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General Information

Desirable Preparation 
General Examination 
Equipment and Facilities


The Department of Geosciences covers a wide range of fields, and actively promotes interdisciplinary study and research.

Students with interest in structural geology, tectonics and geophysics, geochemistry, petrology, mineral physics,geochemistry, biological oceanography, paleontology, paleoceanography and paleoclimate and environmental geology will find most of their research and educational needs accommodated within the laboratories of Guyot Hall, where the Department is located. 

In addition the Department has associated programs in water resources (shared with Civil Engineering), materials science (in collaboration with the Princeton Materials Institute) and  environmental science (Geosciences is currently the leading department within the Princeton Environmental Institute). 

Atmospheric and ocean sciences are an integral part of the Department, but most of the AOS research activities take place at the Geophysical Fluid Dynamics Laboratory, which is located off campus (but is expected to move to campus by the year 2002). Most courses are already taught in Guyot Hall. 

We also provide an recently established computational geosciences as interdisciplinary graduate training program in Computer and Application Sciences-PICASso.  

Desirable Preparation

Advances in the earth sciences depend largely on a basic knowledge of mathematics, chemistry, physics, and biology and on the ability to apply these to geological problems. The best preparation for graduate work in this department combines a solid background in related sciences and mathematics with a basic introduction to the geological sciences. The department welcomes as candidates not only those students whose principal background is in geology, geophysics, or geochemistry, but also those who have concentrated in other sciences, such as biology, chemistry, mathematics, physics, or engineering. Only the Ph.D. program is offered, for which both beginning and advanced students may apply. 

General Examination

Basis of the Examination:  In the General Examination a student is expected to demonstrate competence and professional expertise in the geological sciences and related fields as relevant to the student's major interests.   Accordingly, the examination is designed to explore: (1) the student's ability to organize and conduct an original research program and to present research results and material, (2) the student's depth of knowledge in the chosen fields of specialization, and (3) breadth in the geological and related sciences.
Short Guidelines for the General Examination
       The advisory committee, in consultation with the student, selects the examiners. The student can be charged with the actual arrangements (date, time and place).
       Generally, there are 4-5 examiners (see Examination Committee below). All members of the Geosciences faculty may attend and may ask questions, but members other than the exam committee do not usually do so.  The exam is not open  to the general public.
       The student submits a written research report (10 - 20 pages) in the form of a scientific paper to the examiners at least one week before the exam.  He or she also submits a brief research proposal (at most two pages) at least one week before the exam. In addition to brief mention of methodology, goals, and research objectives, the proposal should include an explanation of why the research is important and how the research will be performed in a timely fashion.  This proposal should be mostly his/her own work and should outline a plan of research for the next two or three years.   Except for references, the papers cannot exceed the lengths above.  Copies of the report and proposal also go to Graduate Administrator for your files.
       Students will be tested on two areas of concentration.  They should choose areas relevant to their expertise and their research.  The 'areas of concentration' can be narrow (e.g. stable isotope geochemistry) or wide.  Students choosing narrow topics will be examined in greater depth.  Areas of concentration can be based on the non-GEO courses (e.g., inorganic chemistry, statistics).
       Timing:   The general examination normally takes place in May of the second year. The examination may be taken earlier (October or January) by well-prepared students.  It can be delayed with the approval of the Graduate Work Committee only under very special circumstances such as serious illness.  Students taking the examination a second time must do so within one year at the most.  Their committee may require that the exam be taken at an earlier time, and can also insist on a minimum interval before the exam is retaken.
Examination Committee
       The committee for the general examination consists of four or five faculty members including the student's advisor, a member of the Graduate Work Committee, and at least one faculty member, the nonexpert, whose expertise is outside the student's research area. The nonexpert and GWC member can be the same person but this is not required.  The committee may include a faculty member from another department of the university.  Each committee, including its chair, must be approved by the DGS prior to scheduling the examination.  These rules ensure some conformity and ensure that standards do not diverge between different groups in the department.  Members of the student's advisory committee during the first two years may be members of the Examination Committee, but it is not required.  The chair of the examination committee, who organizes the question period and insures that the exam proceeds according to the guidelines below, must not be the student's primary advisor.
 Pre-Examination Requirements
      Students should complete a form listing their committee, their areas of specialization, and the date and time of their examination.  The committee, and the areas of specialization, needs to be approved at a meeting of the student’s committee, as signified by the adviser’s signature.  This form, accompanied by a copy of the student’s transcript, must be submitted to the DGS 30 days before the exam for his/her approval.
 Preparing for the General Examination:   Some Suggestions
 ·      There are no formal preparation requirements.  However, all parties will recognize that they have a huge stake in the student’s success.  We recommend that the student’s preparation include the following steps.
  ·       Several months before the examination period, students being examined should meet with students who have passed the general exam to ask for information about preparing for, and taking, the exam.
  ·       The student should work with his/her advisor in the preparation of the report and the proposal.   This means submitting drafts for review well in advance of the due date.  The advisor should read these drafts carefully; making suggestions as to how they can be strengthened, and helping the student identify areas where their knowledge of the subject matter should be improved.
  ·       The student should meet with the examiners individually to discuss the topics to be covered during the examination, to identify readings as part of the preparation, and to ask for any help in understanding the science.
  ·       The student should review all relevant course material in depth prior to the examination.   There is no reason students should be unable to answer questions involving basic information and concepts covered in class.
  ·       1-2 weeks before the exam, the student should convene a group of graduate students to serve as the examining committee in a “mock exam”.
Format and Timing of the General Examination
The first hour of the exam covers the research paper and the thesis proposal.  Students' presentations of their research should be no longer than 20 minutes with minimal interruptions.  Each committee member will question the student on his/her research area.  Then, after a short break, the second part covers the two topics selected by the student, and lasts about an hour and a quarter.  Each committee member will ask questions testing the student's general knowledge of the basic science underlying the areas of specialization and fundamental concepts in earth sciences and related disciplines.  Including the break, the exam does not normally last longer than 2 hours and 30 minutes.
Criteria for Passing the General Exam
     Research paper and thesis proposal:   The research paper does not need to be ready for publication, but the paper should have a scholarly level close to that of a paper submitted to a peer-reviewed journal. The research accomplishments should indicate a reasonable level of productivity and the interpretation should indicate a knowledge of the literature and good critical thinking. The thesis proposal should clearly express the justification and the research plans. In response to questions, students should show a broad knowledge of the relevant literature, an understanding of the underlying principles, knowledge of analytical or modeling tools, an appreciation of uncertainties and limitations of the work, and the skills to interpret the results and draw appropriate conclusions.  In general, students should show intellectual ownership of their research.
     Topics selected by the student:  The student should show an understanding of the basic scientific principles underlying each topic, and a broad knowledge of the field. The required depth increases as the breadth of the topic narrows. Students should show a reasonable knowledge of the literature and an ability to invoke and apply concepts relevant to their topics. 
     Students can discuss with their committees alternative formats for their exams if there are special considerations.
Possible Outcomes of the General Exam, and Instructions to the Examining Committee for Reporting the Outcome
      The student passes unconditionally.   Check the "Pass" box.
      The student fails.  Check the "Fail" box.   If it is the second failure, the student is required to leave the program.   If it is the first failure, the student has the option of retaking the exam according to the rules of the Graduate School.   The Committee should recommend when the exam can be retaken.
      The student passes the exam at the level required for a terminal master's degree, but fails at the level required for advancing for the Ph.D.  Check the "Pass" box and attach a note with the committee's recommendation concerning the level of the pass.
      A student passes one part of the exam but fails the other(s), and the examining committee recommends that he retake part of the exam.  Check the "Fail" box.   Attach a memo explaining what part is satisfactory, what part should be retaken, and when the student should retake part of the exam.
      The student passes the exam but the committee wishes to require certain additional work (a course for example).  Check the "Pass" box.   It will then be up to the committee to monitor completion of the additional work.   If necessary the student can be required to do this work as a condition of re-enrollment.
      The outcome of the general exam is decided by the examining committee at the completion of the exam.   If the decision in favor of any of the options outlined above is unanimous, that decision is final and does not require a vote of the full faculty.   If there is a dissenting vote among the committee, the decision must be presented to and voted upon by the faculty. It is usual for all general exams to be summarized for the full faculty, but only split decisions require a formal vote.
If a Student Decides to Withdraw from Graduate School with a Master’s Degree Before taking the General Exam.
      Under some circumstances, a student may decide prior to the general exam that he or she does not wish to continue in the Ph.D. program but does wish to qualify for a master's degree (M.A.) from the department. In this case, the student should discuss this option with the advisor and advisory committee well in advance.  The general exam for an M.A. degree is similar to that for Ph.D. candidacy but will not include defense of a research plan.   It should be noted that passing the general exam for a terminal M.A. degree does not quality the student for Ph.D. candidacy, and some or all of the exam would need to be retaken if the student later decides to pursue a Ph.D. in the department. The requirements for the M.A. degree are as follows:  Completion of all required coursework with no Incompletes, satisfactory completion of the required pre-general exam research project or paper, and the student must stand for the general exam.
Regulations of the Graduate School
      Attention is drawn to the general regulations for the general examination as published in the Graduate Catalogue and particularly to the following paragraphs:   A student is not admitted to the examination until he or she has devoted at least one year or the equivalent of one year entirely to graduate study at Princeton University.
       A graduate student who withdraws from the University in good standing before passing the general examination, and who is therefore not enrolled as a resident graduate student, may ask to stand for the examination with the approval of the Dean on the advice of the department, provided he/she has met the residence and language requirements.
       In case the general examination is not passed, the student will be allowed to stand for re-examination within one year.  If unsuccessful the second time, the student may not stand for the examination again.
       Should a student's performance on the general examination, though judged as passing, raise serious doubt about that student's capacity for doing the scholarly work which is required for the Ph.D. degree, the Department may rule that qualifying for the Master's Degree terminates the student's degree candidacy.  The termination of degree candidacy at the Master's level shall stand without further appeal unless new evidence of scholarly promise or capacity is provided by the student's subsequent professional achievement as shown by scholarly publication. In the latter event, the Dean may entertain a recommendation that the student be readmitted to candidacy for the Ph.D. degree.


The dissertation shall show that the candidate has technical mastery in the chosen field and is capable of independent research. It is expected to be a positive contribution to knowledge, which may consist of a new scientific generalization, a new body of integrated facts that carries scientific implications that extend beyond itself, or a substantial improvement in technique or procedure. The final public oral examination is a final examination in the field of study. In addition to defending the dissertation, candidates are expected to respond to questions relating to the specific principles involved in their research and to questions ranging widely over related subjects.

Equipment and Facilities

Modern earth science has a continuum of approaches, ranging from field studies to laboratory and theoretical work using sophisticated instrumentation and large computers. In addition to collections of appropriate materials and the petrographic, mineralogic, sedimentologic, and paleontologic facilities to study them, the department has specialized equipment for laboratory and field studies of seismology and for experimental studies on rocks at high pressure and temperature; for crystal structural studies by X-ray diffraction and by ultraviolet, visible, infrared, and Raman spectroscopy; for the study of fluid inclusions; for compositional and radioisotopic studies of ocean and river water; and for stable carbon, oxygen, and nitrogen isotope analysis of fluids, organic remains, and minerals. Extensive laboratory facilities for chemical and biological work include a wide array of analytical instruments, molecular biological and microbiological facilities, clean room, and state-of-the-art mass spectrometry. 

Geochemistry: Specific instruments include argon plasma and atomic absorption spectrometers; gas chromatographs, HPLC, and ion analyzers; infrared, ultraviolet and fluorescent spectrometers; gamma and scintillation counters; ultracentrifuges; a Cameca electron microprobe, single-crystal cameras, and an automated powder X-ray diffraction system for work at room and high temperatures; field gun emission scanning  and transmission electron microscopes; dissolved- and solid-carbon analyzers; and modern wet-chemical laboratory facilities. There is also a hydrothermal laboratory, including large-capacity rocking autoclaves, kinetic flow systems, optical high-pressure and high-temperature cells, and an internally heated high-pressure system. 

The Ocean Tracer Laboratory includes alpha detectors and scintillation detectors for measuring low levels of radon and radium radioisotopes and a high-resolution intrinsic germanium well detector for gamma ray measurement. 

The Stable Isotope Laboratory contains a new V. G. Optima gas source mass spectrometer, with peripheral devices for automated analysis of carbonate minerals and for automated loading and cleaning of CO2, H2O, and N2 gas mixtures. Off-line preparation facilities are available for water samples, organic materials, and minerals. 

Biological Oceanography Research focuses on carbon and nitrogen cycle processes and trace metals in the oceans.  Instruments include controlled temperature rooms for phytoplankton and bacterial culture, epifluorescence microscopes, centrifuges, scintillation counter, gamma counter, autoclave, atomic absorption spectrometer, laminar flow hoods, trace metal clean room, Europa 20/20 mass spectrometer, automated DNA sequencer, gel documentation system, and fully equipped molecular biological laboratories for protein and nucleic acid research. 

Geophysics and Structural Geology: The High-Pressure Mineral Physics Laboratory contains diamond anvil cells for high-pressure/temperature studies. Included in the facility are stereomicroscopes, microdrill, gas loading system, and photoluminescence, Raman and Brillouin spectroscopy. Access to second- and third-generation synchrotron radiation facilities is available. All these facilities are supported by a departmental machine shop and lapidarian shops. 

The Department owns three 6-channel digital portable seismometers along with support equipment for a wide variety of small-scale field experiments. In addition, we have developed low-cost broad band seismometers that are used in high schools around the country. For larger experiments abroad, we use portable seismographs from the Passcal Instrument Center. 

Much of the seismological data analysis and geodynamical computations are performed in our "computer laboratory," which consists of three computer workrooms with a dozen workstations,  a Beowulf cluster with 136 Pentium processors in parallel, a Sun Enterprise 3000 computer server, and numerous peripherals for text and color graphics output. And an expresso machine! We obtain our data from digital archives around the world, as well as from our own field experiments with portable seismic instrumentation (such as in the Sierras and on Iceland). Large disk storage devices ease the processing of seismological data considerably. 

We also have a "structural geology laboratory" consisting of a seminar/layout room and two computer workrooms with workstations (SGI and Sun), Macs, and peripherals for dealing with large maps and images. 

First-year graduate students in geophysics receive brief training to serve as assistant system managers for the computer labs. 

Paleontology: Under construction 


The department library collection holds more than 75,000 volumes (with an additional 25,000 volumes in a storage facility) including all major domestic and foreign journals in the earth sciences and worldwide government survey publications. The library's map collection contains over 300,000 geologic, topographic, physical, cultural, and political maps. The library also houses the Digital Map and Cartographic Information Center which provides access to geospatial data, digital map services, GIS, reference, instruction and consultation. The library has remote and local electronic access to all major indexes covering the sciences and technology .