Rocks near continents(on the margins of oceanic basins) are generally older and rocks near a center of sea floor spreading are younger
Magnesium is used to support the theory of seafloor spreading because as new oceanic crust forms at mid-ocean ridges, it contains higher levels of magnesium compared to older crust. This can be observed through magnetic anomalies in the oceanic crust, where variations in magnesium content create distinct magnetic stripes that align with the spreading centers. This provides evidence that new crust is being continuously generated at mid-ocean ridges, supporting the process of seafloor spreading.
Spreading centers.
Spreading centers are geological formations where tectonic plates are moving away from each other, resulting in the upwelling of magma from the mantle and the formation of new oceanic crust. This process is known as seafloor spreading and occurs mainly along mid-ocean ridges, creating new oceanic crust and contributing to the Earth's tectonic activity.
Volcanoes at spreading centers is referred to as spreading center volcanism. This usually takes place on mid-oceanic ridges where the plates diverge.
1. New sea-floor is created by the upwelling of magma at mid-ocean spreading centers; old ocean floor is destroyed by subduction at deep sea trenches. 2. The area is a subduction zone. Magma from underground comes up and destroys that crust. That crust is then recycled and the magma cools and hardens. That creates new land, that creates the trenches. Seafloor spreading is in the ocean and happens with convection currents. That is the relationship between. 3. As new seafloor is formed at mid-ocean ridges, the old seafloor is pushed down into trenches at subduction zones.
It is the mid-ocean ridges.
At spreading centers.
Near the trenches, or in the seafloor furthest away from spreading centers.
Ocean crust is formed at seafloor spreading centers. One example of this is the Mid-Atlantic ridge.
Hydrothermal vents are found along seafloor spreading centers on the bottom of the oceans.
hydrothermal vents are found in the deep zone
Magnesium is used to support the theory of seafloor spreading because as new oceanic crust forms at mid-ocean ridges, it contains higher levels of magnesium compared to older crust. This can be observed through magnetic anomalies in the oceanic crust, where variations in magnesium content create distinct magnetic stripes that align with the spreading centers. This provides evidence that new crust is being continuously generated at mid-ocean ridges, supporting the process of seafloor spreading.
rate of spreading for stripe = width of stripe / time duration If a magnetic strips is 60 km wide and formed over 2 million years, then the rate at which spreading formed the was 30 km/m.y. The rate is equivalent to 3 cm/year. Spreading added an equal width of oceanic crust to a plate on the other side of the mid-ocean ridge, so the total rate of spreading across the ridge was 60 km/m.y. (6 cm/year), a typical rate of seafloor spreading.
Spreading centers.
Spreading centers are geological formations where tectonic plates are moving away from each other, resulting in the upwelling of magma from the mantle and the formation of new oceanic crust. This process is known as seafloor spreading and occurs mainly along mid-ocean ridges, creating new oceanic crust and contributing to the Earth's tectonic activity.
Paleomagnetic stripes on either side of mid-ocean ridges demonstrate the symmetric pattern of magnetic reversals found in oceanic crust, supporting the idea of seafloor spreading. Age dating of oceanic crust samples reveals that the further away from mid-ocean ridges, the older the crust gets, providing direct evidence for the continuous creation of new seafloor at spreading centers.
Volcanoes at spreading centers is referred to as spreading center volcanism. This usually takes place on mid-oceanic ridges where the plates diverge.