EarthRef.org Digital Archive (ERDA) -- Illustration of Magnetic Anomalies Forming Along Mid-Ocean Ridge

Description
Step-by-step formation of oceanic crust. Three illustrations depict the formation of magnetic anomalies along a mid-ocean ridge. Over geologic time, two tectonic plates move in opposite directions from the oceanic ridge, and magma rises to the sea floor and solidifies, recording the reversed or normal magnetic field orientation. This creates the striped pattern on the ocean floor. Note that the stripes have irregular boundaries and that they are not perfectly linear due to irregular distribution of volcanism at mid-ocean ridges.

Instructions
Follow progression of seafloor formation from image (a) to image (c) and determine which image is the oldest and which image is the youngest representation.

Keywords
magnetic anomalies, magnetic anomaly, magnetic reversals, magnetic stripes, mid-ocean ridge, seafloor spreading, spreading center, magnetic field reversal, diverging plate boundary

Copyright Owner
Enduring Resources for Earth Science Education (ERESE)

Copyright Description
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