limestone

Question 1

what are limestone environments also known as

Answer 1

karst landscapes

Question 2

what is limestone

Answer 2

name given to rock that is composed mainly of calcium carbonate
sedimentary rock that is formed underwater
some consist of mainly corals/shells of other small marine creatures

Question 3

why is limestone described as being massively jointed

Answer 3

has distinctive plane and joint pattern
joints often spaced quite far apart and often at regular intervals
the joints acts as weaknesses allowing water to percolate into rock and dissolve via chemical weathering processes of carbonation and solution
exposes rock surface and increases surface area vulnerable to further weather

Question 4

what is the chemical equation for the limestone process

Answer 4

H2CO3 + CaCO3 – Ca(HCO3)

Question 5

define limestone pavements

Answer 5

large areas of exposed limestone consisting of flat blocks of exposed limestone called clints which separated by enlarged joints called grykes
when overlying rock was erroded pressure release release on limestone below which cause them to crack even more
allows acidic rain water to seep through joints and dissolve limestone on each side thus widening and deepening joints
grykes run parallel to each other and separate large slabs of limestone called clints

Question 6

define sinkholes

Answer 6

depressions in landscape which may be caused by carbonation and solution of limestone
enlargement of gryke system
by collapse of cavern

Question 7

define doline

Answer 7

enlarged sinkhole
if it grows bigger becomes uvalas which usually form when several dolines coalesce

Question 8

what is the largest depression called

Answer 8

polje
which is hundred or thousands of km^2 in area has flat floor and steep sides

Question 9

define cavern

Answer 9

cave naturally occurring underground which is a hollow passage
forms where many joints or bedding planes close together so that large areas of rock in the same space dissolve quickly via carbonation and solution
this leaves a large space underground called cavern
usually has speleothems which are cave features formed by deposition of minerals and include stalactites and stalagmites

Question 10

stalactites formation

Answer 10

calcium carbonate rich water percolates downwards through joints in limestone
once water comes into contact with air inside cave
however loses some of its carbon dioxide which makes it less acidic and so unable to hold all of the dissolved minerals that picked up on way through cracks above
drop precipitates and leaves few crystals of mineral calcite behind and stalactite begins to grow
as water continues to drip length and thickness of calcite grows and over time deposition of calcium carbonate will form elongated icicle like feature which hangs down from ceiling

Question 11

stalagmite formation

Answer 11

when water containing dissolved calcium carbonate falls onto floor of cave some of the calcite precipitates
buildup of deposits forms mound growing up from the floor

Question 12

define pillars and columns

Answer 12

stalagmites may form directly below stalactite as water drips from ceiling of cave onto floor
may continue to grow downwards and stalactite may continue to grow upwards
until two limestone features eventually meet when this happens forms columns and pillars
extends all the way from ceiling of cave to floor

Question 13

resurgent streams

Answer 13

rivers flowing onto limestone often vanish from surface down sinkholes and flow down through joints and bedding planes
this carves out caverns until reach impermeable layer of rock below limestone later
at this point
flows on impermeable layer of rock until reaches surface and reemerges as spring
this is called resurgence