Intrusive Volcanic Landforms
Refers to AQA A2 Geography
Plate Tectonics and Assosiated Hazards Topic
- Created by: Bethany
- Created on: 31-03-14 15:44
View mindmap
- Intrusive Volcanic Landforms
- Batholiths
- DESCRIPTION
- Often several hundreds of km in diameter.
- They appear dome shaped and are often exposed by later erosion e.g. Dartmoor/ Isle of Arran, Scotland.
- e.g. Hambledown Tor, Dartmoor batholith
- FORMATION
- Formed deep below the surface when large masses of magma cool and solidify.
- As the magma cools, large crystals are formed in the rock e.g. granite.
- The area around the batholith is altered by heat and pressure to form a METAMORPHIC AUREOLE.
- Here limestone may be transformed into marble.
- Smaller injections of magma form a lens shape that is intruded between layers of rock.
- Forces the overlying strata to arch upwards forming a dome.
- This feature is known as a LACCOLITH
- May be exposed by later weathering/ erosion to form a small range of hills for example, the Eildon Hills, Scottish borders.
- This feature is known as a LACCOLITH
- Forces the overlying strata to arch upwards forming a dome.
- Formed deep below the surface when large masses of magma cool and solidify.
- DESCRIPTION
- Dykes
- FORMATION
- Vertical intrusions with hotizonatal colling cracks.
- They cut across the bedding planes of the rocks into which they have been intruded.
- When magma is forced to the surface, only a small amount of the mass actually reaches it
- DESCRIPTION
- Occur in groups known as 'DYKE SWARMS'
- Many Scottish islands, such as Mull and Skye, have clusters of dykes all assosiated with one intrusive event.
- FORMATION
- Sills
- FORMATION
- When magma is forced to the surface, only a small amount of the mass actually reaches it
- Horizonatal intrusions along the lines of bedding plances.
- Vertical cooling cracks
- DESCRIPTION
- Examples include the Great Whin Sill, and Drumadoon on the Isle of Arran.
- FORMATION
- Intrusive Features
- Most magma is INTRUDED into the crust where it solidifies into a range of features
- These features are often exposed by later erosion
- e.g. Hambledown Tor, Dartmoor batholith
- These features are often exposed by later erosion
- Most magma is INTRUDED into the crust where it solidifies into a range of features
- Batholiths
Comments
No comments have yet been made