Lesson 4 - Ridge push and Rift valley Flashcards
What is the first stage of ridge push?
Magma from asthenosphere pushes up on lithosphere
Creates raised slope
How do gravitational forces influence ridge push?
Pull plates down the slope
What happens to the lisospheric material during ridge push?
It is pushed further from the ridges.
A rift valley is formed as a result of what?
The sinking portion of the crust between cracks on the surface of the earth
What is the first stage in the formation of rift valley?
Layers of rock are subject to tension or stress
What is the second stage in the formation of a rift valley?
Faults or cracks develop in the layers and the central block begins to subside
What is the third stage in the formation of a rift valley?
After subsidence a depression with steep sides is formed, this is a rift valley
The Great Rift Valley of where is a special physical feature of the southern plateau?
Africa
Why has the Great Rift Valley of Africa formed?
It has formed because of vertical cracks that developed due to movements within the earth
The Great Rift Valley of Africa extends for a total distance of how many kilometres?
5000
The Great Rift Valley of Africa extends from Lake Malawi through the Red Sea and the Gulf of Aquaba to where?
The Dead Sea in Jordan
Name three freshwater lakes found in the Great African Rift Valley?
Malawi
Rudolph
Taganyika
