Question

Mode of occurrence of minerals

Answer 1

i.In igneous and metamorphic rocksminerals occur in the veins andthe lodes. Major metallic minerals like tin, copper, zinc and lead etc. areobtained from these veins and lodes.

ii. In sedimentary rocksminerals occur in layers. Coal and some forms ofiron ore are found like this. Minerals such as gypsum, potash salt andsodium salt are formed as a result of evaporation especially in aridregions.

Answer 2

Minerals generally occur in rocks of these forms:

i.In igneous and metamorphic rocksminerals occur in the veins andthe lodes. Major metallic minerals like tin, copper, zinc and lead etc. areobtained from these veins and lodes.

ii. In sedimentary rocksminerals occur in layers. Coal and some forms ofiron ore are found like this. Minerals such as gypsum, potash salt andsodium salt are formed as a result of evaporation especially in aridregions.

iii. In the decomposed surface rocks(a residual mass of weatheredmaterial) Bauxite is formed.

iv. In alluvial deposits or placer depositsminerals which are not corrodedby water are found. Such as Gold, silver, tin and platinum.

v. In ocean floorvast quantities of manganese nodules are found.Common salt, magnesium and bromine are largely derived from oceanwaters.