geo

2. A) 2 oceanic
plates move
away from
each other
Bi) Magma
rises from the
mantle to fill
the gap
between the
plates as they
diverge.
1. Oceanic-oceanic plate divergence
P11. The Mid-Atlantic Ridge is found in the middle of the Atlantic
Ocean cutting across Iceland, a volcanic island.

3. Bii) New sea floor is
formed when the
magma cools and
solidifies. This process
is called sea-floor
spreading.
Bii) Magma rises at the
zone of
divergence/spreading
zone to form a ridge of
new ocean floor called
mid-oceanic ridge.
1. Oceanic-oceanic plate divergence

4. Ci) The newly formed (youngest) rocks are closest to
the middle of the ridge/plate boundaries.
Cii) At various points along the ridge, magma builds up
above the ocean to form volcanic islands.

5. 1. Oceanic-oceanic plate divergence

6. 2. Continental–continental plate divergence
A)2 continental plates move away from each other
B)Stretched and causes fractures at boundaries
C)Land in between sinks and forms rift valley and
volcanoes

7. 2. Continental–continental plate
divergence
• Can result in the breakup of
continents
• E.g. Great Rift Valley (East Africa)
– a lowland with steep sides and flat valley
floor
– formed by Somalian boundary of the
African Plate moving away from the
Nubia plate boundary of the African
Plate
– 6,000 kilometres long
– between 30 to 100 kilometres wide

8. • Can result in the formation of linear sea
• E.g. Red Sea and Gulf of Aden near the Great Rift
Valley
– Elongated/linear shape
– 1,900 km long
– 300 km at its widest
– Average depth of 500 m
– Evidence of tectonic
activity formation of
new volcanic island in
Red Sea

9. IMPT! P25 Rift valleys and block mountains

10. • A fault is a fracture in the rocks along which the
rocks are displaced.
• The tensional forces result in parts of the crust
being fractured.
• This process is called faulting.
FAULTING

11. • A rift valley is a valley with steep sides formed
along fault lines. E.g. East African Rift Valley
Formation of Rift Valley

12. • A block mountain is a block of land with steep sides. It is
formed when sections of the crust extend along fault lines
and rock masses surrounding a central block sink due to
tensional forces.
Block mountains