Mineral Resources Program
The USGS National Geochemical Database: A tool for environmental and resource management
The U.S. Geological Survey (USGS) has been chemically analyzing samples of geologic material such as rocks, soils, and stream sediments since shortly after it was established in 1879. In the late 1960s, computer technology had evolved to the point where it became possible to store chemical analyses in digital databases. Over the course of the past 30 years, the analytical laboratories of the USGS's Geology Discipline have analyzed about 1.2 million samples and have preserved these analyses, along with information on the nature of the samples analyzed and their locations, in digital format. In 1985, the USGS inherited responsibility for all the data generated during the U.S. Department of Energy's (DOE) National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) Program, which was conducted from the late 1970s through the early 1980s. The NURE HSSR data represent about half a million samples of stream sediments, soils, and waters. Together, these analyses of approximately 1.7 million samples of geologic materials from USGS and DOE programs make up the USGS National Geochemical Database (NGDB). The USGS Mineral Resources Program is currently responsible for managing this important database.
For many years, two separate chemical laboratories within the USGS Geology Discipline maintained their own databases for storing chemical analyses. One of these databases was called RASS (Rock Analysis Storage System). RASS primarily contained data generated from assessments and investigations of the Nation's nonfuel mineral resources. The other database was called PLUTO (named for the god of the underworld from classical mythology). PLUTO contained data generated from many topical investigations in the Geology Discipline such as geologic mapping, volcanic hazards, energy resources, and so on. A summary of each of the three databases making up the NGDB is given below.
RASS (Rock Analysis Storage System)
Figure 3 - NURE sediment and soil sample types. Water sample locations not shown. Compiled by J.N. Grossman, 1998. Link to larger, 61 kb, version of map.
The evolution of each database has led to inevitable inconsistencies, omissions, and, on occasion, incorrect information. The Mineral Resources Program has initiated a long-term effort to improve the quality of these databases through systematic error-identification and correction. As this effort progresses, the upgraded data are released to the public via web sites and (or) CD-ROM publications. At the moment, data are available from the following sources:
In addition to these three sources, files containing data for streams sediments, rocks, and soils from the original (pre-upgrade) RASS and PLUTO databases, as well as many other databases, can be downloaded from the following web site: http://tin.er.usgs.gov/
The geochemical data in the NGDB represent an extremely valuable tool for both resource and environmental management. Customers regularly using data from the NGDB represent Federal, State, and local environmental and public health agencies, mineral exploration companies, and companies in the private sector engaged in risk-based assessment of contaminated land. A potential user of the NGDB must recognize that the data were generated for many different purposes over the past thirty-plus years. The samples in the NGDB were collected by many different sample protocols and analyzed by many different techniques. Putting together an appropriately consistent data set from the NGDB is not a trivial effort. The contacts listed below are always happy to assist in navigating successfully through this database.
For more information
For any aspect of the National Geochemical Database, please contact:
David B. Smith
NURE HSSR data, please contact:
Steven M. Smith
Geochemical data for Alaska, please contact:
Elizabeth A. Bailey