GLY 101LEC Lecture 6: GLY101LEC6
26 Sep 2018
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Document Summary
Lithosphere is the crust and the rigid upper part of mantle. Earth"s polarity of magnetic field has been constantly changing between north and south as shown by iron rich rocks. Aura is caused by electrons falling back in from the magnetic field. Amount of change from true north is magnetic declination. Magnetic inclination is the direction of the magnetic field lines or degree of the magnetic field lines. Magma/lava has magnetic minerals (magnetite) that align to the earth"s magnetic field. As iron rich rocks cool, the particles align to the magnetic field and become frozen in place. Igneous and sedimentary rocks can trap earth"s magnetic field. If the pole is fixed, the continents must drift. When the pole is fixed and the polar-wandering pattern/path is mapped, the continents go back to form pangea. The magnetic field would reverse about every 5 ma years. Possibly due to cooling or inner core disrupting the flow.
