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USGS1947

Geology of the Borah Peak quadrangle, Idaho

This report is on result of a long program of geologic investigation in south-central Idaho, undertaken as an aid in the development of the mineral resources of the region. This quadrangle was examined because of the exceptional opportunities for the study of stratigraphy and structure afforded by the Lost River Range, which is the highest in Idaho and contains comparatively few intrusive igneous rocks. The Borah Peak quadrangle differs from the region to the west and northwest in that it contains parts of two sharply defined, narrow ranges elongated in a north-westerly direction, instead of broad, irregular mountain masses, in which the trends of most local topographic units are ill-defined. These ranges, the Lost River and the Lemhi, are flanked by intermontane valleys sparsely populated by stock ranchers. The Lemhi and Swauger quartzites, regarded as of Belt (pre-Cambrian) age, are named. The two Cambrian (?) formations of the Bayhorse region are not recognized in this quadrangle. The Ramshorn slate (Lower Ordovician), widespread and thick there, does not appear to be exposed anywhere in the Borah Peak quadrangle with the possible exception of small areas east of the Elkhorn Ranch, where relations are obscure. The higher Paleozoic formations, named in order of decreasing age, are the Kinnikinic quartzite, Saturday Mountain formation, Laketown dolomite, Jefferson dolomite, Grand View dolomite, Three Forks limestone, Milligen formation, Brazer limestone, and Wood River formation. The Three Forks limestone, nowhere much over 250 feet thick, is the only one of these not recognized farther west. It provides substantial aid in the interpretation of upper Paleozoic stratigraphy. Equivalent beds to the west are presumably grouped with the Milligen. The grit that introduced uncertainties into the correlation of the Wood River and Milligen formations in the southeastern part of the Bayhorse quadrangle is absent here, and both formations have close lithologic resemblances to those in the type localities in the Wood River region. Wood River strata (Pennsylvanian) crop out only in the southwest corner of the quadrangle, and the Brazer may have been the last Paleozoic unit to be deposited over most of the area. Certainly it can have had comparatively little cover over it throughout the Mesozoic. The Brazer is regarded as Mississippian, but some of the fossils in it have Pennsylvania affinities. The carbonate rocks in the Three Forks and later formations are dominantly calcareous, while those in earlier units are dolomitic. Carbonaceous matter is present in most of the formations but is abundant only in the Milligen. The Challis volcanics (Oligocene or Miocene) constitute the first stratified unit to be laid down after Paleozoic deposition ceased, although there was a little intrusive activity late in the Mesozoic. The volcanics were once widely distributed on the flanks of the mountains and are still plentiful in the northwestern corner of the quadrangle, near the head of the valley of the Pahsimeroi, and in smaller areas. They are neither so abundant nor so diversified as they are farther west. They are locally succeeded by an alluvial formation, here termed the Donkey fanglomerate, of possible Pliocene age. Abundant Quaternary glacial and alluvial deposits are present in the larger valleys. The Lemhi and Swauger quartzites were broadly folded before Paleozoic sedimentation began. Apparently the later deformation affected them only enough to render the more impure beds somewhat schistose. The Paleozoic rocks have been folded into closely spaced, asymmetric anticlines, locally broken by thrusts at and near their crests. These folds approximately parallel the trends of the present range, whereas those in the old rocks strike more nearly north. Later deformation twisted some of the folds and produced thrusts of lower dip and greater extent. The folded rocks in the Lost River Range have been arched into an anticlinorium. The original, tight folds may have preceded the emplacement of the Idaho batholith farther west, while the anticlinorium and the late twists and low thrusts result from deformation during the long period in which the batholith came to place and adjusted itself. Local intricately contorted beds in the Brazer limestone are interpreted as the effects of flowage in calcareous material subjected to tangential pressure under comparatively light supercumbent load. The quadrangle contains numerous normal faults of diverse trends. Most of those that can be conclusively demonstrated strike transverse to the trends of the ranges, but especially along parts of the southwest front of the Lemhi Range normal faults along the range fronts may have helped locally to guide erosion of the mountains. Some of the faults have displacements of thousands of feet and are thought to have originated in connection with the low-angle thrusts. Most of these, as well as minor breaks of diverse trends, affect also the Challis volcanics, which shows that renewed movement occurred in Tertiary time. The present mountain masses and broad intermontane valleys are in about the positions occupied by similar features in the early Tertiary. Several incomplete erosion cycles since then have greatly modified the topography but have not obliterated the influence of these ancient land forms. The results of early episodes in the development of the topography are much obscured by the rugged forms that result from active Pleistocene glaciation and later vigorous stream erosion, but modified remnants of the post-Challis and Donkey Hills surfaces can be clearly distinguished. Several less widespread remnants mark intermediate steps in the process. Exceptionally abundant and permeable, coarse alluvial and glacial deposits floor intermontane valleys and choke the larger mountain gorges to such an extent as to interfere with normal erosion and make the surface-water supplies even scantier than might be expected from the climate of the region, which is moderately humid in the mountains and semiarid in the valleys. Active erosion in the high mountains and comparatively static conditions on fans at the range borders result in striking contrasts.

Idaho↗

USGS1960

Stratigraphic and geotectonic relationships in northern Vermont and southern Quebec

Stratified rocks of early and middle Paleozoic age form a belt of northeast-trending anticlinoria and synclinoria of middle Paleozoic age, in northern Vermont and adjacent parts of southern Quebec . The foreland margin of this belt, in the Champlain and St. Lawrence valleys to the west, is cut by eastward-dipping thrust faults of middle Paleozoic age and by later northeast-trending normal faults. The Green Mountain anticlinorium, which is the dominant structure of the region, is flanked to the west, on the foreland, by the St. Albans-Hinesburg-Middlebury synclinorium and to the east, in the midst of the folded belt, by the Connecticut Valley-Gaspe synclinorium. The principal thrust faults, notably the Champlain and Philipsburg thrusts, are in the west limb of the St. Albans-Hinesburg-Middlebury synclinorium. East of the Connecticut Valley-Gaspe synclinorium is the Boundary Mountain anticlinorium, in eastern Vermont and adjacent New Hampshire and along the international boundary between Quebec and Maine. Two contrasting intergradational lithic assemblages, the graywacke-shale assemblage and the carbonate-quartzite assemblage, characterize the protolith of the bedded rocks. The graywacke-shale assemblage includes thick sections of lower Paleozoic strata, portions of which lap both gradationally and unconformably westward on the foreland, particularly in Quebec ; it also includes middle Paleozoic strata that offlap eastward away from the foreland. The carbonate-quartzite assemblage laps both unconformably and gradationally eastward over the graywacke-shale assemblage in sections of the middle Paleozoic east of the axis of the Green Mountain anticlinorium. Stratigraphic correlation has become well established in the foreland belt where numerous distinctive and fossiliferous strata, chiefly of the carbonate-quartzite assemblage, have escaped metamorphism. It is also fairly clear in sections in the eastern foreland and western part of the Green Mountain anticlinorium, where the strata of the carbonate-quartzite assemblage extend eastward and interfinger with rocks of the graywacke-shale terrane. Rocks that are entirely of the graywacke-shale assemblage have been correlated in the present study. The stratified rocks west of the axis of the Green Mountain anticlinorium are of Cambrian(?), Cambrian, and Ordovician age; those to the east range in age from Cambrian to Devonian. The geotectonic setting of the region is the once mobile belt of the Appalachian orthogeosyncline, which is at the southeastern margin of the stable continental block, or craton, of North America. The orthogeosyncline was a belt, chiefly of subsidence, that embraced two parallel and adjoining longitudinal zones: the eugeosynclinal zone, which was more mobile, and the miogeosynclinal zone, which was less mobile. Second- and third-generation geosynclines are superimposed not only on the orthogeosyncline but also on adjoining parts of the craton. Uplift, and finally folding, gradually superseded subsidence in the orthogeosyncline. Local uplift, chiefly within the eugeosynclinal zone, provided most of the clastic sediments, principally those of the graywacke-shale assemblage. General stabilization of the western part of the orthogeosyncline at the end of the Ordovician was accompanied by eastward migration of the miogeosynclinal zone. Localized uplift within the eastern part of the orthogeosyncline at this time is marked by unconformities referred to the Taconic disturbance. Folding and uplift after the Early Devonian is shown by angular unconformities referred to the Acadian and Appalachian orogenies. The interpretation of the geotectonic relations of the bedded rocks is aided by critical features of the magmatic activity that began with, accompanied, and followed the diastrophism.

Vermont, Quebec↗

USGS2003

The early Mesozoic Birdsboro central Atlantic margin basin in the Mid-Atlantic region, eastern United States

The early Mesozoic Birdsboro basin (new name) was a single, elongate depositional trough in the present Mid-Atlantic area of the eastern United States, extending north-eastward from central Virginia across Maryland, Pennsylvania, and New Jersey into southern New York. What now remains after erosion comprises the Barboursville, Culpeper, Gettysburg, and Newark remnants. Some 7?? km of late Triassic and early Jurassic continental sediments of varying provenances entered and spread across in the Birdsboro basin in several depositional environments. The five resulting sedimentary lithosomes include feldspathic sandstone, quartzose sandstone, red silty mudstone, gray shale, and fanglomerate. The extensive interbedding, intertonguing, and lateral gradation among these lithosomes suggest that they were contemporary and closely interrelated. The feldspathic sandstone lithosome contains sediment with a southeastern provenance that accumulated in a bajada environment extending the length of the southeastern side of the basin. Sediment in the quartzose sandstone lithosome had a northwestern provenance-the coarse-grained fraction formed regional alluvial fans at the mouths of four major input centers. The finer-grained fraction was deposited in the distal reaches of these fans and in the playa environments in the interfan areas; this fraction formed the red silty mudstone lithosome. Gray/black shales and argillites of the gray shale lithosome accumulated in lacustrine environments in the interfan areas. The fanglomerate lithosome comprises numerous small, lobate deposits of poorly sorted sediment along both basin margins. The location and time of activity of the northwest input centers largely determined the distribution and areal extent of the various depositional environments and consequent lithosome along the length and across the width of the basin. The Birdsboro basin was deformed (tilted, faulted, and folded) sometime after the deposition of the youngest preserved rocks (early Sinemurian). The deformation varied along the length of the basin, producing differences in the amount of tilting, structural elevation, and subsequent erosion. The present erosional remnants create the illusion of four originally separate depositional basins.

Geological Society of America Bulletin↗

USGS2022

Spaceborne InSAR mapping of landslides and subsidence in rapidly deglaciating terrain, Glacier Bay National Park and Preserve and vicinity, Alaska and British Columbia

The Glacier Bay area in southeastern Alaska and British Columbia, encompassing Glacier Bay National Park and Preserve, has experienced rapid glacier retreat since the end of the Little Ice Age in the mid-1800s. The impact that rapid deglaciation has had on the slope stability of valley walls and on the sedimentation of fans and deltas adjacent to fjords and inlets is an ongoing research topic. Using 3-year (2018–2020) Sentinel-1 datasets, and an automated time-series persistent scatterer interferometric synthetic aperture radar (PSInSAR) processing method, we detected landslides or delta subsidence at 27 sites within a vast 180 × 180 km remote region encompassing Glacier Bay proper. Most of the sites that we identified had not been previously identified. We categorized the hazard source areas that we identified into three general types:1) slow-moving landslides on steep rocky slopes not near (> 2 km away from) present-day glacier termini (e.g., Tidal Inlet landslide), 2) slow-moving landslides directly adjacent to (< 2 km away from), and associated with glacier thinning and retreat, and 3) subsidence of glacial outwash fan deltas. In categories 1 and 2, we observed 22 landslides moving at velocities ranging from 0.5 to 4 cm/yr. In category 3, we detected five fan deltas subsiding at velocities ranging from 0.5 to 6 cm/yr. Within our measurement error, these velocities were consistent during the monitoring period. Because acceleration was not observed, the issuance of warnings of imminent rapid failure is not warranted, however, continued remote monitoring is warranted. Our interferometric synthetic aperture radar (InSAR) results could be combined with other data sets including field observations, subaerial and submarine landslide inventories, bedrock fabric mapping from newly available light detection and ranging (lidar) data, and geologic maps to produce an inherent susceptibility map for landslides in bedrock and fan deltas. This map could be used to forecast susceptibility for both earthquake and climatically induced landslides.

Alaska, British Columbia↗

USGS2003

Stable lead isotopes reveal a natural source of high lead concentrations to gasoline-contaminated groundwater

Concentrations of total lead as high as 1,600 μg/L were detected in gasoline-contaminated and uncontaminated groundwater at three gasoline-release sites in South Carolina. Total lead concentrations were highest in turbid groundwater samples from gasoline-contaminated and uncontaminated wells, whereas lower turbidity groundwater samples (collected using low-flow methods) had lower total lead concentrations. Dissolved lead concentrations in all wells sampled, however, were less than 15 μg total lead/L, the current United States Environmental Protection Agency (US EPA) maximum contaminant level (MCL). Because many total lead concentrations exceeded the MCL, the source of lead to the groundwater system at two of the three sites was investigated using a stable lead isotope ratio approach. Plots of the stable isotope ratios of lead (Pb) in groundwater as 207 Pb/ 206 Pb versus 208 Pb/ 206 Pb, and 208 Pb/ 204 Pb versus 206 Pb/ 204 Pb were similar to ratios characteristic of lead-based minerals in local rocks of the southeastern US, and were not similar to the stable lead isotopes ratios characteristic of distant lead ore deposits such as Broken Hill, Australia, used to produce tetraethyl lead in gasoline products prior to its phase-out and ban in the United States. Moreover, the isotopic composition of dissolved lead was equivalent to the isotopic composition of total lead in turbid samples collected from the same well, suggesting that the majority of the lead detected in the groundwater samples was associated with sediment particulates of indigenous aquifer material, rather than lead associated with spilled leaded gasoline. The results of this investigation indicate that (1) lead detected at some gasoline-release sites may be derived from the local aquifer material, rather than the gasoline release, and consequently may affect site-specific remediation goals; (2) non-low flow groundwater sampling methods, such as a disposable bailer, may result in turbid groundwater samples and high total lead concentrations, and; (3) stable lead isotopes can be used to clarify the source of lead detected above permissible levels in gasoline-contaminated groundwater systems.

Environmental Geology↗

USGS1964

Floods of January-February 1957 in southeastern Kentucky and adjacent areas

Heavy rains over an extensive area on January 27-February 2, caused extreme flooding in southeastern Kentucky and adjacent areas in West Virginia, Virginia, and Tennessee. Total rainfall for the storm period ranged from 6-9 inches over most of the report area and was 12? inches at the eastern end of the Virginia-Kentucky State line. The principal basins affected by the storm were those of the Big Sandy, Kentucky, Cumberland, and Tennessee Rivers. Maximum discharge of record occurred in many streams. On Levisa Fork near Grundy, Va., the peak discharge of 33,200 cfs was 50 percent greater than the previous maximum in 17 years of record and was 3.3 times the mean annual flood. The peak discharges on-tributaries of the Kentucky River and on ,the Holston and Clinch Rivers were also the greatest of record and .those on the upper Cumberland River were nearly as great as .those during the historic floods of 1918 and 1946. Total flood damage was estimated at $61 million of which $39 million was in the Big Sandy River basin (mostly in Kentucky) and $15 million was in the Kentucky River basin--$52 million of the total damage was in Kentucky.

Water Supply Paper↗

USGS2016

California State Waters Map Series — Offshore of Santa Cruz, California

Introduction In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow subsurface geology. The Offshore of Santa Cruz map area is located in central California, on the Pacific Coast about 98 km south of San Francisco. The city of Santa Cruz (population, about 63,000), the largest incorporated city in the map area and the county seat of Santa Cruz County, lies on uplifted marine terraces between the shoreline and the northwest-trending Santa Cruz Mountains, part of California’s Coast Ranges. All of California’s State Waters in the map area is part of the Monterey Bay National Marine Sanctuary. The map area is cut by an offshore section of the San Gregorio Fault Zone, and it lies about 20 kilometers southwest of the San Andreas Fault Zone. Regional folding and uplift along the coast has been attributed to a westward bend in the San Andreas Fault Zone and to right-lateral movement along the San Gregorio Fault Zone. Most of the coastal zone is characterized by low, rocky cliffs and sparse, small pocket beaches backed by low, terraced hills. Point Santa Cruz, which forms the north edge of Monterey Bay, provides protection for the beaches in the easternmost part of the map area by sheltering them from the predominantly northwesterly waves. The shelf in the map area is underlain by variable amounts (0 to 25 m) of upper Quaternary shelf, estuarine, and fluvial sediments deposited as sea level fluctuated in the late Pleistocene. The inner shelf is characterized by bedrock outcrops that have local thin sediment cover, the result of regional uplift, high wave energy, and limited sediment supply. The midshelf occupies part of an extensive, shore-parallel mud belt. The thickest sediment deposits, inferred to consist mainly of lowstand nearshore deposits, are found in the southeastern and northwestern parts of the map area. Coastal sediment transport in the map area is characterized by northwest-to-southeast littoral transport of sediment that is derived mainly from ephemeral streams in the Santa Cruz Mountains and also from local coastal-bluff erosion. During the last approximately 300 years, as much as 18 million cubic yards (14 million cubic meters) of sand-sized sediment has been eroded from the area between Año Nuevo Island and Point Año Nuevo and transported south; this mass of eroded sand is now enriching beaches in the map area. Sediment transport is within the Santa Cruz littoral cell, which terminates in the submarine Monterey Canyon. Benthic species observed in the Offshore of Santa Cruz map area are natives of the cold-temperate biogeographic zone that is called either the “Oregonian province” or the “northern California ecoregion.” This biogeographic province is maintained by the long-term stability of the southward-flowing California Current, the eastern limb of the North Pacific subtropical gyre that flows from southern British Columbia to Baja California. At its midpoint off central California, the California Current transports subarctic surface (0–500 m deep) waters southward, about 150 to 1,300 km from shore. Seasonal northwesterly winds that are, in part, responsible for the California Current, generate coastal upwelling. The south end of the Oregonian province is at Point Conception (about 300 km south of the map area), although its associated phylogeographic group of marine fauna may extend beyond to the area offshore of Los Angeles in southern California. The ocean off of central California has experienced a warming over the last 50 years that is driving an ecosystem shift away from the productive subarctic regime towards a depopulated subtropical environment. Biological productivity resulting from coastal upwelling supports populations of Sooty Shearwater, Western Gull, Common Murre, Cassin’s Auklet, and many other less populous bird species. In addition, an observable recovery of Humpback and Blue Whales has occurred in the area; both species are dependent on coastal upwelling to provide nutrients. The large extent of exposed inner shelf bedrock supports large forests of “bull kelp,” which is well adapted for high-wave-energy environments. The kelp beds are the northernmost known habitat for the population of southern sea otters. Common fish species found in the kelp beds and rocky reefs include lingcod and various species of rockfish and greenling.

California↗

USGS1997

Biogeochemical phosphorus mass balance for Lake Baikal, southeastern Siberia, Russia

Extensive data for Lake Baikal have been synthesized into a geochemical mass balance for phosphorus (P). Some of the P budget and internal cycling terms for Baikal have been compared to similar terms for oligotrophic Lake Superior, mesotrophic Lake Michigan and the Baltic Sea, and the Ocean. Lake Baikal has a large external source of fluvial P compared to the Laurentian upper Great Lakes and the Ocean. The major tributary to Lake Baikal has experienced substantial increases in organic P loading during the past 25 years. This, coupled with potential P inputs from possible phosphorite mining, may threaten Baikal's oligotrophic status in the future. Water-column remineralization of particulate organic P is substantially greater in Lake Baikal than in the Laurentian Great Lakes. This is probably due to the great water depths of Lake Baikal. There is a gradient in P burial efficiency, with very high values (80%) for Lake Baikal and Lake Superior, lower values (50%) for Lake Michigan and the Baltic Sea, and a low value (13%) for the Ocean. The accumulation rate of P in Lake Baikal sediments is somewhat greater than that in the Laurentian upper Great Lakes and the Baltic Sea, and much greater than in the Ocean. Benthic regeneration rates are surprisingly similar for large lacustrine and marine environments and supply less than 10% of the P utilized for primary production in these aquatic environments.

Marine Geology↗

USGS2020

Precipitation, temperature, groundwater-level elevation, streamflow, and potential flood storage trends within the Brazos, Colorado, Big Cypress, Guadalupe, Neches, Sulphur, and Trinity River basins in Texas through 2017

The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (USACE), analyzed streamflow trends and streamflow-related variables through 2017 in seven important water-supply basins to provide information that can help water managers with the USACE and river authorities make future water management decisions. The primary purpose of this report is to document trends in long-term streamflow data at 114 selected USGS streamflow-gaging stations and 36 simulated reservoir-inflow stations in 7 river basins primarily in Texas: Brazos, Colorado, Big Cypress, Guadalupe, Neches, Sulphur, and Trinity. In this report, trends were considered statistically significant if their p -values were less than or equal to 0.05 ( p -value ≤0.05). Streamflow data selected for temporal trend analyses included annual minimum streamflow, annual peak streamflow, and streamflow volume. Precipitation, air temperature, and groundwater-level-elevation data were analyzed for trends that may help to explain changes observed in the streamflow statistics. Basins were divided into sections along county lines for precipitation analyses. Streamflow volumes were analyzed for associations with potential flood storage. The potential flood storage, defined as the difference between maximum storage and normal storage, was computed for each dam from the National Inventory of Dams database and accumulated over time based on the completion date of the dam. Precipitation and air temperature trends were analyzed for each of the eight climate divisions (High Plains, Trans-Pecos, Low Rolling Hills, Edwards Plateau, North Central Texas, South Central Texas, East Texas, and Upper Coast). Results of precipitation trend analyses indicated moderate upward trends in the Upper Coast and East Texas Climate Divisions analyzed on an annual time step from 1900 through 2017. These two climate divisions are in the eastern and southeastern parts of the State, and they receive more mean annual precipitation (45.88 and 46.09 inches, respectively) than the other climate divisions. The results of air temperature analyses indicated upward trends in annual mean air temperature within all climate divisions, with a mean slope of 0.02 degree Fahrenheit per year, or 1 degree every 50 years. Within the Brazos River Basin, results of precipitation trend analyses on an annual time step indicated that precipitation amounts are most likely increasing in the lower and middle sections of the basin. Downward trends in annual streamflow and in the ratio of streamflow volume to precipitation volume were indicated at 7 of the 15 stations in the upper sections of the basin. The lower sections of the basin had mostly downward trends in annual minimum streamflow, whereas upward trends in annual minimum streamflow were indicated in the upper sections of the basin. Downward trends in annual peak streamflow were indicated at many of the stations in the upper sections of the basin. At the same seven stations in the upper sections of the basin where there were downward trends in annual streamflow, there were also downward trends in the ratio of streamflow volume to precipitation volume. The data from the same seven stations indicated negative associations between potential flood storage volume and annual streamflow volume and downward trends in the ratio of annual streamflow volume to potential flood storage volume. With the known addition of 13,006,394 acre-feet of potential flood storage between 1900 and 2010 in the subbasins analyzed, streamflow volumes have decreased in the upper sections of the Brazos River Basin. Within the Colorado River Basin, results of precipitation trend analyses on an annual time step indicated no trends in the basin. Downward trends in annual streamflow were indicated at 16 stations in the upper sections of the basin, whereas no trends in annual streamflow were indicated in the lower section of the basin. In the lower section of the basin, one station that was operated as a continuous streamflow-gaging station through 2017 had a downward trend in annual minimum streamflow, and another station (operated through 2007) had an upward trend in annual minimum streamflow. In the upper sections of the basin, data from seven stations indicated upward trends in annual minimum streamflow, and data from six stations indicated downward trends. Data from 18 stations in the upper sections of the basin indicated downward trends in annual peak streamflow. Thirteen of the 16 stations in the upper sections of the basin with data that indicated downward trends in annual streamflow also have data that indicated downward trends in the ratio of streamflow volume to precipitation volume. Data from the same 13 stations indicated negative associations between potential flood storage volume and annual streamflow volume and downward trends in the ratio of annual streamflow volume to potential flood storage volume. With the known addition of 7,193,147 acre-feet of potential flood storage between 1891 and 2014 in the subbasins analyzed, streamflow volumes have decreased in the upper sections of the Colorado River Basin. Within the Big Cypress Basin, results of precipitation trend analyses on annual, seasonal, and monthly time steps indicated almost no trends in the basin as defined in this report. However, the annual precipitation p -value only slightly exceeded the p -value threshold for a statistically significant trend. Given the upward trend in precipitation in the East Texas Climate Division, which includes the Big Cypress Basin, and the low p -value for annual precipitation within the basin, precipitation in the basin may be increasing over time. Two annual streamflow trends, one upward and one downward, were in the upper parts of the basin. Data from USGS streamflow-gaging station 07346000 Big Cypress Bayou near Jefferson, Texas, indicated an upward trend in annual minimum streamflow and a downward trend in annual peak streamflow. The station is immediately downstream from Lake O’ the Pines; presumably, minimums have increased because of regulated releases, and annual peaks have decreased because of storage from the lake for flood control. Despite the known addition of 2,737,154 acre-feet of potential flood storage between 1898 and 2011 in the subbasins analyzed, there have not been widespread reductions in streamflow volumes in the Big Cypress Basin, except for within the drainage area for the farthest upstream station on the main stem downstream from Mount Pleasant, Texas. Within the Guadalupe River Basin, results of precipitation trend analyses on an annual time step indicated an upward trend in the lower section of the basin, but no trends in annual streamflow were indicated in the lower section of the basin. In the upper section of the basin, data from 1 of the 13 stations indicated an upward trend in annual streamflow. Data from 6 of the 13 stations in the upper section of the basin indicated a trend in annual minimum streamflow with 4 upward and 2 downward trends. Data from 2 of the 13 stations in the upper section of the basin indicated downward trends in annual peak streamflow. Despite the known addition of 2,016,534 acre-feet of potential flood storage between 1849 and 2013 in the subbasins analyzed, streamflow volumes have not decreased in the Guadalupe River Basin. Within the Neches River Basin, results of precipitation trend analyses on an annual time step indicated upward trends in the basin. None of the data from stations analyzed in the Neches River Basin indicated annual trends in streamflow despite upward trends in annual precipitation within the basin. Data from 9 of the 19 stations analyzed in the basin indicated upward trends in annual minimum streamflow. Data from one of the simulated-inflow stations indicated a downward trend in annual minimum streamflow into Sam Rayburn Reservoir. Data from two stations indicated downward trends in annual peak streamflow, and data from one small subbasin indicated an upward trend in annual peak streamflow. Despite the known addition of 4,839,609 acre-feet of potential flood storage between 1888 and 2008 in the subbasins analyzed, there have not been widespread reductions in streamflow volumes in the Neches River Basin. Within the Sulphur River Basin, results of precipitation trend analyses on an annual time step indicated a moderate upward trend within the basin. Data from only one of the stations, the simulated inflow to Jim Chapman Lake, indicated an annual upward trend in streamflow despite an upward trend in annual precipitation throughout the basin. Data from three of the six stations in the Sulphur River Basin indicated upward trends in annual minimum streamflow, and data from one of the six stations indicated a downward trend in annual peak streamflow. Despite the known addition of 6,933,361 acre-feet of potential flood storage between 1904 and 2006 in the subbasins analyzed, streamflow volumes have not decreased in the Sulphur River Basin. Within the Trinity River Basin, results of precipitation trend analyses on an annual time step indicated upward trends in most sections of the basin. Data from 8 of the 36 stations analyzed for trends in annual streamflow indicated upward trends, and all 8 stations are in the upper sections of the basin. None of the data from stations in the lower sections of the basin indicated trends in annual streamflow. Data from 16 of the 36 stations indicated upward trends in annual minimum streamflow. Upward trends in annual minimum streamflow could be the result of managed reservoir releases in combination with wastewater treatment plant releases in the large Dallas-Fort Worth metroplex in the upper sections of the basin. All the trends in annual peak streamflow were in the sections of the basin that include the Dallas-Fort Worth metroplex. Data from two stations, one USGS streamflow-gaging station and one simulated-inflow station, indicated upward trends in annual peak streamflow, and data from one streamflow-gaging station indicated a downward trend in annual peak streamflow. Of the basins included in this study, the Trinity River Basin has the second largest amount of potential flood storage of 8,947,349 acre-feet from dams added between 1890 and 2013. Eleven stations in the Trinity River Basin had positive associations between potential flood storage volume and annual streamflow volume, indicating that annual streamflow increases as potential flood storage increases. Data from 7 of the 11 stations also indicated upward trends in annual streamflow. The positive associations may be the result of increases in minimum streamflow, which could be the result of any combination of managed reservoir releases, wastewater treatment plant releases, or increased runoff from urbanized areas, particularly in the urbanized area of the Dallas-Fort Worth metroplex.

Texas↗

USGS2012

Hydrogeologic framework of the Wood River Valley aquifer system, south-central Idaho

The Wood River Valley contains most of the population of Blaine County and the cities of Sun Valley, Ketchum, Hailey, and Bellevue. This mountain valley is underlain by the alluvial Wood River Valley aquifer system, which consists primarily of a single unconfined aquifer that underlies the entire valley, an underlying confined aquifer that is present only in the southernmost valley, and the confining unit that separates them. The entire population of the area depends on groundwater for domestic supply, either from domestic or municipal-supply wells, and rapid population growth since the 1970s has caused concern about the long-term sustainability of the groundwater resource. As part of an ongoing U.S. Geological Survey effort to characterize the groundwater resources of the Wood River Valley, this report describes the hydrogeologic framework of the Wood River Valley aquifer system. Although most of the Wood River Valley aquifer system is composed of Quaternary-age sediments and basalts of the Wood River Valley and its tributaries, older igneous, sedimentary, or metamorphic rocks that underlie these Quaternary deposits also are used for water supply. It is unclear to what extent these rocks are hydraulically connected to the main part of Wood River Valley aquifer system and thus whether they constitute separate aquifers. Paleozoic sedimentary rocks in and near the study area that produce water to wells and springs are the Phi Kappa and Trail Creek Formations (Ordovician and Silurian), the Milligen Formation (Devonian), and the Sun Valley Group including the Wood River Formation (Pennsylvanian-Permian) and the Dollarhide Formation (Permian). These sedimentary rocks are intruded by granitic rocks of the Late Cretaceous Idaho batholith. Eocene Challis Volcanic Group rocks overlie all of the older rocks (except where removed by erosion). Miocene Idavada Volcanics are found in the southern part of the study area. Most of these rocks have been folded, faulted, and metamorphosed to some degree, thus rock types and their relationships vary over distance. Quaternary-age sediment and basalt compose the primary source of groundwater in the Wood River Valley aquifer system. These Quaternary deposits can be divided into three units: a coarse-grained sand and gravel unit, a fine-grained silt and clay unit, and a single basalt unit. The fine- and coarse-grained units were primarily deposited as alluvium derived from glaciation in the surrounding mountains and upper reaches of tributary canyons. The basalt unit is found in the southeastern Bellevue fan area and is composed of two flows of different ages. Most of the groundwater produced from the Wood River Valley aquifer system is from the coarse-grained deposits. The altitude of the pre-Quaternary bedrock surface in the Wood River Valley was compiled from about 1,000 well-driller reports for boreholes drilled to bedrock and about 70 Horizontal-to-Vertical Spectral Ratio (HVSR) ambient-noise measurements. The bedrock surface generally mimics the land surface by decreasing down tributary canyons and the main valley from north to south; it ranges from more than 6,700 feet in Baker Creek to less than 4,600 feet in the central Bellevue fan. Most of the south-central portion of the Bellevue fan is underlain by an apparent topographically closed area on the bedrock surface that appears to drain to the southwest towards Stanton Crossing. Quaternary sediment thickness ranges from less than a foot on main and tributary valley margins to about 350 feet in the central Bellevue fan. Hydraulic conductivity for 81 wells in the study area was estimated from well-performance tests reported on well-driller reports. Estimated hydraulic conductivity for 79 wells completed in alluvium ranges from 1,900 feet per day (ft/d) along Warm Springs Creek to less than 1 ft/d in upper Croy Canyon. A well completed in bedrock had an estimated hydraulic conductivity value of 10 ft/d, one well completed in basalt had a value of 50 ft/d, and three wells completed in the confined system had values ranging from 32 to 52 ft/d. Subsurface outflow of groundwater from the Wood River Valley aquifer system into the eastern Snake River Plain aquifer was estimated to be 4,000 acre-feet per year. Groundwater outflow beneath Stanton Crossing to the Camas Prairie was estimated to be 300 acre-feet per year.

Idaho↗

USGS1995

Water quality of the Boca Raton canal system and effects of the Hillsboro Canal inflow, southeastern Florida, 1990-91

The City of Boca Raton in southeastern Palm Beach County, Florida, is an urban residential area that has sustained a constant population growth with subsequent increase in water use. The Boca Raton network of canals is controlled to provide for drainage of excess water, to maintain proper coastal ground-water levels to prevent saltwater intrusion, and to recharge the surficial aquifer system from which the city withdraws potable water. Most of the water supplied to the Boca Raton canal system and the surficial aquifer system, other than rainfall and runoff, is pumped from the Hillsboro Canal. The Biscayne aquifer, principal hydrogeologic unit of the surficial aquifer system, is highly permeable and there is a close relation between water levels in the canals and the aquifer. The amount of water supplied by seepage from the conservation areas is unknown. Because the Hillsboro Canal flows from Lake Okeechobee and Water Conservation Areas 1 and 2, which are places of more highly mineralized ground water and surface water, the canal is a possible source of contamination. Water samples were collected at 10 canal sites during wet and dry seasons and analyzed for major inorganic ions and related characteristics, nutrients, and trace elements. All concentrations were generally within or less than the drinking-water standards established by the Florida Department of Environmental Protection. The high concentrations of sodium and chloride that were detected in samples from the Boca Raton canal system are probably from the more mineralized water of the Hillsboro Canal. Other water-quality data, gathered from various sources from 1982 through 1991, did not indicate any significant changes nor trends. The data include pesticide and metal analyses of water samples and bottom sediments collected at four canal sites in the Boca Raton study area by the U.S. Geological Survey during 1982-84. The effects of the Hillsboro Canal on the water quality of the Boca Raton canal system are indicated by increased concentrations of sodium, chloride, dissolved solids, and total organic carbon. Concentrations of the constituents in the canal water generally decrease with distance from the Hillsboro Canal pumping station and are the result of dilution by receiving canal waters.

Florida↗

USGS2009

Did the Middlesboro, Kentucky, bolide impact event influence coal rank?

The Middlesboro Basin, southeastern Kentucky, occurs on the Cumberland Overthrust Sheet and includes a ca. 5.5-km diameter impact structure. The Lower and Middle Pennsylvanian coal-bearing strata are faulted, with some evidence for shock metamorphism. The event post-dated the latest-Pennsylvanian-early-Permian thrusting and was likely prior to late-Mesozoic entrenchment of drainages. The impact of a 0.5-km meteor traveling at ca. 60,000??km/h would release about 1??EJ, the approximate equivalent of the instantaneous combustion of 30??Mt of coal. The coal rank, while increased slightly above the regional level, still is within the upper portion of the high volatile A bituminous rank range. This helps to constrain the depth of burial at the time of the impact. The coal would have had to have been at a depth of a few kilometers to have avoided a more substantial rank increase. In addition, it is possible that some of the coal rank increase might be attributable to movements along the cross-cutting Rocky Face fault, unrelated to the impact. ?? 2009 Elsevier B.V. All rights reserved.

International Journal of Coal Geology↗

USGS1981

Rates and possible causes of neotectonic vertical crustal movements of the emerged southeastern United States Atlantic coastal plain

Emerged Pliocene and Pleistocene shorelines and associated marine deposits were used to determine the magnitude and rate of vertical crustal movement during the past 3 m.y. in the United States Atlantic Coastal Plain of South and North Carolina. On the basis of a new regional ostracode assemblage zonation, planktic biostratigraphic data, and radiometric data, emerged marine deposits were determined to be primarily interglacial and can tentatively be correlated with hemispheric warm intervals in evidence from deep-sea data. The paleontologic evidence indicates a primary glacio-eustatic component to the local sea-level record and a secondary tectonic component. Net vertical uplift rates averaging 1 to 3 cm/1,000 yr, but perhaps as high as 5 to 10 cm/1,000 yr, are in evidence for the emerged Coastal Plain. Although details of the timing of regional rheological events remain obscure, the trend of net uplift contrasts with general subsidence rates of about 2 to 4 cm/1,000 yr since the Cretaceous in submerged parts of the continental margin near subsiding sedimentary troughs. Hydro-isostatic crustal response to multiple deglaciation events may have periodically uplifted the coast, but long-term lithospheric flexural upwarping in response to sediment loading offshore is a more plausible mechanism to explain the present positions of shorelines above present mean sea level. A eustatic sea-level model is proposed for interglacial high stands of the past 3.0 m.y.

Geological Society of America Bulletin↗

USGS2022

Utah and Landsat

Utah’s list of notable features runs long, but scenery rises to the top. The Colorado River does not simply run through southeastern Utah; it meanders through steep canyons of the eroded sedimentary rock that colors the sweeping vistas of the Colorado Plateau. Stone arches, spires, hoodoos, cliffs, and bridges in hues of red enchant residents and tourists. Mountain ranges extending through the State add dynamic views—and skiing opportunities. The Great Salt Lake in northern Utah is the largest saltwater lake in the Western Hemisphere. The western part of Utah, including the Great Salt Lake, lies in the Great Basin, a multi-State drainage area with no outlet. Because the lake has no outlet to flush out any salt, evaporation produces a higher concentration of salts in the water or soils, called salinity. The lake lacks fish but supports algae and brine shrimp, and extensive wetlands around the lake attract millions of migratory birds. Landsat imagery is useful for showing surface changes, such as the fluctuating water levels of the shallow Great Salt Lake. The lake flooded in the 1980s, but the southern part dropped to its lowest level in recorded history in 2021. Landsat data also can take a much deeper look at land and water conditions. Here are several ways Landsat benefits Utah.

Utah↗

USGS2017

Saltwater intrusion in the Floridan aquifer system near downtown Brunswick, Georgia, 1957–2015

Introduction The Floridan aquifer system (FAS) consists of the Upper Floridan aquifer (UFA), an intervening confining unit of highly variable properties, and the Lower Floridan aquifer (LFA). The UFA and LFA are primarily composed of Paleocene- to Oligocene-age carbonate rocks that include, locally, Upper Cretaceous rocks. The FAS extends from coastal areas in southeastern South Carolina and continues southward and westward across the coastal plain of Georgia and Alabama, and underlies all of Florida. The thickness of the FAS varies from less than 100 feet (ft) in aquifer outcrop areas of South Carolina to about 1,700 ft near the city of Brunswick, Georgia. Locally, in southeastern Georgia and the Brunswick– Glynn County area, the UFA consists of an upper water-bearing zone (UWBZ) and a lower water-bearing zone (LWBZ), as identified by Wait and Gregg (1973), with aquifer test data indicating the upper zone has higher productivity than the lower zone. Near the city of Brunswick, the LFA is composed of two permeable zones: an early middle Eocene-age upper permeable zone (UPZ) and a highly permeable lower zone of limestone (LPZ) of Paleocene and Late Cretaceous age that includes a deeply buried, cavernous, saline water-bearing unit known as the Fernandina permeable zone. Maslia and Prowell (1990) inferred the presence of major northeast–southwest trending faults through the downtown Brunswick area based on structural analysis of geophysical data, northeastward elongation of the potentiometric surface of the UFA, and breaches in the local confining unit that influence the area of chloride contamination. Pronounced horizontal and vertical hydraulic head gradients, caused by pumping in the UFA, allow saline water from the FPZ to migrate upward into the UFA through this system of faults and conduits. Saltwater was first detected in the FAS in wells completed in the UFA near the southern part of the city of Brunswick in late 1957. By the 1970s, a plume of groundwater with high chloride concentrations had migrated northward toward two major industrial pumping centers, and since 1965, chloride concentrations have steadily increased in the northern part of the city. In 1978, data obtained from a 2,720-ft-deep test well (33H188) drilled south of the city showed water with a chloride concentration of 33,000 milligrams per liter (mg/L), suggesting the saltwater source was located below the UFA in the Fernandina permeable zone (FPZ) of the LFA. All U.S. Geological Survey (USGS) data collected for this study, including groundwater levels in wells and water-chemistry data, are available in the USGS National Water Information System.

Georgia↗

USGS2006

Hydrogeologic Framework and Ground Water in Basin-Fill Deposits of the Diamond Valley Flow System, Central Nevada

The Diamond Valley flow system, an area of about 3,120 square miles in central Nevada, consists of five hydrographic areas: Monitor, Antelope, Kobeh, and Diamond Valleys and Stevens Basin. Although these five areas are in a remote part of Nevada, local government officials and citizens are concerned that the water resources of the flow system eventually could be further developed for irrigation or mining purposes or potentially for municipal use outside the study area. In order to better understand the flow system, the U.S. Geological Survey in cooperation with Eureka, Lander, and Nye Counties and the Nevada Division of Water Resources, is conducting a multi-phase study of the flow system. The principal aquifers of the Diamond Valley flow system are in basin-fill deposits that occupy structural basins comprised of carbonate rocks, siliciclastic sedimentary rocks, igneous intrusive rocks, and volcanic rocks. Carbonate rocks also function as aquifers, but their extent and interconnections with basin-fill aquifers are poorly understood. Ground-water flow in southern Monitor Valley is from the valley margins toward the valley axis and then northward to a large area of discharge by evapotranspiration (ET) that is formed south of a group of unnamed hills near the center of the valley. Ground-water flow from northern Monitor Valley, Antelope Valley, and northern and western parts of Kobeh Valley converges to an area of ground-water discharge by ET in central and eastern Kobeh Valley. Prior to irrigation development in the 1960s, ground-water flow in Diamond Valley was from valley margins toward the valley axis and then northward to a large discharge area at the north end of the valley. Stevens Basin is a small upland basin with internal drainage and is not connected with other parts of the flow system. After 40 years of irrigation pumping, a large area of ground-water decline has developed in southern Diamond Valley around the irrigated area. In this part of Diamond Valley, flow is from valley margins toward the irrigated area. In northern Diamond Valley, flow appears to remain generally northward to the large discharge area. Subsurface flow through mountain ranges has been identified from Garden Valley (outside the study area) through the Sulphur Springs Range to Diamond Valley and from southeastern Antelope Valley through the Fish Creek Range to Little Smoky Valley (outside the study area). In both cases, the flow is probably through carbonate rocks. Ground-water levels in the Diamond Valley flow system have changed during the past 40 years. These changes are the result of pumpage for irrigation, municipal, domestic, and mining uses, mostly in southern Diamond Valley, and annual and longer-term variations in precipitation in undeveloped parts of the study area. A large area of ground-water decline that underlies an area about 10 miles wide and 20 miles long has developed in the basin-fill aquifer of southern Diamond Valley. Water levels beneath the main part of the irrigated area have declined as much as 90 feet. In undeveloped parts of the study area, annual water-level fluctuations generally have been no more than a few feet.

Scientific Investigations Report↗

USGS1993

Ground-water withdrawals, water levels, and ground-water quality in the Houston district, Texas, with emphasis on 1985-89

This report is one in a series of reports prepared by the U.S. Geological Survey, beginning in 1937, on the ground-water resources in the Houston district. The Houston district includes Harris and Galveston Counties, and parts of Brazoria, Fort Bend, Waller, Montgomery, Liberty, and Chambers Counties. The primary emphasis of this report includes ground-water resources information for the district from 1985-89. Some data collected before 1985 and in early 1990 are included to present long-term trends and relations. Ground-water withdrawal in the Houston district decreased from 451 to 419 Mgal/d (million gallons per day) between 1985 and 1989. Public supply used 77 percent of the ground water withdrawn in the district in 1985. From 1985 through 1989, withdrawals for public supply decreased from 349 to 338 Mgal/d, withdrawals for industrial use decreased from 37 to 32 Mgal/d, and withdrawals for irrigation use decreased from 65 to 49 Mgal/d. From 1985 through 1989, ground-water withdrawals decreased from about 197.9 Mgal/d to about 166.9 Mgal/d in the Houston area and increased from about 179.5 Mgal/d to about 180.8 Mgal/d in the Katy area, and remained constant at about 67 Mgal/d in the rest of Harris County. Galveston County ground-water withdrawal decreased from about 6.1 to 4.0 Mgal/d during 1985-89. During 1977-90, water levels in wells completed in the Chicot aquifer in the eastern part of the Houston district rose as much as 160 ft (feet) and declined as much as 80 ft in the western part. During 1985-90, water levels in wells completed in the Chicot aquifer in the western part of the Houston district rose as much as 140 ft, and declined as much as 40 ft in the western part. During 1977-90, water levels in wells completed in the Evangeline aquifer in the southeastern part of the Houston district rose as much as 140 ft and declined as much as 200 ft in the northwestern part. During 1985-90, water levels in wells completed in the Evangeline aquifer in the eastern part of the Houston district rose as much as 40 ft, and declined as much as 140 ft in the northern part. Dissolved-chloride concentrations in water from wells in the Houston district have not changed more than 100 mg/L during 1985-89, except for a decrease at one well in the eastern part of Galveston County. Well KH-65-48-316 yielded water with dissolved-chloride concentration decreasing from 720 mg/L in 1986 to 590 mg/L in 1989.

Texas↗

USGS1996

Environmental setting and factors that affect water quality in the Georgia-Florida Coastal Plain study unit

The Georgia-Florida Coastal Plain study unit covers an area of nearly 62,000 square miles in the southeastern United States, mostly in the Coastal Plain physiographic province. Land resource provinces have been designated based on generalized soil classifications. Land resource provinces in the study area include: the Coastal Flatwoods, the Southern Coastal Plain, the Central Florida Ridge, the Sand Hills, and the Southern Piedmont. The study area includes all or parts of seven hydrologic subregions: the Ogeechee-Savannah, the Altamaha- St.Marys, the Suwannee, the Ochlockonee, the St. Johns, the Peace-Tampa Bay, and the Southern Florida. The primary source of water for public supply in the study area is ground water from the Upper Floridan aquifer. In 1990, more than 90 percent of the 2,888 million gallons per day of ground water used came from this aquifer. The population of the study area was 9.3 million in 1990. The cities of Jacksonville, Orlando, St. Petersburg, Tallahassee, and Tampa, Florida, and parts of Atlanta and Savannah, Georgia, are located in the study area. Forest and agricultural areas are the most common land uses in the study area, accounting for 48 percent and 25 percent of the study area, respectively. Climatic conditions range from temperate in Atlanta, Georgia, where mean annual temperature is about 61.3 degrees Fahrenheit, to subtropical in Tampa, Florida, where mean annual temperature is about 72.4 degrees Fahrenheit. Long-term average precipitation (1961-90) ranges from 43.9 inches per year in Tampa, Florida, and 44.6 in Macon, Georgia, to 65.7 inches per year in Tallahassee, Florida. Floods in the study area result from frontal systems, hurricanes, tropical storms, or severe thunderstorms. Droughts are not common in the study area,especially in the Florida part of the study area due to extensive maritime exposure. The primary physical and cultural characteristics in the study area include physiography, soils and land resource provinces, geologic setting, ground-water systems, surface- water systems, climate, floods, droughts, population, land use, and water use. Factors affecting water quality in the study area are land use (primarily urban and agricultural land uses), water use in coastal areas, hydrogeology, ground-water/surface-water interaction, geology, and climate. Surface-water quality problems in urban areas have occurred in the Ogeechee, Canoochee, Ocmulgee, St. Marys, Alapaha, Withlacoochee (north), Santa Fe, Ochlockonee, St. Johns, and Oklawaha Rivers and include nitrogen and phosphorus loading, low dissolved oxygen, elevated bacteria, sediment, and turbidity, and increased concentrations of metals. In agricultural areas, surface-water quality problems include elevated nitrogen and phosphorus concentrations, erosion, and sedimentation and have occurred in the Ocmulgee, St. Marys, Santa Fe, Ochlockonee, St. Johns, Oklawaha, Withlacoochee (South), Hillsborough, and Alafia Rivers. Ground water-quality problems such as saltwater intrusion have occurred mostly in coastal areas and were caused by excessive withdrawals.

Florida, Georgia↗