Dr. Joseph Hodych: Did Earth's entire crust and mantle rotate ~90⁰ back and forth about an equatorial axis in the mid-Ediacaran? A test from Avalonia in Newfoundland
EARTH SCIENCE SEMINAR SERIES PRESENTS:
Dr. Joseph Hodych, Professor Emeritus, Memorial University
Thursday, November 20, 12-1 pm in room 4065
Did Earth's entire crust and mantle rotate ~90⁰ back and forth about an equatorial axis in the mid-Ediacaran? A test from Avalonia in Newfoundland.
Ediacaran paleogeography is controversial due to conflicting paleomagnetic data. This is most clearly seen in Laurentia where some paleomagnetic data suggest that Laurentia remained near the equator throughout the Ediacaran. Other paleomagnetic data suggest that Laurentia moved from equator to south pole between ~ 610 and ~ 585 Ma and back to the equator by ~ 565 Ma. This led to the popular hypothesis of extreme true polar wander in the mid Ediacaran, with Earth's entire crust and mantle rotating ~90⁰ back and forth about an equatorial axis. To help test this hypothesis, we studied the paleomagnetism of ~606 Ma volcanics near Colliers on the Avalon Peninsula and compared this with other Ediacaran paleomagnetic data from Avalonia in Newfoundland. We show that the Newfoundland data do not support the extreme true polar wander hypothesis. Apparent paleomagnetic support for extreme true polar wander is likely an artifact of Earth’s field being ~10x weaker than at present in the mid Ediacaran.
EARTH SCIENCE SEMINAR SERIES PRESENTS:
Dr. Joseph Hodych, Professor Emeritus, Memorial University
Thursday, November 20, 12-1 pm in room 4065
Location: Earth Sciences Building ER-4065
Date and Time: Thursday, Nov. 20 at 12:00 PM - 01:00 PM (NST)