The Mississippi Valley-Type (MVT) Central and East Tennessee (TN) Districts contain economically significant lead-zinc deposits that occur in the Early Ordovician carbonates of the Knox Group. Although both districts share similar host rock, have similar temperatures of formation, and typically fill open spaces of collapse breccias or replace their host carbonates, previous studies may suggest that these ores did not form from the same mineralizing fluids and may have different Pb sources.

Many new mineral species have been documented in Arizona since the third edition of Mineralogy of Arizona was published in 1995. This new edition adds to the extensive work of the previous authors, who built the foundation on which this new effort rests. This edition is dedicated to these men: John Anthony, Sidney Williams, and Richard Bideaux.The field of mineralogy has undergone many changes since the third edition.

This report responds to a request by the U.S. Geological Survey (USGS) that the National Research Council (NRC) review its concept of The National Map. The National Map is envisioned by USGS as a database providing “public domain core geographic data about the United States and its territories that other agencies can extend, enhance, and reference as they concentrate on maintaining other data that are unique to their needs” (USGS, 2001).

This five day field trip is a general overview of the geology and tectonic history of central Colorado and of the geology of seven famous mining districts. Some of these mining districts had their most productive years in the latter decades of the 19th century, whereas others reached their peak production more recently. At present mining activity in some of them has ceased. In others it is at low levels compared to earlier years. The regional geology and the road log are compiled from numerous sources. The principal ones are field trip guides by Tweto (1978), Reed and others (1988), Lipman (in press) and unpublished field guides of the Colorado Scientific Society and the Society of Economic Geologists. Figure 1 shows the principal geographic features along the route of the trip. <...>

The 2014 SME Guide for Reporting Exploration Results, Mineral Resources, and Mineral Reserves (the 2014 SME Guide) has been adopted by the Society for Mining, Metallurgy, and Exploration, Inc. (SME) and is therefore strongly recommended to be used by members of this organization.

This SME Guide for Reporting Exploration Information, Mineral Resources, and Mineral Reserves (the SME Guide) has been adopted by the Society for Mining, Metallurgy, and Exploration, Inc. (SME) for use by members of this organization and others. A history of the Guide is provided in Appendix H.

Understanding the relations between faults and the flow of thermal fluids is key to successful exploration for new geothermal resources in Dixie Valley and other Basin and Range geothermal systems. Mapping fault patterns within these basins and recognizing their connections at depth are key to improving this understanding. However, most of the faults are shallowly buried, making them difficult to locate and map. Moreover, drill holes and seismic profiles cannot give a comprehensive view of fault attitudes and patterns because the information they provide is only for limited areas.

The U.S. Congress directed the U.S. Geological Survey (USGS) to develop a program plan for its mineral-resource activities. In 1995, the USGS completed the Mineral Resource Surveys Program (MRSP) plan requested by Congress (Appendix A). To obtain an independent review of the five-year MRSP plan, the U.S. Geological Survey, in a letter from Dr. Willis H. White, the Chief of the USGS Office of Mineral Resources, requested in July, 1995, that the National Research Council (NRC) evaluate the MRSP plan and recommend improvements.

Exceptional oblique-dip exposures of submarine fan complexes of the Brushy Canyon Fm. allow reconstruction of channel geometries and reservoir architecture from the slope to the basin floor. The Brushy Canyon conslsts of 1,500 ft. of basinally restricted sandstones and siltstones that onlap older carbonate slope deposits at the NW margin of the Delaware Basin.