scholarly journals Macrofossils from a Late-Glacial Deposit at Cambridge, Massachusetts

1962 ◽  
Vol 67 (1) ◽  
pp. 106 ◽  
Author(s):  
George W. Argus ◽  
Margaret B. Davis
Keyword(s):  
Late Glacial ◽  
Glacial Deposit

CONTRIBUTIONS TO THE HOLOCENE PALEOECOLOGY OF WESTCENTRAL CANADA: A LATE-GLACIAL DEPOSIT FROM THE MISSOURI COTEAU

1964 ◽  
Vol 42 (6) ◽  
pp. 677-692 ◽  
Author(s):  
J. C. Ritchie ◽  
Bernard de Vries
Keyword(s):  
Great Plains ◽  
Late Glacial ◽  
Pollen Spectrum ◽  
Pollen Diagram ◽  
Glacial Deposit ◽  
Carbon 14 ◽  
Missouri Coteau ◽  
Plant Assemblages ◽  
Mixed Prairie ◽  
Artemisia Pollen

A buried deposit of limnic sediment was excavated from a site on the Missouri Coteau of Saskatchewan, within the Mixed Prairie section of the Great Plains. Carbon-14 determinations indicate that the section is late-glacial, possibly deposited during an interstadial terminated by the Condie (= Valders?) re-advance. On the basis of the records of about 60 taxa of Tracheophyta and a pollen diagram, the section is characterized by lower, middle, and upper plant assemblages. It is suggested that the lower and upper assemblages, distinguished mainly by a Picea – Shepherdia canadensis – Salix – Artemisia pollen spectrum, indicate the prevalence on mesic sites of a spruce forest. The middle assemblage, having an array of macrofossils and a few microfossils of temperate geographical affinity and a pollen spectrum suggesting relatively less spruce and (or) more herbaceous vegetation, is interpreted in terms of a mixed spruce–poplar forest on mesic sites with shrub and grassland communities on the more xeric habitats. This tripartite division of the section in terms of ecologically concordant plant assemblages suggests an amelioration of environment followed by a deterioration which was probably correlative with the Condie re-advance.

BRYOPHYTE SUBFOSSILS OF A LATE-GLACIAL DEPOSIT FROM THE MISSOURI COTEAU, SASKATCHEWAN

1965 ◽  
Vol 43 (8) ◽  
pp. 947-953 ◽  
Author(s):  
B. de Vries ◽  
C. D. Bird
Keyword(s):  
Boreal Forest ◽  
Higher Plants ◽  
Late Glacial ◽  
Organic Layer ◽  
Middle Zone ◽  
Higher Plant ◽  
Glacial Deposit ◽  
Boreal Species ◽  
The North ◽  
Missouri Coteau

Bryophyte and associated macro-subfossils were recovered from a kettle located in prairie southwest of Moose Jaw in the Missouri Coteau of southern Saskatchewan. The higher plants were discussed in an earlier paper.Three samples taken from the organic layer gave C14 datings ranging from 11,650 ± 150 to 10,270 ± 150 B.P.Sixteen species and one variety of Musci were recovered. Eleven of these were found in the lowermost zone at a depth of 510–450 cm. This zone was composed of bryophytes and higher plants characteristic of a modern Picea forest. Fifteen bryophyte taxa were recovered from the middle zone at a depth of 450–290 cm. The macro-subfossils in this zone are typical of a present-day Populus–Picea forest. No bryophytes were found in the upper layer, 290–280 cm characterized by higher plant macro-subfossils and pollen typical of a modern Picea forest.All bryophytes recovered belong to present-day taxa; however, many of the boreal species are not now found in the region as the southern margin of the boreal forest is now 200 miles to the north.

On the extent of the Last Glaciation in eastern England

1959 ◽  
Vol 150 (939) ◽  
pp. 263-282 ◽  
Keyword(s):  
Pollen Analysis ◽  
Age Determination ◽  
Carbonaceous Material ◽  
Late Glacial ◽  
Glacial Deposit ◽  
Southern Limit ◽  
Radiocarbon Age ◽  
Last Glaciation ◽  
Boulder Clay

From pollen analysis of a Late-glacial deposit in east Lincolnshire, it is inferred that the earliest sedimentation in a depression in boulder clay immediately followed melting of the ice. Radiocarbon age determination confirms the Late-glacial age. The boulder clay is the Hessle Boulder Clay of Lincolnshire, and the correlation of this with the Hessle Boulder Clay of Holderness and with the Hunstanton Brown Boulder Clay of north Norfolk is accepted. The evidence from the Late-glacial site, from the stratigraphical position of the boulder clay, and from the topographical form of the boulder clay, all point to the Last Glaciation ice having extended south of the Humber as far as north Norfolk, with a lobe pushing into the Wash. This conclusion reasserts the traditional southern limit of Last Glaciation ice in eastern England, on which doubt had recently been cast by various authors on topo­graphical inference alone. The pollen analysis has been made more accurate by the introduction of a method of correcting for derived pollen, using derived Carboniferous and Mesozoic spores as a control. Significant errors in the radiocarbon age determination are shown to be caused even in peat by derived carbonaceous material from the boulder clay.

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