The magma rises and erupts, creating volcanoes. These coastal volcanic mountains are found in a line above the subducting plate Figure below. The volcanoes are known as a continental arc.
Subduction of an oceanic plate beneath a continental plate causes earthquakes and forms a line of volcanoes known as a continental arc. The movement of crust and magma causes earthquakes. The Juan de Fuca plate is created by seafloor spreading just offshore at the Juan de Fuca ridge.
If the magma at a continental arc is felsic, it may be too viscous thick to rise through the crust. The magma will cool slowly to form granite or granodiorite. These large bodies of intrusive igneous rocks are called batholiths , which may someday be uplifted to form a mountain range Figure below. The Sierra Nevada batholith cooled beneath a volcanic arc roughly million years ago. The rock is well exposed here at Mount Whitney.
Similar batholiths are likely forming beneath the Andes and Cascades today. Ocean-ocean : When two oceanic plates converge, the older, denser plate will subduct into the mantle. An ocean trench marks the location where the plate is pushed down into the mantle. The line of volcanoes that grows on the upper oceanic plate is an island arc. Do you think earthquakes are common in these regions Figure below?
Continent-continent : Continental plates are too buoyant to subduct. What happens to continental material when it collides? Magma cannot penetrate this thick crust so there are no volcanoes, although the magma stays in the crust.
Metamorphic rocks are common because of the stress the continental crust experiences. With enormous slabs of crust smashing together, continent-continent collisions bring on numerous and large earthquakes. The Appalachian Mountains are the remnants of a large mountain range that was created when North America rammed into Eurasia about million years ago. Transform plate boundaries are seen as transform faults , where two plates move past each other in opposite directions.
Transform faults on continents bring massive earthquakes Figure below. At the northern end of the picture, the transform boundary turns into a subduction zone. California is very geologically active. What are the three major plate boundaries in or near California Figure below?
Geologists know that Wegener was right because the movements of continents explain so much about the geology we see. Most of the geologic activity that we see on the planet today is because of the interactions of the moving plates. In the map of North America Figure below , where are the mountain ranges located? Using what you have learned about plate tectonics, try to answer the following questions:. Remember that Wegener used the similarity of the mountains on the west and east sides of the Atlantic as evidence for his continental drift hypothesis.
The Appalachian mountains formed at a convergent plate boundary as Pangaea came together Figure below. About million years ago, the Appalachian Mountains of eastern North America were probably once as high as the Himalaya, but they have been weathered and eroded significantly since the breakup of Pangaea.
Before Pangaea came together, the continents were separated by an ocean where the Atlantic is now. The proto-Atlantic ocean shrank as the Pacific ocean grew. Currently, the Pacific is shrinking as the Atlantic is growing. And ara Na natutuhan ko mula sa akin karanasan at? Un an inverse variation, if one quantity increases, the other quantity also A increases. In a direc Dahil dito lalong napaunlad ang transportasyon at industriyang pagtrotroso. Bakit mahalaga ang liderat mga tagasunod sa isang pangkat?
Activity 7. Follow the given pattern to continue the series 1. Which biconditional is NOT a good definition? A whole number is odd if and only if the number is not divisible by 2. An angle is straight if and only if its measur Other tasks in the category: Science More task.
Total solved problems on the site: Crust is destroyed at a convergent boundary. A divergent boundary is a linear feature between two tectonic plates that are moving away from each other. The crust near a divergent boundary is younger compared to the crust farther away from the boundary. New oceanic crust is formed at a divergent boundary.
A convergent boundary neither creates nor destroys crust. Well if by "crust" you mean the Lithosphere, then the boundary is called the the "asthenosphere". The crust is part of the lithosphere, so there is no boundary between them. There is a boundary between the crust and the other part of the lithosphere which is the uppermost mantle.
It is called the Mohorovicic Discontinuity or the 'Moho' for short. The magma flows upward from the split in the crust caused by the boundary. Divergent Boundary, Constructive Boundary.
Convergent boundary. A divergent boundary. The boundary between Crust and Mantle is referred to as the Mohorovicic Discontinuity. Crust is destroyed at the convergent plate boundary. This is usually between the oceanic and continental plates. This is where subduction of the more dense crust occurs. No edge is like to a cliff but a boundary is like a football field or a basketball court.
At a transform boundary, plates slide past each other, and crust is conserved. Divergent plate boundary. Divergent boundary. New crust is formed at a divergent boundary. A convergent plate boundary. The oceanic crust is denser than the continental crust.
Log in. Study now. See Answer. Best Answer. New crust is being added to the other edge of the boundary.
0コメント