Early Pleistocene sediments on Store Koldewey, northeast Greenland

Abstract

Marine Quaternary deposits, here named the Store Koldewey Formation, are found at $120 m above sea level in northeast Greenland (761N). The sequence is referred to the Olduvai normal polarity subchron at 1.95-1.78 Ma BP based on palaeomagnetic studies (palaeomagnetically reversed), amino acid epimerization ratios and evidence from marine and non-marine fossils. The sediments and the fauna show that the sequence was deposited on a mid or inner shelf, and some elements of the marine mollusc and foraminiferal assemblages indicate water temperatures between À1 and 111C and seasonal sea ice cover during deposition. Mean summer air temperatures were around 61C higher than at present, as demonstrated by the occurrence of southern extralimital terrestrial species. Wellpreserved remains of land plants indicate that the adjacent land area was dominated by sub-arctic forest-tundra with the trees Larix and Betula, shrubs, herbs and mosses. Most of the species represented as fossils have recent circumpolar geographical ranges. An extinct brachiopod species and an extinct gastropod species have been found, but the other macrofossils are referred to extant species. The brachiopod is erected as a new genus and species, Laugekochiana groenlandica.

Annually resolved temperature reconstructions from a late Pliocene–early Pleistocene polar forest on Bylot Island, Canada

“…Their premise was that oxygen isotopes incorporated into cellulose from water are subject to fractionation at several points and can be modeled by Eq. (1): (Funder et al, 2001;Bennike et al, 2010), Hvitland Beds (HB) (Fyles et al, 1998), Ile de France (IF) (Bennike et al, 2002) and Meighen Island (MI) (Matthews and Ovenden, 1990) deposits. where f o is the fraction of carbon-bound oxygen that undergoes exchange with xylem water (≈35%); δ 18 O wx is the oxygen isotope ration of xylem water; ε o is the biological fractionation factor for oxygen during conversion from sugar to cellulose (27‰); δ 18 O wl is the oxygen isotope ratio of leaf water as determined by the Flanagan et al (1991) model presented in Eq.…”

A greener Greenland? Climatic potential and long-term constraints on future expansions of trees and shrubs

“…Albae, A. viridis ssp . crispa and the now extinct Larix groenlandii and Myrica arctogale [11,26,27]. In some Middle Pleistocene interglacial episodes, southern Greenland was also covered by rich boreal forest, including species of Picea, Abies , Pinus , Taxaceae, Alnus and probably also Betula and Populus [28,29].…”

Holocene environmental change in theSkallingen area, easternNorthGreenland, based on a lacustrine record

“…nidifica oospores were also been recorded from member B of the Kap København Formation in eastern Greenland (Bennike ), which is currently dated to c. 2 Ma (Bennike et al . ). Tolypella nidifica grows in hardwater lakes and in brackish water.…”