1. Caves

2. Caves
A cave or cavern is a natural underground space large enough for a human to enter.
The word "cave" can also refer to much smaller openings such as sea caves, rock shelters, and grottos.

3. How do caves form?
Basically, caves form naturally by the weathering of rock and they often extend deep underground.

4. How do caves form?
62) Caves form from slightly acidic ground water slowly seeping through slightly basic rocks underground. The acid slowly caused the rock to dissolve and wash away.

5. Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite.
Many limestone's are composed from shells and skeletal fragments of marine organisms such as coral or foraminifera.

6. 63) Caves often form where ancient seas once existed
63) Caves often form where ancient seas once existed. The seashells left behind for millions of years form limestone and this rock reacts with acids in rain water to form large underground caves.

7. Caves

8. 64) Caves have rock structures that look like giant icicles called stalactites and stalagmites.

9.   66) Stalagmites form on the ground of caves.

10.   65)Stalactites form on the ceilings of caves.

11. Remember the difference between Stalagmite and Stalactites?

12. How do I remember? stalaCtite --- Ceiling stalaGmite --- Ground
StalaCtites hang from the Ceiling; stalaGmites rise from the Ground.

13. How do stalagmites and stalactites grow?
67) Water that has natural minerals floating inside slowly drip from the ceilings of caves. Over thousands of years the minerals slowly harden.

14. Review Continued
What rock is most often associated with cave formation?
A. Igneous
B. Metamorphic
C. Sedimentary