Paleogeography of Early Paleozoic Laurentia and Meguma, Avalonia terranes via paleomagnetism and faunal review

• Main Author: Warsame, Halima S
• Format: Text
• Language: English
• Published: Scholarship@Western 2017
• Subjects: paleomagnetism; paleogeography; Laurentia; Meguma; Avalonia; Geology; Paleobiology; Tectonics and Structure; Table Head; Newfoundland
• Online Access: https://ir.lib.uwo.ca/etd/5080; https://ir.lib.uwo.ca/context/etd/article/6891/viewcontent/Warsame__H.S._MSc_Thesis___final_submission.pdf

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 southwestern Nova Scotia has revealed an overprint magnetization (D=161º, I=4º; D=155º, I=8º) that was acquired when Laurentia and the accreted Meguma terrane were near the equator during the Mid-to-Late Paleozoic. The effects of the Alleghenian orogeny may have been responsible for a significant overprint event during the Carboniferous that resulted in remagnetization of these rocks.