Geology Department

If you are interested in Earth—how it formed and then evolved over 4.56-billion years, how it functions as a complex physical and chemical system, how and why our planet supports us, and how our actions affect the world around us—a major in geology may be right for you.

The Geology Department is deeply committed to undergraduate engagement in scientific research, and geology students routinely use an array of cutting-edge instrumentation, including a powder X-ray diffractometer (powder-XRD) for determining mineral identities and a scanning electron microscope (SEM) equipped with an energy-dispersive X-ray-fluorescence spectrometer (EDS) system, an electron-backscatter-diffraction (EBSD) system, and a cathodoluminescence (CL) detector for complete characterization of solid materials at the micrometer scale. The department also possesses ice and sediment core storage facilities, sediment coring equipment, research-grade stereo and petrographic microscopes, and rock and sediment processing equipment. Additional instrumentation and equipment shared with other departments in the Division of Natural Sciences includes a C,H,N,O,S elemental analyzer, an inductively coupled plasma atomic emission spectrometer (ICP-AES) for determining elemental compositions, a micro-CT X-ray scanner for sub-mm-scale mapping of 3D sample volumes, and the Colby Compass, a research vessel equipped with an array of instrumentation for real-time environmental analyses.

Colby’s setting provides an intriguing and exciting area for field study, enabling students to integrate field and laboratory experiences in most geology courses. Students and faculty also enjoy extracurricular field trips within Maine and longer trips to visit special geologic localities in nearby states and Canadian provinces. The Geology Department also provides off-campus international experiences, including study in Bermuda.

The Geology Department offers both a major and a minor for students with different interests. The point scale for retention of the major applies to all courses taken in the major; no requirement may be taken satisfactory/unsatisfactory. Students should consult regularly with their advisor in selecting courses appropriate for meeting their goals for post-graduation employment and/or graduate study. Importantly, the Geology Department is committed to an inclusive Earth science education for all students regardless of race, ethnicity, gender, sexuality, learning differences, and differences in physical ability.


ChairAssociate Professor Tasha Dunn
Associate Professors Tasha Dunn and Walter “Bill” Sullivan; Assistant Professors Bess Koffman and Alejandra Ortiz; Visiting Assistant Professors Bruce Rueger and Alena Giesche

Requirements +

Requirements for the Major in Geology

Requirements for the geology major are:

  • A 100-level gateway course (Geology 122, 123, 125, 127, 129, or 141)
  • Four core courses (Geology 228, 231, 254, and 262)
  • Four geology elective courses numbered 200 or above
  • Three credits of geology seminar (Geology 391)
  • A capstone experience; and
  • Two cognate courses from the following list: Biology 163, 164; Chemistry 121, 122, 141, 142, 147; Computer Science 151, 152, 153; Physics 141, 143, 145; Math 120j, 125, 130, 135, 160, 165; and Statistics 212.

Capstone experiences may include independent research projects earning at least four credits of Geology 491/492, significant off-campus research experiences, or a geology honors thesis. Geology majors may substitute one course in biology, chemistry, computer science, GIS, mathematics, physics, or statistics numbered 200 or above (excluding Statistics 212) for one of the four geology elective courses. Additional coursework in chemistry, physics, and mathematics beyond the minimum requirements is strongly encouraged to broaden students’ skill sets and maximize options after graduation. Students should consult one of the major advisors in the first and second years regarding election of languages and other Colby-required courses. Students should consult with their advisor about capstone experiences during their junior year.

Requirements for Honors in Geology

The Geology Department’s honors program involves a substantial research component in the student’s senior year, with no fewer than six credit hours of Geology 483/484 and completion of a thesis detailing this work. Participation in the honors program requires a 3.5 GPA in the major by the end of the junior year before a faculty sponsor can consider the project. The honors program involves presentation of a research proposal to a faculty committee early in the fall semester, drafting and approval of introductory sections before January, submission of a full draft of the thesis for review by spring break, and approval of the final thesis by the faculty committee. Satisfactory progress will result in credit for Geology 483 and 484. Successful completion of an honors research project, and the major, will enable the student to graduate with “Honors in Geology.” Students who wish to pursue an even more intensive research agenda should consider the Senior Scholars Program, an all-campus honors program in which half the student’s academic credits in the senior year are devoted exclusively to a major research project.

Requirements for the Minor in Geology

A minor in geology is available to students majoring in other disciplines who also desire an introductory understanding of the Earth sciences. Minor programs are tailored to the needs of individual students; courses should be elected in consultation with a Geology Department faculty member. Requirements are:

  • A 100-level gateway course (Geology 122, 123, 125, 127, 129, or 141)
  • Four geology courses selected from courses numbered 228 and above.