Giving examples describe how each of the following features are formed: (i). A lava plateau. (ii) Caldera

      

Giving examples describe how each of the following features are formed:
i. A lava plateau.
ii. Caldera.

  

Answers


william
A lava plateau.
-Lava plateau is formed when magma reaches the surface of the earth through either
a single or multiple vents/fissures
- The lava is extremely fluid or low viscosity
- The lava flows spreading evenly over a large area before cooling
- The lava cools slowly forming an extensive plateau
- The lava fills former valleys and covers most of the hills
- The plateau may form through a series of eruptions which result into thick layers of lava.

OR

Example of lava plateau is:
-Yatta plateau
-Laikipia plateau
-Uasin Gishu plateau
-North West Kenya plateau
-Maralal-stony Athi plateau

Caldera
Can form in either of the following ways. Outward collapsing
-Volcanic eruption of pyroclasts /cinder and ash through a central vent forms a volcanic cone.
-Several subsequent eruption result in the formation of a high steep sided and unstable volcano.
-The weight of the upper part of the volcano exerts pressure on the lower part making it unstable.
-The material at the base begin to spread outwards.
-The top of the volcano collapses inwards forming a depression.
-*The resultant large circular depression in the top of the volcano is the caldera.
OR -Lava pouring out of a central vent forms a volcanic core.
-The magma reservoir below the crust is left partly empty/develops a void/ cavity.
-Over time the weight of the rocks of the volcano exerts pressure on the crustal rocks below.
-The pressure/earth movements cause cracks to develop making the volcano unstable.
-Eventually the middle portion of the volcano collapses into the void forming a depression.
-The large depression on top of the now lower volcano is called a caldera
Example Menengai, Ngorongoro, Lake Shala
steve williams answered the question on November 17, 2017 at 10:33


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