Geomorphology Questions and Answers

Answer: B

The correct matching is i-b, ii-a, iii-c.

The magma chamber is the reservoir where molten rock is stored beneath the surface (i-b). The conduit is the pipe through which magma rises from the chamber (ii-a). The vent is the opening at the surface through which lava, gases and other material escape (iii-c).

The trap is mixing up the conduit and the vent: the conduit is the passage, while the vent is its opening at the top.

Answer: C

A debris flow is a rapid, fluid-like movement of a mixture of water, rock, soil and organic debris.

Debris flows usually follow heavy rain on steep slopes. Water saturates loose material until it behaves like a thick liquid and surges down channels at high speed, carrying boulders, mud and trees.

The other options describe different kinds of mass movement. Slow, gradual movement of soil is creep. The free fall of rock is a rockfall. Movement of dry, unconsolidated material, such as a dry granular avalanche, lacks the water that makes a debris flow fluid.

Answer: B

The upper course features are the V-shaped valley and gorges.

In its upper or mountain course, a river flows steeply and erodes mainly downwards (vertical erosion), cutting V-shaped valleys, gorges, waterfalls and rapids.

Meanders, river cliffs, flood plains and oxbow lakes form in the middle and lower courses, where lateral erosion and deposition dominate. U-shaped valleys are carved by glaciers, not rivers, which rules out that option even though potholes can form in a river's upper course.

Answer: D

Kame terraces are formed by the deposits of a valley glacier.

A kame terrace is a flat, terrace-like ridge of sand and gravel laid down by meltwater streams flowing in the trough between the side of a valley glacier and the valley wall. When the glacier melts away, the deposit is left as a bench along the valley side.

A niche glacier is a small patch of ice in a hollow on a mountain slope and does not build such terraces. Glacier plucking is an erosional process, not a glacier or a deposit. 'Alpine glacier' is a broad term for mountain glaciers; the landform is specifically tied to the margins of a glacier confined in a valley.

Answer: A

The layer is called Naleds.

A naled (also called aufeis or icing) is a sheet of ice built up when water seeping from a river, spring or the ground spreads over the surface and freezes layer upon layer, on top of a frozen river or land. They are common in cold regions with permafrost.

A cirque is a bowl-shaped hollow carved by a glacier at the head of a valley. A snow cap is a covering of snow on a mountain top, and the snow line is the altitude above which snow lies all year. None of these is a layer of frozen water on a river or land surface.

Answer: A

The answer is Compound coasts.

A compound coast shows landforms of both emergence (such as raised beaches and marine terraces, left as the land rose or sea level fell) and submergence (such as rias or drowned valleys, formed as the sea rose), because the coast has gone through both kinds of change.

Neutral coasts, such as deltas, alluvial plains and volcanic coasts, owe their form to neither emergence nor submergence. 'Simple' and 'retrograded' coasts do not describe a coast with both sets of features.

Answer: A

A 'tor' is a small hill.

In geomorphology a tor is a small rocky hill or outcrop of bare, weathered rock, often granite, standing above the surrounding land, formed when the softer rock around it has been weathered and removed. Granite tors are common in the Bundelkhand region of Madhya Pradesh.

A peneplain is a nearly flat erosion surface, a valley is a low area between hills, and a plateau is an extensive elevated flat land. None is a tor.

Answer: D

The valley that is not a rift valley is the Chambal Valley.

The Narmada flows west through a rift valley between the Vindhya and Satpura ranges, and the Tapti through a parallel rift between the Satpuras and the Ajanta-Gawilgarh hills. The Son, rising near the Narmada at Amarkantak, flows along the eastern continuation of the same fault zone, the Narmada-Son lineament. These faulted troughs are why the Narmada and Tapti flow west, against the general slope of the peninsula, and form estuaries rather than deltas.

The Chambal is different: it flows north across the Malwa plateau to join the Yamuna, through a valley carved by river erosion, famous for its ravines, not through a rift.

Answer: D

Coal and petroleum are found in Sedimentary rocks.

Both are fossil fuels formed from organic matter buried in layers of sediment. Coal forms from plant remains compressed over millions of years in sedimentary basins, such as India's Gondwana basins, and petroleum from marine organisms trapped and heated in sedimentary strata, where porous rocks like sandstone hold it.

Igneous rocks, such as granite, form from cooled magma, and metamorphic rocks form when existing rocks are altered by heat and pressure. Both processes would destroy organic material, so they do not contain coal or oil.

Answer: A

The mountain that is not a young fold mountain is the Sierra Nevada.

The Sierra Nevada of California is a block (fault-block) mountain: a huge block of the crust tilted up along a fault, with a steep eastern face and a gentle western slope.

The Rocky Mountains, the Himalaya and the Alps are young fold mountains, raised in relatively recent geological time (the Alpine and related orogenies) by the compression and folding of sedimentary layers where plates collide. They have high, rugged peaks typical of young folding.