Sample submittal manual
Instructions for submitting samples to the Branch of Analytical Laboratories and laboratories of the Field Services Section of the Branch of Exploration Research.
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Instructions for submitting samples to the Branch of Analytical Laboratories and laboratories of the Field Services Section of the Branch of Exploration Research.
Trace-element data obtained from stream-sediment, soil, and rock-chip samples by semiquantitative spectrographic and atomic absorption analyses. Geochemical data are grouped alphabetically by letter prefix and arranged in numerical order within the lettered groups. The listed data were obtained from samples collected in 1977 and 1978 by Jacob E. Gair and John F. Slack, assisted by Andrew Grosz, Richard Ketelle, Donald Henry, Thomas Hanley, Ann Stevens, and Gregory R. Morley. The spectrographic and atomic absorption analyses were done in laboratories of the Branch of Exploration Research, U.S. Geological Survey, Denver. The spectrographic analyses were done by David F. Siems and Elwin L. Mosier; the atomic absorption analyses, by Allen L. Meier. Data retrieval from the computerized storage file of the U.S. Geological Survey was made by Nancy A. Wright.
Misinformation carries the potential for immense damage to public understanding of science and for evidence-based decision making at an individual and policy level. Our research explores the following questions within seismology: which claims can be considered misinformation, which are supported by a consensus, and which are still under scientific debate? Consensus and debate are important to quantify, because where levels of scientific consensus on an issue are high, communication of this fact may itself serve as a useful tool in combating misinformation. This is a challenge for earthquake science, where certain theories and facts in seismology are still being established. The present study collates a list of common public statements about earthquakes and provides–to the best of our knowledge–the first elicitation of the opinions of 164 earth scientists on the degree of verity of these statements. The results provide important insights for the state of knowledge in the field, helping identify those areas where consensus messaging may aid in the fight against earthquake related misinformation and areas where there is currently lack of consensus opinion. We highlight the necessity of using clear, accessible, jargon-free statements with specified parameters and precise wording when communicating with the public about earthquakes, as well as of transparency about the uncertainties around some issues in seismology.
Although there is widespread agreement that future climates tend toward warming, the response of aquatic ecosystems to that warming is not well understood. This work, a continuation of companion research, explores the role of distinct watershed pathways in lagging and dampening climate-change signals. It subjects a synthetic flow and transport model to a 30-year warming signal based on climate projections, quantifying the heat breakthrough on a monthly time step along connected pathways. The system corresponds to a temperate watershed roughly 27 km on a side and consists of (a) land-surface processes of overland flow, (b) infiltration through an unsaturated zone (UZ) above an unconfined sandy aquifer overlying impermeable bedrock, and (c) groundwater flow along shallow and deep pathlines that converge as discharge to a surface-water network. Numerical simulations show that about 40% of the warming applied to watershed infiltration arrives at the water table and that the UZ stores a large fraction of the upward-trending heat signal. Additionally, once groundwater reaches the surface-water network after traveling through the saturated zone, only about 10% of the original warm-up signal is returned to streams by discharge. However, increases in the simulated streamflow temperatures are of similar magnitude to increases at the water table, due to the addition of heat by storm runoff, which bypasses UZ and groundwater storage and counteracts subsurface dampening. The synthetic modeling method and tentative findings reported here provide a potential workflow for real-world applications of climate-change modeling at the full watershed scale.
While researchers have pondered the possibility of extraterrestrial caves for more than 50 years, we have now entered the incipient phase of planetary caves exploration. Our knowledge of planetary caves varies from body to body. Earth represents the most advanced level of exploration, but many unanswered questions remain. Beyond Earth, identification of possible caves is most advanced for the Moon and Mars , with hundreds of documented candidate cave entrances and several proposed cave mission concepts. To date, the community has catalogued 2,660 SAPs on eight planetary bodies (excluding Earth) across our Solar System. Planetary caves science has the potential to significantly expand over the next decade. A potential roadmap for planetary cave research and exploration is discussed.
Topography provides information about the structural controls of the Great Basin and therefore information that may be used to identify favorable structural settings for geothermal systems. The Nevada Machine Learning Project (NVML) tested the use of a digital elevation map (DEM) of topography as an input feature to predict geothermal system favorability. A recent study re-examines the NVML data, identifying the DEM as the most important feature, showing a broad uniform pattern of high-favorability in the lower-elevation west and low-favorability in the higher elevation east of their study area in north-central Nevada. This regional elevation trend conflicts with the geologic notion that local relative topography should be used to identify geologic structures associated with favorable structural settings for hydrothermal upflow. Specifically, local relative topography gives information about position in the mountains, in the valleys, or at the transitions between, aiding in identification of faults and fault intersections. As part of U.S. Geological Survey efforts to engineer features that are useful for predicting geothermal resources, we construct a detrended elevation map that emphasizes local relative topography and highlights features that geologists use for identifying geothermal systems (i.e., providing machine learning algorithms with features that may improve predictive skill by emphasizing the information used by geologists). Herein, we describe the removal of the regional trend in elevation to emphasize the basin-and-range scale structural features, creating detrended elevation maps. Regional elevation trends were estimated using a local linear regression and subtracted from the actual elevation using a 30-m DEM. In an effort to optimize the detrended surface, alternate versions were produced with different rates of smoothness resulting in three detrended elevation maps. The resulting elevation trend surfaces (a proxy for crustal thickness) are compared with conductive heat flow maps, and a general pattern was observed of a negative correlation between heat flow and regional elevation in many areas, indicating that thinner crust may be causing elevated heat flow in some areas and thicker crust may cause the observed heat flow lows. Because these detrended elevation maps emphasize geologic structure and relative displacement, these products may also be useful for other geologic research including mineral exploration, hydrologic research, and defining geologic provinces.
A brief examination of the Bartin-were whether earthquake area was made on September 23 and September 24,1968, by the authors to determine whether or not geologic effects had been produced that were significant enough to warrant further detailed study by the Mineral Research and Exploration Institute of Turkey or by the National Center for Earthquake Research of the U.S. Geological Survey. In particular, the questions to be answered were whether this "natural experiment" had produced unique or unusual results that would cast light on means of controlling damage by geologic conditions, and whether or not surface faults or other tectonic deformation, h.ad developed which might help define the geologic control of earthquakes in northern Turkey. The brief field examination was made jointly by personnel of the U.S. Geological Survey and Mineral Research and Exploration Institute of Turkey, because of the interest of both agencies in the earthquake hazard problem. Both agencies had participated in the Conference on Earthquake Hazard Minimization sponsored by the Central Treaty Organization held in Ankara in July 1968. The brief examination was, in part, prompted by the recommendations of the Conference group to take advantage of each significant earthquake to learn "how to live with earthquakes in greater safety." No additional study of this earthquake by either organization seems warranted at this time, and our observations made during the brief investigation are reported here.
The Gulf of Mexico is a semi-enclosed sea that borders the USA and Mexico and covers approximately 1.5 million square kilometers. The northern Gulf is topographically complex and is a rich source of oil and gas deposits, which has led to a great deal of research on benthic ecosystems from the coastal zone to the deep sea. While not fully explored, the distribution of cold seeps and deep corals in the northern Gulf is reasonably well described. The eastern Gulf has a moratorium on energy industry development and consequently less exploration and research has been conducted in this region; however, recent explorations have revealed deep scleractinian reefs on the west Florida slope and extensive octocoral gardens on the deep escarpment. The Gulf is a productive sea with lucrative fisheries in addition to oil and gas. Exploitation of natural resources and potential climate change impacts threaten vulnerable ecosystems in the Gulf, including those in the deep sea. This chapter describes the oceanography and geology of the Gulf of Mexico, presents the current state of the knowledge of cold-water coral distribution, physiology and ecology, and provides an assessment of the threats to these vulnerable ecosystems.
Planetary caves have been identified on the Moon and on Mars, and are likely to occur across the Solar System. They present a new frontier for planetary science, subsurface astrobiology, geology and human exploration. The fourth in a series of scientific meetings focusing on the science and exploration of planetary caves brought together 55 terrestrial and planetary scientists, robotics and instrumentation engineers, and students (16 including 1 undergraduate). Conference participants discussed the state of the art of relevant sciences and current engineering capabilities as applied to planetary cave exploration and research. Specifically, they considered cave formation mechanisms, preserved geological records, cave micro-climate and astrobiological potential, engineering challenges of subsurface exploration, and potential robotic mission concepts to explore the subsurface of other worlds, especially the Moon and Mars.
Geologic, or naturally occurring, hydrogen has the potential to become a new, low-carbon, primary energy resource. Often referred to as “white” or “gold” hydrogen, this gas occurs naturally in the Earth’s subsurface, similar to petroleum resources. However, unlike petroleum, which releases carbon dioxide when burned, burning hydrogen only produces water as a byproduct. Exploration for geologic hydrogen remains in an early stage and discoveries of high concentrations of subsurface hydrogen are still relatively rare. To facilitate research and exploration for this potential resource, this report presents the first publicly available prospectivity map of geologic hydrogen accumulations in the conterminous United States. Prospective regions are those regions in which all major components necessary for a hydrogen accumulation likely are present—a source of sufficient hydrogen generation, porous reservoirs for storage, and seals to prevent leakage. The midcontinent region of the United States and the central California coast are revealed as having high prospectivity. This analysis also identifies previously unrecognized prospective regions that may be favorable due to long distance lateral migration of subsurface hydrogen, such as the offshore eastern seaboard of the United States, and can provide a linkage between surface observations of hydrogen degassing and far-field source regions. The methodology developed to create this map is expandable and flexible and may be adapted to incorporate new concepts in the hydrogen system and for application to other regions of the world.
The timing of spring phenology can be influenced by several drivers. Many studies have shown the effect of temperature on spring vegetation growth, but the role of moisture is complex and not as well researched. We explored drivers for aspen spring phenology in the mountains of the western U.S. While temperature exerted control over the timing of aspen green-up in the spring, snow moisture as measured by April 1 snow water equivalent (SWE), played a significant role especially in southern locations bordering the Colorado Plateau. Maximum spring temperatures (March-May) were significantly (p<0.01) correlated with the start of the growing season across the entire Wasatch and Uinta Mountains and most of the western and northern Southern Rocky Mountains. Spring SWE was significantly (p<0.01) correlated with the growing season start across all of the Wasatch and Uinta Mountains and more than half of the Southern Rockies. The locations that experienced a larger snow influence, given by linear regression and R2 values, were located adjacent to the drier Colorado Plateau and south of 40oN latitude. Historical spatial patterns of regional snow accumulations and anomalies in the western U.S. have been chiefly explained by decadal antiphasing patterns across a north-south dipole. Anomalously low SWE co-occurs with a Pacific/North American teleconnection winter circulation associated with strong high pressure over the Pacific Northwest. The pattern shown in aspen phenology in this study, where the timing of spring green-up in the southern half of the intermountain West (south of a zone from 40oN - 42oN and mainly west of the continental divide in Colorado) showed higher sensitivity to winter snow moisture, and this spatial pattern was supported by other studies. Although winter moisture was not as consistent a factor as temperature in driving the start of the season, this study shows evidence that possible future winter drought could shift the growing season earlier than temperature increases alone.
In the summer of 2007, the U.S. Geological Survey (USGS) began an exploration geochemical research study over the Pebble porphyry copper-gold-molydenum (Cu-Au-Mo) deposit in southwest Alaska. The Pebble deposit is extremely large and is almost entirely concealed by tundra, glacial deposits, and post-Cretaceous volcanic and volcaniclastic rocks. The deposit is presently being explored by Northern Dynasty Minerals, Ltd., and Anglo-American LLC. The USGS undertakes unbiased, broad-scale mineral resource assessments of government lands to provide Congress and citizens with information on national mineral endowment. Research on known deposits is also done to refine and better constrain methods and deposit models for the mineral resource assessments. The Pebble deposit was chosen for this study because it is concealed by surficial cover rocks, it is relatively undisturbed (except for exploration company drill holes), it is a large mineral system, and it is fairly well constrained at depth by the drill hole geology and geochemistry. The goals of the USGS study are (1) to determine whether the concealed deposit can be detected with surface samples, (2) to better understand the processes of metal migration from the deposit to the surface, and (3) to test and develop methods for assessing mineral resources in similar concealed terrains. This report presents analytical results for geochemical samples collected in 2007 from the Pebble deposit and surrounding environs. The analytical data are presented digitally both as an integrated Microsoft 2003 Access? database and as Microsoft 2003 Excel? files. The Pebble deposit is located in southwestern Alaska on state lands about 30 km (18 mi) northwest of the village of Illiamna and 320 km (200 mi) southwest of Anchorage (fig. 1). Elevations in the Pebble area range from 287 m (940 ft) at Frying Pan Lake just south of the deposit to 1146 m (3760 ft) on Kaskanak Mountain about 5 km (5 mi) to the west. The deposit is in an area of relatively subdued topographic relief with an elevation of around 300 m (1000 ft). This portion of Alaska is part of the subarctic regime mountains division, Yukon intermontane plateaus-tayga-meadow province ecoregion, as defined by Bailey (U.S. Forest Service, 2007). Between June 28th and July 12th, 2007, scientists from the USGS collected soil, water, stream sediment, vegetation, heavy-mineral concentrate, till, and rock samples from the deposit area. This report contains analytical results for soil, water, stream sediment, and vegetation samples. Analyses for the heavy-mineral concentrate, till, and rock samples are still in progress. The sampling was undertaken during relatively dry and stable weather conditions. Only minor scattered rain showers occurred during the sampling period, so surface conditions were largely unaffected by weather. The predominant sample media collected were soils and surface waters. Soil and water (mostly from ponds and springs, some from small creeks) samples were collected along a single 7.8 km-long (4.8 mi) east-west traverse across the Pebble East and Pebble West zones and from more distal background areas around Koktuli and Kaskanak Mountains. Sample sites are shown on figure 2 and plate 1, and locality coordinates are provided in the accompanying Access and Excel files named FieldSite. Water samples were analyzed by USGS laboratories with one subset analyzed by Activation Laboratories (Actlabs), as indicated below. Soils and stream sediments were analyzed for their total content by SGS Minerals Services under a contract with the USGS. Soil samples were also leached by selected partial-extraction leaching procedures and then analyzed by several commercial laboratories, as described below. Vegetation samples were analyzed as indicated below.
Executive Summary The National Park Service (NPS), in collaboration with the U.S. Geological Survey (USGS), recognizes the need to quantify the sediment budget of the barrier islands within the Gulf Islands National Seashore (GINS) to understand the coastal processes affecting island resiliency. To achieve this goal, identifying and quantifying the physical parameters that drive long-term change is necessary to model the processes that are both generative and terminal in island evolution and capture island response to long-term human alteration and climatic patterns. For example, measuring change across periods of storminess is more effective at assessing island resiliency than measuring change resulting from a single storm impact. Understanding changes to the physical environment over time is key to successfully predicting island responses to future storm impacts, human alteration, and sea-level rise and is necessary for effective decision making and management response. Yet, the diversity of factors affecting natural and cultural resources necessitates a strategic approach to data collection priorities that can inform sediment budget quantification and integrated resource management. This study sought to advance sediment budget modeling efforts by conducting a “Needs Assessment Workshop” at the GINS. The purpose of the workshop was to identify and prioritize the specific research and data needs regarding the sediment budget at the GINS that can enhance the NPS efforts to conserve the islands’ natural resources, cultural resources, and the facilities and infrastructure that support both conservation and visitor use of those resources. This effort explored two research questions: (1) “what research and data needs exist for the sediment budget at Gulf Islands National Seashore” (research question 1) and (2) “how can research to address these needs capitalize on regional partnerships to advance natural and cultural resource conservation at Gulf Islands National Seashore” (research question 2)? The workshop was conducted virtually in a two-part, two-day series. The workshop series was organized by researchers from North Carolina State University in collaboration with NPS and USGS staff and was facilitated by National Oceanographic and Atmospheric Administration staff. The workshop series (two paired, sequential, partial-day workshops) addressed two target audiences: (1) NPS and USGS staff (April workshop) and (2) regional Federal, State, county, and nongovernmental organization staff, including NPS and USGS staff (May workshop). A total of four workshop sessions were held, comprising two sessions with each target audience. The workshop series intended to identify sediment management research and data needs that could enhance natural and cultural resource stewardship at the GINS. One objective was to share information about regional sediment transport and management, available sediment management plans, and predictive modeling capabilities, including geomorphologic and hydrodynamic predictive models. This information was shared through a series of presentations by park managers and NPS and USGS researchers that identified park issues and available capabilities and data. The second objective was to elicit research and data needs, with a primary goal of assessing the importance and urgency of the identified needs. This assessment was partly determined by requesting that the workshop participants identify and prioritize research themes through polls, comments, and discussion. The polls explicitly asked participants to qualitatively evaluate the importance (not at all, slightly, somewhat, very, or extremely) and urgency (not at all, slightly, somewhat, very, or extremely) of the thematically grouped research and data needs. These evaluations were plotted and shared during the workshop to visualize how the relative importance ( x -axis) and relative urgency ( y -axis) of each “need,” relative to other needs, to identify the most necessary (importance) and time-sensitive (urgent) items, thereby allowing an enhanced, holistic understanding of the sediment budget at GINS. Results of the poll are published as a USGS data release. The assessment results revealed that the most important and urgent research and data needs included mapping (for example, elevation, habitat, and cultural resources), a regional sediment budget and management plan, and the dynamic modeling of sediment processes. During the workshop, these issues were visualized using scatter plots to demonstrate the relative importance and urgency of each theme, provide descriptive statistics, and elicit discussion. This format of iterative presentation, discussion, and prioritization allowed the project team to effectively accomplish their objective of identifying important and urgent research needs for natural and cultural resource stewardship at the GINS. Through the workshop, it was determined that expanded communication with the broader research community was needed to coordinate research activities and streamline potential funding opportunities and that research and policy should be integrated through a structured decision-making process. At the conclusion of the workshop, an administered poll showed that the presentations effectively identified data and research needs and that the goals of the workshop were achieved. The results suggest that this type of needs-assessment workshop can effectively identify existing research capabilities and data, determine and prioritize research and data needs, and address how these efforts can use regional partnerships to aid natural and cultural resource conservation and management at National Parks.
This is the second report concerning results of a joint project between the U.S. Geological Survey and the Tianjin Geological Academy to study sedimentary rock-hosted Au deposits in P.R. China. Since the 1980s, Chinese geologists have devoted a large-scale exploration and research effort to the deposits. As a result, there are more than 20 million oz of proven Au reserves in sedimentary rock-hosted Au deposits in P.R. China. Additional estimated and inferred resources are present in over 160 deposits and occurrences, which are undergoing exploration. This makes China second to Nevada in contained ounces of Au in Carlin-type deposits. It is likely that many of the Carlin-type Au ore districts in China, when fully developed, could have resource potential comparable to the multi-1,000-tonne Au resource in northern Nevada. The six chapters of this report describe sedimentary rock-hosted Au deposits that were visited during the project. Chapters 1 and 2 provide an overview of sedimentary rock-hosted Au deposits and Carlin-type Au deposits and also provide a working classification for the sedimentary rock-hosted Au deposits. Chapters 3, 4, and 5 provide descriptions that were compiled from the literature in China in three main areas: the Dian-Qian-Gui, the Qinling fold belt, and Middle-Lower Yangtze River areas. Chapter 6 contains a weights-of-evidence (WofE), GIS-based mineral assessment of sedimentary rock-hosted Au deposits in the Qinling fold belt and Dian-Qian-Gui areas. Appendices contain scanned aeromagnetic (Appendix I) and gravity (Appendix II) geophysical maps of south and central China. Data tables of the deposits (Appendix III) also are available in the first report as an interactive database at http://geopubs.wr.usgs.gov/open-file/of98-466/. Geochemical analysis of ore samples from the deposits visited are contained in Appendix IV.
In the summer of 2007, the U.S. Geological Survey (USGS) began an exploration geochemical research study over the Pebble porphyry copper-gold-molybdenum deposit. This report presents the analytical data collected in 2008. The Pebble deposit is world class in size, and is almost entirely concealed by tundra, glacial deposits, and post-Cretaceous volcanic rocks. The Pebble deposit was chosen for this study because it is concealed by surficial cover rocks, is relatively undisturbed (except for exploration company drill holes), is a large mineral system, and is fairly well-constrained at depth by the drill hole geology and geochemistry. The goals of this study are to 1) determine whether the concealed deposit can be detected with surface samples, 2) better understand the processes of metal migration from the deposit to the surface, and 3) test and develop methods for assessing mineral resources in similar concealed terrains. The analytical data are presented as an integrated Microsoft Access 2003 database and as separate Excel files.
INTRODUCTION Antarctica is the planet's fifth largest continent [13.2 million km2 (5.1 million mi2)]; it contains the Earth's largest (of two) remaining ice sheets; it is considered to be one of the most important scientific laboratories on Earth. This report is the introduction to a series that covers 60 years of U.S. Geological Survey (USGS) scientific activity in Antarctica. It will concentrate primarily on three major topics: 1) a brief chronological record of the historical search, discovery, and exploration of the southern continent by humans; 2) early USGS scientific activities in Antarctica, listing expeditions, projects, people and resulting professional publications for Operation Highjump, 1946-47; Operation Windmill, 1947-48; USS Atka Reconnaissance Cruise, 1954-55; and Operation Deep Freeze I, II, III, and IV, 1955-59, including IGY; 3) significant changes that have occurred in Antarctic exploration and research since World War II will be discussed at the end of this report. Subsequent Open-File Reports will provide a year-by-year documentation of USGS scientific activities and accomplishments in Antarctica beginning with the post-IGY, 1959-60 research team. One Open-File Report is planned to be written for each field-based season. For an example of the series format, see Open-File Reports 2006-1113 (Meunier, 2007a) and 2006-1114 (Meunier, 2007b). This report is a companion document to Open-File Report 2006-1116 (Meunier, 2007c). The USGS mapping and science programs in Antarctica are among the longest continuously funded projects in the United States Antarctic Program (USAP). The 2005-06 field season is the 56th consecutive U.S. expedition in which USGS scientists have been participants, starting in 1946. USGS and the National Science Foundation (NSF) cooperation began with the establishment by NSF of the U.S. Antarctic (Research) Program [USA(R)P] in 1958-59 under Operation Deep Freeze IV (DF IV) and was given the responsibility for the principal coordination and management of all U.S. scientific activities in Antarctica in Deep Freeze 60 (DF 60) (1959-60). Financial support from NSF, mostly in the form of Memorandum of Understandings (MOUs) and Cooperative Agreements, extends back to this period and can be attributed to the need for accurate geologic, geophysical, and topographic base maps of specific field areas or regions where NSF-funded science projects were planned. The epoch of Antarctic exploration during the IGY was driven by science and, in a spirit of peaceful cooperation, the international scientific community wanted to limit military activities on the continent to logistical support (Meunier, 1979 [2007], p. 38). The USGS, a Federal civilian science agency in the Department of the Interior, has, since its founding in 1879, carried out numerous field-based national (and some international) programs in biology, geology, geophysics, hydrology, and mapping. Therefore, the USGS was the obvious choice for these tasks, because it already had a professional staff of experienced mapmakers, scientists, and program managers with the foresight, dedication, and understanding of the need for accurate maps to support the science programs in Antarctica when asked to do so by the U.S. National Academy of Sciences. Public Laws 85-743 and 87-626, signed in August 1958, and in September 1962, respectively, authorized the Secretary, U.S. Department of the Interior, through the USGS, to support mapping and scientific work in Antarctica (Meunier, 1979 [2007], appendix A). Open-File Report 2006-1116 includes scanned facsimiles of postal cachets. It has become an international practice to create postal cachets to commemorate special events and projects in Antarctica. A cachet is defined as a seal or commemorative design printed or stamped on an envelope to mark a philatelic or special event. The inked impression illustrates to the scientist, historian, stamp collector, and general public the multidisciplinary science projects staffed by USGS and collaborating scientists during the field season. Since 1960, philatelic cachets have been created by team members for each USGS field season and, in most cases, these cachets depict the specific geographic areas and field season program objectives. The cachets become a convenient documentation of the people, projects, and geographic places of interest for that year. Because the cachets are representative of USGS activities, each year's cachet is included as a digital facsimile in that year's Open-File Report. In the 1980s, multiple USGS cachets were prepared each year, one for use by the winter team at Amundsen-Scott South Pole Station and the other for the project work areas of the austral summer field season programs.
Mankind will continue to need ores of more or less the types and grades used today to supply its needs for new mineral raw materials, at least until fusion or some other relatively cheap, inexhaustible energy source is developed. Most deposits being mined today were exposed at the surface or found by relatively simple geophysical or other prospecting techniques, but many of these will be depleted in the foreseeable future. The discovery of deeper or less obvious deposits to replace them will require the conjunction of science and technology to deduce the laws that governed the concentration of elements into ores and to detect and evaluate the evidence of their whereabouts. Great theoretical advances are being made to explain the origins of ore deposits and understand the general reasons for their localization. These advances have unquestionable value for exploration. Even a large deposit is, however, very small, and, with few exceptions, it was formed under conditions that have long since ceased to exist. The explorationist must suppress a great deal of "noise" to read and interpret correctly the "signals" that can define targets and guide the drilling required to find it. Is enough being done to ensure the long-term availability of mineral raw materials? The answer is probably no, in view of the expanding consumption and the difficulty of finding new deposits, but ingenuity, persistence, and continued development of new methods and tools to add to those already at hand should put off the day of "doing without" for many years. The possibility of resource exhaustion, especially in view of the long and increasing lead time needed to carry out basic field and laboratory studies in geology, geophysics, and geochemistry and to synthesize and analyze the information gained from them counsels against any letting down of our guard, however (17). Research and exploration by government, academia, and industry must be supported and encouraged; we cannot wait until an eleventh hour to mount a "crash program.".
The increasing global demand for critical minerals to support energy and technological advancement has accelerated exploration and research efforts for these essential resources. Since 2019, the United States Geological Survey (USGS) Earth Mapping Resources Initiative (EMRI) has worked to modernize geologic mapping of the Nation to better understand its critical mineral resources. To further this initiative, the USGS has flown a series of high-resolution airborne magnetic and radiometric surveys over large areas of the southern Midcontinent. The surveys cover known critical mineral deposits and areas with the potential to host additional critical minerals based on the presence of one or more overlapping mineral systems. One aspect of EMRI emphasizes close collaboration between the USGS and the Association of American State Geologists, as well as other government and industry partners to leverage geophysical, geological, and geochemical expertise on both regional and local scales. The EMRI high-resolution airborne survey data provide new insights into the geophysical framework of the southern Midcontinent and its critical mineral endowment. Additionally, discoveries made from the data have directed new studies for critical mineral exploration.