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15 Cards in this Set
- Front
- Back
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What does limestone consist mainly of?
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calcium carbonate which is insoluble
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Why are rain water and rivers able to remove limestone in solution?
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Because the carbon dioxide which rain water absorbs from the air turns the insoluble carbonate into soluble bicarbonate.
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What is one of the most noticeable features of a limestone landscape?
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The almost complete absence of surface drainage.
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How are grikes formed and what are the intervening blocks of limestone surface are called?
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When joints rapidly beocme excavated and deepened,with the result that the surface becomes criss-crossed with wide irregular gullies,known as grikes.
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How are underground rivers formed?
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When rising rivers in anon-limestone region sometimes flow into a limestone region,the rivers diappear into vertical holes and continue to flow as underground rivers inside the limestone.
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What are the vertical holes called and how are they formed?
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swallow holes or sink holes,they are formed by rivers and they are ususally widened vertical joints.
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Give an example of a sink hole.Swallow holes may join together to give a very large opening called ...and dolines that join up to give even larger openings are called..
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Gaping Ghyll in Yorkshire England.a doline.uvala
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Name one cave of great size.
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Carlbad Cave(New Mexico- U.S.A)is 1200 metres long and 183 m wide.
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How does a gorge develop?
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Sometimes the roof of an underground cave or cavern collapses and a gorge,with almost vertical sides,then develops.eg.Cheddar Gorge,U.K
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Where do rivers reappear after they diappear underground when entering a limestone region?
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They reappear on the surface again where the junction of the limestone and the underlying impermeable rocks meet the surface
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In Yugoslavia and other parts of the Mediterranean region,these soils are usually red and valuable for farming,it is called...
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terra rossa
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What is limestone quarried as?...
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A building stone and for making cement
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Chalk like limestone is made of __________ ________ but it is much softer than limestone.
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calcium carbonate
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Describe chalk's surface.
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it is usually undulating with rounded hills called downs in England,and wide open valleys which are usually without rivers.
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Chalk is a ___________ rock and rain falling on its surface will....
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porous,rapidly soaks into the ground
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