Question

Mushroom rocks are found in _________.
a)River valleys
b)Deserts
c)Glaciers
d)Flood plain

Answer 1

Hint:Weathering and erosion are two processes which continuously change our landforms. Weathering is the process which breaks up the rocks on Earth’s surface. Erosion is the process by which agents like wind , water and ice wear the landscape of earth away. Eroded material gets deposited somewhere else and eventually forms new landscapes.

Complete answer:Mushroom rock is a type of rock formed due to erosion carried out by wind. This kind rock is also called pedestal rock. It is called so because of its narrower base and wider top. It looks like a mushroom.

These kinds of rocks are mostly found in desert areas. This happens as the wind erodes the lower part of a rocky outcrop quicker than its upper part.
In desert areas, wind carries fine grains of sand which cause more abrasion at the bottom than the top. This is due to the fact that though the speed of wind increases with height, sediment load is highest only a few feets above the ground. Therefore wind speed and high sediment load erodes the bottom part away.

Another reason for formation of mushroom rocks is if the upper part of a rock is made of chemically resistant and harder rock, and the lower part is made of softer rock. The layer of soft rock at the bottom is therefore more easily eroded.

Mushroom rocks are found in Wadi Rum in Egypt, Sierra de Organos in Mexico, Goblin Valley park in Utah, Mushroom rock state park in Kansas etc.

Option (A) river valley is incorrect as landforms like waterfall and gorges are formed there.
Option (C )glacier is incorrect as landforms like glacial moraines are formed due to depositional activity of glaciers.
Option (D )Floodplain is incorrect as landforms like ox-bow lakes and levees are formed here.

Therefore the correct option is option ( B).

Note:Landforms formed by erosion or deposition caused by wind are called aeolian landforms.Wind is a strong agent of erosion in deserts and it forms erosional landforms like pediplains, deflation hollows and ventifacts. Ventifacts are rocks that have been eroded by wind driven sand and mushroom rock is one type of ventifacts.Sand dunes and loess are depositional landforms formed by wind in desert areas.