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EVALUATION OF THE MRSP PLAN AND RECOMMENDATIONS FOR 25 SUBPROGRAMS The panel respects the USGS for responding to the needs of the federal land-management agencies to understand environmental consequences of mineral resource development. Nonetheless, the panel notes that the rationale in the MRSP Plan for continued mineral resource assessments does not include the important aspect of mineral resource supply as a continuing, legitimate national need. Evaluation of Components Resource and Environmental Assessments Component The panel understands the rationale presented in the MRSP Plan for building on traditional mineral resource assessments to incorporate environmental data and interpretations. However, it is not clear from the MRSP Plan how this process will be accomplished, nor is it clear what exact relationships will exist between the traditional resource assessments and the new mineral-environmental assessments. For example, the Plan calls for a prototype National Mineral- Environmental Assessment for selected deposit types to be undertaken in FY 1999 and 2000. The panel is concerned about the potential uses of this assessment because of the lack of clarity regarding the level of detail that will be employed in the work and the map scale to be used in the presentation of results. Insufficient detail and inappropriate map scales may leave the predictive aspects of the assessments vulnerable to legitimate scientific criticism. This concern also is identified in the following evaluation of the Mitigation Studies Subprogram, and is a topic that the proposed advisory panel, suggested in General Recommendation 4, could help to resolve. Users of mineral resource assessments who addressed the panel repeatedly stressed their needs for detailed geologic maps (at scales of 1:24,000 to 1:100,000), descriptions of known ore deposits, geochemical sampling, geophysical surveys, and other basic geoscience data. Such data are also particularly attractive to many other customers, including industry and academia. Geologic mapping at scales of 1:24,000 to 1:100,000 generally provides the context that is necessary to identify major hydrothermal systems, geologic structures, and types of ore deposits that occur in a
EVALUATION OF THE MRSP PLAN AND RECOMMENDATIONS FOR 26 SUBPROGRAMS given area. Such detailed investigations are the hallmark of classic USGS studies of mineral districts, such as Terlingua (Yates and Thompson, 1959), Mother Lode (Knopf, 1929), and Comstock (Becker, 1882). However, many recent USGS mineral resource assessments have lacked this level of detail, and uncertainties remain regarding locations of areas permissible for the occurrence of different types of ore deposits. Industry routinely conducts detailed geologic mapping at scales of 1:10,000 and larger to help identify specific targets for explorations drilling and to help design mining plans. In its role of assessing mineral resources and in beginning to address the environmental consequences of extracting these resources, however, the USGS (and the land management agencies) needs geologic and alteration mapping scales generally in the range of 1:24,000 to 1:100,000. In the case of mineral-environmental assessments, it is likely that the insufficient scientific detail of investigations will not support the large map scale at which the National Assessments are to be presented. Therefore it seems logical for the MRSP staff to accumulate experience and data on specific sites before attempting to conduct such assessments at a national level. The recent MRSP work at Summitville, Colorado provides an example of useful site-specific investigations. Similar issues of map scale have been confronted by the USGS's National Water Quality Assessment Program (NAWQA), and it may be useful for MRSP and NAWQA to address these issues jointly. The panel is concerned that the MRSP Plan does not discuss in detail the linkages and possible overlaps between work on mineral-environmental assessments and the Mitigation Studies Subprogramâin particular, how geoenvironmental models and baseline geochemistry will be formulated into environmental assessments. According to the Plan, a geoenvironmental model for a given type of mineral deposit characterizes the environmental behavior of rocks, soils, sediments, and waters prior to mining. It also describes and predicts the environmental effects likely to result from mining and processing of metals from such a depositâthe character and size of mine workings, the character and mass of waste products, and the processes of their interactions with the environment. At present, geoenvironmental models are available for only a few deposit types. Recognizing that the MRSP staff will be developing protocols for mineral-environmental assessments over the
