CV2013 AI

What is the theory that explains movement of Earth’s lithospheric plates?

Plate tectonics → Driven by mantle convection, slab pull, ridge push

What is the rigid layer consisting of crust + upper mantle called?

Lithosphere

Which boundary creates new crust?

Divergent boundary → Mid-ocean ridges

Which boundary destroys crust?

Convergent boundary → Subduction zones

What is the most abundant mineral group in Earth’s crust?

Silicates

Two main types of silicate minerals?

Ferromagnesian (mafic, dark, Fe-Mg rich) vs Non-ferromagnesian (felsic, light, Si-Al rich)

What are the three major rock types?

Igneous, sedimentary, metamorphic

How does igneous rock form?

From cooling and crystallization of magma or lava

Difference between intrusive vs extrusive igneous rocks?

Intrusive = coarse-grained (slow cooling, e.g., granite, gabbro). Extrusive = fine-grained (fast cooling, e.g., basalt, rhyolite)

What is the rock cycle?

Continuous transformation between igneous, sedimentary, and metamorphic rocks through melting, cooling, weathering, lithification, and metamorphism

Sedimentary rocks form by what processes?

Weathering → Transport → Deposition → Lithification

Metamorphic rocks form by what?

Heat, pressure, and fluids altering existing rocks without melting

What is the largest division of geological time?

Eon → divided into Eras → Periods → Epochs

What principle is used to interpret relative dating?

Uniformitarianism (“the present is the key to the past”)

What are the two main types of geological dating?

Relative dating (order of events) and Absolute dating (numerical ages via isotopes)

What are the main soil-forming processes?

Weathering (physical & chemical), organic activity, climate, parent material, topography, time

Main end-products of weathering?

Quartz, clays, oxides, soluble ions

What is a fold?

Bending of rock layers due to compressional stress

What is a fault?

Fracture along which displacement occurs

Difference between normal, reverse, strike-slip faults?

Normal: Hanging wall down (tension). Reverse: Hanging wall up (compression). Strike-slip: Lateral motion (shear)

What is a joint?

Fracture in rock without displacement

What are rock mass properties important for civil engineering?

Strength, discontinuities, permeability, weathering condition

Why are geological maps important in engineering?

They show rock types, structures, faults, folds, and help in site investigations