Geomorphology - Geography Objective Questions with Answers | Page-15

Answer: Option [D]

None of the above. Continental crust is typically 40 km (25 miles) thick, while oceanic crust is much thinner, averaging about 6 km (4 miles) in thickness. The effect of the different densities of lithospheric rock can be seen in the different average elevations of continental and oceanic crust.

Answer: Option [C]

The correct answer is Basalt. Basalt is mainly used for structural building materials such as bricks, tiles, foundations and sculptures, as well as within stonewalls for thermal purposes and rail tracks.

Answer: Option [B]

Pediplanation is process associated with Wave action. In geology and geomorphology a pediplain is an extensive plain formed by the coalescence of pediments. The processes through which pediplains forms is known as pediplanation.

Answer: Option [B]

Sills are formed by intrusive volcanicity. Intrusive volcanism is when magma is forced into the rocks that make up the Earth's crust. Sills and Dikes are tabular bodies of magma that intrude into a fracture. Sills follow bedding planes, whereas dikes cross-cut beds. Monadnocks, also called Inselbergs, are isolated rock hills standing in a level plain.

Answer: Option [B]

Arches are an advanced form of Caves. Cracks are formed in the headland through the erosional processes of hydraulic action and abrasion. As the waves continue to grind away at the crack, it begins to open up to form a cave. The cave becomes larger and eventually breaks through the headland to form an arch.