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Full-Text Articles in Physical Sciences and Mathematics
Ordovician Continental Paleogeography And Paleoenvironment For The Michigan Basin From Paleomagnetic Analysis, Michelle Macrae
Ordovician Continental Paleogeography And Paleoenvironment For The Michigan Basin From Paleomagnetic Analysis, Michelle Macrae
Electronic Thesis and Dissertation Repository
This study investigates the paleomagnetic record of Paleozoic rocks from two Michigan basin localities in southwestern Ontario to help close the 40 myr gap in Paleozoic paleomagnetic data. Paleomagnetic data from the Queenston (Upper Ordovician) formation consistently exhibits easily removed viscous remanence, an intermediate and a high temperature component consistent with the unblocking temperatures of magnetite and hematite respectively. Alternating-field and thermal demagnetization in 16–20 steps up to 670º C typically reveal a southeastern, shallow up direction removed from magnetite, and a southwestern, steep up direction removed from hematite. A Late Paleozoic overprint was preserved in the magnetite and a …
Paleogeography Of Early Paleozoic Laurentia And Meguma, Avalonia Terranes Via Paleomagnetism And Faunal Review, Halima S. Warsame
Paleogeography Of Early Paleozoic Laurentia And Meguma, Avalonia Terranes Via Paleomagnetism And Faunal Review, Halima S. Warsame
Electronic Thesis and Dissertation Repository
Paleomagnetic assessment of 821 Cambrian to Silurian-aged rock specimens of igneous and sedimentary origin was used as a means to provide insight on the ancient geographies of the region in which these rocks are currently found. The Earth’s magnetic field direction can be recorded at the time of rock formation and/or at a later significant event by magnetic minerals, allowing these signatures to be used to track the past motions of the continents. Stepwise demagnetization of the Port au Port, St. George and Table Head Groups in western Newfoundland, and the Mavillette gabbro (426 +/- 2 Ma, U-Pb baddeleyite) of …
Allostratigraphy, Sedimentology And Paleogeography Of The Cretaceous Upper Fort St. John Group (Upper Albian-Lower Cenomanian) In Northeastern British Columbia, Piotr Jan Angiel
Allostratigraphy, Sedimentology And Paleogeography Of The Cretaceous Upper Fort St. John Group (Upper Albian-Lower Cenomanian) In Northeastern British Columbia, Piotr Jan Angiel
Electronic Thesis and Dissertation Repository
The upper Albian to lower Cenomanian succession in northeastern British Columbia was deposited in the proximal foredeep and is greatly vertically expanded relative to the more eastern part of the basin. The study interval has a wedge-shaped geometry, and is ~780 m thick in the west and thins dramatically to ~280 metres over a distance of ~170 km. Rapid facies changes result in lithostratigraphic units being strongly diachronous. In order to determine depositional history, the present study subdivided the Upper Fort St. John Group into 16 genetically-related allomembers. The new allostratigraphic correlations established in this thesis combined with previous studies, …