Question

1 pt D Question 24 Match land and ocean formations with the type of plate boundary that would create them. earth's deepest ocean trenches [Choose] ocean ridges [Choose] rift valleys [Choose] San Andreas Fault [Choose] ocean trenches next to coastal volcanoes [Choose] earth's highest mountains [Choose] accreted terranes [Choose] [Choose] continent-continent convergence continent-continent divergence ocean-continent convergence ocean-ocean convergence Question 25 transform boundary ocean-ocean divergence 1 pts

Answer 1

Ans. 24. Deepest oceanic trenches - Oceanic - oceanic convergence. Deep oceanic trenches are formed from collision of two oceanic plates. During the convergence, the older plate (which is the most dense) undergoes subduction beneath the lighter plate to form deep trenches. For example: the Mariana trench, which is the world's deepest trench, is formed due to convergence between the Pacific plate and the Philippines plate.

Ocean ridges : Oceanic Oceanic divergence. When two oceanic plates drift apart from each other, new crust is formed from the junction. The new crust is the liquid molten material beneath the surface, which when cool down form the mid oceanic ridges. For example, the Mid Oceanic Ridge in the Atlantic Ocean.

Rift valleys: Continental - continental divergence. When two continental plates move away from each other a new crust called rift valley is formed from within. For example, the Rhine rift valley in Germany.

San Andreas fault: Transform boundary. When two plates move past one another or slide past one another, it is called transform fault. The San Andreas fault is formed from two plates namely, the North American plate and the Pacific Plate slide past each other.

Ocean trenches next to coastal volcanoes: Ocean - continental convergence. When an oceanic and a continental plate collide, the ocean plate being denser subducts beneath the continental plate. A chain of volcanic islands are formed called coastal volcanoes. for example, the Aleutian Islands in Russia.

Earth's highest mountains: Continental - continental convergence. When two continental plates converge, the plates undergo deformation and uplift. These processes lead to the formation of mountains and mountain ranges. For example, the Himalayas are formed from the collision between the Indian plate and the Eurasian plate.

Accreted terranes : Continental - oceanic convergence. Accreted terranes are formed when these plates hit each other and crust gets added to one plate. For example, the North American Cordillera.

Ans. 25. The Himalayas : Collision of the Indian Plate with Asia. The Himalayas were formed when two continental plates, namely the Indian and the Eurasian plates converged, underwent upliftment, forming the Himalayas.

Alps: Collision of the African and Eurasian plates. The Alps were formed when the African and the Eurasian plates collided.

Rocky mountains: Shallow oceanic continental subduction. The oceanic plate, the Pacific plate collided with the continental plate - the North American plate, when the oceanic plate underwent subduction beneath the North American plate and formed the Rocky mountains.

Appalachian mountains: Old, eroded and folded crust. The crust that has emerged into the Appalachian mountains is an ancient one with multiple folding and thus eroded one. this eventually led to the formation of the Appalachian mountains.

Sierra Nevada mountains: A normal fault on one side. The mountains were formed from a normal type of fault, which is an active fault. The Sierra Nevada acts as the footwall against the Owens Valley as the hanging wall.

Ans. 26. The given statement is true. The tectonic plates move very slowly. The dynamic nature of the earth, rather the lithospheric plates are in constant motion over the asthenosphere. The rate of movement is about 2 - 2.5 cm / year.