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Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean conventional resources of 12 million barrels of oil and 184 billion cubic feet of gas in the Buda Limestone of Texas.
Tungsten appears on the 2018 and 2022 U.S. Geological Survey critical mineral lists in part because of a very high global production concentration in China, which produces almost 83 percent of the world’s mined tungsten. Using known parameters and values from other tungsten mining operations, we created hypothetical scenarios in which three tungsten deposits in Uzbekistan are considered for development. Our results show that all three deposits are likely to be economically viable to develop under 2024 market conditions. If the three studied tungsten deposits were put into production, Uzbekistan could become the third-leading tungsten-producing country in the world and increase world output of tungsten by 2.7 percent. Putting these tungsten deposits in Uzbekistan into production could slightly reduce the tungsten global market concentration, therefore reducing the supply disruption potential for tungsten.
Introduction In 2024, the U.S. Geological Survey's (USGS) National Minerals Information Center (NMIC) completed the project titled "Compilation of geospatial data for the mineral industries of select countries in the Indo-Pacific." This project aimed to leverage the expertise and capabilities of the NMIC to collect, synthesize, and interpret geospatial data to inform on the extractive resources of select countries in the Indo-Pacific region (area of study) and expand the NMIC's understanding on the impact of mineral industry of these countries in the global economy. The 19 countries of interest in the Indo-Pacific study area include Bangladesh, Bhutan, Brunei, Burma, Fiji, Malaysia, Mongolia, Nauru, New Caledonia, New Zealand, Papua New Guinea, Philippines, Singapore, Solomon Islands, South Korea (Republic of Korea), Sri Lanka, Taiwan, Timor-Leste, and Vietnam. The primary objective of this effort was to create a fully attributed Geographic Information System (GIS) portraying existing mining infrastructure, resources, and production capacities across the Indo-Pacific study area as well as highlight mineral production and processing sites under development and potential areas of future extractive industry operations and development in the region. The compiled GIS geodatabase with supporting documentation including comprehensive metadata was published as a USGS data release titled "Compilation of Geospatial Data (GIS) for the Mineral Industries of Select Countries in the Indo-Pacific." This georeferenced portable document format (GeoPDF) map sheet presents a new geographic information product containing a partial representation of the GIS data. This GeoPDF map provides a visual comparison of the distribution of mineral industry GIS data, which contributes to a deeper understanding of the intersections and complexities of the extractive industries within the select countries in the Indo-Pacific region.
Introduction New bedrock and surficial geologic mapping in the Sparta East, Sparta West, and parts of the Glade Valley and Whitehead 7.5-minute quadrangles, North Carolina and Virginia, investigates the geologic framework and causative mechanisms of the August 9, 2020, Mw 5.1 earthquake near Sparta, North Carolina. The mapping documents (1) the coseismic surface rupture from the 2020 earthquake and related brittle structures in the bedrock; (2) the fault contact between the western Blue Ridge and eastern Blue Ridge; (3) lithostratigraphy in the Lynchburg Group, Ashe Metamorphic Suite, and Alligator Back Metamorphic Suite; (4) the nature of the contact between the Lynchburg Group, Ashe Metamorphic Suite, and Alligator Back Metamorphic Suite; and (5) surficial deposits.
The Harrat Rahat volcanic field, located in the west-central part of the Kingdom of Saudi Arabia, is one of the larger Cenozoic harrats among the more than 17 harrats situated upon the Arabia Plate. The map plate contained herein shows, at a scale of 1:100,000, the mapped volcanic geology of northern Harrat Rahat, which consists of the northernmost one-fifth of Harrat Rahat. Northern Harrat Rahat has an area of about 3,340 square kilometers (km 2 ), of which 2,567 km 2 is covered by Harrat Rahat volcanic rocks and deposits, and it encompasses more than 900 exposed vents (that is, craters, cryptodomes, maars, and scoria cones), 289 of which are isolated by younger volcanic deposits and have not been correlated with the 234 volcanic rock units distinguished by geologic mapping. Northern Harrat Rahat is of special interest owing to its proximity to the city of Al Madinah al Munawwarah, which sits within, and is continuing to expand southward over, the north end of the volcanic field. Al Madinah is home to an expanding population, currently at more than 2 million residents, together with the intermittent addition of approximately 3 million pilgrims during Hajj and Umrah (religious visitations). The center of Al Madinah is less than 8 km from lava flows of the only confirmed historically documented eruption, which occurred in 1256 C.E. (654 A.H.). Earlier prehistoric lava flows also encroached into the area of the present-day city limits, as demonstrated by volcanic rocks exposed widely throughout the city in roadcuts, parks, and excavations for new buildings, although no evidence has been found of any other than the 1256 C.E. lava having reached that area during times of human habitation. Geologic mapping was undertaken by the U.S. Geological Survey in collaboration with the Saudi Geological Survey. The features of primary interest within the map area are scoria cones, lava flows, lava domes, craters, and pyroclastic deposits from the Quaternary, which have compositions of basalt, hawaiite, mugearite, benmoreite, and trachyte. The geologic mapping was published by Downs and others (2019) on a single sheet at 1:75,000 scale and two detailed sheets at 1:25,000 scale, accompanied by detailed explanations of the geology. This report presents the geology on a single sheet at 1:100,000 scale and provides condensed geologic explanations for the convenience of readers of this volume. Some minor errors of nomenclature and lava source regions that do not change fundamental interpretations have been corrected herein.
Widespread urbanization on the Edwards aquifer recharge zone in south-central Texas has prompted the development of new approaches and tools for evaluating the current and future status of water quality in the San Antonio and Barton Springs segments of the Edwards aquifer. The U.S. Geological Survey, in cooperation with the San Antonio Water System and the City of Austin, applied continuous monitoring of fluorescence of dissolved organic matter (fDOM) to characterize the sources and transport of dissolved organic matter and associated constituents in the Edwards aquifer. Continuous fDOM time-series data were adjusted using empirically derived temperature, turbidity, and inner-filter-effect correction factors prior to analysis and interpretation. Fully corrected fDOM time-series data from the study sites were evaluated for short- and long-term temporal variability in fDOM in the context of the hydrologic and climatic conditions that occurred during the 5-year study period to understand vulnerability of the aquifer to potential contaminants in recharge. Study results indicate that fDOM is an effective proxy for dissolved organic carbon that, in turn, is indicative of the influx of recent surface water and associated contaminants, and thus, aquifer vulnerability to those contaminants. Although other continuously monitored water-quality parameters provide insights into changes in water quality in response to varying hydrologic conditions, the quantitative relation between fDOM and dissolved organic carbon directly indicates the timing and magnitude of pulses of organic constituents derived from the land surface, whereas other water-quality parameters do not.
n the Gulf of Alaska, a series of marine heat waves depleted Pacific cod ( Gadus macrocephalus ) biomass to the lowest abundance ever recorded and led to the fishery’s closure in 2020. Although the fishery has been productive for decades, this collapse may have historical precedents. Traditional knowledge holders refer to cod as ‘the fish that stop’, and there is a suggested period of decline in the 1930s. Here we conduct a catch reconstruction of the early commercial fishery (1864–1950), confirming a rapid catch decline in the 1920s and 1930s. Next, we evaluate evidence for possible drivers. We document changes to demand and technology that contributed to declining catch. However, we also find both qualitative and quantitative evidence of depletion, suggesting catch declines were not driven entirely by social factors. Overfishing may have contributed to localized catch declines as evidenced by declining catch rates in heavily fished localities. We also find evidence for climate as a driver of regional decline, with the period of catch decline characterized by up to 2°C higher temperatures as compared to the earlier period of high fisheries production. Our analysis underscores the importance of understanding long-term drivers of fisheries productivity and the value of linking fisheries and climate histories.
The fission-track technique has been applied to uranium analysis of natural waters using a single drop of water. Samples may be collected in the field by evaporating a drop of water on a detector, and samples may then be analyzed by returning the detector to the laboratory. A sample collecting kit has been assembled, which facilitates the designed sampling method. Some unique advantages of this technique are picogram sensitivity (10 -12 g) for uranium on single drops of water, maintenance of sample integrity during transport and storage, and the ability to discern whether the uranium is in solution or in the suspended material. Counting the tracks is the most time-consuming part of the analysis, but it can be reduced by using automatic counting systems. The analytical error is generally ± 10 percent over the entire range of concentrations.
Active volcanic systems pose serious hazards to people and property including inundation and incineration by lava, blanketing by tephra (volcanic ash), exposure to noxious volcanic gases, and damage from shallow earthquakes triggered by ascending molten material (magma). To improve understanding of volcanism and associated seismicity on the western Arabia Plate, the Saudi Geological Survey and the U.S. Geological Survey conducted a multi-year investigation of the northern Harrat Rahat volcanic field adjacent to the city of Al Madīnah al Munawwarah, Kingdom of Saudi Arabia. Project components included creation of a high-resolution digital topographic base; interpretation of eruptive history supported by detailed geologic mapping, paleomagnetism, and abundant high-precision geochronology of volcanic deposits; assessments of eruptive styles and volcanic hazards by physical volcanology; investigation of the origins of magmas in the mantle and of their differentiation in the crust revealed by chemical and isotopic petrology; gravity and magnetotelluric surveys to reveal crustal structures and to search for magma reservoirs; and regional and local seismic tomography and analyses of seismic hazards. Project results are presented in this Professional Paper as chapters written for technical scientific audiences. This initial chapter introduces the project and briefly summarizes results in plain language for readers who have more general backgrounds.
Extensive development on Long Island since the late 19th century and projections of increased urbanization and ground-water use makes effective water-resource management essential for preservation of the island's hydrologic environment and maintenance of a reliable source of water supply. This report presents results of a ground-water flow simulation analysis of the effects of development on the Long Island ground-water system. It describes ground-water levels, stream-flow, and the ground-water budget for the predevelopment period (pre-1900), the 1960's drought, and a more recent (1968-83) period with significant hydrologic stress. The report also presents estimated effects of a proposed water-supply strategy for the year 2020. Long Island has three major aquifers-the upper glacial (water-table), the Magothy, and the Lloyd aquifers-that are separated to varying degrees by confining units. Before development, recharge from precipitation entered the ground-water system at a rate of more than 1.1 billion gallons per day. An equal amount discharged to streams (41 percent), the shore (52 percent), and subsea boundaries (7 percent) . Urbanization and withdrawal of more than 400 Mgal/d (million gallons per day) from wells have resulted in local effects that include declines in ground-water levels, drying up and burial of streams and wetlands, reduction of ground-water recharge by increased overland flow to the ocean, a general decrease in ground-water discharge, and salt water intrusion. In some areas, the reduction in recharge is mitigated by leakage from water-supply and wastewater disposal lines, and infiltration of storm water through recharge basins. During 1968-83, a net loss of 240 Mgal/d from the ground-water system caused a decrease in ground-water discharge to streams (135 Mgal/d), to the shore (82 Mgal/d), and to subsea boundaries (23Mgal/d).The greatest adverse effects have been in western Long Island, where the most severe development has occurred. This analysis shows stream base flow to be highly sensitive to water-table fluctuations, and long streams to be more sensitive than short ones. A water-supply scenario for the year 2020 was simulated that employs redistribution of pumping centers to mitigate extreme local effects . Although the net stress on the ground-water system was projected to increase 57 Mgal/d (24 percent) above that of 1968-83, redistribution of ground-water withdrawals across the island would allow recovery of cones of depression in western Long Island, thereby reducing the threat of salt water intrusion and increasing base flow of some streams . The increased stress would cause a net decrease in base flow island wide of 44 Mgal/d; total base flow would be 281 Mgal/d - 39 percent below predevelopment levels or 14 percent below 1968-83 levels. The most severe effects would be in Nassau and western Suffolk Counties.
Microearthquakes can be dynamically triggered in southern California by remote earthquakes. However, directly connecting dynamic triggering mechanisms with observational data remains challenging. One proposed failure mechanism suggests that both the amplitude and duration of cyclic fatigue caused by the passing seismic wave contribute to triggering occurrence. Here, we measure dynamic strains recorded by borehole strainmeters in the Anza section of the San Jacinto fault zone from 710 earthquakes that occurred over 300 km away between 2008 and 2017 to systematically investigate the role of elevated and sustained strain in controlling dynamic triggering. We design a suite of tests to evaluate whether specific amplitude thresholds and durations of strain can predict dynamic triggering cases. We further test whether the peak dynamic strain (PDS) can predict triggering occurrence in combination with the strain amplitude and duration. Based on these tests, there is no strain amplitude–duration threshold that can distinguish triggering occurrence in Anza. Dynamic triggering is more likely to occur if a remote earthquake causes a PDS above 100 nanostrain, though many cases were triggered at smaller PDSs. The lack of clear correlation between triggering and characteristics of the dynamic strain field suggests that the tested features of the incoming waves do not determine triggering occurrence and local fault conditions and slip processes are more important in controlling dynamic triggering in Anza.
Introduction The U.S. Geological Survey (USGS)—a Federal civilian agency—and U.S. military and intelligence agencies collaborate on mapping and remote sensing and have since the establishment of the USGS. The organizations exchange data and information and share technology to further their respective missions in service to the American people. Often referred to as examples of “good government” or “whole of government,” the collaboration avoids costly duplication and maximizes time and effort for the government sectors. Collaboration between these sectors started with the original mapping of the United States and evolved to include remote sensing after the advent of aerial photography and satellite imagery.
Directivity, or the focusing of energy along the direction of an earthquake rupture, is a common property of earthquakes of all sizes and can cause increased hazard due to azimuthally dependent ground‐motion amplification. For small earthquakes, the effects of directivity are generally less pronounced due to reduced rupture size, yet the directivity in small events can bias source property estimates and provide important insights into general regional faulting patterns. However, due to observational limitations, directivity is usually only measured and modeled for large events. As such, many studies of small earthquakes either ignore directivity altogether or assume a constant rupture direction for all events in a cluster. In our study, we apply a refined directivity fitting method constrained with two separate methods of source deconvolution to the dataset of aftershocks of the 2019 Ridgecrest earthquakes, which contain a large number of well‐recorded small‐to‐mid sized earthquakes occurring in close proximity to each other. The revealed directivity of 100+ small (M 2.4–5) earthquakes is highly heterogeneous and primarily oblique to and away from the main fault strike, suggesting a complex postseismic stress redistribution. In addition, the energy focusing effect of directivity appears to bias the selection of high‐quality data from stations in the direction of rupture, leading to average stress‐drop increases of 50% if directivity is not accounted for.
Characteristics of Streamflow at ungaged sites in coal-mining areas of the Cumberland Plateau may be estimated with regression equations that relate streamflow characteristics to the physiographic and climatic characteristics of the corresponding drainage basins. An experiment was performed to compare the accuracy of equations using basin characteristics derived from maps and climatological records (control group equations) with the accuracy of equations using basin characteristics derived from digital processing of Landsat spectral data as well as maps and climatological records (experimental group equations). Results of this experiment show that (with the exception of low flows and four of six annual peak logarithms) drainage area can explain more than 90 percent of the variance in all streamflow characteristics in both groups of equations. Seventeen of 39 experimental group equations that have two basin characteristics each are different from the corresponding control group equations. Five of the 17 differing experimental group equations have no counterpart in the control group because of lack of significance in control group basin characteristics, seven are slightly more accurate, and five are not measurably different in accuracy. When the equations in both groups are arranged into six flow categories, there is no substantial difference in accuracy between equations using basin characteristics derived from maps and climatological records (control group) and equations using basin characteristics derived from Landsat tapes as well as maps and climatological records (experimental group) for this particular study area, the Cumberland Plateau of Tennessee.
The Maverick Basin of south Texas is currently undergoing active exploration and production of gas and oil from tight sandstone reservoirs. The most productive tight sandstones in the basin are in the Upper Cretaceous San Miguel, Olmos, and Escondido Formations. These units are second only to the Eagle Ford Shale in terms of cumulative production volumes. The structural history of the Maverick Basin, from rifting to subsidence to exhumation, has had a profound effect on the characteristics of these reservoirs and the petroleum resources contained therein. This U.S. Geological Survey review of the production history of these strata reflects a recent shift from conventional production to horizontal drilling (unconventional) that exploits low permeability reservoirs in previously overlooked areas of existing oil and gas fields in southern Texas, typically outside of established field boundaries. To investigate the physical properties of the Maverick Basin hydrocarbon accumulations, this case study compiled American Petroleum Institute (API) gravity measurements and calculated cumulative gas/oil ratios (GOR) for thousands of producing wells from the San Miguel, Olmos, and Escondido Formations. Maps were generated from the compiled well production data to show the spatial heterogeneity of API gravity and GOR values for the three formations within the Maverick Basin and immediately outside the basin to the northeast. Within the Maverick Basin, the spatial patterns of API gravity values indicate lighter oils downdip towards the southern basin edge. GOR values indicative of wet and dry gases within the basin are seen interspersed, with values that correspond to black and heavy oils. Differences in the spatial patterns of the petroleum properties within the Maverick Basin are interpreted as effects of Eocene basin inversion caused by Laramide orogenic deformation, and the resulting reservoir exhumation of basin strata. East of the Maverick Basin, spatial distributions of API gravity and GOR values show progressively heavier oils updip to the northwest, grading to dry gases downdip to the southeast, which correlates to the oil and gas windows of the underlying Eagle Ford Shale. Correlation of API gravity and GOR values from the San Miguel, Olmos, and Escondido Formations with thermal maturity data from the Eagle Ford Shale suggests that the Eagle Ford Shale is the petroleum source, and that petroleum migration was approximately vertical for areas to the east of the Maverick Basin. The discontinuity of API gravity and GOR properties within the Maverick Basin implies a complex petroleum charge history, possibly involving the remigration of petroleum and the addition of petroleum from other source intervals in Mexico, to the southwest. Depressurization of exhumed, overpressured reservoirs of the San Miguel, Olmos, and Escondido Formations can explain the intermittent occurrence of gas production throughout the southern Maverick Basin by exsolution of gas from formation brines and the resulting dry gas flushing of hydrocarbon-charged reservoirs. The introduction of dry gas through flushing can, in turn, explain why the patterns of API gravity and GOR values are so dissimilar in the Maverick Basin. This process has implications for possible future production of unconventional resources from undiscovered tight-gas reservoirs in strata of the San Miguel, Olmos, and Escondido Formations, and a different approach to petroleum exploration may be needed in the Maverick Basin relative to exploration techniques applied in other basins within the northern Gulf of Mexico.
The Water-budget Accounting for Tropical Regions Model (WATRMod) code was used for Kauaʻi, Oʻahu, Molokaʻi, Maui, and the Island of Hawaiʻi to estimate the spatial distribution of groundwater recharge, soil moisture, evapotranspiration, and climatic water deficit for a set of water-budget scenarios. The scenarios included historical and future drought conditions, and a land-cover condition where shrubland and forest within the cloud zone were converted to grassland. For the historical drought condition, island-wide mean annual recharge estimates range from a decrease of 30 percent (239 million gallons per day [Mgal/d]) for Kauaʻi to a decrease of 39 percent (2,706 Mgal/d) for the Island of Hawaiʻi, relative to the reference condition consisting of 1978–2007 rainfall and 2020 land cover. For the future drought condition, estimates of island-wide mean annual recharge range from a decrease of 40 percent (477 Mgal/d) on Maui to a decrease of 51 percent (116 Mgal/day) on Molokaʻi. Complete conversion of all shrubland and forest within the cloud zone to grassland for each drought condition produces estimated land-cover-related decreases in island-wide mean annual recharge (in addition to the drought-related decreases) of 11–12 Mgal/d on Oʻahu, 119–135 Mgal/day on Maui, and 689–849 Mgal/d on the Island of Hawaiʻi. The spatial distributions of increases in conditions indicative of moisture stress and potential wildfire hazard were quantified using the relative frequency of soil moisture less than a selected threshold value (monthly mean soil moisture less than 0.074, expressed as a fraction of available water capacity), evapotranspiration less than a selected threshold value (monthly evapotranspiration less than 0.96 inches), and climatic water deficit greater than a selected threshold value (monthly climatic water deficit greater than 0.77, expressed as fraction of potential evapotranspiration). For the historical drought condition, the greatest increases in the relative frequency for the moisture-stress indicators occur across parts of east and southwest Kauaʻi; central, east, and west Oʻahu; central Molokaʻi; central Maui and low- to mid-altitude parts of West Maui volcano; and the northwestern and southern parts of the Island of Hawaiʻi. For the future drought condition, the greatest increases in the relative frequency of the moisture-stress indicators occur across parts of west Kauaʻi; central and west Oʻahu and Molokaʻi; a band of mid-altitude area on the southern slope of West Maui volcano and across the southwestern slope of Haleakalā; and mid-altitude areas of the northwestern and southern parts of the Island of Hawaiʻi. Complete conversion of all shrubland and forest within the cloud zone to grassland for each drought condition results in land-cover-related increases in the relative frequency of moisture-stress indicators around Kaʻala in the Waiʻanae Range and the southeastern part of the Koʻolau Range on Oʻahu, the southern part of West Maui volcano and the southwestern slope of Haleakalā on Maui, and the upland regions of the western and southern parts of the Island of Hawaiʻi.
Data on the occurrence of agricultural chemicals in ground wafer in Tennessee are sparse. The surficial alluvial aquifer is an important source of domestic water supply in West Tennessee, and potentially is subject fo contamination from the application of agricultural chemicals in the area. Nineteen shallow wells completed in the alluvial aquifers in areas of high density agricultural use were sampled in the winter and again in the summer of 1988 to ascertain the occurrence of agricultural chemical in ground water. Although no triazine herbicides or organophosphorus insecticides were detected in any of the wells sampled, elevated nitrite plus nitrate (as nitrogen) concentrations were detected. Results from the winter sampling period indicate a range of nitrite plus nitrate (as nitrogen) concentrations of less than 0.1 to 7.8 milligrams per liter with a median concentration of 2.6 milligrams per liter. Results from the summer sampling period indicate a range of nitrite plus nitrate (as nitrogen) concentrations of less than 0.1 to 8.9 milligrams per liter, median, 2.5 milligrams per liter. The highest concentrations occurred in the shallowest wells, and, in one instance, in a shallow well near a heavily irrigated field.
Paleomagnetic rock samples were collected from 173 drill sites in the Quaternary alkali basaltic volcanic field of northern Harrat Rahat, Kingdom of Saudi Arabia. Laboratory measurements on these samples established that lava flows and vent complexes—identified and mapped from field characteristics, rock types, and compositions as products of single or temporally close eruptions—typically record single, or very similar, directions of remanent magnetization. Correlations defined through geologic mapping, spatial association, geochemistry, geochronology, and identical mean remanent directions indicate at least 16 brief episodes of temporally clustered eruptions. These episodes had durations of a few centuries or less. Anomalous remanent magnetic directions were found for at least 13 mapped lavas of northern Harrat Rahat, which demonstrate that they were acquired during brief geomagnetic cryptochrons during the Brunhes Normal Polarity Chron. These uncharacteristic directions enhance the opportunity to identify common eruptive episodes, and to better understand and evaluate assessments of eruption ages based on 40 Ar/ 39 Ar geochronology. Combining paleomagnetic and regional archaeomagnetic results for the youngest eruptions allows us to evaluate their historical age assignments and, in one case, refute a previously assigned provisional age.