JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech II FUNDAMENTALS OF GEOLOGY Previous Question Paper (September - 2021 - R13)

The Earth's internal structure is divided into three primary concentric layers based on chemical composition and physical properties:

1. Crust: The outermost, thin, rocky shell. It is divided into the continental crust (granitic, thicker, less dense) and the oceanic crust (basaltic, thinner, denser).
2. Mantle: Extending to a depth of about 2,900 km, it consists of silicate rocks rich in iron and magnesium. The upper mantle contains the asthenosphere, a semi-plastic layer that facilitates tectonic plate movement.
3. Core: The central part, composed primarily of iron and nickel. It is split into the liquid outer core, which generates the Earth's magnetic field, and the solid inner core due to extreme pressure.

Sketch description: A cross-sectional diagram showing the crust as a thin surface layer, the mantle as the thick middle section, and the core as the central sphere, with the outer core marked as liquid and inner core as solid.

Glacial landforms are shaped by the erosional and depositional activities of moving ice masses. Key features include U-shaped valleys, cirques, moraines (accumulations of unsorted debris), and drumlins.

Engineering considerations for these landforms include:

• Slope Stability: Glacial deposits like moraines are often unconsolidated and highly prone to landslides or slope failure, requiring extensive stabilization measures for infrastructure.
• Foundation Challenges: Glacial till is heterogeneous, containing a mix of clay, sand, and boulders. This leads to differential settlement risks for heavy structures.
• Permeability and Drainage: Glacial deposits can have erratic permeability. High-clay content areas may cause water logging, while sandy lenses can lead to piping or internal erosion.
• Excavation Difficulty: The presence of large, embedded glacial erratics (boulders) within finer deposits makes excavation and piling operations difficult and costly.