Late Quaternary history around Nioghalvfjerdsfjorden and Jøkelbugten, North‐East Greenland

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The Kap Mackenzie area on the outer coast of northeast Greenland was glaciated during the last glacial stage, and pre-Holocene shell material was brought to the area. Dating of marine shells indicates that deglaciation occurred in the earliest Holocene, before 10 800 cal. a BP. The marine limit is around 53 m a.s.l. In the wake of the deglaciation, a glaciomarine fauna characterized the area, but after c. one millennium a more species-rich marine fauna took over. This fauna included Mytilus edulis and Mysella sovaliki, which do not live in the region at present; the latter is new to the Holocene fauna of northeast Greenland. The oldest M. edulis sample is dated to c. 9500 cal. a BP, which is the earliest date for the species from the region and indicates that the Holocene thermal maximum began earlier in the region than previously documented. This is supported by driftwood dated to c. 9650 cal. a BP, which is the earliest driftwood date so far from northeastern Greenland and implies that the coastal area was at least partly free of sea ice in summer. As indicated by former studies, the Storegga tsunami hit the Kap Mackenzie area at c. 8100 cal. a BP. Loon Lake, at 18 m a.s.l., was isolated from the sea at c. 6200 cal. a BP, which is distinctly later than expected from existing relative sea-level curves for the region.

Section: Fossils From the Loon Lake Vicinitymentioning

confidence: 97%

Late Quaternary history of the Kap Mackenzie area, northeast Greenland

Wagner¹,

Bennike²,

Cremer³

et al. 2010

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“…The presence of Potamogeton liformis is surprising, as this macrolimnophyte does not grow this far north in Greenland. There is a northern extralimital occurrence of the species in mid-Holocene layers in Northeast Greenland (Bennike & Weidick 2001), but the fossil occurrence in Washington Land is far north of the species' present northern range limit. Therefore, it is suggested that the fruits are derived from unknown interglacial deposits in the area.…”

Section: Non-marine Biotasmentioning

confidence: 98%

“…Macoma calcarea and Serripes groenlandicus were found in many samples. These species are also quite common around Nioghalvfjerdsfjorden in Northeast Greenland (Bennike & Weidick 2001), but they have not been recorded further north in Holocene deposits in East Greenland. North of Washington Land, the northernmost Holocene records come from Hall Land and Nyeboe Land (Kelly & Bennike 1992).…”

Section: Marine Macrofossilsmentioning

confidence: 99%

“…The oldest previous Holocene nd of this mammal from Greenland is dated to around 6400 cal. yr BP (Bennike 1997;Bennike & Weidick 2001), but the record from Washington Land is the rst from western North Greenland. Lemmings are not found west of Washington Land, presumably because the animal has not been able to cross the broad Humboldt Gletscher.…”

Section: Land Mammalsmentioning

confidence: 99%

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Late Quaternary history of Washington Land, North Greenland

Bennike¹

2002

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During the last glacial stage, Washington Land in western North Greenland was probably completely inundated by the Greenland Ice Sheet. The oldest shell dates from raised marine deposits that provide minimum ages for the last deglaciation are 9300 cal. yr BP (northern Washington Land) and 7600 cal. yr BP (SW Washington Land). These dates indicate that Washington Land, which borders the central part of Nares Strait separating Greenland from Ellesmere Island in Canada, did not become free of glacier ice until well into the Holocene. The elevation of the marine limit falls from 110 m a.s.l. in the north to 60 m a.s.l. in the southwest. The recession was followed by readvance of glaciers in the late Holocene, and the youngest shell date from Neoglacial lateral moraines north of Humboldt Gletscher is 600 cal. yr BP. Since the Neoglacial maximum, probably around 100 years ago, glaciers have receded. The Holocene marine assemblages comprise a few southern extralimital records, notably of Chlamys islandica dated to 7300 cal. yr BP. Musk ox and reindeer disappeared from Washington Land recently, perhaps in connection with the cold period that culminated about 100 years ago.

“…High elevation erratics, trimlines and moraines have been reported up to 500 m above sea level (a.s.l.) in the Store Sødal Balascio et al (2015) and Zackenberg valleys (Bretz 1935;Christiansen & Humlum 1993), suggesting that outlet glaciers from the GrIS and local ice cap(s) previously extended into major valleys and fjords, and reached the shelf edge (Bennike & Weidick 2001;O Cofaigh et al 2004;Evans et al 2009). Regional deglaciationbeganafter the Last GlacialMaximum (LGM) and continued through the Holocene.…”

Section: Glacial History and Geomorphologymentioning

confidence: 99%

High‐resolution proglacial lake records of pre‐Little Ice Age glacier advance, northeast Greenland

Adamson

Lane

Carney

et al. 2018

Understanding Arctic glacier sensitivity is key to predicting future response to air temperature rise. Previous studies have used proglacial lake sediment records to reconstruct Holocene glacier advance–retreat patterns in South and West Greenland, but high‐resolution glacier records from High Arctic Greenland are scarce, despite the sensitivity of this region to future climate change. Detailed geochemical analysis of proglacial lake sediments close to Zackenberg, northeast Greenland, provides the first high‐resolution record of Late Holocene High Arctic glacier behaviour. Three phases of glacier advance have occurred in the last 2000 years. The first two phases (c. 1320–800 cal. a BP) occurred prior to the Little Ice Age (LIA), and correspond to the Dark Ages Cold Period and the Medieval Climate Anomaly. The third phase (c. 700 cal. a BP), representing a smaller scale glacier oscillation, is associated with the onset of the LIA. Our results are consistent with recent evidence of pre‐LIA glacier advance in other parts of the Arctic, including South and West Greenland, Svalbard, and Canada. The sub‐millennial glacier fluctuations identified in the Madsen Lake succession are not preserved in the moraine record. Importantly, coupled XRF and XRD analysis has effectively identified a phase of ice advance that is not visible by sedimentology alone. This highlights the value of high‐resolution geochemical analysis of lake sediments to establish rapid glacier advance–retreat patterns in regions where chronological and morphostratigraphical control is limited.