CGRG Bibliography of Canadian Geomorphology
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Author : Froese, D.G.; Westgate, J.A.; Barendregt, R.W.; Villeneuve, M.; Jackson, L.E.; Baker, J.; Enkin, R.; Irving, E.; Hart, C.; Preece, S.J.; and Sandhu, A.
Date : 2001.
Title : Normal magnetization at ca. 1.5 Ma at three sites in Yukon Territory, Canada: The Gilsa Sub-chron?
Publication : AGU 2001 Fall Meeting, Moscone Centre, San Franciso, California, December 10-14, 2001.
Issue :
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Abstract
Normally magnetized sediment is associated with Fort Selkirk and Paradise Hill tephras in central Yukon Territory. The Fort Selkirk tephra, sourced in the Wrangell Mountains of southeastern Alaska, is dated by the isothermal plateau fission track method (ITPFT) at 1.48 +/- 0.11 Ma. Fort Selkirk tephra is reversely magnetized, however a normal polarity interval occurs between the tephra and an overlying reversely magnetized basalt flow, dated by the Ar-Ar method, at 1.37 +/- 0.03 Ma. This succession is found at two sites in the Fort Selkirk area. At Paradise Hill, 120 km to the northwest, the Paradise Hill tephra, also sourced in the Wrangell Mountains of southeastern Alaska, has an ITPFT age of 1.54 +/- 0.13 Ma and is normally magnetized. The Paradise Hill and Fort Selkirk normal polarity intervals are certainly older than the Jaramillo (1.07-0.99 Ma) and Cobb Mountain (1.24-1.21 Ma) sub-chrons, and younger than the Olduvai (1.95-1.77 Ma). Our age estimates for this normal interval indicate a more plausible correlation to the Gilsa sub-chron estimated at 1.55 Ma from marine records and 1.6 Ma from Icelandic lavas.
Bibliography of Canadian Geomorphology