Status of the Nevada Geologic Quadrangle Mapping Program

Winter 1993

Geologic mapping and publishing geologic maps have been integral parts of the mission of NBMG throughout its existence. In addition to publishing its own maps, NBMG has long encouraged non-Bureau geologists to submit geologic maps to the Bureau for potential publication. As a further step in the effort to produce high-quality geologic maps, NBMG established the Nevada Geologic Quadrangle Mapping Program in 1991. Supported by contributions from NBMG, the Geological Society of Nevada (GSN), mining companies, and other sources, this program awards funds to geologic mappers through a competitive proposal process to assist mapping throughout Nevada. The program is open to all geologists, including students, professors, consultants, company geologists, and U.S. Geological Survey geologists.

The mapping program has been a resounding success, and it is worthwhile to review how it works and what has been produced over the last few years. The map on the next page shows the current status of large-scale (larger than 1:100,000-scale) geologic maps in Nevada, including maps that have been published, are in review, or are in progress as part of the Quadrangle Mapping Program.

Proposals to the program are reviewed by a committee of representatives from GSN and NBMG. Geologists whose proposals are chosen for funding receive $500 for initial field expenses, $500 when a completed map is submitted to NBMG for review, and $1,500 when the reviewed map is accepted for publication. Of course, this amount of money is not enough to support a geologist through complete mapping of a 7.5' quadrangle but is enough to encourage publication of a map that might not be published otherwise. To make most effective use of the funds, most maps are published at 1:24,000 scale in black and white as part of the new Field Studies Map series.

Quadrangle maps and all geologic maps submitted to NBMG for publication are reviewed extensively. First, the map is reviewed in the office by at least three geologists, and comments are relayed to the author. Subsequent field review of the revised map commonly involves the office reviewers and geologists from GSN or companies that contributed to the mapping. From three to as many as twenty geologists have participated in recent field reviews, although only a few of these are formal reviewers. Nevertheless, the presence of a large number of eyes and opinions greatly helps review and is always welcome.

Fifteen proposals covering 20 quadrangles were funded during 1991, the first year of the program. Sources of funds included GSN, NBMG through its Mining Cooperative Fund, and individual mining companies. Seven quadrangles were supported in 1992; the smaller number largely reflects reduction in funds to support mapping at NBMG and among companies. Five quadrangles were supported in 1993.

Nine maps have been published since 1991 and two are in press. All but two of the quadrangles chosen in 1991 are either published or far along in review. Of the seven 1992 quadrangles, one is published and one has completed review. Several maps by NBMG geologists and volunteered maps are also published or in final stages approaching publication. Some of these maps have been or will be published in color, where additional funds were available, and are at scales ranging from 1:12,000 to 1:48,000. Geologic maps covering 17 quadrangles are in review, and maps covering 19 quadrangles are in progress.

The importance of geologic maps to understanding and solving many societal problems, such as locating mineral resources and ground water, planning waste disposal, and protecting wetlands, has been discussed in several previous newsletters. Most of the geologic mapping supported by the program focuses on areas of significant magmatic, tectonic, or mineralization problems, all critical to the state's economy. Other maps depict the geology and distribution of wetlands in Carson Sink, including large areas in the Stillwater National Wildlife Refuge. Still other maps are of areas adjacent to the proposed nuclear waste repository at Yucca Mountain and should help those involved in waste disposal understand the critical geologic issues.

That's the good news about geologic mapping in Nevada. The bad news is that budgets for geologic mapping are tight at both the state and national level. The National Geologic Mapping Act of 1992, which was enacted to expand geologic mapping throughout the United States, has not yet been meaningfully funded. Nevertheless, mapping and production of geologic maps will continue to be high priority at NBMG. We thank the Geological Society of Nevada for its support of mapping and the many geologists who have participated in the Quadrangle Mapping Program, both as mappers and as reviewers.

---Chris Henry, Research Geologist