Theory Of Sea Floor Spreading
Convection current theory convection current theory is the soul of seafloor spreading theory.
Theory of sea floor spreading. Supporters of continental drift originally theorized that the continents moved drifted through unmoving oceans. As upwelling of magma continues the plates continue to diverge a process known as seafloor spreading samples collected from the ocean floor show that the age of oceanic crust increases with distance from the spreading centre important evidence in favour of this process. The age of different rocks on earth s surface e. The theory of seafloor spreading.
The motivating force for seafloor spreading ridges is tectonic plate slab pull at subduction zones rather than magma pressure although there is typically. Seafloor spreading proves that the ocean itself is a site of tectonic activity. Seafloor spreading is a geologic process where there is a gradual addition of new oceanic crust in the ocean floor through a volcanic activity while moving the older rocks away from the mid oceanic ridge. Sea floor spreading theory.
This idea played a pivotal role in the development of the theory of plate tectonics which revolutionized geologic thought during the last quarter of the 20th century. Seafloor spreading disproves an early part of the theory of continental drift. When oceanic plates diverge tensional stress causes fractures to occur in the lithosphere. As per seafloor spreading theory the mid oceanic ridge is the region where at the crest of oceanic ridges through the rupture of the oceanic crust and the crack continuous new lava eruption thrusts into it consequently pushing the oceanic crust on either side.
The plates on either side of the. Hess its major tenets gave great support to the theory of continental drift continental drift geological theory that the relative positions of the continents on the earth s surface have. Check all that apply. Seafloor spreading theory of lithospheric evolution that holds that the ocean floors are spreading outward from vast underwater ridges.
These cornerstones are convectional current theory and paleomagnetism. According to hess s theory what might happen if the magma under a mid ocean ridge cools. Seafloor spreading theory that oceanic crust forms along submarine mountain zones known collectively as the mid ocean ridge system and spreads out laterally away from them. In 1912 when alfred wegener proposed that the continents had once been joined together and had split apart the biggest weakness in his hypothesis was the.
The direction iron in ocean rocks points d. To understand the concept of seafloor spreading we must first understand some basic concepts that form the cornerstones for the concept of seafloor spreading. Pillow shaped rocks found in the sea. These age data also allow the rate of seafloor spreading to be determined and they show that rates.
What evidence supports hess s theory of seafloor spreading. First proposed in the early 1960s by the american geologist harry h.