Yardang;
Characteristics:
(i) Found in desert
(ii) Hard and soft rocks are in vertical bands
(iii) A ridge and furrow landscape
(iv) Common in Atacama Desert, Chile and Central Asia
(v) Aligned in the direction of the prevailing wind
(vi) Height between 5 and 15 metres.
Formation: Band of hard and soft rocks which lie parallel to the prevailing winds in the desert are turned into another type of ridge and furrow landscape by wind and abrasion
(b) Block Mountains
Characteristics:
(i) Found in areas of ancient fold mountains
(ii) Associated with rift valleys
(iii) Uplifted area in the block mountain or horst
(iv) Steepsided
(v) Generally flat topped
(vi) Examples are Ruwenzori in East Africa, Vosges Black Forest in France.
Formation: When parallel vertical faults develop in the crust, they divide the land into blocks. When tensional force sets on the blocks and presses the outside block down while the middle block stands, a block mountain is formed