Comparison of Continental Drift Theory, Seafloor Spreading and Plate Tectonics
| Criteria | Continental Drift | Seafloor Spreading | Plate Tectonics |
|---|---|---|---|
| Proposed by | Alfred Wegener in 1912 | Harry Hess in the 1960s | D.P. McKenzie, R.L. Parker, W.C. Morgan, and X. Le Pichon in 1967-1968 |
| Theory | Suggests that continents are in motion | Explains the movement of oceanic plates due to seafloor spreading | States that Earth’s lithospheric plates, both continental and oceanic, move horizontally |
| Driving Forces | Gravity and tidal currents | Convection currents within Earth’s mantle | Convection currents within Earth’s mantle |
| Evidence | – Jigsaw Fit: Coastlines of South America and Africa align perfectly. – Fossil Evidence: Similar fossils like Cynognathus found in Argentina and South Africa. – Paleoclimatic Evidence: Presence of coal deposits in mid-latitude regions such as North America, Europe, and China. – Tillite Deposits: Found across Gondwana regions like Africa, Antarctica, India, Australia, and more. – Geological Evidence: Similar rock formations of the same age on opposite Atlantic coasts. |
– Geology of the Ocean Floor: The seafloor features ridges, peaks, and active volcanic regions. – Age of Rocks: Younger rocks found along the Mid-Atlantic Ridge, older ones further away. – Thickness of Sediments: Sediment layers increase in thickness with distance from mid-oceanic ridges. – Paleomagnetism: Magnetic reversal patterns recorded in rocks on either side of the ridge. |
– Polar Wandering: Changes in magnetic pole positions over time. – Paleomagnetism: Polar reversals recorded in solidified rocks. – Distribution of Earthquakes and Volcanoes: Correlation with plate boundaries. |
| Significance | Laid the groundwork for the concept of seafloor spreading | Formed the basis for the theory of plate tectonics | Explains geomorphic processes, as well as the distribution of earthquakes and volcanic activity |
|
||||||||||
