<p>I think if you are more interested in the Natural Sciences and making new discoveries Geology would be more suited to you. If you are more interested in developing technical solutions to achieve a certain outcome Petroleum Engineering would hold more interest for you. For both you need a strong background in Math, Physics and Chemistry. For Geology, courses in Paleontology and Biology might also be needed since one of things a geologist has to be able to do is examine and identify fossils of micro-organisms that come up in the well cuttings to determine where they are in the Geologic Column. My oldest son is a college sophomore majoring in Geology and I think he has so far taken more Calculus and Physics courses than Geology courses at this point.</p>