Table of Contents
Where do molten materials from the mantle rise during the process of sea floor spreading?
As two tectonic plates slowly separate, molten material rises up from within the mantle to fill the opening. In this way the rugged volcanic landscape of a mid-ocean ridge is created along the plate boundary.
What is molten material in seafloor spreading?
The Process of Sea Floor Spreading The oceanic crust is composed of rocks that move away from the ridge as new crust is being formed. The formation of the new crust is due to the rising of the molten material (magma) from the mantle by convection current.
How does molten rock cause the sea floor spread?
Seafloor Spreading at Mid-Ocean Ridges. Convection currents drive the movement of Earth’s rigid tectonic plates in the planet’s fluid molten mantle. Hot magma rises to the crust’s surface, cracks develop in the ocean floor, and the magma pushes up and out to form mid-ocean ridges.
Where do the molten materials emerge?
Magma originates in the lower part of the Earth’s crust and in the upper portion of the mantle. Most of the mantle and crust are solid, so the presence of magma is crucial to understanding the geology and morphology of the mantle.
Why does partly molten material rises toward Earth’s surface?
Some partly molten material rises to the surface because it is less dense than cooler denser magma that is underneath it and so it moves up. The ideas of Hess, Wegener and others emphasize that earth is a dynamic planet.
Where does the material involved in sea-floor spreading come from?
Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor.
What is causing sea-floor spreading?
Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor. Eventually, the crust cracks.
Where does molten magma rise from the mantle?
Molten magma rises from the mantle at the places where the plates are moving apart. Immediatelypart of a plate moves away from its neighbour, molten magma immediately wells up from the mantle to filll the gap.
How is seafloor spreading related to mantle convection?
Vocabulary Seafloor spreading is a geologic process in which tectonic plate s—large slabs of Earth’s lithosphere —split apart from each other. Seafloor spreading and other tectonic activity processes are the result of mantle convection. Mantle convection is the slow, churn ing motion of Earth’s mantle.
How did scientists discover the spreading of the ocean floor?
Geomagnetic Reversals The magnetism of mid-ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century. Basalt, the once- molten rock that makes up most new oceanic crust, is a fairly magnetic substance, and scientists began using magnetometer s to measure the magnetism of the ocean floor in the 1950s.
What happens when tectonic plates crash on the seafloor?
Subduction happens where tectonic plates crash into each other instead of spreading apart. At subduction zones, the edge of the denser plate subduct s, or slides, beneath the less-dense one. The denser lithospheric material then melts back into the Earth’s mantle. Seafloor spreading creates new crust.