Table of Contents
What is organic limestone?
Limestone is usually a biological sedimentary rock, forming from the accumulation of shell, coral, algal, fecal, and other organic debris. It can also form by chemical sedimentary processes, such as the precipitation of calcium carbonate from lake or ocean water.
Is limestone organic or chemical?
Organic Sedimentary Rocks When shells are cemented together they make a type of limestone. So limestone can be considered chemical or organic.
What is chemical limestone?
Limestone is a sedimentary rock made of calcium carbonate (CaCO3), usually in the form of calcite or aragonite. It may contain considerable amounts of magnesium carbonate (dolomite) as well. However, minor constituents of clay, iron carbonate, feldspar, pyrite, and quartz is also commonly present.
What makes limestone organic?
Limestone is composed mostly of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate ( CaCO 3). Organic matter typically makes up around 0.2\% of a limestone and rarely exceeds 1\%.
What is the difference between chemical and biochemical sedimentary rocks?
The difference between chemical and biochemical sedimentary rocks is that in biochemical sedimentary rocks, organisms play a role in turning the ions into sediment. In chemical sedimentary rocks, the process is inorganic, often resulting from a body of water evaporating and concentrating the ions.
How can you distinguish between a chemical and an organic bioclastic limestone?
The key difference between organic and chemical sedimentary rocks is the process that forms them — and often their texture, composition and appearance bear mute witness to that process. Geologists can determine whether a sedimentary rock is organic or chemical by looking at its texture.
What is the difference between shale and limestone?
Limestone forms in a deep marine environment from precipitation of calcium carbonate. Shale is made of fine clay particles, and therefore indicates deposition in relatively still water.
Where is chemical limestone found?
Chemical limestones Some limestones are formed in freshwater environments associated with caves (stalactites and stalagmites), springs (tufa and travertine) and lakes. Stalactites and stalagmites form in caves as water evaporates from calcium carbonate-rich waters that drip from the roof of the cave and onto the floor.
Is limestone a chemical or biochemical?
Many limestones are biochemical; some may be chemical (inorganically precipitated). Evaporite rocks form when sea water or lake water dries up and precipitates gypsum (CaSO4·2H2O), halite (NaCl), or other minerals. Evaporites are chemical sedimentary rocks.
Why is limestone called limestone?
limestone (n.) late 14c., from lime (n. 1) + stone (n.). So called because it yields lime when burnt. Another name for it, mostly in American English, is limerock.
What is the difference between chemical and biochemical limestone?