The PhD in Geological Sciences was approved in 1974 as the first doctoral degree program of the University. The PhD program embraces a variety of advanced disciplines in Earth and Environmental Sciences, with research themes focused in Earth System Geochemistry, Geospatial Research, Professional and Entrepreneurial Geosciences, Science Learning and Education, Solid Earth and Geophysics, and Tectonics and Sedimentation, although PhD degrees may be obtained in any field of the geological sciences. The program has a vibrant group of 20 tenured and tenure-track faculty, with a research portfolio addressing global challenges in the environment and natural resources, while taking advantage of the unique and excellent geological settings in our region for research and education. The PhD program is hosted in the attractive Geological Sciences Building with 90,000-sq.ft spaces for offices, laboratories, and classrooms. The department facilities that support our PhD research include a variety of geochemical instruments for advanced isotope and element analysis (MC-ICP-MS, ICP-MS, ICP-OES, IRMS, Laser isotope analyzer, electron microprobe, laser diffraction particle size analyzer and many others), geophysical research infrastructure (seismometers, gravimeters, magnetometers, differential GPS receivers, surface and downhole conductivity and resistivity tools, ground-penetrating radar), geospatial facility, and extensive computational and software resources.