• Earth is a large magnet probably because of convective motions in the outer core
• Declination - angle east or west between geographic north pole and magnetic north pole
• Inclination - angle between dip of magnetic field and earth’s surface

• Thermoremanent magnetization -
• Permanent magnetization acquired by igneous rocks after cooling below Curie point (~580°C) (Rocks become magnetized!)
• Measure with a magnetometer

• Earth’s magnetic field flip-flops at a frequency of 10⁵ to 10⁶ years (Fig 19.14)
• Recorded in the magnetization of rocks

• Paleolatitude
• Inclination used to determine paleolatitude and paleopole position
• Movement of continents only explanation for different pole positions (polar wandering curves) obtained from different continents (Fig. 19.11)

• Magnetic stratigraphy
• Basalts formed during geomagnetic reversals retain that unusual signature-- magnetic anomaly
• Method of correlation¹ of basalts - correlate normal and reverse polarity in rocks (Fig. 19.13, 19.14)
• Correlate undated basalts to basalts dated with radioactive age dating techniques

¹Correlation - correspondence between two comparable entities