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2 formation of limestone
Limestone forms primarily from calcium carbonate in marine environments. It most commonly forms in warm, shallow seas where calcium carbonate from shells and skeletons of marine organisms accumulates over time and lithifies into sedimentary rock. Limestone can also form through chemical precipitation of calcium carbonate in ocean or lake water, or through evaporation in cave systems, leaving behind deposits like stalactites and stalagmites. Overall, limestone forms through either biological or chemical processes involving calcium carbonate in various marine and coastal environments.
2 formation of limestone
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- 2. Structure of limestone •Carboniferous limestone is a hard grey sedimentary rock which was laid in layers on the sea-bed • The horizontal junctions between the layers are called bedding planes • Joints are lines of weakness at right angles to the bedding planes
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- 4. FORMATION OF LIMESTONE •Limestone is a sedimentary rock composed primarily of calcium carbonate (CaCO3) in the form of the mineral calcite. • It most commonly forms in clear, warm, shallow marine waters. It is usually an organic sedimentary rock that forms from the accumulation of shell, coral, algal and fecal debris. • It can also be a chemical sedimentary rock formed by the precipitation of calcium carbonate from lake or ocean water.
- 5. FORMATION OF LIMESTONE LIMESTONEFORMING MARINE ENVIRONMENT
- 6. FORMATION OF LIMESTONE •Most limestones form in shallow, calm, warm marine waters. • When organisms capable of forming calcium carbonate die their shell and skeletal debris accumulate as a sediment that might be lithified* into limestone. • Limestones formed from this type of sediment are biological sedimentary rocks. • Their biological origin is often revealed in the rock by the presence of fossils. *Lithify- transform (a sediment or other material) into stone.
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- 8. FORMATION OF LIMESTONE •Limestone can also form through evaporation • In a cave, droplets of water seeping down from above enter the cave through fractures or other pore spaces in the cave ceiling • There they might evaporate before falling to the cave floor. • When the water evaporates, any calcium carbonate that was dissolved in the water will be deposited on the cave ceiling.
- 9. FORMATION OF LIMESTONE •This evaporative process can result in an accumulation of icicle-shaped calcium carbonate on the cave ceiling. • These deposits are known as stalactites • If the droplet falls to the floor and evaporates there a stalagmite could grow upwards from the cave floor. • The limestone that makes up these cave formations is known as "travertine" and is a chemical sedimentary rock.