Geologic features of divergent boundaries - can not
The Cretaceous—Paleogene K—Pg boundary , formerly known as the Cretaceous—Tertiary K-T boundary , [a] is a geological signature , usually a thin band of rock. Its age is usually estimated at around 66 Ma million years ago , [2] with radiometric dating yielding a more precise age of The K—Pg boundary is associated with the Cretaceous—Paleogene extinction event , a mass extinction which destroyed a majority of the world's Mesozoic species, including all dinosaurs except for birds. Strong evidence exists that the extinction coincided with a large meteorite impact at the Chicxulub crater and the generally accepted scientific theory is that this impact triggered the extinction event. The word "Cretaceous" is derived from the Latin "creta" chalk. When it was originally proposed, one issue with the " Alvarez hypothesis " as it came to be known had been that no documented crater matched the event. This was not a lethal blow to the theory; while the crater resulting from the impact would have been larger than km mi in diameter, Earth's geological processes hide or destroy craters over time. The crater is estimated to be over kilometres 93 miles in diameter [9] and 20 km 12 mi in depth, well into the continental crust of the region of about 10—30 km 6. It makes the feature the second of the largest confirmed impact structures on Earth , and the only one whose peak ring is intact and directly accessible for scientific research.Geologic features of divergent boundaries Video
Divergent Boundary geologic features of divergent boundaries
As these plates slowly move about, they interact with each other, forming boundary zones.
Each of these different types of plate boundaries produces unique geographical features on the surface, including fault lines, trenches, volcanoes, mountains, ridges and rift valleys. A transform boundary connects two diverging boundaries, creating a fault line.
This line represents an area of shear, where two plates are moving horizontally against one another. Trenches are geological features formed by convergent boundaries. When two tectonic plates converge, the heavier plate is forced downward, creating a subduction zone.
This process results in the formation of a trench.
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The Marianas Trench is an example of a trench boundaties by the convergence of two oceanic plates. The deepest part of this trench, called the Challenger Deep, is over 36, feet deep, deeper than Mount Everest is tall. Another geological feature that results from a subduction geologic features of divergent boundaries is volcanoes. When the plate being forced downward begins to melt, this magma rises to the surface, forming volcanoes. Mount Saint Helens is an example of a volcano formed by an oceanic plate that is subducting under the North American continental plate. When two oceanic plates converge, both a trench and a string of volcanoes are formed.
These volcanoes can build to produce island chains, such as the Mariana Islands, which are located alongside the Marianas Trench.
When two continental plates converge, neither of the buoyant plates is able to give way and subduct beneath the other. This results in a powerful collision that produces tremendous, crushing pressure.
Ultimately, this pressure causes large vertical and horizontal displacements, forming towering mountain ranges. The Himalayas, one of the tallest mountain ranges in the world, is an example of a geological feature that is formed when continental plates collide. Opposite of a convergent boundary, a divergent boundary is formed by the spreading of a tectonic plate. This process feeds magma to the surface, creating new crust. Divergent zones in oceanic plates form a geological feature called a ridge, forced upward by the pressure of the rising magma.
Fault Lines
The Mid-Atlantic Ridge is an example of an oceanic divergent boundary formation. When divergent boundaries occur in continental plates, a different geological feature, called a rift valley, is formed. These depressions slowly fill with water, forming lakes, as their level drops. Ultimately, they veatures form the floor of a new ocean. An example of this type of geological feature is the East African Rift Zone.]
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