3.1 Plate Tectonics Flashcards
What is sedimentary rock?
Rocks that are characterised by their layers. Formed under oceans and lakes. e.g. limestone.
What is metamorphic rock?
Rocks that are formed under extreme heat/pressure. e.g. slate.
What is igneous rock?
Rocks that form when magma cools and hardens. e.g. granite.
What is the core?
The centre of the earth’s structure, with a solid inner and liquid outer.
What is the mantle?
The large layer of the earth. The closer to the core then the more liquid the rock.
What is the crust?
Top layer of earth and the thinnest layer too. It is broken into pieces called plates.
What is the lithosphere?
Another term to describe the upper layer of the earth - the crust and the solid part of the upper mantle.
What is the asthenosphere?
This is the area below the lithosphere - still the upper mantle. The rock here has plastic-like features.
What is SiMa?
Another term for oceanic crust, containing large amounts of Silica and MAgnesium.
What is SiAl?
Another term for continentAL crust. Contains large amounts of Silica and ALuminium.
What is a tectonic plate?
A piece of lithosphere or crust. It is a large slab of rock and moves at slow speeds due to convection currents in the mantle.
What is rheid?
Material in the asthenosphere that, although appearing solid, can behave like a plastic over hundreds of thousands of years.
What is the moho?
The boundary between the crust and the mantle.
What is ridge push?
Intrusion of magma into the spreading ocean ridges propels plates apart.
What is convection drag?
Convection currents on the plastic mantle drag the lithosphere. The heat source is below the oceanic ridges and comes from radioactive decay in the mantle. Involves subduction zones.
