Fine-grained bed of an ephemeral lake in a desert is also known as
- (a)Playa
- (b)Oasis
- (c)Drumlin
- (d)Natural levee
Correct — A, Playa. In a desert basin, water collects after rare rains to form a short-lived (ephemeral) lake; when it evaporates it leaves behind a flat floor of fine silt and clay, often crusted with salt. That flat, fine-grained dry bed is called a playa (also a salt flat or dry lake). An oasis, a drumlin and a natural levee are all different landforms with different origins.
- (b)Oasis — An oasis is a fertile desert spot where groundwater reaches the surface and supports vegetation — it is a place with water, not the dry bed of a vanished lake.
- (c)Drumlin — A drumlin is a streamlined hill of glacial till deposited under moving ice — a glacial, not a desert, landform.
- (d)Natural levee — A natural levee is a ridge of sediment built up along a river bank during floods — a fluvial feature unrelated to desert lakes.
A playa is the flat floor of an interior desert basin (often the lowest part of a bolson) that holds water only briefly after rain. As the shallow lake dries up, fine sediment and dissolved salts settle out, leaving a smooth, hard, fine-grained surface — hence the term ephemeral (short-lived) lake bed.
The distractors are landforms from other environments — glacial (drumlin), fluvial (natural levee) and a water-rich desert spot (oasis). Anchor on the words 'ephemeral' and 'desert', and only the playa fits.
- A playa forms in an arid interior basin with no outlet to the sea (inland drainage).
- It is the dry, fine-grained bed left when an ephemeral desert lake evaporates.
- Playas are often coated with salt and are also called salt flats or dry lakes.
- The lowest part of a desert basin (bolson) is typically occupied by a playa.
- Choosing 'oasis' because both relate to deserts — but an oasis has water, a playa is a dry bed.
- Mixing up depositional landforms from glacial (drumlin) and river (levee) settings with a desert feature.
Asked as a one-line definition — read 'ephemeral lake in a desert' as the cue and match it to playa.
No directly related past PYQ was found.
- practice — not a real PYQ
The lowest part of a desert basin (bolson), occupied by the dry bed of a temporary lake, is called a
- (a)Drumlin
- (b)Playa
- (c)Delta
- (d)Cirque
Answer(b) Playa — the fine-grained floor of an ephemeral desert lake.
- practice — not a real PYQ
A drumlin is a landform associated with which one of the following agents?
- (a)Wind
- (b)Rivers
- (c)Glaciers
- (d)Sea waves
Answer(c) Glaciers — a drumlin is a streamlined hill of glacial till.