Theory question 304
Rocks(a) What is an igneous rocks? (b) State three characteristics of igneous rocks. (c) Explain five economic importance of igneous rocks.
Show the model answer
Model answer
(a) Igneous rocks are rocks formed from the cooling and solidification of molten magma or lava.
(b) Crystalline; hard and compact; not in layers (unstratified); no fossils; mostly impermeable; may be acidic (granite) or basic (basalt).
(c) Building stone and road chippings (granite); sources of minerals (gold, tin, copper, iron); weather to fertile soils (volcanic soils); tourist attractions (inselbergs, volcanic features); granite and basalt for monuments and ornaments; contain groundwater in joints; geothermal energy in volcanic areas.
Explanation
Give an example for each importance.