Question

During this semester we analyzed different types of lava/magma. Please name and describe the characteristics of the major lava/magma types that exist on Earth. Please be very specific.

Answer 1

The study about lava belong to any fields including environmental biology and geobiololgy. Lava is prepared under high temperature and pressure conditions in the inner layers of earth by melting the rocks and fossil. Different types of lava is characterised on the basis of its flow, content and viscosity.

1) Pahoehoe lava flow - Basalt characterised, dark colored, mafic lava is known by two forws pahoehoe and a'a. These are hawaiian names. Pahoehe lava has a characteristic smooth and gentle flow. Beneath a thin plastic crust, the liquid lava flows. This plastic crust slowly become solidifies completely or partially but beneath it the lava still remain liquid and flows.

2) A'a lava flow - This the another form of flow of mafic lava. A'a and pahoehoe has almost same chemical composition. But the surface of a'a lava is rough, with a layer of loose and irregular fragments called clinkers. This lava flow is more in the central area like a narrow river flow and these clinkers are driven along the sideways. It is like a river of lava flowing in a open channel. Upon hardening the surface of a'a lava become spiny.

3) Andesitic lava - This lava has a intermediate composition which is not that viscous and has a different type of lava flow. It is know as block lava flow. This lava flow also have irregular fragments but are more regular in shape with smooth sides.

4) Basaltic lava flow - This type of flow contains many holes formed due to the bubbles of gas left in the hot liquid. This flow is thick and remain hot for long which slowly looses its gases.

5) Pillow lava - This type of lava usually comes out of the underwater lava vents. As the lava flows and come out making its contact with water cools and hardens fast, remaining underwater. The hardened structure is solid and looks like a "pillow" hence, got its name.

6) Trubulent lava flow is not of much theoretical interest because this type of lava flow is not seen easily.