B. Name the agents of erosion or deposition responsible for the creation of the following landform features
1. Delta
3. Sand dune
5. Loess
7. Sand bar
2. Natural levee
4. Flood plain
6. Sea cave
8. U-shaped valley
9. Moraine
10. Beach
Answers
Answer:
The features formed by wind are as follows:
(a) Mushroom Rocks: In deserts you can see rocks in the shape of a mushroom, commonly called mushroom rocks. Winds erode the lower section of the rock more than the upper part. Therefore, such rocks have narrower base and wider top.
(b) Sand Dunes: When the wind blows, it lifts and transports sand from one place to another. When it stops blowing the sand falls and gets deposited in low hill – like structures. These are called sand dunes.
(c) Barkhan: A crescent shaped sand dune is called a barkhan.
(d) Loess: When the grains of sand are very fine and light, the wind can carry it over very long distances. When such sand is deposited in large areas, it is called loess.
The features formed by sea waves in the coastal areas are as follows:
(a) Sea Caves: Sea waves continuously strike at the rocks. Cracks develop. Over time they become larger and wider. Thus, hollow like caves are formed on the rocks. They are called sea caves.
(b) Sea Arches: When these cavities become bigger and bigger only the roof of the caves remain, thus forming sea arches.
(c) Stacks: Further, erosion breaks the roof and only walls are left. These walls like features are called stacks.
(d) Sea Cliff: The steep rocky coast rising almost vertically above sea water is called sea cliff.
(e) Beaches: The sea waves deposit sediments along the shores forming beaches.
The features formed by ice are as follows:
(a) Lakes: Glaciers carve out deep hollows. As the ice melts they get filled up with water and become beautiful lakes in the mountains.
(b) U-Shaped Valley: Formation of "U" shaped valleys, which are deep and have steep sides.
(c) Glacial Moraines: The material carried by the glacier such as rocks big and small, sand and silt gets deposited. These deposits form glacial moraines.