tectonics Flashcards
meaning of tectonic plate
a large piece of the Earth’s crust floating on the mantle
meaning of plate boundary
where 2 or more tectonic plates meet
meaning of oceanic plate
a tectonic plate that has water on top of it.these are normally heavier/denser
meaning of continental plate
a tectonic plate that has land on top of it.these are normally lighter/less dense
density of continental crust
2.6g/cm cubed
thickness of continental crust
30-70 km deep
how old is continental crust
1500 million years old
density of oceanic crust
3.0g/cm cubed
thickness of oceanic crust
6-10km deep
how old is oceanic crust
less than 200 million years old
which is denser:oceanic or continental?
oceanic
which is thicker:oceanic or continental?
continental
which is older:oceanic or continental?
continental
how do tectonics move?
convection currents
what are the 4 plate boundaries?
destructive,constructive,collision and conservative
which plate boundaries create volcanoes?
destructive and constructive
which plate boundary creates fold mountains?
collision
which plate boundary forms composite volcanoes?
destructive
which plate boundary forms shield volcanoes?
constructive
which plate boundary releases very strong earthquakes?
conservative
