Geologic Maps in the Research Center
Map Reading Tips |
Research Center Map Series & Locations
Map Indexing & Ordering |
Geological Web Sites
Most types of maps show man-made or natural features found on the earth's surface. Geologic maps are different from other maps since they typically show what is beneath the surface of the earth. Geology itself is the study of the earth and its history. Thus, geologic maps are used to present, among other things, formations of rocks and minerals, underground liquids and gases, and the movements and changes of the earth that occur over time.
Geologic maps serve an important purpose since, as stated by the United States Geological Survey (USGS), 'the geology of an area has a profound effect on many things, from the likelihood of landslides, to the availability of groundwater in wells, from the amount of shaking suffered in an earthquake, to the presence of desirable minerals, from the way the landscape is shaped to the kinds of plants that grow best there. Understanding the earth underneath is the first step in understanding the world around us.'
Map Reading Tips
The USGS has detailed information on reading geologic maps. Some of the basic things to remember are:
- A base map, which is a regular map, is printed under the geologic map in light colors to help orient the user.
- Look for a map key to identify symbols and colors used in the map. Sometimes the key is on a separate map sheet if it is extensive.
- Letters on the map refer to the age and name of the particular geologic unit.
- Lines on the map represent contact between geologic units. The shorter the dashes in the line, the more uncertain the location of the units.
- Short lines with numbers are used to show the angle and direction of tilted rock beds that have been thrust up unevenly.
Research Center Map Series and Locations
The Tulsa City-County Library's Central Library has geological maps on the state, national, and international levels. These maps, which are mainly published by state or national geological societies, are located on the fourth floor in the Research Center.
State Geological and Mineral Maps
These maps are arranged alphabetically by state in map
cabinets. Each drawer includes an index of the maps found within
that drawer. In general, geology maps are on top, followed by oil
and mineral maps, and then miscellaneous
maps. There is also a full set of indexes in the geological map indexes
vertical file.
USA and North
American Geological and Mineral Maps
USA and North American
maps are arranged similarly to the state maps with geology maps first, then the oil, mineral, and miscellaneous
maps. Indexes for these are also found in each drawer again with a set in the geological map indexes vertical
file. Remember, if you are looking for Canadian maps check both the North American and Canadian map series. Some
United States petroleum maps also fall in the North American drawer.
Foreign Geological and Mineral Maps
This collection is
organized mainly by continent and then by country. However, we do also have ocean and world maps included at the
end of this series. Indexes are located in each drawer and in the geological map indexes vertical file. More
Canadian series maps as well as the Levorsen series maps are in storage.
Special State Series Geological Maps
Many state geological societies issue geological maps
in special series. These are filed in the vertical
file drawers on the fourth floor in the Research Center
and are arranged alphabetically by state. Included
among these are the GM
(Geologic Maps) and HA
(Hydrological Atlases) Oklahoma Geological Survey series.
Indexes for these state series, as well as for other
geological maps, are also in the vertical files in the
top left drawer. In the drawer beneath the geological
map indexes, we have geological map catalogs.
Geological Highway Maps
These maps produced by the American Association of Petroleum Geologists (AAPG) are found in the front of the
vertical file drawer containing the state geological map indexes. The maps cover the United States and are
divided into multiple state regions. In addition to the standard geological map, they list places of geological
interest, fossil localities, and mineral and gemstone locations.
Tulsa's Physical Environment in the Research Center 's workroom has some useful maps too.
- Surface Geology and Bouguer Gravity of Tulsa County, Oklahoma.
- General Soil Map of Tulsa County, Oklahoma, and Environs.
- General Construction Conditions At a Glance, Tulsa County, Oklahoma, and Environs.
- Locations of All Known or Reported Oil Wells, Gas Wells, and Dry Holes Drilled in Tulsa County and Adjacent Portions of Creek, Osage, Rogers, and Wagoner Counties, Oklahoma Prior to January 1, 1971.
Map Indexing and Ordering
State geological map indexes, found in the vertical file drawers on the fourth floor in the Research Center, typically show a map divided into areas boxed off with colored borders. The colors sometimes indicate the scale of the maps while the numbers in each boxed-off area correspond to a numbered key showing the appropriate map source. Other indexes may be available, but it varies from state to state.
State geological publications catalogs can be helpful in determining what publications are available and, if we do not have them, how to order them. To find these, check the vertical files beneath the geological map index drawer. Each state will differ in the types of catalogs it offers. Oklahoma puts out special publications which have year-by-year indexes and bibliographies. When searching the alphabetical indexes, use key geological features, map series names, or the term 'counties.'
Publications of the U.S. Geological Survey is an annual catalog of all of the USGS publications grouped by type of publication and indexed by subject and author. When looking for maps in the subject index, search by state, type of map, or the word 'maps.' An abbreviations list is located at the front of the alphabetical index to identify the series or type of publication containing the information. The Research Center has these in print dating back to 1879. As of January 2004, the printed version of the catalog of publications of the U.S. Geological Survey was discontinued and made available online only.
Online indexing and ordering information is also available through the USGS. The National Geologic Map Database (NGMDB) allows searching by place and feature names or even by lithologic and geochronologic unit names. The USGS in its Maps, Imagery, and Publications site, offers links to the USGS Store, finding USGS publications, and the Publications Warehouse. To find more tips for ordering USGS products look under Ordering USGS Products and USGS Map Dealer. For background information about geologic maps, check the Geology Research and Information page. Their Geologic Mapping page located under their list of ‘Programs’ gives an introduction, some history, and techniques of geologic mapping. Other useful links are given for world geological organizations and state geological surveys. You can use these sites to find publications and ordering information for maps issued by agencies other than the USGS.
Geological Web Sites
USGS Geology
This site provides a gateway into the USGS world of geology. Some of the links take you into the realm of volcanoes, earthquakes
and landslides, while others explore our mineral and energy resources. Check out information on our continually changing earth, our marine and
coastal areas, or reach out into our solar system with the astrogeology page. The USGS also provides links at the bottom of their site for
searching their own publications as well as making connections to partnering agencies.
Geological
Surveys
Use this site for a worldwide view of geological organizations. International surveys are listed alphabetically by country and
grouped by continents. Links to United States geological surveys are at the bottom of the page. You can also find university departments, geologic
journals, geologic societies, oil and gas companies, geo-software, and job postings in the field of geology on this site.
USGS Education and Outreach
This USGS site is rich in learning resources for children, educators, and the general public. Educators can find teaching
resources divided up by primary, secondary and undergraduate levels. For more fun at school, check out the
Schoolyard Geology.
More geological information than you can imagine is available in the fact sheets which are keyword searchable.
USGS Geology
in the Parks
This site contains basic explanatory information about geologic maps and about the impressive geologic formations found in
some of our national parks. The Basics provides an introduction to geology and geologic maps, gives a glossary of terms, and links
to some educational resources. In another section titled More, discover how formations such as sand dunes, caves, and glaciers formed.
For a detailed look at some of the geologic wonders within our national parks and the forces that worked on them, delve into the Park
Geology section. This site provides a wealth of information for the beginning geologist.