Question

Consider the following Assertion and reason. Which one of the following statements is/are true?

1. Assertion (A): The Himalayas are highly prone to landslides.
2. Reason (R): Young, tectonically active mountains with steep slopes and fragile rocks are particularly susceptible to slope instability.

• A. Both A and R are true, and R correctly explains A
• B. Both A and R are true, but R does not explain A
• C. A is true, but R is false
• D. Both A and R are false

Answer 1

Answer:

A. Both A and R are true, and R correctly explains A

Geological Instability of the Himalayas

• Tectonic Activity: The Himalayan range is a result of the ongoing collision between the Indian Plate and the Eurasian Plate. This continuous tectonic movement makes the region highly seismically active, leading to frequent earthquakes that destabilize mountain slopes.

• Young Fold Mountains: Geologically, the Himalayas are considered 'young' fold mountains. Their formation process is not yet complete, meaning the rock strata are still adjusting, which contributes to inherent instability.

• Fragile Rock Composition: Large portions of the Himalayas consist of sedimentary rocks like shales and sandstones, which are structurally weak and highly susceptible to weathering and erosion compared to the stable igneous rocks found in older geological shields (e.g., the Deccan Plateau).