What is continental in plate tectonics?
Tectonic plates not only move land masses (continental crust) but also oceans (oceanic crust). As the plates float on liquid rock, they are constantly moving and bumping into each other. Seafloor spreading occurs on the ocean floor where oceanic plates move away from each other (divergent).
What are the places where tectonic plates meet called?
Most volcanoes, mountains and earthquakes occur where plates meet. Places where plates meet are called plate boundaries. There are seven major slabs along with countless smaller slabs. You can see that a plate can be made of both oceanic crust and continental crust.
What is a continental tectonic plate mostly covered by?
The plates are about 100 km (62 mi) thick and consist of two main types of material: oceanic crust (also called sima from silicon and magnesium) and continental crust (sial from silicon and aluminum).
What is the edge of a tectonic plate called?
Continental coastlines that occur within the interior of a tectonic plate are called ________ margins. Nice work! You have just read 30 terms! Now step up your study game with Learn mode. Pillow basalts achieve their characteristic blob-like shapes because their parent lavas do not travel far before solidification. This is because the parent lavas ________.
Which type of plate is older continental or oceanic?
Exposed continental shields (or cratons) of primarily Precambrian (older than 570 million years) crystalline igneous and high-grade (formed at high temperatures and pressures) metamorphic rocks. Continental platforms mainly of gently folded younger low-grade (formed at low temperatures) metamorphic rocks overlying Precambrian basement rocks.
Where does most plate tectonics take place?
The lithosphere consists of rigid plates on a non-rigid subsurface (from about 70 km – 700 km in depth). Tectonic processes mostly take place at plate edges. A plate moves as a single unit along the Earth's surface over a plastic mantle. There are two types of plates: Oceanic plates form at mid-ocean ridges.
How are volcanoes related to plate tectonic boundaries?
Summarized over the entire Earth's surface, the rate of spreading at divergent boundaries is ________ lithospheric consumption at subduction zones. When transforming plate boundaries, ________. The volcanoes of the Cascades Mountains in the northwestern United States are related to the melting of rocks associated with a ________ boundary.