Define Faulting. Describe types of faults and the resultant landforms.
Structure:
Introduction: (upto 30 words) Define Faulting
Body: (upto 100 words) Describe major types of faults and explain landforms due to faulting
Conclusion: (upto 30 words) Conclude with significance of faulting
Supporting Points:
When the crustal rocks are displaced due to tension/compression - movement caused by the endogenic forces along a plane, the resultant structure is called a fault and the process is known as faulting. A fault may be vertical, inclined, horizontal or any of type and form.
Types of Faults:
The different types of faulting of the crustal rocks are determined by the direction of motion along the fracture plane. Based on this several types of faults have been recognised
Normal Fault: These faults developed mainly due to the vertical movements that occur as the rocks are pulled apart due to tension. Between two normal faults, the block that is elevated is called Horst and block that drops down is a Graben. The horsts make block-like plateaus or mountains often with flat top but steep sides.
Reverse Fault: The Reverse faults are formed due to the movement of both the fractured rock blocks towards each other. On account of extreme compression, rocks snap and one stratum is pushed over the underlying stratum.
Lateral Fault or Strike-slip fault: A lateral fault is formed when the rock blocks are displaced horizontally (like sliding past one another) along the fault plane due to horizontal movement.
Landforms Associated with Faulting:
Block Mountains: These Mountains are formed when great blocks of the Earth’s crust may be raised or lowered due to normal faulting. For example: Black forest in Germany and Ruwnzori in Uganda.
Rift Valley: It is a trough or basin, formed due to displacement of crustal parts and subsidence of middle portion between two normal faults. For example: East African rift valley and Narmada rift valley.
Plateaus and Basins: These are the result of warping of the Earth’s crust. Uplifted area due to warping are called plateaus. For example: Deccan Plateau (India) whereas depressed areas due to warping are called basins for e.g. Victoria Basin (Africa).
Faulting not only has geomorphological importance but it also has great socio-economic significance. For e.g. Petroleum deposits are found in porous sedimentary rocks that have been faulted against impervious shale beds.
