What is the evidence for sea floor spreading?
The theory of seafloor spreading states that new ocean crust is continually being formed, and that this crust is slowly carried away from its point of origin over a period of time. The study of the repeated reversal of the Earth’s magnetic poles over time has provided convincing evidence of seafloor spreading.
What evidence is there to support sea floor spreading and plate tectonics?
Evidence of Sea Floor 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 are the evidences of plate movements?
Modern continents hold clues to their distant past. Evidence from fossils, glaciers, and complementary coastlines helps reveal how the plates once fit together. Fossils tell us when and where plants and animals once existed. Some life “rode” on diverging plates, became isolated, and evolved into new species.
What are three kinds of evidence of the ocean floor spreading?
What three types of evidence provided support for the theory of sea floor spreading? eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves.
What are the 3 types of evidence that support sea floor spreading?
Which of the following can be used as evidence for sea-floor spreading at a mid-ocean ridge?
Abundant evidence supports the major contentions of the seafloor-spreading theory. Magnetic surveys conducted near the mid-ocean ridge showed elongated patterns of normal and reversed polarity of the ocean floor in bands paralleling the rift and symmetrically distributed as mirror images on either side of it.
What are three kinds of evidence scientists have found to support this idea?
Molten Material (magma/lava) – scientists have found strange rocks shaped like pillows in the central valley of the ocean ridge.
What are the lines of evidence that support the plate movement?
What are the four lines of evidence that support plate movements? They based their idea of continental drift on several lines of evidence: fit of the continents, paleoclimate indicators, truncated geologic features, and fossils.
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 five observations or lines of evidence that support Wegener’s theory?
Alfred Wegener, in the first three decades of this century, and DuToit in the 1920s and 1930s gathered evidence that the continents had moved. They based their idea of continental drift on several lines of evidence: fit of the continents, paleoclimate indicators, truncated geologic features, and fossils.
What is the name given to the feature created as sea-floor spreading occurs?
The phenomenon is known today as plate tectonics. In locations where two plates move apart, at mid-ocean ridges, new seafloor is continually formed during seafloor spreading.
What is the first line of evidence in plate tectonics?
One of the first lines of evidence suggesting the existence of plate tectonics was the discovery of very similar fossils in rock masses separated by vast distances and by ocean expanses. It suggested that those land areas had in the past been connected.
What are the steps in the process of sea floor spreading?
What are the steps in the process of sea floor spreading? 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.
What are facts about seafloor spreading?
Molten material. Hess’s discovery on the warmer temperature near the mid-Atlantic ridge when he began the ocean mapping,led to his evidence about the molten material underneath the ocean.
What is an example of sea floor spreading?
New geographic features can be created through seafloor spreading. The Red Sea, for example, was created as the African plate and the Arabian plate tore away from each other. Today, only the Sinai Peninsula connects the Middle East (Asia) with North Africa.
What are some examples of seafloor spreading?
Seafloor spreading takes place at midocean ridges and produces basalt , the rock that makes up the oceanic crust. The Mid-Atlantic Ridge and East Pacific Rise are examples of midocean ridges.