The term for a person who studies geology is "geologist." Geologists are scientists who specialize in the Earth’s physical structure, substances, history, and the processes that shape it. Their work involves studying rocks, minerals, and soil, and understanding the forces that have shaped the Earth over time, including plate tectonics, erosion, and volcanic activity. Geologists often conduct fieldwork to collect samples and data and may work in a variety of sectors, including research, education, environmental consulting, and resource extraction. Their expertise is crucial for addressing issues such as natural resource management, environmental hazards, and climate change.