A ROBBER INDUSTRY
Unlike agriculture or forestry where crops can be grown over and over again, mining is a robber industry.
- However large the deposit of a given mineral it, continuous mining will exhaust the ores.
- With better technology, we can extract more and more from existing reserves as well as discover new reserves but cannot restore the reserve we have already exploited.
- The mineral resources have been formed by geological processes over a long period of time. Therefore, their exploitation at a faster rate would deplete them.
OCCURRENCE OF MINERALS
- Wide variety of minerals are found in a variety of conditions. Therefore a good understanding of these conditions is required to extract them economically:
- Veins and loads:
- Rocks have crevices, fractures, faults etc. where the fluids can enter. These fluids are a result of either metamorphic or igneous activities. Hence they are found mostly in igneous and metamorphic rocks and sedimentary rocks found in close vicinity of these rocks. Pre Cambrian rocks which have undergone maximum metamorphosis have the highest probability of occurrence of these deposits. Veins and loads are also found in aureoles (rocks surrounding igneous intrusions).
- Veins are smaller in size than loads. Other characteristics are same.
- Many of the major minerals such as tin, copper, silver, lead and zinc are found in veins and loads.
- Silver, lead and zinc are often found in association and hence mined together. Are
- Those deposits are found which can precipitate from either solution or melt.
- Beds and Seams:
- Formed as a result deposition, accumulation and concentration in horizontal of earth’s crust
- Coal, some grades of iron ore (concentrated as a result of long period under great heat and pressure), gypsum, potash salts, common salts (evaporation of lakes in dry areas).
- Some depositions are also taking place at ocean floor today (Iron manganese nodules)
- Weathering products:
- Ex. Bauxite is found in Laterite formation. Fe, Ni and Mn are also found in these conditions.
- The distribution of Aluminum ores is so dispersed and almost never found alone (native). Aluminum has highest concentration in bauxite. Therefore, it is the most valuable ore.
- Alluvial or placer deposits:
- Only highly inert (corrosion resistant), dense and hard to weather elements like Gold, tin and platinum.
- These metals get detached from the source and they flow with the streams into the river valleys where they are then found with clay, sands, pebbles etc. and they have to be recovered by placer mining methods.
FACTORS AFFECTING EXPLOITATION OF MINERAL RESOURCES
1. Distribution: It is highly uneven. Some elements like Tin, Cobalt, Gold, Platinum, vanadium and nickel, asbestos have very localized occurrences.
2. Factors affecting exploitation:
- Value of metal and mineral
- Mining costs
- Size of deposit
- Grade of ore
- Method of mining
- Transport costs
IMPACT OF MINING ON NATIONAL ECONOMY
- The importance of coal in development of industries and industrial regions has already been discussed.
- Employment: likely to affect developing countries more
- Development of transport systems: Inaccessible areas become connected to the rest of the part. Mining stimulates the development of such systems. Congo: Benguela railways (Copper), Malaysia: North South rail and road network (Tin).
- Migration: Large population migrates to these sites hence cities development provides employment in services and processing industries associated with minerals.
- Export earnings and royalty: Very good for underdeveloped countries.
- Domestic industries associated with metals may be stimulated in agricultural or little industrialized countries.
- Mining in the long term has detrimental effects in the form of dereliction.
- Declining mining will leave the area depressed and increased level of unemployment.
- Environmental impact: Decrease water table, pollution and deforestation. Often area becomes uninhabitable.
Resource Curse: Most of the mineral rich states despite being rich in minerals and income from mining have low human development and high incidence of poverty, Area becomes uninhabitable. Ex. Odisha, Jharkhand and Chhattisgarh despite being rich in mineral resources have remained large backward. This is also true for many African countries.
- Mauritiana: Iron ore -> traditional Agri society in South and nomadic herding in North transformed to mining based economy in North leading to development in North.
- Zaire/Congo: (Effect of political instability on mining): Copper belt: Mining started under colonialism -> growth of towns and transport links subsequent independence and instability (Biggest drawback of a landlocked mining areas) -> Decline in output -> successive political stability -> regaining production.
- Malaysia: Tin: led to the development of North South running road and rail network and east west linking every region to Strait of Malacca. It also led to immigration of Chinese laborers which subsequently settled there and now Chinese form a significant percentage of population. Rubber, Cocoa and oil palm are providing the cushion effect of decline in Tin industry.
- Australia: Gold rush: brought many people here. Wide variety minerals discovered in the interior desert and Savanna regions-> development of transport links. Australia, being a developed country, mining forms a very small component of either employment or total contribution to the economy.