kelly et al. 2008). Funder (1970). The moraines consist of an outer and an The Milne Land Stade moraines have been tentati- inner belt, and they are exposed widely in the central vely correlated with fresh-looking moraines on eastern parts of the Scoresby Sund region, on Milne Land and in Jameson Land adjacent to former outlets of a Liverpool Polar Research 2014. # 2014 H. Alexanderson & L. Ha˚ kansson. This is an Open Access article distributed under the terms of the Creative Commons Attribution- 1 Noncommercial 3.0 Unported License (http://creativecommons.org/licenses/by-nc/3.0/), permitting all non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Citation: Polar Research 2014, 33, 20313, http://dx.doi.org/10.3402/polar.v33.20313 (page number not for citation purpose) Coastal glaciers advanced onto Jameson Land H. Alexanderson & L. Ha˚ kansson logical descriptions and logging of glacially associated landforms in eastern Jameson Land valleys. Geological setting The Jameson Land peninsula (708Á718N) is located at the northern side of Scoresby Sund, the largest fjord system in East Greenland (Fig. 1). The distance between the fjord mouth and the present margin of the Greenland Ice Sheet is about 200 km. Mesozoic sandstones and shales make up the low-relief ice-free terrain in Jameson Land. The peninsula has an asymmetric topographic profile; from the Scoresby Sund coast the terrain rises gently towards the plateau areas of interior Jameson Land, ca. 500 m a.s.l., whereas in the east the plateau margins drop steeply (Fig. 1). The central plateau is dissected by fluvial erosion that has created a radiating drainage pattern from central Jameson Land towards the Scoresby Sund and Hurry Fjord coasts. Liverpool Land is situated at the outer coast and is separated from Jameson Land to the west by the Hurry Fjord and the Klitdal valley. The crystalline terrain of Liverpool Land is characterized by an alpine topography with local glaciers and small ice caps. Earlier studies have suggested that the interior of Jameson Land was ice-free during the last glacial cycle Fig. 1 Map of Greenland and the Scoresby SundÁJameson Land area. and that the last advance of the Greenland Ice Sheet The open squares mark our study areas (see Fig. 2). The filled triangle overriding the peninsula occurred during Marine Isotope represents the Mestersvig delta and the filled circles with roman numbers the positions of radiocarbon samples (see Table 2 for site Stage (MIS) 6 (Funder et al. 1994, 1998; Mo¨ ller et al. numbers). Thick black lines represent Milne Land Stade moraines as 1994). This was based on the weathered appearance of described by Funder (1970) in Milne Land and by Denton et al. (2005) the central plateau areas of the peninsula and the lack of north of Hall Bredning. The following river names are abbreviated: glacial deposits of Weichselian age. However, studies Depotelv (De), Draba Sibirica Elv (Dr), Lollandselv (Lo) and Falsterselv applying cosmogenic exposure dating to erratics perched (Fa) rivers. Copyright background map: National Survey and Cadastre, at 250 m a.s.l. on the Kap Brewster Peninsula at the Denmark. mouth of the Scoresby Sund fjord indicate that ice Land-based ice cap (Funder 1990; Lilliesko¨ld & Salvigsen reached more than 250 m above the present sea level 1991). No absolute ages are available for these moraines, during the last glacial maximum. This suggests that the but from the stratigraphic record we know that glaciers Greenland Ice Sheet was considerably more extensive on Liverpool Land advanced onto eastern Jameson Land during this time than previously thought (Ha˚kansson at least twice during the last two glacial cycles: two tills et al. 2007). are placed in the Saalian (170Á150 Kya) and in the In most of the east-facing valleys on eastern Jameson Weichselian (100Á10 Kya), respectively (Adrielsson & Land, there are prominent moraine ridges which are Alexanderson 2005). concave towards the east and reflect former ice-marginal In this paper, we attempt to test the correlation of the positions of outlet glaciers from the Liverpool Land ice youngest Liverpool Land advance with the Milne Land cap. These moraines have been tentatively assigned to Stade, as proposed by Funder (1990), among others. To the Milne Land Stade (Funder 1972). Further, they were do so, we apply cosmogenic 10Be dating to constrain the mapped from aerial photographs and shown on the age of moraines and optically stimulated luminescence Quaternary map of Scoresby Sund (Funder 1990). Series (OSL) to date glacial lake sediments associated with these of deltas deposited in lakes dammed during these glacier ice-marginal positions in four valleys in eastern Jameson advances have also been described from some of these Land. We further want to reconstruct depositional valleys (Lilliesko¨ld & Salvigsen 1991). environments associated with the westward advance of In this study, we have investigated four valleys in two Liverpool Land glaciers. This is done through sedimento- different areas on eastern Jameson Land. In the Lejrelv 2 Citation: Polar Research 2014, 33, 20313, http://dx.doi.org/10.3402/polar.v33.20313 (page number not for citation purpose) H. Alexanderson & L. Ha˚ kansson Coastal glaciers advanced onto Jameson Land Fig. 2 Maps showing the study areas: (a) the Lejrelv area (contour interval of 50 m); (b) the Ga˚ seelv area (contour interval of 100 m). The bold line marks the 500 m contour and light grey areas show terrain above 500 m a.s.l. Stars mark the sites from which samples for 10Be (white) and optically stimulated luminescence (OSL; black) dating have been taken and numbers refer to site numbers (Table 1). The geomorphological features are based on the maps by Lilliesko¨ ld & Salvigsen (1991) and our field survey. Topographic information is from copyright, National Survey and Cadastre, Denmark. The following river names are abbreviated: Depotelv (De), Draba Sibirica Elv (Dr), Lejrelv (Le) and Umingmelv (Um). The following names of mountains are abbreviated: Centralbjerg (C.M.); Skansen (S.M.) and Umingmak (U.M.). area (Fig. 2a), the Lejrelv and Umingmakelv valleys between the valleys and a nameless mountain to the (informal names) are situated about 5 km apart, approxi- south (Fig. 2a).