-
Chaulk
Alternative spelling of chalk.
-
Chalk
Chalk ( ) is a soft, white, porous, sedimentary carbonate rock, a form of limestone composed of the mineral calcite. Calcite is an ionic salt called calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite shells (coccoliths) shed from micro-organisms called coccolithophores. Flint (a type of chert) is very common as bands parallel to the bedding or as nodules embedded in chalk. It is probably derived from sponge spicules or other siliceous organisms as water is expelled upwards during compaction. Flint is often deposited around larger fossils such as Echinoidea which may be silicified (i.e. replaced molecule by molecule by flint).
Chalk as seen in Cretaceous deposits of Western Europe is unusual among sedimentary limestones in the thickness of the beds. Most cliffs of chalk have very few obvious bedding planes unlike most thick sequences of limestone such as the Carboniferous Limestone or the Jurassic oolitic limestones. This presumably indicates very stable conditions over tens of millions of years.
Chalk has greater resistance to weathering and slumping than the clays with which it is usually associated, thus forming tall steep cliffs where chalk ridges meet the sea. Chalk hills, known as chalk downland, usually form where bands of chalk reach the surface at an angle, so forming a scarp slope. Because chalk is well jointed it can hold a large volume of ground water, providing a natural reservoir that releases water slowly through dry seasons.
-
Chaulk (noun)
alternative spelling of chalk
-
Chaulk (verb)
alternative spelling of chalk
-
Chalk (noun)
A soft, white, powdery limestone.
-
Chalk (noun)
A piece of chalk, or nowadays processed compressed gypsum, that is used for drawing and for writing on a blackboard.
-
Chalk (noun)
Tailor’s chalk.
-
Chalk (noun)
A white powdery substance used to prevent hands slipping from holds when climbing, sometimes but not always limestone-chalk.
-
Chalk (noun)
A platoon-sized group of airborne soldiers.
-
Chalk (noun)
The prediction that there will be no upsets, and the favored competitor will win.
-
Chalk (verb)
To apply chalk to anything, such as the tip of a billiard cue.
-
Chalk (verb)
To record something, as on a blackboard, using chalk.
-
Chalk (verb)
To use powdered chalk to mark the lines on a playing field.
-
Chalk (verb)
To record a score or event, as if on a chalkboard.
-
Chalk (verb)
To manure (land) with chalk.
-
Chalk (verb)
To make white, as if with chalk; to make pale; to bleach.
-
Chalk (noun)
a white soft earthy limestone (calcium carbonate) formed from the skeletal remains of sea creatures.
-
Chalk (noun)
a substance (calcium sulphate) that is similar to chalk, made into white or coloured sticks for writing or drawing.
-
Chalk (noun)
a series of strata consisting mainly of chalk.
-
Chalk (noun)
short for French chalk
-
Chalk (verb)
write or draw with chalk
“he chalked a message on the board”
-
Chalk (verb)
draw or write on (a surface) with chalk
“blackboards chalked with Japanese phrases”
-
Chalk (verb)
rub the tip of (a snooker cue) with chalk.
-
Chalk (verb)
charge (drinks bought in a pub or bar) to a person’s account
“he chalked the bill on to the Professor’s private account”