What is limestone? • Limestone = a biochemical sedimentary rock made up mostly of calcium carbonate
How do limestones form? • Most limestones are simply the cemented remains of marine shells • Limestone “anatomy” • Grains • Skeletal particles, ooids, peloids • Lime mud • Microscopic crystals produced by calcareous algae and through abrasion of larger particles • Cement • Inorganically precipitated CaCO3 crystals
Where do limestones form? • Because CaCO3 precipitates most readily in warm, well lit, agitated water of normal marine salinity…..most limestones form in shallow, tropical depositional environments • e.g., Bahamas, central America, Persian Gulf, NW shelf of Australia, Great Barrier Reef, Malaysia, Indonesia, etc.
Modern CaCO3 depositional environments *Note: Although cool water carbonates Are forming in many places, they are highly prone to dissolution and therefore do not become major limestone accumulations
Caicos Platform Reef tract Quiet water high-energy sand shoals Prevailing winds
What are limestone products? • Whole rock • Crushed limestone • Dolomitic limestone • Burned lime (calcium oxide) • High calcium lime • Dolomitic lime • Hydrated lime (calcium hydroxide)
How is limestone used? • Construction • Soil stabilization • Flue Gas Desulfurization • Steel Production (flux for blast furnaces) • Glass Production • Water Treatment • Waste Treatment • Paper Production (filler) • Chemical Production • Masonry, Mortars and Other Building Materials