What are the evidence of seafloor spreading?
What are the evidence of seafloor spreading?
Abundant evidence supports the major contentions of the seafloor-spreading theory. First, samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid-ocean ridge is approached, and the sediment cover is thinner near the ridge.
What are 3 types of evidence for seafloor spreading?
Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading-evidence from molten material, magnetic stripes, and drilling samples.
What are the 4 key pieces of evidence supporting sea floor spreading?
In particular, four major scientific developments spurred the formulation of the plate-tectonics theory: (1) demonstration of the ruggedness and youth of the ocean floor; (2) confirmation of repeated reversals of the Earth magnetic field in the geologic past; (3) emergence of the seafloor-spreading hypothesis and …
What is the importance of seafloor spreading?
Significance. Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere.
What are the steps in the process of seafloor spreading?
Terms in this set (7)
- Magma comes out of the rift valley.
- Magma cools to rock and hardens.
- Rock is pushed away as new rock is formed at MOR.
- Oceanic crust and continental crust meet at the trench.
- Oceanic crust bends down under the continental crust.
- Gravity pulls rock towards mantle.
- Rock melts to mantle.
Which of the following is not evidence for seafloor spreading?
Your answer: The distribution of ice sheets across the planet is not an evidence of sea-floor spreading.
What is seafloor spreading and why is it important?
Today it refers to the processes creating new oceanic lithosphere where plates move apart. Seafloor spreading replaces the lithosphere destroyed by subduction, and exerts important influences on Earth’s chemical and biological evolution.
Which is the first step in the seafloor spreading process?
1. A long crack in the oceanic crust forms at a mid ocean ridge. 2. Molten material rises and erupts along the ridge.
What are examples of seafloor spreading?
Seafloor spreading occurs along mid-ocean ridges—large mountain ranges rising from the ocean floor. The Mid-Atlantic Ridge, for instance, separates the North American plate from the Eurasian plate, and the South American plate from the African plate.
What is the first step in seafloor spreading?
What are 2 pieces of evidence supporting seafloor spreading?
Harry Hess’s hypothesis about seafloor spreading had collected several pieces of evidence to support the theory. This evidence was from the investigations of the molten material, seafloor drilling, radiometric age dating and fossil ages, and the magnetic stripes.
What is the benefits of seafloor spreading?
Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere.
What are facts about seafloor spreading?
What Happens During the Process of Seafloor Spreading? History. Scientists originally believed that drifting was an occurrence exclusive to continents through continental drifts. Geographic Features. The process of seafloor spreading leads to the formation of numerous geographical features which can be terrestrial, sub-terrestrial, or marine features. Mid-Ocean Ridges.
What is sea floor spreading and why is it important?
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. This idea played a pivotal role in the development of plate tectonics, a theory that revolutionized geologic thought during the last quarter of the 20th century.
What is the theory of seafloor spreading?
The Theory of Seafloor Spreading. 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.