EARTH SCIENCE
TECTONICS
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
Young rocks are at mid ocean ridges.
|
|
The cool magma sinks back into the mantle.
|
|
Mesosaurus
|
|
Glossopteris
|
Detailed explanation-1: -Different seafloor magnetic stripes equal different ages. By using geologic dating techniques, scientists could figure out what these ages are. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest.
Detailed explanation-2: -Mid-ocean ridges occur along divergent plate boundaries, where new ocean floor is created as the Earth’s tectonic plates spread apart. As the plates separate, molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt.
Detailed explanation-3: -Scientists found that the youngest rocks are located at the mid-ocean ridges. The ages of the rocks become increasingly older in samples obtained farther from the ridges, adding to the evidence for seafloor spreading.
Detailed explanation-4: -Seismic studies. More proof for sea floor spreading comes from seismic studies indicating that earthquakes occur along the rift valley of a midoceanic ridge and the cross‐cutting fractures that offset it.
Detailed explanation-5: -Scientists discovered that as they moved away from the mid-ocean ridge, the samples of both the crustal rock and sediments on the ocean floor increased in age. The newest, youngest rock was closest to the mid-ocean ridge. This evidence supported the theory of seafloor spreading.