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Cite GSA Style

Guide to GSA style as developed by the Geological Society of America.

Creating your reference list

Your reference list should include all references that are mentioned in the text, figures, captions, tables, and appendixes of your paper.  This page should be titled References Cited.

The content of citations will vary according to type of media being cited, but the following rules apply to all types of citations:

  • List references alphabetically by author's surname.

  • List authors by full last name and initials for first and (if applicable) middle names.

    Example: Joseph Walter Pierce would be listed as Pierce, J.W.

  • If there are multiple authors in a reference, separate the authors by commas. Place an "and" before the last author.

    Example: Pierce, J.W., Moore, E.M., and Sadler, J. V.

  • Do not cite unpublished sources, unless the source has been accepted for publication but has not yet gone to print.

  • All references should have a hanging indent.

If you encounter a reference that does not match any of the examples below, include all information that will help a reader locate the reference.


Citing Articles

Use this format when making citations for articles in periodicals (newspapers, magazines, academic journals).


Author, Year of publication, Title: Subtitle (if applicable): Publication, Volume number, Page numbers.


Leigh, D.S., 1994, Roxana silt of the Upper Mississippi Valley: Lithology, source, and paleoenvironment:

Geological Society of America Bulletin, v. 106, p. 430–442.

Citing Books

Use this format when making references for non-periodical print publications such as books, pamphlets, and multi-volume publications such as encyclopedias.

Format for single-author book:

Author, Year of Publication, Title: Place of publication, Publisher, Number of pages.


Twiss, R.J., and Moores, E.M., 1992, Structural geology: New York, W. H. Freeman and Company, 532 p.

Format for chapter in a book or a paper in a multi-author volume:

Author name, Year of Publication, Chapter name, in Editor name, ed., Book title: Place of publication, Publisher,

Volume (if applicable), Page numbers.


Sawyer, D.S., Buffler, R.T., and Pilger, R.H., 1991, The crust under the Gulf of Mexico basin, in Salvador, A.,

ed., The Gulf of Mexico Basin: Boulder, Colorado, Geological Society of America, Geology of North

America, v. J, p. 53–72.

Citing Websites


Author, Year of publication, Title of webpage: URL (Month and year that site was accessed).


Scotese, C.R., 2003, PALEOMAP Project: (accessed August 2011).

Citing Comments, Discussions, & Replies


Author(s), Year, Title: Content type: Publication, Volume (if applicable), Pages.


Selverstone, J., and Gutzler, D.S., 1994, Post–125 Ma carbon storage associated with continent-continent collision: Reply, Geology, v. 22, p. 382–383.

Citing Maps


Author(s), Year of publication, Title: Publisher, Series number if available, Scale if available, Number of sheets if available, Number of text pages (if applicable).


Bayley, R.W., and Muehlberger, W.R., compilers, 1968, Basement rock map of the United States, exclusive of Alaska and Hawaii: U.S. Geological Survey, scale 1:2 500 000, 2 sheets.

Ernst, W.G., 1993, Geology of the Pacheco Pass quadrangle, central California Coast Ranges: Geological Society of America Map and Chart Series MCH078, scale 1:24 000, 1 sheet, 12 p. text.

Citing Guidebooks


Author(s), Year of publication, Title, in Author/Editor, Title of publication: Place of publication, Publisher, Pages.


Barton, C.C., and Hsieh, P.A., 1989, Physical and hydrologic-flow properties of fractures, in International Geological Congress, 28th, Field Trip Guidebook T385: Washington, D.C., American Geophysical Union, 36 p.

Citing Theses


Author, Year [thesis information]: University, Pages.


Wopat, M.A., 1990, Quaternary alkaline volcanism and tectonics in the Mexican Volcanic Belt near Tequila, Jalisco, southwestern Mexico [Ph.D. thesis]: Berkeley, University of California, 277 p.

Citing Multi-Author Publications


Author(s) of article/chapter, Year of publication, Title of article/chapter, in Author(s)/editor(s) of full volume, Title, Place of publication (if available), Publisher (if available), Volume (if applicable), Pages.


Keller, G., 1992, Paleoecologic response of Tethyan benthic foraminifera to the Cretaceous-Tertiary transition, in Takayanagi, Y., and Saito, T., eds., Studies in benthic foraminifera: Tokyo, Tokai University Press, p. 77–91.

Sawyer, D.S., Buffler, R.T., and Pilger, R.H., 1991, The crust under the Gulf of Mexico basin, in Salvador, A., ed., The Gulf of Mexico Basin: Boulder, Colorado, Geological Society of America, Geology of North America, v. J, p. 53–72.

Citing Symposiums & Conferences


Author(s), Year, Title, in Title of proceedings, Month and year of conference (include this only if year of conference differs from publication year): Place of publication, Publisher, Pages


Baar, C., 1972, Creep measured in deep potash mines vs. theoretical predictions, in Proceedings, Canadian Rock Mechanics Symposium, 7th, Edmonton: Ottawa, Canada Department of Energy, Mines and Resources, p. 23–77.

MacLeod, N.S., Walker, G.W., and McKee, E.H., 1976, Geothermal significance of eastward increase in age of upper Cenozoic rhyolitic domes in southeastern Oregon, in Proceedings, Second United Nations Symposium on the Development and Use of Geothermal Resources, San Francisco, May 1975, Volume 1: Washington, D.C., U.S. Government Printing Office (Lawrence Berkeley Laboratory, University of California), p. 465–474.

Citing Government or University Serial Publications


Author(s), Year of publication, Title: Publisher, Volume (if applicable), Pages


Hay, R.L., 1963, Stratigraphy and zeolitic diagenesis of the John Day Formation of Oregon: University of California Publications in Geological Sciences, v. 42, p. 199–262.

Yager, R.M., 1993, Estimation of hydraulic conductivity of a riverbed and aquifer system on the Susquehanna River in Broome County, New York: U.S. Geological Survey Water-Supply Paper 2387, 49 p.

Citing Abstracts


Author(s), Year of publication, Title, Source, volume (if applicable), Pages.


Baker, V.R., 1991, Ancient oceans on Mars: American Astronomical Society Division of Planetary Sciences, 23rd Annual Meeting, Palo Alto, California, Abstracts, p. 99.

Fitzgerald, P.G., 1989, Uplift and formation of Transantarctic Mountains: Applications of apatite fission track analysis to tectonic problems: International Geological Congress, 28th, Washington, D.C., Abstracts, v. 1, p. 491.

Citing Open-File Reports

Use this format to cite materials on items such as CDs and diskettes.


Author(s), Year of publication, Title: Source name (Type of media, page numbers if applicable)


Alpha, T.R., 1993, Landslide effects: U.S. Geological Survey Open-File Report 93-0278-A (paper copy, 43 p.) or 93-0278-B (4 3/4'' optical disk).

Citing Materials In-Press

Use this format when creating citations for materials that have been accepted for publication but have not yet been printed.


Author(s), Year of publication, Title: Publisher, volume (if applicable) followed by (in press).


Hoffman, H.J., and Masson, M., 1994, Archean stromatolites from Abitibi greenstone belt, Quebec, Canada: Geological Society of America Bulletin, v. 106 (in press).