Mammoth Cave
저자: Korren Pugh
1. time
1.1. millions of years
1.1.1. before the dinosaurs roamed the earth
2. limestone
2.1. soft
2.1.1. dissolves
2.1.1.1. creates the cave hollow
2.2. light/gray
2.2.1. smooth
2.2.1.1. made from shells and bones
3. water
3.1. snow
3.2. rain
3.3. surface river
3.4. surface streams
3.4.1. goes in holes & crack
4. rock
4.1. sandstone
4.1.1. hard rock
4.1.1.1. creates the outer walls of cave
4.1.1.1.1. the roof of rock on the top of the cave
4.1.2. red/brown/
4.1.2.1. made from layers of sand and silt
4.1.2.1.1. rough
5. plants and animals
5.1. decay
5.1.1. acid