Question

3. Differentiate between. a) Igneous and sedimentary rock b) Sedimentary and metamorphic rock 4. Classify the following rocks Marble, Pumice, Slate, Obsidian, Limestone 5. Write answer in brief a) What is rock? b) How are igneous rocks formed? c) What type of rock is called sedimentary rock? d) Which rock consists of fossils? e) How are metamorphic rocks formed? Give example also. 6. Write any four uses of rocks.​

Answer 1

3.igneous and sedimentary and sedimentary and metamorphic.

4. Marble- metamorphic

pumice-igneous

slate- metamorphic

obsidian- igneous

limestone-sedimentary

5. a) A rock is a solid mass of geological materials. Geological materials include individual mineral crystals, inorganic non-mineral solids like glass, pieces broken from other rocks, and even fossils. A rock can be composed of only one type of geological material or mineral, but many are composed of several types.

b) Igneous rocks form when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust. When lava comes out of a volcano and solidifies into extrusive igneous rock, also called volcanic, the rock cools very quickly.

c) Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus (organic matter).

d) sedimentary rock consits of fossils.

e) Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors. Conditions like these are found deep within the Earth or where tectonic plates meet.

6. Any four uses of rocks are:

•Making Cement (Limestone) (Sedimentary Origin)

•Writing (Chalk) (Sedimentary Origin)

•Building Material (Sandstone) (Sedimentary Origin)

•Bath Scrub (Pumice) (Igneous Origin)

•Kerb Stone (Granite) (Igneous Origin)