Migration and Environmental Change in North America (USA and Canada)

2013 ◽  
pp. 135-153
Author(s):  
Susana B. Adamo ◽  
Alexander M. de Sherbinin
Keyword(s):  
North America ◽  
Environmental Change

Diachronic variation in insectivores from Cheek Bend Cave and environmental change in the Midsouth

Paleobiology ◽  
1982 ◽  
Vol 8 (4) ◽  
pp. 447-458 ◽  
Author(s):  
Walter E. Klippel ◽  
Paul W. Parmalee
Keyword(s):  
North America ◽  
Environmental Change ◽  
Relative Frequency ◽  
Marked Decrease ◽  
Eastern North America ◽  
Faunal Assemblages ◽  
Holocene Climatic Optimum ◽  
Equable Climate ◽  
Frequency Changes ◽  
Cave Deposit

Diachronic variation in insectivore remains from a deeply stratified cave deposit in southeastern North America is described. The paleobotanical record for the region is congruent with variation in the soricid (shrew) and talpid (mole) faunal assemblages. Both faunal and floral records reflect considerable climatic change since the full Wisconsinan in this unglaciated portion of eastern North America. Variations in the insectivore assemblages indicate the presence of a more equable climate during the late Pleistocene. Continental climates ushered in at the end of the Pleistocene resulted in a marked decrease in insectivore diversity. Relative frequency changes in taxa throughout the Holocene reflect the mid-Holocene Climatic Optimum.

Holocene Environmental Change on the Great Plains of North America

2000 ◽  
Vol 67 (1) ◽  
pp. 1-3
Author(s):  
Stephen Wolfe ◽  
Glenn Goodfriend ◽  
Richard Baker
Keyword(s):  
North America ◽  
Environmental Change ◽  
Great Plains ◽  
Holocene Environmental Change

The Limnology and Fishes of Oligotrophic Glacial Lakes in North America (about 1800 A.D.)

1972 ◽  
Vol 29 (6) ◽  
pp. 617-628 ◽  
Author(s):  
R. A. Ryder
Keyword(s):  
North America ◽  
Adverse Effects ◽  
Species Composition ◽  
Environmental Change ◽  
Growing Season ◽  
Fish Populations ◽  
Chemical Characteristics ◽  
General Description ◽  
Glacial History ◽  
Physical And Chemical

The general limnology and fish composition of 14 North American oligotrophic lakes is described as it likely was about the year 1800, prior to the adverse effects of man-made eutrophication, exploitation, and introductions of exotic species. The general description includes glacial history and geomorphology, climate and growing season, morphometry of the lake basins, physical and chemical characteristics, macroinvertebrates, and zooplankton. Fish populations are described with respect to their zoogeographic origins and the species composition of each lake. The relative degree of environmental change brought about by the activities of man in each lake is summarized.

scholarly journals Carbon isotopes, stratigraphy, and environmental change: the Middle–Upper Cambrian Positive Excursion (SPICE) in Port au Port Group, western Newfoundland, Canada

2018 ◽  
Vol 55 (11) ◽  
pp. 1209-1222 ◽  
Author(s):  
Rosalia Barili ◽  
Joyce Elaine Neilson ◽  
Alexander Thomas Brasier ◽  
Karin Goldberg ◽  
Tatiana Pastro Bardola ◽  
...  
Keyword(s):  
North America ◽  
Environmental Change ◽  
Carbon Isotope ◽  
Carbon Isotopes ◽  
Carbonate Rocks ◽  
Isotopic Signature ◽  
Upper Cambrian ◽  
Carbon Isotopic ◽  
Carbon Isotope Excursion ◽  
Diagenetic Environment

In many basins, Upper Cambrian carbonate successions display intervals with a positive carbon isotope excursion (CIE) of up to +5‰. In North America, this marks the boundary between the Sauk II–III super-sequences. A Steptoean positive carbon isotope excursion (SPICE) locality previously identified in the Port au Port peninsula, western Newfoundland, has been revisited and an additional potential SPICE locality found. In both locations, a CIE is found to be associated with a prominent bioherm and sandstone layer within a sequence of carbonate rocks. At March Point columnar stromatolites occur, whereas at Felix Cove thrombolites can be seen. In the latter, the sandstone immediately overlies the thrombolites coincident with the CIE, whereas at March Point a dolomitized grainstone occurs above the stromatolites. The sandstone at this locality post-dates the CIE. Although lower than the SPICE in some localities, a positive CIE is present in both sections: March Point (+1.1‰) and Felix Cove (+1.8‰). Additionally, δ13Corg rises from −30.0‰ to −22.0‰ at March Point and from −27‰ to −24.0‰ at Felix Cove and, in accordance with previously published work, we suggest that this could be the SPICE. Comparison of the stratigraphy and petrography between the two localities suggest that both depositional and diagenetic factors could have influenced the nature of the interpreted SPICE in Newfoundland. It is also possible that the local carbon isotopic signature may have been influenced by a semi-restricted depositional and early diagenetic environment related to the paleogeographic configuration rather than the global marine excursion.

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