What is the importance of Seafloor Spreading to the Theory of Plate Te
Where coal deposits have been found connect to other plates
Where new crust is created as plates move and pull apart
Where glacial deposits indicate it was oncé frozen
Where many fossils have been found on the sea floor
Seafloor spreading is crucial to the theory of plate tectonics for several reasons:
1. Formation of new crust: Seafloor spreading occurs at the mid-oceanic ridges, where magma rises and creates new oceanic crust. This process contributes to the continuous movement of the lithospheric plates and the expansion of the seafloor. It supports the concept of plate tectonics, as it explains how new crust is generated and pushes older crust away from the ridge.
2. Magnetic striping: As new crust forms at mid-oceanic ridges, it acquires the magnetic field of Earth at that time. Due to reversals in Earth's magnetic field throughout history, this creates a pattern of alternating magnetic stripes on the seafloor. This magnetic striping provides evidence for seafloor spreading and the movement of the plates.
3. Age of the seafloor: By analyzing the magnetic striping patterns, scientists can estimate the age of the seafloor. This has helped establish that the oceanic crust is younger compared to continental crust, supporting the idea that new crust is continuously formed at mid-oceanic ridges and spreads outward.
4. Fossil record: Seafloor spreading has led to the discovery of numerous fossils on the ocean floor. As the seafloor moves away from the mid-oceanic ridges, sediments, and fossils accumulate. By studying these fossils, scientists have gained insights into past marine life and the history of the Earth's oceans.
5. Oceanic trenches: Seafloor spreading is also responsible for the formation of oceanic trenches, where two plates converge and one is subducted beneath the other. This subduction process completes the plate tectonic cycle and contributes to the recycling of the Earth's crust.
In summary, seafloor spreading provides crucial evidence for the theory of plate tectonics. It demonstrates the continuous creation of new crust, the movement of plates, and the formation of various geological features and deposits on the seafloor.