What did we find out?

In the bottom of the first sinkhole, we found a little bit of limestone and a shell fossil. The hole wasn't very deep or wide, but we thought the limestone might be a clue to how the hole formed. The second hole was wider and deeper than the first and there was a lot of wood debris at the bottom. It reminded us of a kitchen sink drain, except this drain led underground. The last sinkhole was huge! It was so deep that we couldn't safely climb into it to measure the depth. We saw a lot of limestone shelves and another drain at the bottom. We explored some more and found that the drain led to an underground cave. From all these sinkholes we learned that limestone and water play a big part in making sinkholes. We figured that limestone layers must dissolve over time and then collapse to form a sinkhole. more...