Limestone

Question 1

What are the characteristics of limestone ?

Answer 1

1. Organic sedimentary rock
2. Cemented and compressed remains of fish and other sea creatures
3. Over millions of years compress and formed slowly into solid rock
4. Contains calcium carbonate

Question 2

Explain carbonation

Answer 2

1. Carbon dioxide mixes with rainwater creating a weak carbonic acid
2. Calcium carbonate ( insoluble) in limestone from bones of dead animals
3. They mix and create calcium bicarbonate( soluble) and it dissolves the limestone

Question 3

Describe a limestone pavement

Answer 3

1. Karst is large flat area of expose limestone with no soil
2. Carbonation worked on the joints that widened them and deepened to form grikes
3. Grikes are separated by flat topped blocks calle clints
4. Water rests on the clints and causes hollows (karrens) and their edges become fluted

Question 4

What are swallow-holes ?

Answer 4

They are large cones shaped cavities on a stream bed ( stream disappears underground)

Question 5

Explain caves and caverns

Answer 5

1. It’s a large underground passage
2. Acidic groundwater flows along cracks and dissolves limestone through carbonation
3. They get enlarged over times by erosion, hydraulic action and abrasion
4. Most caves are formed below the zone of saturation as flowing groundwater is needed to dissolve the limestone
5. Many are currently dry sur to water table rising

Question 6

Explain stalactites

Answer 6

1. Water containing dissolved limestone drips fr the ceiling
   2.As it drips the water evaporates and the carbon dioxide is released
2. This deposits and tiny specknof calcite
3. This crystalises into calcite rings forming straw stalactites ( originally hollow but straw gets blocked by debris )
4. As a result it starts to thicken into a carrot shaped stalactite

Question 7

Explain stalagmites

Answer 7

1. Water drips to the floor and deposits of calcite build up

Question 8

What are hums ?

Answer 8

The walls of the cave that were left standing when a cave collapsed ( limestone outcrops)

Question 9

What are the three types of collapses ?

Answer 9

1. Doline ( smallest )
2. Uvula ( several dolines combined)
3. Polje ( several uvulas combined )