The lowest part of most bolsons is occupied by a landform called playa. Which category of landform formation does it represent?
- A.Fluvial landforms
- B.Arid landforms
- C.Glacial landforms
- D.Periglacial landforms
Correct answer
Explanation
The correct answer is B, Arid landforms. A playa is the flat, shallow lake bed at the bottom of a desert basin, so it belongs to the landforms of arid regions.
A bolson is a basin in a desert surrounded by mountains, with no outlet to the sea. During rare heavy rains, streams wash sediment down from the slopes and the water collects at the lowest point as a temporary shallow lake. When the water evaporates, a smooth, level plain of fine silt and clay is left, often crusted with salt; such a salty playa is called an alkali flat or salina. Pediments and bajadas surround it on the slopes above.
A is wrong because fluvial landforms, such as meanders, deltas and floodplains, are shaped by permanent rivers.
C is wrong because glacial landforms, such as cirques, moraines and U-shaped valleys, are made by moving ice.
D is wrong because periglacial landforms, such as pingos and patterned ground, form by freezing and thawing near ice sheets.
Exam tip: desert basin sequence – mountain front, pediment, bajada, then playa at the lowest point.
Practice Questions
View allDoldrum are
1. equatorial calms
2. calm and light winds
3. roaring forties
4. variable both in position and in extent
Select the correct answer using the code given below:
- A.1, 2 and 4
- B.2 and 3 only
- C.1 and 3
- D.2, 3 and 4
Show answer
The doldrums are the equatorial belt of calm and light, variable winds, and the belt shifts with the seasons; they have nothing to do with the roaring forties.
Read the full explanation →Which one of the following Indian cities is not located on a river bank ?
- A.Agra
- B.Bhagalpur
- C.Bhopal
- D.Kanpur
Show answer
Bhopal, the capital of Madhya Pradesh, is not built on a river bank; it is known instead as the City of Lakes.
Read the full explanation →Milpa and Ladang are different names for
- A.shifting cultivation.
- B.mixed farming.
- C.truck farming.
- D.plantation agriculture.
Show answer
Milpa is the name for shifting cultivation in Mexico and Central America, and Ladang is its name in Malaysia and Indonesia.
Read the full explanation →The Tetrahedral Hypothesis of the origin of continents and ocean basin was proposed by
- A.F.B. Taylor
- B.Lowthian Green
- C.Alfred Wegener
- D.W.M. Davis
Show answer
The English geologist William Lowthian Green put forward the Tetrahedral Hypothesis in 1875 to explain how continents and ocean basins are arranged.
Read the full explanation →Which one of the following statements is correct?
For the purpose of Census 2011
- A.a person aged seven and above who can both read and write with understanding in any language is treated as a literate
- B.a person aged eight and above who can both read and write with understanding in any language is treated as a literate
- C.a person aged nine and above who can both read and write with understanding in any language is treated as a literate
- D.a person aged ten and above who can both read and write with understanding in any language is treated as a literate
Show answer
In Census 2011, a person aged seven and above who could both read and write with understanding in any language was counted as literate.
Read the full explanation →