T3 Flashcards
What are the two major geological theories, one of which is the one that’s widely accepted?
The Continental Drift theory and the Shrinking theory.
What evidence supports the idea of Pangaea having been a reality?
- Certain coastlines which fit together almost perfectly.
- Fossils of plants and animals which couldn’t cross oceans found on different continents.
- Similar rock formations.
- General idea of continental drift.
What is paleomagnetism?
It’s the idea of being able to track the age of parts of rocks through the fact certain rocks can store information about the polarity of the magnetic field.
What can convection currents do?
They can move the crust.
Name some geologically important places.
East African Rift - The only above sea divergent boundary.
Himalayas Mountain Range
San Andreas Fault
What is the zone where a plate goes under another plate?
The subduction zone.
What are the different reactions from convergent boundaries that are:
1. Sea-sea
2. Land-land
3. Sea-land
- One goes under and there’s a lot of volcanic activity.
- One goes under while the other one is stopped and gets bigger, creating mountains.
- The sea plate goes under, and there’s a small amount of volcanic activity.
What’s a mantle “hotspot”?
It’s a point in the mantle that, as the crust goes over it, creates mountains at various points, usually volcanoes.
What are the three types of faults, not boundaries?
- Normal. The block slides down.
- Reverse. The block slides up.
- Strike-slip/transcurrent. The block moves to the side.
(the block is the hanging wall piece)
What force is associated with a normal fault?
Tensional (pull apart forces)
What force is associated with a reverse fault?
Compressional (push together forces)
What force is associated with a strike-slip fault?
Shearing (push to the side forces)
What are anticlines and synclines?
Anticlines - Upfolds (peaks like a hill)
Synclines - Downfolds (a ditch)
What are the speed, in ascending order, of different waves?
L-waves, S-waves, P-waves
