Today, we know that the continents rest on massive slabs of rock called tectonic plates. The plates are always moving and interacting in a process called plate tectonics . The continents are still moving today. Some of the most dynamic sites of tectonic activity are seafloor spreading zones and giant rift valleys.
What is the movement of continental to oceanic?
When oceanic crust converges with continental crust, the denser oceanic plate plunges beneath the continental plate . This process, called subduction, occurs at the oceanic trenches. The entire region is known as a subduction zone.
What is the movement of continental Continental?
The movement of these tectonic plates is likely caused by convection currents in the molten rock in Earth’s mantle below the crust. Earthquakes and volcanoes are the short-term results of this tectonic movement. The long-term result of plate tectonics is the movement of entire continents over millions of years (Fig.
Which way are the continents moving?
Several of the tectonic plates are currently moving north , including both Africa and Australia. This drift is believed to be driven by anomalies left by Pangea, deep in the Earth’s interior, in the part called the mantle.
Where do continental plates move?
The movement of the plates creates three types of tectonic boundaries: convergent , where plates move into one another; divergent, where plates move apart; and transform, where plates move sideways in relation to each other. They move at a rate of one to two inches (three to five centimeters) per year.
What are the 4 evidence of continental drift?
The evidence for continental drift included the fit of the continents; the distribution of ancient fossils, rocks, and mountain ranges; and the locations of ancient climatic zones .
What are the 3 causes of plate movement?
Mantle dynamics, gravity, and Earth’s rotation taken altogether causes the plate movements. However, convectional currents are the general thought for the motion.
What is an example of oceanic continental convergence?
Examples of ocean-continent convergent boundaries are subduction of the Nazca Plate under South America (which has created the Andes Mountains and the Peru Trench) and subduction of the Juan de Fuca Plate under North America (creating the Cascade Range).
Where is an example of a continental continental plate boundary?
Examples of continent-continent convergent boundaries are the collision of the India Plate with the Eurasian Plate, creating the Himalaya Mountains , and the collision of the African Plate with the Eurasian Plate, creating the series of ranges extending from the Alps in Europe to the Zagros Mountains in Iran.
What are the 4 types of tectonic plate movement?
- Divergent: extensional; the plates move apart. Spreading ridges, basin-range.
- Convergent: compressional; plates move toward each other. Includes: Subduction zones and mountain building.
- Transform: shearing; plates slide past each other. Strike-slip motion.
Will Pangea ever form again?
The answer is yes . Pangea wasn’t the first supercontinent to form during Earth’s 4.5-billion-year geologic history, and it won’t be the last. [What Is Plate Tectonics?] ... So, there’s no reason to think that another supercontinent won’t form in the future, Mitchell said.
Why is the continental drift theory not accepted?
The main reason that Wegener’s hypothesis was not accepted was because he suggested no mechanism for moving the continents . He thought the force of Earth’s spin was sufficient to cause continents to move, but geologists knew that rocks are too strong for this to be true.
What did Earth look like before Pangea?
But before Pangaea, Earth’s landmasses ripped apart and smashed back together to form supercontinents repeatedly . ... Just like other supercontinents, the number of detrital zircon grains increased during formation and dropped off during breakup of Rodinia.
What happens when two continental plates collide?
Plates Collide When two plates carrying continents collide, the continental crust buckles and rocks pile up, creating towering mountain ranges . ... Plates Slide Past One Another Plates grinding past each other in opposite directions create faults called transform faults.
How many continental plates are there?
how many tectonic plates are there? There are major, minor and micro tectonic plates. There are seven major plates : African, Antarctic, Eurasian, Indo-Australian, North American, Pacific and South American.
What are the two main factors of tectonic plates movement?
Heat and gravity are fundamental to the process
The energy source for plate tectonics is Earth’s internal heat while the forces moving the plates are the “ridge push” and “slab pull” gravity forces. It was once thought that mantle convection could drive plate motions.
