Chapter 16 section 2Chapter 16 section 2Groundwater & Chemical Groundwater & Chemical

WeatheringWeathering

The warmer the rock + long The warmer the rock + long periods of contact with water will periods of contact with water will

cause greater amounts of cause greater amounts of dissolved minerals from that rock.dissolved minerals from that rock.

What is “hard water”?What is “hard water”?

Water that contains large amounts of Water that contains large amounts of dissolved minerals. i.e. calcium, dissolved minerals. i.e. calcium, magnesium, and iron.magnesium, and iron.

Of course low amounts of minerals = Of course low amounts of minerals = soft water.soft water.

What can happen in your What can happen in your household due to hard water?household due to hard water?

Appliances may develop hard water Appliances may develop hard water mineral buildups.mineral buildups.

Many people do not like the metallic Many people do not like the metallic taste of hard water.taste of hard water.

It may not produce many suds from It may not produce many suds from your soap.your soap.

Water dissolves minerals as it Water dissolves minerals as it moves through the ground.moves through the ground.

This will cause “chemical weathering”.This will cause “chemical weathering”. The water will pick up CO2 as it travels The water will pick up CO2 as it travels

through the ground and this produces a through the ground and this produces a weak acid called “Carbonic acid”.weak acid called “Carbonic acid”.

This weak acid can chemically weather This weak acid can chemically weather the rocks. It does this by dissolving the the rocks. It does this by dissolving the minerals and therefore breaking down minerals and therefore breaking down the rock.the rock.

Caverns are limestone that has Caverns are limestone that has been chemically weathered.been chemically weathered.

Water passes through caverns and Water passes through caverns and drips-leaving dissolved calcite which is drips-leaving dissolved calcite which is

deposited in the cavern.deposited in the cavern.

Stalactite and stalagmite are two of Stalactite and stalagmite are two of the formations made of calcite.the formations made of calcite.

What happens if the stalagmite What happens if the stalagmite and stalactite grow together?and stalactite grow together?

You have a column.You have a column.

Sinkholes occur when rock Sinkholes occur when rock dissolves, sediment is dissolves, sediment is

removed, or a cave collapses.removed, or a cave collapses.

What is a natural bridge?What is a natural bridge?

When the roof of a cavern collapses When the roof of a cavern collapses in several places, a straight line of in several places, a straight line of sinkholes can form. The uncollapsed sinkholes can form. The uncollapsed rock is the natural bridge.rock is the natural bridge.

Karst topographyKarst topography

This is irregular topography caused This is irregular topography caused by chemical weathering of limestone by chemical weathering of limestone or other soluble rock by or other soluble rock by groundwater.groundwater.

Where does karst topography Where does karst topography occur-in humid regions and occur-in humid regions and

where there is a lot of where there is a lot of limestone.limestone.

Karst topography can also Karst topography can also occur where it is a dry area.occur where it is a dry area.

This completes C. 16This completes C. 16

Good luck on your test.Good luck on your test.