Geology books have call numbers starting with QE and are located on the 4th floor of the library

QE1-350.62 General, Including geographical divisions
QE351-399.2 Mineralogy
QE420-499 Petrology
QE500-639.5 Dynamic and structural geology
QE521-545 Volcanoes and earthquakes
QE601-613.5 Structural geology
QE640-699 Stratigraphy
QE701-760 Paleontology
QE760.8-899.2 Paleozoology
QE901-996.5 Paleobotany

You might also find related topics filed under GB for physical geography, and QC851-999 for meteorology and climatology.