Volcanic eruptions are classified in two types depending upon the manner of ejection of the magma:

1.   Central Eruption

2.   Fissure eruption

1.   Central eruption : - This type of eruption is sometimes very explosive  , because lava , steam , gas , dust , smoke , stone fragments are ejected from a narrow pipe from beneath the ground surface . The substances emitted in this type of eruption give rise to conical or dome-shaped hills.

          Some examples of volcanic mountains formed due to central eruptions are Mt.Kilimanjaro in Africa , the fujiyama in Japan  , and the Vesuvius and  Mount Etna in Italy . In India , there was a  Volcanic Eruption on the barren Island ( Andaman group of Islands )  in 1994 .

2.   Fissure Eruption : - A very long fissure develops in the ground surface and so , the molten rock , rock fragments , steam and gases within pour out slowly . These Eruptions take place at a very slow speed . As this lava is more fluid  , it spreads over longer distances .The lava cools down on the ground surface in that area . Basalt plateaus are formed from these eruptions . In very ancient times a huge crack developed in the earth’s crust parallel to the western coast of India . From this crack , the lava poured out a number of times and spread over extensive stretches of land . Basalt rock was created from this lava and the Deccan plateau came into existence . Such Basalt plateaus are aslo found in Brazil in South America and Saudi Arabia in West Asia .In Maharashtra , the fertile black regur soil has formed from basalt rocks .