How was the North American craton constructed?
The new study suggests that any continental lithosphere that has been added since the original North American craton formed came from material scraped off of the ocean floor as the craton plunged beneath the continent and not deposited from below by plumes of hot material welling up through the mantle, as happens at …
Where is the North American Craton?
One of those original continents is the North American craton, located mostly in the Canadian part of North America.
How did North America get its shape?
The Atlantic Ocean opened 200 million years ago, pushing North America westward. As the continent rifted away from the supercontinent Pangaea, it finally earned the name North America.
Is the North American plate convergent or divergent or transform?
transform boundary
The movement of the hot mantle below the lithosphere drives the plate motion. The North American Plate has a transform boundary with the Pacific Plate, dividing California at the San Andreas Fault.
How old is North American Craton?
The rock that comprises the Craton is about 2 billion years old, however it is very rarely visible at the surface in North America, as thick layers of sediment have settled over the bedrock and formed sedimentary rocks over the years.
How old is the North American Craton?
What is a craton in geology?
craton, the stable interior portion of a continent characteristically composed of ancient crystalline basement rock. The term craton is used to distinguish such regions from mobile geosynclinal troughs, which are linear belts of sediment accumulations subject to subsidence (i.e., downwarping).
What does the movement of the North American tectonic plate cause?
Most earthquakes in California occur on faults in the upper 5-10 miles (8-15 km) of the Earth’s crust as the result of failure caused by the strains induced by plate motions. Earthquakes in the Bay Area reflect the relative motion of the Pacific and North America plates.
What type of tectonic plate is the North American Plate?
The plate includes both continental and oceanic crust. The interior of the main continental landmass includes an extensive granitic core called a craton….
| North American Plate | |
|---|---|
| Type | Major |
| Approximate area | 75,900,000 km2 (29,300,000 sq mi) |
| Movement1 | west |
| Speed1 | 15–25 mm (0.59–0.98 in)/year |
What does a craton look like?
Cratons are generally found in the interiors of continents and are characteristically composed of ancient crystalline basement crust of lightweight felsic igneous rock such as granite. They have a thick crust and deep roots that extend into the mantle beneath to depths of 200 km.