The need for more geologic mapping in the United States (including Nevada) has recently been mentioned prominently in a number of articles (see the fall 1991 issue of Nevada Geology, for example). It is clear that many pressing environmental, mineral resource, geologic hazard, and urban planning issues can only be resolved adequately with a base of spatial geologic data. Less than half of Nevada has geologic maps that are representative of modern geologic thought and of adequate scale to be useful in resolving problems related to such issues. Geologic mapping is basic to many of the above important societal issues, but it is not a commodity that can be ordered up in any particular area in a short period of time, like a soil test. Geologic maps for any particular area are built on a long history of previous geologic investigations, in the vicinity as well as regionally. Concepts and information change; thus, geologic mapping is an ongoing, ever-changing process. It must be continued at a certain level, so that the database is available when specific decisions need to be made or more detailed or site-specific geologic or derivative maps are required. Many knowledgeable people believe that the level of geologic mapping in the U.S., including Nevada, is not keeping up. Certainly, the U.S. cannot be considered well mapped, compared to most modern, western nations.
A number of programs, plans, and initiatives to increase the production of geologic maps are in the works within Nevada and nationally. The Nevada Geologic Quadrangle Mapping Program is designed to encourage geologists to submit their 7.5-minute quadrangle maps to NBMG for publication. The program provides a small amount of money to help defray field expenses. It is therefore most attractive to graduate students, professors, consultants, company geologists, and government geologists who have already been mapping in an area or for whom salary expenses are otherwise covered. Geologists wishing to submit proposals for the Nevada Geologic Quadrangle Mapping Program should follow the guidelines set forth in the request for proposals, which appears again in this newsletter. Nationally, as reported in the previous newsletter, the National Geologic Mapping Act of 1991 has been introduced in the Senate as S. 1179 and in the House of Representatives as H.R. 2763. These bills call for systematic geologic mapping of the entire United States. In most states, including Nevada, mapping will be at a scale of 1:24,000. The bill authorizes funding for geologic mapping to be coordinated and published by the USGS and by state geological surveys. It also provides for funding to help universities revitalize training of geologic mappers.
Planning for future geologic mapping (as one of many types of geographic data) is required by the federal government. The Office of Management and Budget (OMB), on October 19, 1990, issued the revised OMB Circular A-16, titled "Coordination of Surveying, Mapping, and Related Spacial Data Activities." The revised circular establishes a new interagency coordinating committee, the Federal Geographic Data Committee (FGDC). The objective of the FGDC is to promote the coordinated development, use, sharing, and dissemination of surveying, mapping, and related spatial data. Geologic mapping was added to the categories of spatial data that are included within the purview of the FGDC. A lead agency is established for each category of spatial data; for geologic mapping, it is the Geologic Division of the U.S. Geological Survey.
The FGDC is responsible for providing guidance and promoting cooperation among federal, state, and local government agencies and between the public and private sectors in the collecting and sharing of spatial data. The objective is a partnership among federal, state, and local government agencies and the private sector in the development of a national spatial geographic data infrastructure. A working group of FGDC has been established on the issue of liaison with state and local governments, academia, and the private sector.
The revised Circular A-16 expands the coordination of spatial data to 10 categories: base mapping and digital cartographic, cadastral, cultural and demographic, geodetic, geologic, ground transportation, certain international boundaries, soils, vegetation, and wetlands data. To geologists and other users of geologic maps, the addition of geologic spatial data is quite significant. Although it appears that there is no mechanism in place yet for input from non-federal agencies concerning geologic mapping priorities, this should happen in the future, according to the Circular A-16 guidelines. At present, NBMG plans to coordinate our perceived Nevada priorities with those federal agencies responsible for land management in Nevada (for example, the Bureau of Land Management and the U.S. Forest Service).
The index map for geologic mapping in Nevada on the next page is a preliminary compilation of modern, high-quality geologic mapping of intermediate scale (1:24,000 to 1:62,500). Quadrangles approved for funding under the Geologic Quadrangle Mapping Program are also shown. The NBMG geologic mapping index database contains digital data on the boundaries of each map, and these can be plotted or displayed by use of the Geographic Information System (GIS) software ARC/INFO in use at NBMG. ARC/INFO at NBMG is operated in both DOS and UNIX environments on PCs and a Sun SPARC2 Workstation. Older and less detailed geologic maps are also in the database (but were not plotted for this figure), and work is in progress to add theses and other mapping. We hope that the database will be helpful to users of geologic maps. Contact Ron Hess, Lindsay Christensen, or Gary Johnson at NBMG for further information on the database.
We are conducting a survey of geologic mapping needs in Nevada and are soliciting your input. Please list the names of those 7.5-minute Quadrangles that you believe are in immediate need of new, 1:24,000- scale geologic mapping, and why you believe the mapping is needed. Send the list along with your name, affiliation, and address to Larry Garside (Nevada Bureau of Mines and Geology, M/S 178, University of Nevada, Reno, NV 89557). We also welcome any other comments you have about geologic mapping in Nevada. Results of the survey will be reported in Nevada Geology.
Your response to this survey is very important for the future of Nevada mapping.