They can take rocks within the caves, and they can slice them and look at the layers within with rocks, much like the rings of a tree, and they can count back in history and learn about the climate on our planet at very different times.
Eles pegam as pedras nas cavernas fatiam e observam suas camadas rochosas, como os anéis das arvores, e assim conseguem remontar  a história e apreender sobre clima do planeta em várias eras.