Which geological process is responsible for the formation of petroleum deposits in Assam?

Volcanic activity
Metamorphism
Sedimentation and decomposition
Plate tectonics

The correct answer is: c) Sedimentation and decomposition.

Petroleum is formed from the remains of ancient organisms that lived in the ocean millions of years ago. These organisms died and sank to the bottom of the ocean, where they were buried under layers of sediment. Over time, the heat and pressure from the overlying sediment caused the organic matter to decompose and form hydrocarbons. These hydrocarbons eventually migrated upward through the porous rock, where they were trapped in underground reservoirs.

Volcanic activity is not responsible for the formation of petroleum deposits. Metamorphism is the process by which rocks are changed from one type to another due to heat and pressure. Plate tectonics is the theory that the Earth’s surface is made up of a number of plates that move around.