FY2009 Mineral Resources Program Accomplishments
Worldwide Compendium of Data on Copper, Lead, and Zinc in Volcanic Rocks
Volcanic-hosted massive sulfide (VMS) deposits have provided copper, lead, and zinc for human use for millennia and continue to be an important source for these metals in developed and emerging economies worldwide. A recently released USGS report (available at http://pubs.er.usgs.gov/usgspubs/ofr/ofr20091034) provides descriptive information, including grades and tonnages, for 1,090 deposits, covering most of the world’s known deposits. These data are essential for scientists, policy makers, land managers, and mineral exploration companies. They underpin USGS assessments of undiscovered deposits in the US and worldwide, providing the basis for quantitative assessments of copper, lead, and zinc. They provide predictive information about deposit size and environmental impact, informing decisions on bonding for both exploration and development activities. Data were provided by partners in industry, government, and academia in the US and around the world. This work supports the goal of the Mineral Resources Program to ensure availability of up-to-date quantitative assessments of potential for undiscovered mineral deposits.
World map showing distribution of volcanic-hosted massive sulfide (VMS) deposits, divided by subtype.
Understanding Mineral Deposits in Humid Environments
Recent USGS studies demonstrate that climate is an important variable in the geochemical processes associated with the weathering of mineral deposits and mine wastes in humid climatic settings, common in the Eastern United States. The release of acid waters and metals from mine wastes, their transport away from the sources, and their eventual fate in the environment are all affected by climate. Recent studies of the complex interaction crucial to understanding environmental impacts associated with abandoned mines are available at http://minerals.usgs.gov/east/humid/index.html. Many legacy issues remain in the humid environments in the Eastern United States and the current studies are used in ongoing abandoned mine remediation activities by Federal agencies, such as the Environmental Protection Agency, Army Corps of Engineers, Fish and Wildlife Service, National Oceanic and Atmospheric Administration, and numerous States, especially Maine, Virginia, and Vermont. USGS studies have contributed to pre-reclamation characterization, evaluation of various remediation strategies, and assessment of the success of completed remediation projects. The newly published studies complement previous and ongoing studies of the behavior of mineral deposits and mine wastes in the alpine climates of the Rocky Mountains and arid climates of the southwestern United States. This work supports the goal of the Mineral Resources Program to ensure availability of up-to-date geoenvironmental assessments of priority Federal lands.
Sampling an acid seep at the base of a waste pile at the Pike Hill mine Superfund site in Vermont, August 2005. A bloom of an acid-loving filamentous algae (Ulothrix sp.) starts at the point where water first emerges from the waste pile. A second seep with bloom can be seen in the background. The site, with three abandoned copper mines, is part of the watershed that forms the headwaters of Pike Hill Brook.
Geologic Research Supporting Alaskan Economic Development
Alaska’s undiscovered mineral endowment is thought to be great, but sparse geologic, geochemical, and geophysical data hamper accurate assessment. Recently completed geologic mapping in a 7,000-square-mile region in southwestern Alaska reveals numerous potential gold-bearing granites and provides new information about their structural setting. A new airborne geophysical survey and a regional geochemical sampling program produced data that spurred exploration by private companies throughout the area. Concurrent USGS studies on the Seward Peninsula provide a better understanding of the nature, age, and significance of scattered base metal (copper, lead, and zinc) occurrences. Using modern geologic, geochemical, and geochronological tools, USGS scientists have identified the processes by which these metals were concentrated and narrowed the margin of when they were formed, facilitating exploration in Alaska and contributing to understanding similar deposits elsewhere in the world. These new studies provide data and interpretations to partners and cooperators from the U.S. Bureau of Land Management, Bristol Bay Native Corporation, Alaska Division of Geological and Geophysical Surveys, academic researchers, and several private mineral exploration companies. Specific information from these studies is available at http://minerals.usgs.gov/alaska/economic/index.html. This work supports the goal of the Mineral Resources Program to ensure availability of reliable geologic, geochemical, geophysical, and mineral locality data for the United States.
View looking south toward the Shotgun gold prospect (arrow) in southwestern Alaska. Recent studies supporting Alaskan economic development indicate that the gold in the Shotgun prospect is associated with granitic intrusions that are 70 million years old.
Updating Mineral Deposit Model for Copper
Mineral deposit models allow geologists to combine what is known about the formation of mineral deposits with what is known about the environments where mineral deposits have been discovered throughout the world. This combination of information is crucial to USGS mineral-resource assessments as well as to other mineral resource-related activities conducted by USGS researchers. It also provides key information used by land managers responsible for multiple use activities on Federal lands. Periodically, models are reviewed to incorporate new concepts and findings on the occurrence, nature, and origin of specific mineral deposit types. A preliminary model of porphyry copper deposits, published in 1986, has been updated to include a greater variety of deposit attributes. The updated model includes an enhanced understanding of geophysical and remote sensing attributes and tools useful in resource evaluations, current theoretical concepts of porphyry copper deposit genesis, and a summary of the environmental attributes of unmined and mined deposits. Contributions to the updated model were made by some of the most prominent experts in the field and involved USGS, academia, and industry scientists. The recently completed publication will be a primary reference for researchers and land managers alike for the foreseeable future. This work supports the goal of the Mineral Resources Program to ensure availability of up-to-date quantitative assessments of potential for undiscovered mineral deposits.
Geophysical Research Applied to Real World Problems
The U.S. Army Corps of Engineers (USACE) uses USGS geophysical expertise for a wide range of projects. In the past year, geophysical investigations at selected dams and levees in California provided the USACE with data that will help determine if the earthen structures need to be remediated or replaced. Additional studies conducted by USGS scientists, in collaboration with colleagues from the USACE, include analyzing geophysical properties of soil and sediment samples as part of an effort to detect illegal tunneling activities along the U.S.-Mexico border and in Iraq. Ongoing evaluation of promising geophysical detection methodologies designed to detect tunnels will benefit greatly from current site characterization work by USGS scientists before and after construction of a new tunnel-detection test-site in Arizona. Numerous techniques, including seismic refraction tomography, seismic reflection, direct current resistivity, ground penetrating radar, self-potential, time-domain electromagnetics, frequency domain electromagnetics, magnetics, and audio-magnetotellurics, which were originally developed for mineral resource assessments on Federal lands are used to characterize subsurface conditions. This work is possible because of expertise developed to support the goal of the Mineral Resources Program to ensure availability of up-to-date quantitative assessments of potential for undiscovered mineral deposits.
USGS scientists conduct water-borne electrical resistivity survey along the American River in Sacramento, Calif.
10th Annual Workshop on Mineral Materials
This year marked the 10th annual workshop on mineral materials for the Industrial College of the Armed Forces (ICAF), conducted by USGS scientists in Reston, Va. Since 1924, ICAF has prepared military and civilian leaders responsible for developing national security strategy. USGS curriculum on strategic materials supports the evaluation and management of the national strategy on resources. ICAF’s commandant, Rear Admiral Garry E. Hall, characterized USGS presentations as exposing “students to the very best technical information available on minerals of key value to our Nation’s defense and industrial base.” Admiral Hall stated that he considers the USGS contributions to the ICAF program an indispensable resource because “many issues surrounding access to critical minerals engage senior policy officials throughout the U.S. Government and stimulate concerns among industrial economists.” Mineral production, consumption, and trade data collected by the USGS through voluntary cooperation of the domestic minerals industry and foreign governments, along with the expertise gained by USGS scientists through years of studying the domestic and international minerals industries, are key components in the development of national security strategy. The data and information that are essential for the publication of the USGS Minerals Yearbook, Mineral Commodity Summaries, and Mineral Industry Surveys are the foundation of mineral materials workshops presented to ICAF, which is part of the National Defense University. This work supports the goal of the Mineral Resources Program to ensure availability of long-term data sets describing mineral production and consumption.
Geology of Cook Inlet Region, Alaska
A new digital compilation of Cook Inlet geology in south-central Alaska encompasses an area with historically active volcanoes and extensive oil and gas resources. The digital map, which includes information on rock age and lithology (physical character of the rocks), was compiled from a wide variety of sources, and can be combined with other geologic, geochemical, geophysical, and historical data to generate derivative maps. The derivative products are used in a wide range of geologic and environmental studies and resource assessments using Geographic Information Systems (GIS). The new compilation, which supports assessment activities of the USGS Energy Resources Program and the Alaska Department of Natural Resources, Division of Oil and Gas, is available at http://pubs.usgs.gov/of/2009/1108/. It is part of a large-scale effort to release geologic map data for the United States in a uniform manner and supports the goal of the Mineral Resources Program to ensure availability of reliable geologic, geochemical, geophysical, and mineral locality data for the United States.
Widespread Impacts on Soil from Historic Mercury Mining
A recent study of the soil biogeochemistry and land forms in an area of California that once supplied the world with mercury demonstrates widespread impacts on soils forming from sediments transported downstream. The Cache Creek watershed, site of the study, is located north of San Francisco Bay. The study was designed to increase understanding about how mercury is released into the soil when areas of historic mining are disturbed during gravel mining, road building, and agriculture. Results tracked mercury tens of kilometers downstream from the mining source. Data from the study were used by the U.S. Bureau of Land Management in a recent assessment of the neighboring Bear Creek watershed. The data will also be used by the California State Water Control Board in their efforts to monitor the total mean daily load of mercury in Davis Creek, a tributary to Cache Creek. This work supports the goal of the Mineral Resources Program to ensure availability of reliable geologic, geochemical, geophysical, and mineral locality data for the United States.
Wetlands along the shoreline of the Davis Creek Reservoir, shown here in December 2005, were identified in the recent study as an area of enhanced mercury methylation. Methylmercury, a neurotoxin that is readily biomagnified, is produced in wetland soils in response to increasing soil moisture and nutrient concentrations. The wetlands have an important role in the stabilization of mercury-rich sediments.
Southern Appalachian Mountains Geologic Map Receives Recognition
A new map designed to introduce students and the general public to the geology of the Southern Appalachian Mountains area has been recognized by the National Association of Government Communicators with a Blue Pencil award which “salutes superior communications efforts of government agencies and recognizes the people that create them.” Geology of the Southern Appalachian Mountains, provides a summary of the geology of the region, shows how the mountains are related to movements of tectonic plates over millions of years, and describes how geologic processes created landforms and resources that affect lives of people in the area. The map has also been recognized with a USGS Shoemaker award, which recognizes products that communicate and translate complex scientific concepts to capture the interest of the American public and by the Association of Earth Science Editors. Available online at http://pubs.usgs.gov/sim/2830/, it is one of a family of USGS general-interest products about the Southern Appalachians. Other products include a 25-minute video/DVD, a teacher’s guide to the video/DVD, and a booklet, accessible at http://education.usgs.gov/common/undergraduate.htm#geologicmaps. This work supports the goal of the Mineral Resources Program to ensure availability of reliable geologic, geochemical, geophysical, and mineral locality data for the United States.
Sample of award-winning new map product.