Studies of Glacial History in Arctic Canada. II. Interglacial Peat Deposits on Bathurst Island

1974 ◽  
Vol 11 (8) ◽  
pp. 1025-1042 ◽  
Author(s):  
Weston Blake Jr.
Keyword(s):  
Vascular Plants ◽  
Organic Materials ◽  
Climatic Conditions ◽  
Glacial History ◽  
Organic Layers ◽  
Radiocarbon Age ◽  
Peat Deposits ◽  
Organic Deposits ◽  
Age Determinations

Sixteen radiocarbon age determinations on peat deposits and buried organic layers at 10 localities within the Queen Elizabeth Islands have resulted in ages between >30 000 and >51 000 years. Similar results have been obtained from the southern Arctic islands, and as yet only one meaningful finite date in the 50 000 to 25 000 year-range has resulted from the dating of driftwood or in situ terrestrial organic materials in the entire archipelago.On Bathurst Island, where two dates of >50 000 years have been obtained, evidence from the assemblages of mosses, vascular plants, and insects in peat and organic layers indicates that climatic conditions were somewhat more favorable than at present when these deposits were forming. The available data are such that all deposits cannot necessarily be related to the same non-glacial interval, but the extensive deposits along the Stuart River are hereby assigned to the Stuart River Interglaciation.The lack of organic materials dating between 50 000 and 25 000 years in the Queen Elizabeth Islands may be because: (1) the area was ice-covered throughout Wisconsin time; (2) any mid-Wisconsin non-glacial interval was too short or had too severe a climate for deposits to accumulate; (3) organic deposits relating to this interval have been eroded; or (4) deposits of this age do exist but they have not been collected.

Radiocarbon Age of Soils in Oases of East Antarctica

Radiocarbon ◽  
2016 ◽  
Vol 59 (2) ◽  
pp. 489-503 ◽  
Author(s):  
E Zazovskaya ◽  
N Mergelov ◽  
V Shishkov ◽  
A Dolgikh ◽  
V Miamin ◽  
...  
Keyword(s):  
Organic Matter ◽  
Vascular Plants ◽  
High Arctic ◽  
Climatic Conditions ◽  
East Antarctica ◽  
Radiocarbon Age ◽  
Antarctic Soils ◽  
Larsemann Hills ◽  
Arctic Soils ◽  
Organic Horizons

AbstractThis article discusses radiocarbon dating results for soils and soil-like systems in the East Antarctic oases, including Schirmacher, Thala Hills, and Larsemann Hills. The organic matter of endolithic and hypolithic systems, soils of wind shelters, and soils under moss-algae vegetation were dated along with micro- and macroprofiles. Organic matter pools formed under extreme climatic conditions and originated not from vascular plants but from cryptogamic organisms, and photoautotrophic microbes have been identified within the oases of the East Antarctica. The organic matter of the most of East Antarctic soils is young and cannot reach a steady state because of the high dynamism in the soil cover due to active erosion. The oldest soil organic matter in East Antarctica was found in the soils formed in wind shelters and endolithic soil-like systems under the protection of consolidated rock surfaces. According to our data, the maximal duration for the formation of organic matter profiles within the oases of East Antarctica is ~500 yr, which is similar to the age determined for High Arctic soils in Eurasia. The absence of older soils, comparable with the Holocene deglaciation, can be due to the extreme conditions resulting in occasional catastrophic events that destroyed the soil organic horizons.

CONSTRAINING GLACIAL HISTORY AND PROCESS ON MOUNT MANSFIELD, VERMONT'S HIGHEST PEAK, WITH IN SITU COSMOGENIC 10BE AND 14C

2018 ◽  
Author(s):  
Lee B. Corbett ◽  
◽  
Paul R. Bierman ◽  
Jeremy D. Shakun ◽  
P. Thompson Davis ◽  
...  
Keyword(s):  
Glacial History ◽  
Cosmogenic 10Be

scholarly journals In situ elastic modulus measurements of ultrathin protein-rich organic layers in biosilica: towards deeper understanding of superior resistance to fracture of biocomposites

RSC Advances ◽  
2013 ◽  
Vol 3 (17) ◽  
pp. 5798 ◽  
Author(s):  
Igor Zlotnikov ◽  
Doron Shilo ◽  
Yannicke Dauphin ◽  
Horst Blumtritt ◽  
Peter Werner ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Organic Layers ◽  
Protein Rich

scholarly journals C14 dating of Survey material performed in 1974

1975 ◽  
Vol 75 ◽  
pp. 19-20
Author(s):  
A Weidick
Keyword(s):  
New Jersey ◽  
Wood Sample ◽  
Field Work ◽  
Plant Anatomy ◽  
Radiocarbon Age ◽  
Apparent Age ◽  
Age Determinations

Thirteen radiocarbon age determinations of shell samples (12) and wood (1) are assembled in tbis account. The material dated was collected in connection with GGU field work. The samples have been dated at Isotopes Inc., Westwood, New Jersey, U.S.A. Determination of the wood sample was kindly made by Jette Dahl Møller, Institute of Plant Anatomy and Cytology, University of Copenhagen. Dating has also been carried out on a number of shelIs, dredged alive prior to 1950, in order to control the apparent age in shell dating determinations (Tauber & Funder, tbis report).

Plant and Insect Remains from the Wisconsinan Interstadial/Stadial Transition at Wedron, North-Central Illinois

1990 ◽  
Vol 33 (3) ◽  
pp. 387-399 ◽  
Author(s):  
Clarke E. Garry ◽  
Donald P. Schwert ◽  
Richard G. Baker ◽  
Tim J. Kemmis ◽  
Diana G. Horton ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Ground Beetle ◽  
Plant Macrofossils ◽  
Climatic Conditions ◽  
Silica Sand ◽  
Insect Fauna ◽  
Vaccinium Uliginosum ◽  
Radiocarbon Age ◽  
Late Wisconsinan ◽  
Central Illinois

AbstractOrganic material exposed within a small swale fill in Pit 6 of the Wedron Silica Sand Co. near Wedron in LaSalle County, Illinois, includes well-preserved pollen, plant macrofossils, and insect remains. This material occurs in slackwater sediment in the lower part of the Peddicord Formation, which was deposited as existing valleys were dammed by fluvial aggradation during the initial late Wisconsinan advance of Laurentide ice into the Wedron area. Wood from the organic horizon has a radiocarbon age of 21,460 ± 470 yr B.P. (ISGS-1486). The pollen spectrum is dominated byPicea, Pinus, and Cyperaceae. Plant macrofossils comprise a mix of boreal-forest taxa, includingPicea, Larix laricina, and the mossCampylium stellatum; subarctic species includingBetula glandulosa, Empetrum nigrum, andSelaginella selaginoides; along with the predominantly arcticVaccinium uliginosumvar.alpinum, Dryas integrifolia, andRhododendron lapponicum. The insect fauna contains the western montane ground beetleOpisthius richardsoni; several arctic-subarctic ground beetles includingDiacheila polita, Helophorus sibiricus, andPterostichus (Cryobius) caribou; and a diverse assemblage of insects that today inhabit the boreal forest. We interpret the biotic record to record a phase in the transition from closed boreal forest to open tundra as climatic conditions deteriorated in advance of continental glaciation.

Distillation in a boreal mossy forest floor

2003 ◽  
Vol 33 (4) ◽  
pp. 663-671 ◽  
Author(s):  
T J Carleton ◽  
K M.M Dunham
Keyword(s):  
Boreal Forests ◽  
Forest Floor ◽  
Growing Season ◽  
Mass Gain ◽  
Dew Point ◽  
Organic Layers ◽  
Dry Down ◽  
Microclimate Monitoring ◽  
Capillary Wicking

The feathermoss-dominated floor of coniferous boreal forests can experience midsummer drought. From ecophysiological studies, based on single shoots, it is unclear how the live moss carpet can survive such stress. External capillary wicking from the lowest, moist organic layers is one possibility. Another is evaporation from the same source followed by condensation on the upper, live moss shoots (distillation). A laboratory wicking experiment showed that, under ideal conditions, much of the organic forest floor profile can be supplied with moisture by capillarity from below. However, the uppermost live moss shoots could not be hydrated by this mechanism. In contrast, a gravimetric field experiment indicated nocturnal mass gain by turves of live moss shoots, placed in situ on the forest floor, during dry-down conditions. For turf treatments with an underlying vapour barrier, no such mass gain was evident. Turf treatments with a vapour barrier on top were little different from controls. It is concluded that nocturnal distillation occurs during all summer dry-downs and that this is likely to ensure moss shoot survival during diurnal periods of drought stress. Limited microclimate monitoring indicated that nocturnal cooling at the forest floor surface was sufficient to bring the moss shoot surfaces to the dew point and to reverse the daytime temperature gradient through the organic forest floor profile. This appears to be most noticeable late in the growing season when the lowermost organic layers have progressively warmed throughout the summer.

Is it possible to determine formation processes of organic deposits through polysaccharides? Pilot study from the prehistoric site in Brandýs nad Labem, Czech Republic

The Holocene ◽  
2017 ◽  
Vol 27 (9) ◽  
pp. 1273-1280
Author(s):  
Klement Rejšek ◽  
Jan Turek ◽  
Valerie Vranová ◽  
Roman Hadacz ◽  
Lenka Lisá
Keyword(s):  
Czech Republic ◽  
Pilot Study ◽  
Organic Material ◽  
Archaeological Site ◽  
Soil Samples ◽  
Formation Processes ◽  
Cultural Layer ◽  
Different Types ◽  
Organic Deposits

This paper deals with a possible interpretation value of biochemical methods in comparison with the classic tools of geoarchaeology for the evaluation of formation processes. Organic rich layers from the archaeological site Brandýs nad Labem-Vrábí were tested with the aim to determine the origin of several different types of soil organic material by analyzing the content of different sugars. The studied soil body showed signs of cultural layer, redeposited soils, and in situ developed soil. The analysis of different sugars was highlighted: soil samples taken from these layers were analyzed to assess the ratios of mannose + galactose to arabinose + xylose, and of rhamnose + fucose to arabinose + xylose, content of Corg and different nitrates, as well as different rates of absorbance. The results show that the interpretation values of polysaccharides evaluation didn’t bring significant results itself, but in combination with classical tools of geoarchaeology may bring interpretable and new results.

Influence of maturity stage on in situ dry matter degradability of six maize varieties in fistulated sheep

2001 ◽  
Vol 2001 ◽  
pp. 89-89
Author(s):  
M. A. Akbar ◽  
P. Lebzien ◽  
G. Flachowsky
Keyword(s):  
Dry Matter ◽  
Nutritive Value ◽  
Climatic Conditions ◽  
Maturity Stage ◽  
Factors Affecting ◽  
Maize Varieties ◽  
Feed Value ◽  
Two Stages

The fresh weight, dry matter (DM) contents and nutritional quality in maize vary considerably with variation in varieties, stages at which harvested, climatic conditions and agronomic factors. Recently, agronomists, nutritionists, and dairy producers have placed increased emphasis on factors affecting the nutritive value of maize. However, very little information is available on quantitative variability of the feed value of maize fodder as affected by such factors. This study was, therefore, carried out to assess the effect of harvesting of six different maize varieties at two stages (dates) of grain maturity on quality of both the stover and cobs.

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