Formations of igneous rocks ГС
Part 5: Hot-spots and Absolute Movement Rates
The Gandalf Islands are analogous to the Hawaiian Islands on Earth. They form a linear chain that originated by the
migration of the plate over a mantle hot spot. Mantle hot spots have a fixed location.
All of the Gandalf islands are volcanic in origin but the easternmost and largest island, which is currently sitting over the
hot spot, is the only one with active volcanoes on it. The rocks on the westernmost island have been dated by radiometric
methods at 32 m. y..
16) Measure the distance between the centers of the westernmost and easternmost Gandalf islands and use this
information to calculate the absolute movement rate (in mm/y) of the Aragorn Ocean (and the Bilbo Continent,
which is connected to it). Show your equations and explain where you got each of your numbers.
Helpful Hint: As you are measuring absolute plate motion, pay no attention to the magnetic anomalies
when answering this question.