Question

characteristics of igneous and sedimentary rocks​

Answer 1

Answer:

Igneous rock

1. Formed by the cooling and solidification of lava.

2. Hard in nature

3. Consists of crystals,hence, also called as crystalline rock

4. Examples are Granite and Basalt. These rocks are formed inside as well as on the earth.

5. Fossils are not present in this rock.

6. Igneous rocks are of two types : a. Extrusive  rocks     b. Intrusive rocks - i Plutonic rocks      ii  Hypabyssal rock

7. It is non porous rock

Sedimentry rocks

(1) Sedimentary rocks are formed of sediments derived from the older rocks, plant and animal remains and thus these rocks contain fossils of plants and animals. The age of the formation of a given sedimen­tary rock may be determined on the basis of the analysis of the fossils to be found in that rock.

(2) Sedimentary rocks are found over the largest surface area of the globe. It is believed that about 75 per cent of the surface area of the globe is covered by sedimentary rocks whereas igneous and metamorphic rocks cover the remaining 25 per cent area. Inspite of their largest coverage the sedimentary rocks constitute only 5 per cent of the composition of the crust whereas 95 per cent of the crust is composed of igneous and metamorphic rocks. Thus, it is obvious that the sedi­mentary rocks are important for extent, not for depth in the earth’s crust.

Explanation:

Answer 2

Explanation:

Igneous rocks are formed when melted lava or magma cools and crystallizes, and their unique traits are based on this process. They are strong because their mineral grains grow together tightly as they cool, and their minerals are usually black, white, or gray.

These atoms and molecule rearrange themselves into mineral grains as the magma cools, forming rock as the mineral grains grow together. There are over 700 different types of igneous rocks.

Igneous rocks can be intrusive or extrusive, depending upon how the rocks are formed. Intrusive or plutonic rocks (e.g., granite) are directly formed from the magma and cooling process occurs below the earth's surface. Extrusive or volcanic rocks (e.g., basalt) are formed after