Earth’s Magnetic Field and
Archaean Plate Motion in the
Pilbara Craton
Alison Campion ‘16
Maloof Earth History Group
Advisor: Professor Adam Maloof
Pilbara Craton
~2.7Ga
How would a hotter Archaean mantle affect plate tectonics?
Rifting
Zone
Convection
Currents
Mantle
Test hypotheses in the field!
Pangea
The Record of Earth’s Magnetic Field
Earth’s magnetic field is induced by convective
Lava flows out of volcanoes and
currents in the liquid outer core.
cools to form basalt, an iron-rich
Igneous rock.
Iron oxide minerals in the basalt
(such as magnetite) record the
direction of Earth’s magnetic
field at the time of cooling.
Correlate paleopole to paleolatitude using simple trigonometry
Sampling
Drilled cores to measure the magnetic field
Stratigraphic Section
Tuff
Cores indicating
magnetic field
Basaltic Flow 4
Basaltic Flow 3
Tuff
Basaltic Flow 2
Basaltic Flow 1
U-Pb Isotope
dating
Δ Geographical
Latitude
Δ Date of
Formation
=
Rate of Plate
Motion
The Team
Adam Maloof
Associate Professor
Earth History
Blair Schoene
Assistant Professor
Geochronology
Jenn Kasbohm
First Year
Graduate Student
Scott Maclennan
First Year
Graduate Student