chapter 8 basics of caves and reefs

Question 1

karst topography

Answer 1

characterized by caves and disappearing streams

Question 2

when does karst topography occur?

Answer 2

when groundwater dissolves soluble rocks

Question 3

is limestone a soluble rock?

Answer 3

yes

Question 4

land subsidence

Answer 4

sinking

Question 5

when does land subsidence occur

Answer 5

groundwater is used faster than it can be replenished

Question 6

what do karst features include?

Answer 6

sinkholes, caves, disappearing and sinking streams

Question 7

what are the different types of reefs?

Answer 7

fringing (near the coastline), barrier(near the coastline), atoll (ring-shaped that protect a central island)

Question 8

how do carbonate rocks form?

Answer 8

• accumulated shells
• precipitate directly from seawater
• most of the caclite precipiated by marine organisms contains a certain percentage of magensium
• the more advanced the organism, the lss mg it will allow in its shells

Question 9

limestone

Answer 9

50% calcite. general rock comprised of calcite. formed from evaporation water

Question 10

dolostone

Answer 10

50% dolomite

Question 11

travertine

Answer 11

limestone that forms from hot groundwater

Question 12

what rocks dissolve and create caves?

Answer 12

limestone

Question 13

what does surface and deeper groundwater contribute to?

Answer 13

development of underground caves

Question 14

what can dissolve rocks?

Answer 14

• usually acidic water
• carbon dioxide absorbed from the atmosphere
• ph of cave water is 4 to 5; neutral water has ph of 7

Question 15

aquifer

Answer 15

geologic formation that stores water undergound

Question 16

aquiclude

Answer 16

does not store water

Question 17

unconfined aquifer

Answer 17

water is not under pressure. need to pump it out of the ground

Question 18

confined aquifer

Answer 18

water is under pressure. it will flow naturally out of a well. it is trapped between layers of impermeable rock