scholarly journals Upper Pleistocene and Holocene marine deposits and faunas on the north coast of Nûgssuaq, West Greenland

1981 ◽  
Vol 140 ◽  
pp. 1-107
Author(s):  
L.A Símonarson
Keyword(s):  
The Arctic ◽  
North Coast ◽  
Last Interglacial ◽  
Quaternary Deposits ◽  
West Greenland ◽  
Marine Deposits ◽  
The North ◽  
The Rich ◽  
Delta Slope ◽  
Rich Fauna

Field relations and the composition of the Quaternary molluscan and barnacle faunas at Pátorfik, Kûtsiaq and Sarfâgfik on the north coast of Nûgssuaq, West Greenland, are described. The marine Quaternary deposits at Pátorfik are older than 35 000 years. The lower part of the deposits seems to represent a prodelta environment, whereas the middle and upper parts apparently correspond to a delta slope. The rich fauna and the field relations differ essentially from what we know from other localities in Greenland where Late Wisconsian or Holocene marine fossiliferous deposits have been found. The faunal composition indicates prevailing water temperatures during deposition similar to those at the boundary between the arctic and boreal faunal regions today and somewhat higher than those in Umanak Fjord at present. It is suggested that the Pátorfik deposits were formed during the last interglacial stage (Sangamon/Eemian). The marine beds at Kûtsiaq and Sarfâgfik are of Early Holocene ages and apparently represent delta deposits.

Enhanced Age Resolution of the Marine Quaternary Record in the Arctic Using Aspartic Acid Racemization Dating of Bivalve Shells

1996 ◽  
Vol 45 (2) ◽  
pp. 176-187 ◽  
Author(s):  
Glenn A. Goodfriend ◽  
Julie Brigham-Grette ◽  
Gifford H. Miller
Keyword(s):  
Aspartic Acid ◽  
The Arctic ◽  
North Coast ◽  
Age Difference ◽  
Baffin Island ◽  
Last Interglacial ◽  
Marine Deposits ◽  
The North ◽  
Younger Age ◽  
Biogenic Carbonates

AbstractAspartic acid (Asp) racemization occurs at a significantly higher rate than isoleucine epimerization and consequently provides better temporal resolution of Arctic marine deposits (from Alaska, Spitsbergen, and Baffin Island). Heating experiments (at 100°C) on the bivalves Mya and Hiatella show the Asp racemization rate decreases with increasing D/L values, as is typical for biogenic carbonates. Based on these experimental racemization rates and rates determined from racemization of samples radiocarbon dated to ca. 10,000–12,000 yr B.P., activation energies for Mya and Hiatella are estimated to be 30.6 and 30.0 kcal/mol, respectively, for Asp racemization, and 29.0 and 29.5 for isoleucine epimerization. Analysis of a time series of Plio–Pleistocene Hiatella from the north coast of Alaska shows that last-interglacial mollusks can be readily distinguished from modern samples by Asp but not by isoleucine. D/L Asp values indicate a younger age for the Fishcreekian transgression than does isoleucine epimerization. For Spitsbergen, D/L Asp shows a slight age difference (ca. 12,000 yr) between two units of the “episode B” interstadial and suggests that the age of these units may be closer to 65,000 than to 80,000 yr B.P., two possible ages suggested by other evidence. The age of the Loks Land Interstadial on Baffin Island is likely to be greater than that indicated by radiocarbon ages. Within deposits from each region, D/L Asp values are less variable among individual shells than isoleucine epimerization values. This may indicate better reliability of Asp for geochronology.

scholarly journals The stratigraphy of the marine Quaternary deposits in West Greenland

1950 ◽  
Vol 2 ◽  
pp. 1-142
Author(s):  
D Laursen
Keyword(s):  
Present Report ◽  
Detailed Examination ◽  
Geological Survey ◽  
The South ◽  
Quaternary Deposits ◽  
West Greenland ◽  
Marine Deposits ◽  
The North ◽  
Field Investigations

The present report deals with the Quaternary marine deposits in West Greenland. The area in question extends from Kugssineq, Svartenhuk peninsula, in the north to the settlement of Sukkertoppen in the south. The field investigations for the paper have been made partly in 1939, partly in 1946, last-mentioned year under the auspices of Grønlands Geologiske Undersøgelse (abb. G.G.U., i. e. Geological Survey of Greenland). All localities visited are described with added lists of the collected shells. On the basis of the investigations made it will be demonstrated that the stratigraphy of the layers at Orpigsôq drawn up by Jensen and Harder in 1910 (30) is applicable to all the area investigated. Furthermore a detailed examination is made of the petrographic structure, the content af shells, and the levels of the various horizons, a discussion of a few errors, and ultimately an attempt at a correllation of the Quaternary marine layers of Greenland with the corresponding postglacial layers of Iceland, Norway, and Denmark.

scholarly journals Quaternary deposits between the Sukkertoppen ice cap and Nordre Strømfjord

1970 ◽  
Vol 28 ◽  
pp. 23-25
Author(s):  
A Weidick ◽  
N.W Ten Brink
Keyword(s):  
Land Area ◽  
The West ◽  
Quaternary Deposits ◽  
Sea Levels ◽  
West Greenland ◽  
Marine Deposits ◽  
Ice Cap

The area investigated during 1969 is located approximate1y between 66° 10' and 67° 30' N, and 50° and 52° W, the eastem half of the West Greenland ice-free land area transected by Søndre Strømfjord. The principal objectives of the work were to map and describe the glacial and emerged marine deposits for a Quatemary map at 1:500 000 scale, and to collect material for establishing a radiometric chronology of former ice-margin positions and sea levels. In order to study as large an area as possible, the investigations north of Søndre Strømfjord and Sondrestrom Airbase were conducted by A. Weidick, the area south of this by N. W. Ten Brink.

Chapter 20 Paleogene history

1997 ◽  
Vol 17 (1) ◽  
pp. 388-417
Keyword(s):  
Early Cretaceous ◽  
The Arctic ◽  
North Coast ◽  
Western Coast ◽  
Central Basin ◽  
Oblique Collision ◽  
The North ◽  
Western Border ◽  
Paleozoic Rocks ◽  
West Spitsbergen

The Paleogene chapter of Svalbard history is a quite distinct one. It begins with an unconformity, albeit a sub-parallel one representing a late Cretaceous hiatus. Resting on Albian and older strata, the Van Mijenfjorden Group of six formations totals a thickness of about 2500 m in the Central Basin of Spitsbergen. The outcrop is ringed by Early Cretaceous strata in a broad syncline (Fig. 20.1). The strata are largely non-marine, coal-bearing sandstones, with interbedded marine shales and they range in age through Paleocene and Eocene.From latest Paleocene through Eocene time the West Spitsbergen Orogeny caused (Spitsbergian) deformation along the western border of the Central Basin, but it is most conspicuous in the folding and thrusting of Carboniferous through Early Cretaceous rocks. The orogen extended westwards to and beyond the western coast of central and southern Spitsbergen including Precambrian and Early Paleozoic rocks, which had already been involved in earlier tectogenesis. The eastward-verging thrusting extended beneath the Tertiary basin and reactivated older faults to the east.In the wider context Svalbard, adjacent to the north coast of Greenland, had been an integral part of Pangea from Carboniferous through Cretaceous time. The northward extension of the Atlantic opening reached and initiated the spreading of the Arctic Eurasia Basin at the beginning of the Paleogene Period. This led to the separation of Svalbard together with the Barents Shelf and northern Europe from Greenland by dextral strike-slip transform faulting. In the course of this progression, oblique collision between northeast Greenland and Svalbard caused

scholarly journals Aspects of the Glaciology of Meighen Island, Northwest Territories, Canada

1965 ◽  
Vol 5 (40) ◽  
pp. 399-410 ◽  
Author(s):  
K. C. Arnold
Keyword(s):  
Snow Accumulation ◽  
The Arctic ◽  
North Coast ◽  
Ice Cap ◽  
The North ◽  
Four Seasons ◽  
Northern Half ◽  
Northern Edge ◽  
Summer Temperatures ◽  
Made In

Abstract Meighen Island lies in the centre of the north coast of the Queen Elizabeth Islands and fronts on the Arctic Ocean. An ice cap of about 76 km.2 covers about one-tenth of the island. Its greatest thickness of 150 m. occurs under the summit, near the south end, which was 268 m. above sea-level in 1960. The northern half of the ice cap is less than 30 m. thick; and the total volume is of the order of 2,000 × 106 m.3. Precipitation is low in the northern Queen Elizabeth Islands, and Meighen Island lies in an area where summer temperatures are lowest. In the winters of 1959–60, 1960–61 and 1961–62, the snow accumulation was 12.6, 18.2 and 14.1 cm. of water equivalent. Some snowfall remained on the higher part of the ice cap in the cold summer of 1961; but the ice cap diminished in volume in each year; by 36 × 106, 72 × 106, 22 × 106 and 91 × 106 m.3 in the 1959, 1960, 1961 and 1962 ablation seasons. If the conditions of these four seasons were maintained the ice cap would disappear in about 100 yr. However, a radio-carbon dating of a saxifrage exposed by the retreat of the ice from a small nunatak near the northern edge gave a date of less than 100 yr., and it appears that the existence of the ice cap might be sensitively related to recent climatic change. Careful surveys were made in 1959, 1960 and 1961 in an attempt to detect movement in the ice cap. Unequivocal evidence is not available from these surveys; but the stake network has been maintained and another survey has recently been completed.

scholarly journals Quaternary palaeoceanography and palaeogeography in northern Denmark: a review of results from the Skagen cores

1996 ◽  
Vol 43 ◽  
pp. 22-31
Author(s):  
Karen Luise Knudsen ◽  
Keld Conradsen ◽  
, Susanne Heier Nielsen ◽  
Marit-Solveig Seidenkrantz
Keyword(s):  
North Atlantic ◽  
Late Quaternary ◽  
Climatic Changes ◽  
Last Interglacial ◽  
North Atlantic Region ◽  
Atlantic Region ◽  
Radiocarbon Dates ◽  
Marine Deposits ◽  
The North ◽  
Late Weichselian

Palaeoenvironmental reconstructions from the Skagen record contribute to the understanding of Late Quatemary climatic changes and variations in the oceanographic circulation pattem in the entire North Atlantic region. The Skagen cores penetrated c. 192 m of Quatemary sediments comprising two marine Late Quaternary records: A 7 m marine unit (185.3-178.3 m) comprised the entire last interglacial, including its lower and upper transitions (Late Saalian-Eemian-Early Weichselian), while the upper 132 m of marine deposits covered the last about 15,000 years from the Late Weichselian through the Holocene, including the Pleistocene-Holocene transition. Results from the study of lithology, foraminifera, stable isotope measurements and radiocarbon dates are reviewed while emphasizing the most important contributions to the general understanding of the North Atlantic Quatemary history

scholarly journals The Walrus

Oryx ◽  
1950 ◽  
Vol 1 (1) ◽  
pp. 10-14
Author(s):  
Colin Matheson
Keyword(s):  
Distinct Species ◽  
The Arctic ◽  
North Coast ◽  
Hudson Bay ◽  
Pacific Walrus ◽  
The North ◽  
The Pacific ◽  
Western Shore ◽  
Far Eastern ◽  
Siberian Coast

The Walrus is confined to the northern circumpolar regions, its range northward apparently extending to the limit of perpetual ice. Now rare in Iceland, Odobenus rosmarus is stated to be still not unfamiliar in Hudson Bay, Davis Strait, and Baffin Bay north to Ellesmere Land, the coasts of Greenland, Spitsbergen, Novaia Zemlia, and the western part of the north coast of Siberia; in all of which regions, however, persecution has greatly diminished its numbers. The species does not extend along the far eastern part of the north Siberian coast, and Walrus are not met with again until the north-eastern extremity of Siberia is reached. Here the Pacific Walrus, which differs somewhat from that of the Atlantic side and is regarded as a distinct species, Odobenus obesus, is reported from Cape Chelagskai, in longitude 170° E., along the Siberian coast as far as northern Kamschatka south to latitude 60°, also on some of the islands in the Bering Sea, and on the opposite coast of Alaska south to about latitude 55° and eastward to Point Barrow. Here again a long gap along the Arctic coast of North America, from Point Barrow in longitude 158° W. to the western shore of Hudson Bay in longitude 97° W., separates the Pacific from the Atlantic Walrus.

Last Interglacial (Eemian) hydrographic conditions in the southwestern Baltic Sea based on dinoflagellate cysts from Ristinge Klint, Denmark

2007 ◽  
Vol 144 (6) ◽  
pp. 987-1013 ◽  
Author(s):  
MARTIN J. HEAD
Keyword(s):  
Baltic Sea ◽  
Cold Water ◽  
Significant Rise ◽  
Pollen Record ◽  
Last Interglacial ◽  
Mild Winter ◽  
Marine Deposits ◽  
The North ◽  
New Information ◽  
Marine Ingression

AbstractA dinoflagellate cyst record with strong Mediterranean/Lusitanian affinities is described from marine deposits of Eemian age (Last Interglacial; Late Pleistocene) at Ristinge Klint, Denmark, revealing new information about the hydrographic evolution of the southwestern Baltic Sea. A revised correlation of the pollen record at Ristinge Klint with that of the annually laminated site at Bispingen in northern Germany provides temporal control. Approximately the first quarter of Eemian time is represented. A marine ingression into a lake took place during theQuercusrise, about 300 years into the interglacial, and is marked by low (<c. 3 psu) salinities at the base of the Cyprina Clay that increased progressively. An abrupt and significant rise in the inflow of warm, saline waters from the North Sea occurred at about 750 years into the interglacial (theCorylusrise), and at about 1900 years into the interglacial, strongly stratified waters developed. Higher in the Cyprina Clay and continuing to its top, at nearly 3000 years into the interglacial, more open-marine waters are indicated, although fully marine conditions were not reached. The dinoflagellate record throughout the Cyprina Clay at Ristinge Klint is therefore one of increasing marine influence. Summer sea-surface temperatures approached, and may have exceeded, 26–28 °C during early Eemian time, indicating temperatures at least 5 °C warmer than at present. These warm conditions persisted to the top of the record at Ristinge Klint. No evidence exists at Ristinge Klint for the influence of Arctic watermasses, and the paucity of cold-water species throughout the section reflects mild winter temperatures in the southwestern Baltic Sea.The new speciesSpiniferites ristingensisis formally described, and the nameOperculodinium centrocarpumvar.cezarede Vernal, Goyette & Rodrigues, 1989 is validated.

scholarly journals Snowfall and Oxygen-Isotope Variations off the North Coast of Ellesmere Island, N.W.T., Canada

1987 ◽  
Vol 33 (114) ◽  
pp. 195-199 ◽  
Author(s):  
Martin O. Jeffries ◽  
H. Roy Krouse
Keyword(s):  
Arctic Ocean ◽  
High Arctic ◽  
Geographic Region ◽  
Ellesmere Island ◽  
The Arctic ◽  
North Coast ◽  
Snow Pack ◽  
The North ◽  
Winter Snow ◽  
The Mean

AbstractSnow-pack along the land-fast ice fringe off the north coast of Ellesmere Island was generally characterized by depth-hoar overlain by dense snow and wind slab. Mean snow depth in the study area was 0.54 m (1982-85) and the mean δ18O value of the snow-pack was -31.3˚/00. Isotope data were not obtained previously for this geographic region and, therefore, complement a previous study of δ18O variations in High Arctic snow (Koerner, 1979). The data are consistent with an Arctic Ocean moisture source. The δ18O profiles show seasonal variations, with winter snow being more depleted in 18O than fall and spring snow. However, the δ18O profiles are dominated by a trend to higher δ18O values with increasing depth. This is attributed to a decrease in δ18O values as condensation temperatures fall during the autumn-winter accumulation period. During this time, there is also a change from relatively open to almost complete ice cover in the Arctic Ocean. The change in evaporation conditions and consequent effect on δ values gives rise to a sharp discontinuity in the δ18O profiles and a bi-modal δ18O frequency distribution. The bi-modal distribution is reinforced by a secondary isotope fractionation that occurs during depth-hoar formation. This isotope effect leads to a wider δ18O range but does not significantly alter the mean δ18O value.

Plants of Subtropical Eastern Australia

2020 ◽  
Author(s):  
Andrew Benwell
Keyword(s):  
Plant Ecology ◽  
North Coast ◽  
Distinct Region ◽  
Rock Outcrops ◽  
The North ◽  
South Wales ◽  
Eastern Australia ◽  
Forest Wetlands ◽  
The Rich ◽  
Rich Flora

Plants of Subtropical Eastern Australia describes the rich flora of this biogeographically distinct region located on the east coast of Australia, covering the north coast of New South Wales and coastal South-East Queensland. This guide presents a selection of common, threatened and ecologically significant plants found in the region’s major vegetation habitats including rainforest, heathland, grassy forest, wetlands and rock outcrops. More than 500 plants are featured, with photographs and descriptive features enabling the reader to identify these species if encountered. Interesting biological, cultural and historical characteristics of each species are included, along with notes on the plant’s biogeography and a map of its distribution. Suitable for anyone with an interest in plant ecology and botany, Plants of Subtropical Eastern Australia is the definitive guide to this fascinating region of Australia and its unique flora.

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