The USGS Geologic Names Archive — a collection of index card files, maintained ca. 1900-1990:

The compilation of geologic names into Geolex will always be a work in progress. This work focuses on evaluating content found in numerous source documents, such as the large collection of the USGS Geologic Name Committee's card files of geologic names.

The Geologic Name Committee (GNC) cards (maintained ca. 1900-1990) are here offered as a supplemental source of information on geologic names. These cards were scanned, but are not yet quality-checked; that work will be conducted as time permits. For the present, we hope you will use the GNC cards as an additional aid for your research, and we invite your comments and corrections (please send to

There are two principal card sets in this Archive:

  1. Files with suffix _ALLr or _ALLm.
    An inventory of geologic names used in reports and maps, ranging from informal Department of Energy Technical Documents, to large bodies of work, such as State geologic maps. Includes usages and definitions adopted (and not adopted) by the USGS and State Geological Surveys. Although a great number of these geologic names have been compiled into Geolex, many remain uncompiled. See George Cohee's explanation (ca. 1958) for information included on these cards, which he called "the Z file."
  2. Files with suffix _GNCr or _GNCm.
    Geologic names adopted by the USGS for use in its publications. See Rudy Kopf's explanation (1970) for information included on these cards, which he called "the B file."

There are approximately 20,000 formal names and 10,000 informal names; about 250,000 index cards in two separate collections:

  1. Geologic names of the U.S. (master set, mostly originals).
    Maintained ca. 1900-1940 by the secretary of the USGS Geologic Names Committee; in the 1950s by the lexicon staff (under USGS Branch of Paleontology and Stratigraphy); and ca. 1960-1990 by the USGS Geologic Names Unit.
    1. [geologic name]_ALLr index card files. Approximately 220,000 index cards were scanned (color, 300 dpi, OCR'd; files processed by Get Imaging, Inc., Norman, OK). These index cards are stored in the small annex room of the library, USGS National Center, Reston, VA.
      image of GNC index card
    2. [geologic name]_ GNCr index card files. These cards are stored in Rm. 4B-100, USGS National Center, Reston, VA, they are being scanned (color, 300 and 600 dpi) and files processed by Nancy Stamm, USGS. Since information on these cards is generally handwritten, they are not OCR'd.
      image of GNC index card
  2. Geologic names of the western conterminous U.S., Alaska, Hawaii, Pacific Islands, and Antarctica (originals and revised copies of master set). Maintained ca. 1960-1990 by the western division of the USGS Geologic Names Unit in Menlo Park, CA. These index cards are stored in Bldg. 25 and are being scanned (color, 300 and 600 dpi) and files processed by Nancy Stamm, USGS. Many of these cards are poor quality copies (generated ca. 1976) of the originals stored in Reston, VA, but include additional notations. A comparison of Menlo Park's "ALL" card set with the original as maintained in the Reston collection is provided below. Menlo's "GNC" card set is similar in design to the set maintained in Reston, but with unique content for the region under Menlo's purview.

    [geologic name]_ALLm
    image of GNC index card

    [geologic name]_ALLr
    image of GNC index card

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