Volcanic eruptions
Describe Pyroclastic materials
What is pyroclastic Material ?
What is a Violent Eruption?
Volcanic ash & volcanic dust
Volcanic ash that is 2 mm in diameter is called volcanic ash. And when it's 0.25mm in diameter it is called volcanic dust.
Lapilli
Large pyroclastic particles that are less than 64 mm in diameter, are called Lapilli which Latin word called little stones.
Volcanic bombs & Volcanic blocks
Volcanic bombs are the largest pyroclastic materials, known as volcanic blocks. Form from solid rock that is blasted from the vent. Some blocks are the size of a small house.
What is a Quiet Eruption?
Pahoehoe
Pahoehoe is the least viscous type of mafic lava. It forms wrinkly volcanic rock when it cools.
Aa
Aa lava is more viscous than pahoehoe lava forms sharp volcanic rock when it cools.
Blocky lava
Blocky lava is the most vicouse type of mafic lava and forms chinky volcanic rock when it cools.
Three types of volcanoes
Shield volcanoes
A shield volcano covers a wide area and generally forms from quiet eruption. And also layers of hot mafic magma flow out around the vent , harden and then it slowly forms a cone.
Cinder cone
The cinder con is a type of volcano that the angle is 40 degrease in slope. The volcano has felsic magma and its made of pyroclastic material material and its explosive.
Composite Volcanoes
Composite volcanoes are made of alternating layers of hardened lava flows and pyroclastic material. The composite volcano is both shield and cinder cone, it first starts as shield volcanoes then ass the lava thikens it starts turning into cone.