Shell Knob Quarry EarthCache

Shell Knob Limestone Quarry
Shell Knob, Missouri

LIMESTONE:

Terms

Calcination (also referred to as calcining) is a thermal treatment process in presence of air or oxygen applied to ores and other solid materials to bring about a thermal decomposition, phase transition, or removal of a volatile fraction. The calcination process normally takes place at temperatures below the melting point of the product materials. Calcination is not the same process as roasting. In roasting, more complex gas–solid reactions take place between the furnace atmosphere and the solids.

Calcareous is an adjective meaning mostly or partly composed of calcium carbonate, in other words, containing lime or being chalky.

Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380–470°C, and vaterite is even less stable.

Lime is a calcium-containing inorganic material in which carbonates, oxides and hydroxides predominate. Strictly speaking, lime is calcium oxide or calcium hydroxide. It is also the name of the natural mineral (native lime) CaO which occurs as a product of coal seam fires and in altered limestone xenoliths in volcanic ejecta. The word "lime" originates with its earliest use as building mortar and has the sense of "sticking or adhering."

Calcareous sedimentary rock is composed of the mineral calcite (CaCO3), which upon calcination yields lime (CaO) for commercial use. In its broadest interpretation the term includes any calcareous material such as marble, chalk, travertine, tufa, lime shell, coral and marl each possessing different and distinct physical properties.

In nature, the limestone bed is found to occur in varying purity, generally a part of the calcium molecules being replaced by magnesium tending towards magnesium limestone or dolomite limestone. Limestone with more than 10% of mineral dolomite is termed dolomite limestone and that with 5 to 10%, magnesium limestone.

The rock containing more than 95% of calcium carbonate is termed high-calcium limestone. Re-crystallized limestone takes good polish and is used as decorative and building stone. It is then called 'marble'.

A variety of other names is associated with limestone depending upon the modes of occurrence, texture, and the remains of foraminifera, mollusks and other shell-forming creatures.

Oolitic limestone is the name given to granular limestone of which each grain consists of a series of concentric layers of calcium carbonate resembling the eggs of the fish. When it resembles the eggs of Roe fish, it is called Roestone.

Crinoidal limestone is a rock composed of encrinites with the remains of foraminifera-mollusks and their lime forming organism. Such beds are commonly found in lower Carboniferous formations, which is about 359.2 to 299 million years ago.

Uses:

Limestone is quarried for roadbeds, building and landscape construction, and cement manufacture.

Limestone is especially popular in architecture, and many landmarks around the world, especially in North America and Europe, are made primarily of the material. Limestone is readily available and relatively easy to cut into blocks or more elaborate carving. It is also long-lasting and stands up well to exposure.

However, it is a very heavy material, making it impractical for tall buildings; it is also quite expensive. Limestone was most popular in the early 20th and late 19th centuries. Train stations, banks and other structures from that era are normally limestone. Limestone is used as a facade on some skyscrapers, but only in thin sheets rather than solid blocks. In North America, most limestone used in construction comes from Indiana.

Though the limestone used for construction is good for humid climates, it is vulnerable to acids, making acid rain a problem when it occurs in places where limestone is used extensively. The acids in the water can wear away the details of statues and other art.

Parking: N36 38.466, W093 39.201

You can park at the gate.
If there is more than one vehicle, if open you can park just inside the gate
but do not go past the Scale House and DO NOT BLOCK THE DRIVE.

**Logging requirements**
DO NOT POST ANSWERS IN YOUR LOG.
Send the following answers to me via email.

1. At waypoint “LIMSTN” you will find a Huge Limestone slab standing upright just behind it lying flat is another huge limestone slab. What color is coming out of the tiny holes all over the top of this limestone slab?
2. At waypoint “Clue2” what is happening here?