Quaternary Environments in Canada as Documented by Paleobotanical Case Histories
T.W. Anderson, M. Boyko-Diakonow, R.W. Mathewes, J.V. Matthews, Jr., J.H. McAndrews, R.J. Mott, P.J.H. Richard, J.C. Ritchie, C.E. Schweger, 1989. "Quaternary Environments in Canada as Documented by Paleobotanical Case Histories", Quaternary Geology of Canada and Greenland, R.J. Fulton
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This chapter is concerned with the scope and significance of paleoecology-related studies, particularly their application in reconstructing Quaternary environments in Canada, with special reference to seven paleobotanical case histories. Though pollen stratigraphy is the principal evidence that is common to each case history, other important paleoecological data (plant macrofossils, insects and other arthropods, ostracodes, molluscs, diatoms, tree rings, vertebrate and invertebrate fossils) and nonpaleoecological indicators (soil profiles, fire history, historical records) and their relevance to paleoenvironmental research are not overlooked.
The first two case histories present evidence for glacial refugia. Fossil occurrences supported by geological mapping on Queen Charlotte Islands, British Columbia indicate the presence of ice-free areas which possibly served as refugia for certain elements of the biota during the Late Wisconsinan maximum. Similar studies focus on the unglaciated parts of Yukon Territory and the ice-free corridor which is presumed to have existed along parts of the Rocky Mountain Foothills during the Late Wisconsinan maximum. Even though the portal areas to the north and south of the ice-free corridor have certain pre-Wisconsinan fossils in common, the corridor itself lacks critical evidence to indicate that it may have served as a north-south dispersal route.
Records from about twenty buried organic deposits in Atlantic Canada delineate the Late Pleistocene sequence of events and environments there. The Sangamon Interglaciation was characterized by at least three climatic episodes which can be correlated provisionally with the stratigraphic framework for the region and with the deep sea oxygen isotope record.
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The three major sections of this volume include six chapters describing the regional Quaternary geology of Canada, two describing the Quaternary geology and climatic history of Greenland, and six that review applied Quaternary geology in Canada, including chapters on paleobotanical analysis, geodynamics, geomorphic processes, terrain geochemistry, Quaternary resources, and the influence of the Quaternary on the present environment. Of the five accompanying plates, three depict eleven stages of Quaternary paleogeographic change between 18,000 B.P. and 5,000 B.P.; one depicts the retreat of the ice from between 18,000 B.P. and the Recent; and another reviews the status of Quaternary geologic mapping in Canada, with an extensive bibliography on the back.