Chronology of the last deglaciation andHolocene environmental changes in theSisimiut area,SW Greenland based on lacustrine records

Abstract

The Sisimiut area was deglaciated in the early Holocene, c. 11 cal. ka BP. At that time the lowlands were inundated by the sea, but the isostatic rebound surpassed the global sea‐level rise, and the lowlands emerged from the sea. The pioneer vegetation in the area consisted of mosses and herbaceous plants. The oldest remains of woody plants (Empetrum nigrum) are dated to c. 10.3 cal. ka BP, and remains of Salix herbacea and Harrimanella hypnoides are found in slightly younger sediments. The maximum occurrence of statoblasts of the bryozoan Plumatella repens from c. 10 to 4.5 cal. ka BP probably reflects the Holocene thermal maximum, which is also indicated in geochemical proxies of the lake sediments. A maximum in organic matter accumulation in one of the three studied lakes c. 3 cal. ka BP can probably be ascribed to a late Holocene short‐duration temperature maximum or a period of increased aridity. Cenococcum geophilum sclerotia are common in the late Holocene, implying increased soil erosion during the Neoglaciation. A comparison with sediment and macrofossil records from inland shows similar Holocene trends and a similar immigration history. It also reveals that there has been a significant gradient throughout the Holocene, from an oceanic and stable climate at the outer coast to a more continental and unstable climate with warmer summers and drier conditions close to the margin of the Greenland ice sheet, where the buffer capacity of the sea is lower.

Slow retreat of a land based sector of the West Greenland Ice Sheet during the Holocene Thermal Maximum: evidence from threshold lakes at Paakitsoq

“…Briner et al, 2010;Young et al, 2011;Wagner and Bennike, 2012). Minerogenic sediment may have accumulated in Lake Lo in three ways: (1) during deglaciation when the ice margin was in the Lake Lo catchment, (2) when the ice margin had a configuration similar to the present causing damming of Lake 187 and overflow of silt-laden meltwater into Lake Lo, or (3) when Lake Lo was isolated from Lake 187, by paraglacial reworking of old glacial sediments from the catchment slopes (Ballantyne, 2002;Rubensdotter and Rosqvist, 2009;Bakke et al, 2010).…”

Evidence of ameliorated Middle Weichselian climate and sub‐arctic environment in the western Baltic region: coring lake sediments at Klintholm, Møn, Denmark

“…However, statoblasts of Fredericella indica have been found in Middle Weichselian interstadial deposits in northern Finland (Helmens et al . ) and they are common in Holocene lake deposits from southwest Greenland and in Lateglacial deposits from Denmark (Wagner & Bennike ; Bennike unpublished data). In Norway Fredericella indica is common in lakes in the northern part of the country (Økland & Økland ).…”

Sulfur Geochemistry of a Lacustrine Record from Taiwan Reveals Enhanced Marine Aerosol Input during the Early Holocene

“…In fact, the high sulfur content in inland freshwater lakes adjacent to coastal zones has been attributed to sea salt spray when bedrock sources were not significant89101127. The sulfur content can reach 8% due to the influence of sea salt spray10.…”

“…However, only limited documentations were reported regarding the history of sea spray or marine aerosol input2. Sulfate, a major ion in seawater and marine aerosol but normally present only in trace amounts in freshwater lakes, makes sulfur a potential proxy to study past environment changes34567891011. However, the complexity of the sulfur cycle and the scarcity of studies of the behaviour of sulfur in heterogeneous lakes hampered the applicability of using sedimentary sulfur geochemistry to construct past environmental conditions7.…”