Geography
Answer
When igneous rocks are exposed on the surface of the earth, they are broken down by weathering and carried away by forces of gradation. They are then deposited as sediments over long periods in seas, lakes, streams etc. Subsequent layers are added and due to their own weight from above, the sediments get cemented together to form sedimentary rocks.
Related Questions
Give a reason for each of the following:
(i) Igneous rocks also called the primary rocks.
(ii) Igneous rocks are used by builders and sculptors.
(iii) Sedimentary rocks are called secondary rocks.
Study the picture. Identify the rocks formed in case of A, B and C. Give reasons to support your answer.
Explain the formation of sedimentary rocks on the basis of agents of formation.
Give a reason for each of the following:
(i) Mechanically formed sedimentary rocks are also termed as stratified rocks.
(ii) Rocks like peat, lignite and anthracite are called carbonaceous rocks.
(iii) Fossils are present in sedimentary rocks.