Intrusive landforms Flashcards
What is the definition of intrusive landforms?
Volcanic features are intruded into the lithosphere - cool/solidify.
Later exposed at the land surface by erosion/weathering.
What are batholiths and how are they formed?
Big coarse grained rocks with large crystals.
Magma intruded into the ground and cool very slowly.
Outer magma edge is in contact with existing rocks.
Heat/pressure changes the rock through metamorphosis creating a metamorphic aureole (recrystallised).
Exposed due to erosion.
What are created as a result of batholiths?
HORIZONTALLY squeezed magma along bedding planes through layers of existing rock - sill
VERTICALLY upward squeezed magma cuts across bedding planes of sedimentary rocks - dyke.
What is an example of a batholith?
The Isle of Arran in Western Scotland.
Includes dykes and sills e.g. the Drumadoon Sill.
Dolerite.
What is a laccolith?
Smaller injections of magma form a lens shape between layers of rock.
Arches upwards - forms done shape.
E.g. Eildin Hills, Scotland.
