Available Answers

1. 1.

   Fill in the blanks.

   1. A ________________ is a plutonic rock structure formed when magma hardens between horizontal layers of rocks.
   2. Fossils appear only in _________________ rocks.
   3. __________________ weathering is most common in equatorial and tropical regions.
   4. The lowest layer of a soil profile is the __________________ horizon or _________________.
   5. Steps cut into hill slopes to prevent soil erosion are called ___________________.
2. 2.

   Tick the sentences that are true. Correct the others.

   1. Peat and coal are examples of plutonic rocks.
   2. Limestone changes to diamond and coal changes to marble as a result of metamorphosis.
   3. When water freezes, its volume reduces.
   4. Biological weathering takes place when the chemical components of rocks undergo changes.
   5. The subsoil contains the maximum amount of humus.
3. 3.

   Fossils are formed in sedimentary rocks alone. Give reasons.

4. 4.

   Exfoliation is also sometimes referred to as 'onion peeling'. Give reasons.

5. 5.

   Frost action causes cracks to appear in rocks. Give reasons.

6. 6.

   Chemical weathering is most common in equatorial and tropical regions. Give reasons.