Hi Anna,
We are happy to help. Unfortunately, the librarian staff are not in on Saturdays and the research help desk is purely student-staffed. However, you can set up an email with the LITS liaison for Geology, Mary Glackin, and she'll be happy to to assist with your research. You can email her at mglackin@mtholyoke.edu.
If you have any other questions, don't hesitate to ask!
Best,
Judy