Ashi SharmaAIR 12 · CSE 2024 · 211 wordsTheir whole copy
Opening
A rock is an aggregation of soil particles with definite physical & chemical properties.
Sedimentary rocks
Body
(1) [Sandstone] are formed when sediments are compacted one over the other in layers and are subjected to high heat & temperature over a period of time. These come in various colours like redsandstone, yellow Sandstone etc.
(2) [Limestone] is formed by the chemical action of mildly acidic rain (carbonic acid) on rock formations over a period of time under high heat & pressure conditions.
(3) [Shale] is formed by the deposition and aggregation of remains of fauna under high heat & pressure over a period of time.
(4) [coal] is formed by the decomposition and deposition of flora remains over long courses of time under high heat & pressure conditions.
Economic Relevance
(1) [Construction]: rocks like sandstone are used in monuments (Red fort, Taj Mahal etc) and are used in vernacular architecture.
Limestone is a key ingredient in the making of cement which [is] essential for RCC construction.
(2) [Energy]: shale & coal are [important] sources of fossil fuel based energy.
(Eg) In India 54% energy → coal.
(3) [Employment]: mining of these rocks provides employment to people.
(4) [Growth]: boost GDP.
(5) [Export potential]
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Therefore sedimentary rocks are both geologically and economically significant.