Keyword(s)
Title

Refers to the Title of a map, report, or Larger Work. You can enter the complete title or a partial title. The search will be performed on the entire string of characters you enter. This search is case-insensitive, so either upper or lower case characters may be used. Also, because punctuation is ignored in the search, you don't need to worry about properly entering dashes, spaces, etc., in the title.

When searching for a specific map title, we recommend that you enter a partial title rather than what you think might be the entire title. For example, if searching for map entitled "Complete Bouguer and isostatic residual gravity maps of the Anadarko Basin, Wichita Mountains, and surrounding areas, Oklahoma, Kansas, Texas and Colorado", you're most likely to find it by entering something like "Anadarko basin", "Witchita", etc.

Author

Refers to an author (or co-author) of a map or other publication. You don't need to enter an author's complete name. This search is case-insensitive, so either upper or lower case characters may be used. The same recommendation for the "Title" field applies here. For example, if searching for a publication by G.M. Flint and J.A. Pitken, you're more likely to find it by entering "Flint" or "pitken" than by entering the entire author string in the correct format ("Flint, G.M.; Pitken, J.A.").

Map Number

This applies to maps that have been assigned a Map Number. The Map Number typically refers to a publication series abbreviation (e.g., "GQ" for the USGS series name "Geologic Quadrangle") followed by the series number assigned by the organization publishing the map. Not all published maps contain a Map Number. This search criteria can be difficult to use, because you must know what you're looking for, and you must also know the Map Number abbreviation we use — for these reasons, we do not highly recommend using this search criteria.

The abbreviation for the map series (the characters that precede the number) may follow different formats depending on conventions established by the publisher or by the NGMDB project. Therefore, if searching for a specific map, we recommend that only the numeric portion of the Map Number be entered within the search field (please see examples below). It is important to note that the Map Number entry on the search page is considered a sub-string when performing a search. That is, the search will find all maps in the database whose Map Number contains the search page entry string.

Geologic Themes and Definitions
Themes

The maps and reports in the Map Catalog contain information pertaining to one or more of the following geoscience themes. Please choose themes to search by, or ignore this option to search ALL themes.

Data Theme		Definition
Geology	Bedrock	geologic maps and reports of rocks at or near the Earth's surface
	Surficial	geologic maps and reports of sediment at the Earth's surface
	Structural	maps and reports of structure, or thickness, of buried geologic units
	Engineering	maps and reports of soils or engineering properties of surficial geologic units
	Other	other types of geologic information
Geophysics	Magnetics	maps and reports of the magnetic field induced in different rocks
	Gravity	maps and reports of variations in Earth's gravity field
	Radiometrics	maps and reports of natural radioactivity of different rocks
	Other	other types of geophysical information
Marine	Geophysics	geophysical maps and reports of submerged earth materials
	Coastal	maps and reports of the coastal zone (e.g., areas of erosion or sedimentation)
	GLORIA	images of the ocean floor, as detected by the GLORIA surveys
	Other	other types of marine geologic information
Resources	Metals	maps and reports of metallic resources (e.g., copper)
	Nonmetals	maps and reports of nonmetallic resources (e.g., sand and gravel)
	Petroleum	maps and reports of oil and gas, oil shale, tar sands, etc.
	Coal	maps and reports of coal beds, mining, etc.
	Other Energy	maps and reports of uranium, geothermal sites, etc.
	Water	maps and reports of ground water aquifers, water quality, etc.
	Other	other types of geologic resource information (e.g., geothermal resources)
Hazards	Earthquakes	maps and reports related to earthquake hazards (e.g., faults, earthquake zones)
	Volcanoes	maps and reports related to volcano hazards (e.g., eruption history)
	Landslides	maps and reports of existing landslides or landslide potential
	Environmental	maps and reports specifically noting environmental hazards
	Other	various hazards, not restricted to a single hazard listed above
Other	Geochronolgy	isotopic age estimates, shown on a map or spatially referenced in a database
	Paleontology	fossil localities, descriptions, and ages, shown on a map or spatially referenced in a database
	Geochemistry	geochemical analyses, shown on a map or spatially referenced in a database

Location
State or Territory

Refers to the location of a map or publication within the United States or U.S. Territories. To select specific States or Territories, click on one or more selections from the scrollable list provided. Press the "control" key while making multiple selections (on a Macintosh, use the Apple "command" key). Also press the "control" key when de-selecting previously selected entries. After selecting one entry, press the "shift" key to select a sequential range of entries.

County

Refers to the location of a map or publication within counties, parishes, or boroughs of the United States or U.S. Territories. This option must be used in combination with the "State" search option. After selecting a State or Territory, the Counties window will show all Counties for that State. Press the "control" key while making multiple County selections (on a Macintosh, use the Apple "command" key). Also press the "control" key when de-selecting previously selected entries. After selecting one entry, press the "shift" key to select a sequential range of entries.

Bounding Coordinates

When you enter the coordinates manually, or use the map to specify the bounding box, the search routine will find all maps and reports that are partially or fully contained by this box. This offers a very precise way to search for maps of a given area, but it can be challenging to use because generally you need to know the latitude and longitude, and must enter it in a very specific format. However, if you zoom into the map area in which you're interested, and click "Use area shown on map", the Bounding Coordinates will be automatically filled in.

If you prefer to manually specify the Bounding Coordinates, please enter the latitude and longitude of the "bounding box" as follows:

Values must be in decimal degrees. In many cases, you may decide to specify whole degrees. However, if you need to be more precise, here's how to convert degrees, minutes, and seconds to decimal degrees: (1) to convert minutes to degrees, divide by 60; (2) to convert seconds to degrees, divide by 3600, (3) then add the result of both divisions to derive the decimal portion of a degree.

Other Criteria
Map Scale

Map scale can be expressed as the ratio or proportion between a distance on a map and the actual distance on the land surface. This ratio is called the Representative Fraction (RF). A RF of 1:100,000 indicates that 1 unit of measure on the map represents 100,000 units on the land surface (i.e., 1 inch = 100,000 inches ~ 1.58 miles). To search by scale, you may specify:

Publication Date

Refers to the publicaton date (year) of maps and reports. Use four-digits (for example, "2012"). Enter a single date, or a date range (by using the First and Ending year fields). To search by publication date, you may specify:

Product Format

Most recent geologic maps and reports are published online, either as images, PDF files, or as the more special-purpose Geographic Information Sytstem (GIS) format. Many older maps and reports, originally published on paper, are now also available in a digital format. You can search for these different types of digital products:

Publisher