Results for “Mississippi Geology” — Page 50

USGS2014

The 3D Elevation Program: summary for Mississippi

Elevation data are essential to a broad range of applications, including forest resources management, wildlife and habitat management, national security, recreation, and many others. For the State of Mississippi, elevation data are critical for infrastructure and construction management, flood risk management, agriculture and precision farming, natural resources conservation, forest resources management, water supply and quality, and other business uses. Today, high-density light detection and ranging (lidar) data are the primary sources for deriving elevation models and other datasets. Federal, State, Tribal, and local agencies work in partnership to (1) replace data that are older and of lower quality and (2) provide coverage where publicly accessible data do not exist. A joint goal of State and Federal partners is to acquire consistent, statewide coverage to support existing and emerging applications enabled by lidar data. The National Enhanced Elevation Assessment evaluated multiple elevation data acquisition options to determine the optimal data quality and data replacement cycle relative to cost to meet the identified requirements of the user community. The evaluation demonstrated that lidar acquisition at quality level 2 for the conterminous United States and quality level 5 interferometric synthetic aperture radar (ifsar) data for Alaska with a 6- to 10-year acquisition cycle provided the highest benefit/cost ratios.The 3D Elevation Program (3DEP) initiative selected an 8-year acquisition cycle for the respective quality levels. 3DEP, managed by the U.S. Geological Survey, the Office of Management and Budget Circular A–16 lead agency for terrestrial elevation data, responds to the growing need for high-quality topographic data and a wide range of other 3D representations of the Nation’s natural and constructed features.

Mississippi↗

USGS2008

Gas and gas hydrate distribution around seafloor seeps in Mississippi Canyon, Northern Gulf of Mexico, using multi-resolution seismic imagery

To determine the impact of seeps and focused flow on the occurrence of shallow gas hydrates, several seafloor mounds in the Atwater Valley lease area of the Gulf of Mexico were surveyed with a wide range of seismic frequencies. Seismic data were acquired with a deep-towed, Helmholz resonator source (220-820 Hz); a high-resolution, Generator-Injector air-gun (30-300 Hz); and an industrial air-gun array (10-130 Hz). Each showed a significantly different response in this weakly reflective, highly faulted area. Seismic modeling and observations of reversed-polarity reflections and small scale diffractions are consistent with a model of methane transport dominated regionally by diffusion but punctuated by intense upward advection responsible for the bathymetric mounds, as well as likely advection along pervasive filamentous fractures away from the mounds.

Marine and Petroleum Geology↗

USGS2014

Effects of hydrologic modifications on salinity and formation of hypoxia in the Mississippi River-Gulf Outlet and adjacent waterways, southeastern Louisiana, 2008 to 2012

The Mississippi River-Gulf Outlet (MRGO) was constructed between 1958 and 1968 to provide a safer and shorter route between the Gulf of Mexico and the Port of New Orleans for ocean-going vessels. In 2006, the U.S. Congress directed the U.S. Army Corps of Engineers (USACE) to develop and implement a plan to deauthorize a portion of the MRGO ship channel from its confluence with the Gulf Intracoastal Waterway to the Gulf of Mexico. In 2009, in accordance with plans submitted to Congress, the USACE built a rock barrier across the MRGO near Hopedale, Louisiana. Following Hurricane Katrina, Congress also authorized the USACE to implement the Hurricane Storm Damage Risk Reduction System (HSDRRS) by building structures in the MRGO and adjacent surface waters, to reduce vulnerability of this area to storm surge. The HSDRRS includes the Gulf Intracoastal Waterway-Lake Borgne Surge Barrier and Gate Complex near mile 58 of the deauthorized portion of the MRGO and the Seabrook Gate Complex on the Inner Harbor Navigation Canal (IHNC). By blocking or limiting tidal exchange in the MRGO, these barriers could affect water quality in the MRGO and nearby waters including Lake Pontchartrain, the IHNC, and Lake Borgne. In 2008, the U.S. Geological Survey, in cooperation with the USACE, began a study to document the effects of the construction activities on salinity and dissolved oxygen in these surface waters. Data were collected from August 2008 through October 2012. Completion of the rock barrier in the vicinity of mile 35 in July 2009 reduced hydrologic circulation and separated the MRGO into two distinct salinity regimes, with substantially fresher conditions prevailing upstream from the rock barrier. The rock barrier also contributed to a zone of hypoxia (dissolved oxygen less than 2 milligrams per liter) that formed along the channel bottom during the warmer summer months in each year of this monitoring; the zone was much more developed downstream from the rock barrier. The most extensive hypoxic zone was measured in October 2009 when it extended at least 34 miles in the MRGO, from mile 20 to mile 54. Construction of the surge barrier and flood gates did not affect salinity or dissolved oxygen in any comparable manner. The factors that contributed the most to hypoxia in the MRGO were the reductions in tidal water movement there after completion of the rock barrier combined with the channel depth in the MRGO, in places 10 to 30 feet deeper than surrounding surface water bodies. These factors helped to stratify salinity by reducing vertical mixing in the water column.

Louisiana↗

USGS1989

Holocene sand shoals offshore of the Mississippi River delta plain

Offshore of the Mississippi River delta plain lies a series of Holocene sand shoals marking the position of ancient submerged shorelines associated with younger shelf-phase delta plains. These submerged shorelines represent positions when sea level stood lower than present. Short periods of rapid sea level rise during the Holocene transgression, in combination with subsidence, led to the submergence of these sandy shorelines, which can be recognized at the -33 ft (-10 m) and -66 ft (-20 m) isobaths on the Louisiana continental shelf The -33 ft (-10 m) shoreline trend is represented by Trinity Shoal and Ship Shoal, which are associated with the late Holocene Mississippi River delta plain. Trinity Shoal is derived from the Cypremont-Sale delta complex and is located 12 mi (20 km) offshore of Marsh Island. This shoal is 22 mi (35 km) long, 5 mi (8 km) wide, and 16 - 20 ft (5 - 6 m) thick. The facies relationships indicate that Trinity Shoal is a submerged barrier system in the initial stages of shoreface reworking. To the east is Ship Shoal which is associated with the Maringouin-Teche delta complex. This shoal is located 12 mi (20 km) offshore of the Isles Dernieres and is 31 mi (50 km) long, 5 - 6 mi (8 - 10 km) wide, and 13 - 20 ft (4 - 6 m) thick. The facies relationships indicate that Ship Shoal is a marine sand body derived from shoreface reworking of a submerged barrier island. The -66 ft (-20 m) shoreline trend is represented by the Outer Shoal and St. Bernard Shoals, which are associated with the early Mississippi River delta plain. The Outer Shoal is a low relief sand body, which lies seaward of Ship Shoal immediately west of the Mississippi Canyon. The eastern continuation of the -66 ft (-20 m) shoreline trend is the St. Bernard Shoals, which lie 16 mi (25 km) offshore of the Chandeleur Islands. In contrast to the other shoal systems, the St. Bernard Shoals form a shore-parallel zone of more than seven smaller sand shoals which, in many respects, are similar to a shore-oblique sand-ridge field. Collectively, these sand shoals represent a large potential source of aggregate for shoreline restoration and erosion control as well as possible hard mineral resources. Scientifically, these shoals provide insight into the processes which control coastal evolution and shelf sand development under the condition of relative sea level rise.

Mississippi River↗

USGS1997

Accelerated relative sea-level rise and rapid coastal erosion: Testing a causal relationship for the Louisiana barrier islands

The role of relative sea-level rise as a cause for the rapid erosion of Louisiana's barrier island coast is investigated through a numerical implementation of a modified Bruun rule that accounts for the low percentage of sand-sized sediment in the eroding Louisiana shoreface. Shore-normal profiles from 150 km of coastline west of the Mississippi delta are derived from bathymetric surveys conducted during the 1880s. 1930s and 1980s. An RMS difference criterion is employed to test whether an equilibrium profile form is maintained between survey years. Only about half the studied profiles meet the equilibrium Criterion this represents a significant limitation on the potential applicability of the Bruun rule. The profiles meeting the equilibrium criterion, along with measured rates of relative sea-level rise, are used to hindcast shoreline retreat rates at 37 locations within the study area. Modeled and observed shoreline retreat rates show no significant correlation. Thus in terms of the Bruun approach relative sea-level rise has no power for hindcasting (and presumably forecasting) rates of coastal erosion for the Louisiana barrier islands.

Marine Geology↗

USGS2001

Water-quality assessment of the eastern Iowa basins– Nitrogen, phosphorus, suspended sediment, and organic carbon in surface water, 1996–98

Twelve sites on streams and rivers in the Eastern Iowa Basins study unit were sampled monthly and during selected storm events from March 1996 through September 1998 to assess the occurrence, distribution, and transport of nitrogen, phosphorus, suspended sediment, and organic carbon as part of the U.S. Geological Survey’s National Water-Quality Assessment Program. One site was dropped from monthly sampling after 1996. Dissolved nitrogen and phosphorus were detected in every water sample collected. Nitrate accounted for 92 percent of the total dissolved nitrogen. About 22 percent of the samples had nitrate concentrations that exceeded the U.S. Environmental Protection Agency’s maximum contaminant level of 10 milligrams per liter as nitrogen for drinking-water regulations. The median concentration of total dissolved nitrogen for surface water in the study unit was 7.2 milligrams per liter. The median total phosphorus concentration for the study unit was 0.22 milligram per liter. About 75 percent of the total phosphorus concentrations exceeded the U.S. Environmental Protection Agency recommended total phosphorus concentration of 0.10 milligram per liter or less to minimize algal growth. Median suspended sediment and dissolved organic-carbon concentrations for the study unit were 82 and 3.5 milligrams per liter, respectively. Median concentrations of nitrogen, phosphorus, and suspended sediment varied annually and seasonally. Nitrogen, phosphorus, and suspended-sediment concentrations increased each year of the study due to increased precipitation and runoff. Median concentrations of dissolved organic carbon were constant from 1996 to 1998. Nitrogen concentrations were typically higher in the spring after fertilizer application and runoff. During winter, nitrogen concentrations typically increased when there was little in-stream processing by biota. Nitrogen and phosphorus concentrations decreased in late summer when there was less runoff and in-stream processing of nitrogen and phosphorus was high. Dissolved organic carbon was highest in February and March when decaying vegetation and manure were transported during snowmelt. Suspendedsediment concentrations were highest in early summer (May–June) during runoff and lowest in January when there was ice cover with very little overland flow contributing to rivers and streams. Based on historical and study-unit data, eastern Iowa streams and rivers are impacted by both nonpoint and point-source pollution. Indicator sites that have homogeneous land use, and geology had samples with significantly higher concentrations of total dissolved nitrogen (median, 8.2 milligrams per liter) than did samples from integrator sites (median, 6.2 milligrams per liter) that were more heterogeneous in land use and geology. Samples from integrator sites typically had significantly higher total phosphorus and suspended-sediment concentrations than did samples from indicator sites. Typically, there was very little difference in median dissolved organic-carbon concentrations in samples from indicator and integrator sites. Concentrations of nitrogen and phosphorus varied across the study unit due to land use and physiography. Basins that are located in areas with a higher percentage of row-crop agriculture typically had samples with higher nitrogen concentrations. Basins that drain the Southern Iowa Drift Plain and the Des Moines Lobe typically had samples with higher total phosphorus and suspended-sediment concentrations. Total nitrogen loads increased each year from 1996 through 1998 in conjunction with increased concentrations and runoff. Total phosphorus loads in the Skunk River Basin decreased in 1997 due to less runoff and decreased sediment transport, but increased in 1998 due to higher runoff and increased sediment transport. Total nitrogen and total phosphorus loads varied seasonally. The highest loads typically occurred in early spring and summer after fertilizer application and runoff. Loads were lowest in January and September when there was typically very little runoff to transport nitrogen and phosphorus in the soil to the rivers and streams. Total nitrogen loads contributed to the Mississippi River from the Eastern Iowa Basins during 1996, 1997, and 1998 were 97,600, 120,000, and 234,000 metric tons, respectively. Total phosphorus loads contributed to the Mississippi River from the Eastern Iowa Basins during 1996, 1997, and 1998 were 6,860, 4,550, and 8,830 metric tons, respectively. Suspendedsediment loads contributed to the Mississippi River from the Eastern Iowa Basins during 1996, 1997, and 1998 were 7,480,000, 4,450,000, and 8,690,000 metric tons, respectively. The highest total nitrogen and total phosphorus yields typically occurred in samples from indicator sites. Sampling sites located in drainage basins with higher row-crop percentage typically had higher nitrogen and phosphorus yields. Sites that were located in the Des Moines Lobe and the Southern Iowa Drift Plain typically had higher phosphorus yields, probably due to physiographic features (for example, erodible soils, steeper slopes). Synoptic samples collected during low and high base flow had nitrogen, phosphorus, and organic-carbon concentrations that varied spatially and seasonally. Comparisons of water-quality data from six basic-fixed sampling sites and 19 other synoptic sites suggest that the water-quality data from basic-fixed sampling sites were representative of the entire study unit during periods of low and high base flow when most streamflow originates from ground water.

Iowa, Minnesota↗

USGS2010

Regional estimates of ecological services derived from U.S. Department of Agriculture conservation programs in the Mississippi Alluvial Valley

The Mississippi Alluvial Valley (MAV) is the Nation?s largest floodplain and this once predominantly forested ecosystem provided significant habitat for a diverse flora and fauna, sequestered carbon in trees and soil, and stored floodwater, sediments, and nutrients within the floodplain. This landscape has been substantially altered by the conversion of nearly 75% of the riparian forests, predominantly to agricultural cropland, with significant loss and degradation of important ecosystem services. Large-scale efforts have been employed to restore the forest and wetland resources and the U.S. Department of Agriculture (USDA) Wetlands Reserve Program (WRP) and Conservation Reserve Program (CRP) represent some of the most extensive restoration programs in the MAV. The objective of the WRP is to restore and protect the functions and values of wetlands in agricultural landscapes with an emphasis on habitat for migratory birds and wetland-dependent wildlife, protection and improvement of water quality, flood attenuation, ground water recharge, protection of native flora and fauna, and educational and scientific scholarship. The degree to which these conservation practices can restore ecosystem functions and services is not well known. This project was initiated to quantify existing ecological services derived from USDA conservation practices in the MAV as part of the USDA Conservation Effects Assessment Project, Wetlands Component (CEAP-Wetlands). The U.S. Geological Survey (USGS), in collaboration with the USDA Natural Resources Conservation Service, the USDA Farm Service Agency, the U.S. Fish and Wildlife Service, and Ducks Unlimited, collected data on soils, vegetation, nitrogen cycling, migratory birds, and amphibians from 88 different sites between 2006 and 2008. Results from restored WRP sites were compared to baseline data from active agricultural cropland (AG) to evaluate changes in ecosystem services.

Arkansas, Kentucky, Louisiana, Mississippi, Missou↗

USGS2009

Sand resources, regional geology, and coastal processes of the Chandeleur Islands Coastal System: An evaluation of the Breton National Wildlife Refuge

Breton National Wildlife Refuge, the Chandeleur Islands chain in Louisiana, provides habitat and nesting areas for wildlife and is an initial barrier protecting New Orleans from storms. The U.S. Geological Survey (USGS) in partnership with the University of New Orleans Pontchartrain Institute for Environmental Sciences undertook an intensive study that included (1) an analysis of island change based on historical maps and remotely sensed shoreline and topographic data; (2) a series of lidar surveys at 3- to 4-month intervals after Hurricane Katrina to determine barrier island recovery potential; (3) a discussion of sea level rise and effects on the islands; (4) an analysis of sea floor evolution and sediment dynamics in the refuge over the past 150 years; (5) an assessment of the local sediment transport and sediment resource availability based on the bathymetric and subbottom data; (6) a carefully selected core collection effort to groundtruth the geophysical data and more fully characterize the sediments composing the islands and surrounds; (7) an additional survey of the St. Bernard Shoals to assess their potential as a sand resource; and (8) a modeling study to numerically simulate the potential response of the islands to the low-intensity, intermediate, and extreme events likely to affect the refuge over the next 50 years. Results indicate that the islands have become fragmented and greatly diminished in subaerial extent over time: the southern islands retreating landward as they reorganize into subaerial features, the northern islands remaining in place. Breton Island, because maintenance of the Mississippi River-Gulf Outlet (MRGO) outer bar channel requires dredging, is deprived of sand sufficient to sustain itself. Regional sediment transport trends indicate that large storms are extremely effective in transporting sand and controlling the shoreline development and barrier island geometry. Sand is transported north and south from a divergent zone near Monkey Bayou at the southern end of the Chandeleur Islands. Numerical simulation of waves and sediment transport supports the geophysical results and indicates that vast areas of the lower shoreface are affected and are undergoing erosion during storm events, that there is little or no fair weather mechanism to rework material into the littoral system, and that as a result, there is a net loss of sediment from the system. Lidar surveys revealed that the island chain immediately after Hurricane Katrina lost about 84 percent of its area and about 92 percent of its prestorm volume. Marsh platforms that supported the islands’ sand prior to the storm were reduced in width by more than one-half. Repeated lidar surveys document that in places the shoreline has retreated about 100 m under the relatively low-energy waves since Hurricanes Katrina and Rita; however, this retreat is nonuniform. Recent high-resolution geophysical surveys of the sea floor and subsurface within 5–6 km of the Chandeleur Islands during 2006 and 2007 show that, in addition to the sand that is rebuilding portions of the island chain, a large volume of sand is contained in Hewes Point, in an extensive subtidal spit platform that has formed at the northern end of the Chandeleur Islands. Hewes Point appears to be the depositional terminus of the alongshore transport system. In the southern Chandeleurs, sand is being deposited in a broad tabular deposit near Breton Island called the southern offshore sand sheet. These two depocenters account for approximately 70 percent of the estimated sediment volume located in potential borrow sites. An additional large potential source of sand for restoration lies in the St. Bernard Shoals, which are estimated to contain approximately 200 × 10 6 m 3 of sand. Successful restoration planning for the Breton National Wildlife Refuge should mimic the natural processes of early stages of barrier island evolution including lateral transport to the flanks of the island chain from a centralized sand source that will ultimately enhance the ability of the islands to naturally build backbarrier marsh, dunes, and a continuous sandy shoreline. Barrier island sediment nourishment should be executed with the understanding that gulf shoreline erosion is inevitable but that island area can be maintained and enhanced during retreat (thus significantly prolonging the life of the island chain) with strategic sand placement.

Louisiana↗

USGS2026

Water use in Louisiana, 2020

The U.S. Geological Survey (USGS), in cooperation with the Louisiana Department of Transportation and Development, collected water-withdrawal and water-use data from a 2020 inventory of water withdrawals in Louisiana. In 2020, approximately 8,700 million gallons per day (Mgal/d) of water was withdrawn from groundwater and surface-water sources in Louisiana, which represented a 0.22-percent decrease from 2015. Total groundwater withdrawals were about 1,900 Mgal/d, an increase of 7.1 percent from 2015, and total surface-water withdrawals were about 6,800 Mgal/d, a decrease of 2.1 percent from 2015 to 2020. Total water withdrawals, in million gallons per day, in 2020 for the various categories of use were as follows: public supply, 720; industry, 2,100; power generation, 4,100; rural domestic, 39; livestock, 7.0; rice irrigation, 930; general irrigation, 250; and aquaculture, 590. From 2015 to 2020, Louisiana’s total withdrawals for public supply increased by 1.4 percent, industry decreased by 2.3 percent, power generation decreased by 4.9 percent, rural domestic decreased by 1.2 percent, livestock increased by 11 percent, rice irrigation increased by 13 percent, general irrigation increased by 12 percent, and aquaculture increased by 20 percent. About 51 percent (approximately 960 Mgal/d) of all groundwater withdrawn was from the Chicot aquifer system and 24 percent (approximately 450 Mgal/d) was withdrawn from the Mississippi River alluvial aquifer. Since 2015, withdrawals from the Chicot aquifer system increased by 13 percent, and withdrawals from the Mississippi River alluvial aquifer increased by 18 percent. About 72 percent (4,900 Mgal/d) of all surface water withdrawn was from the Mississippi River main stem. This value represents a 1.1-percent decrease in withdrawals from 2015 to 2020. All water-withdrawal and water-use data presented in this report should be considered estimates. Because of rounding, totals and percentages presented in the tables, figures, and text in the report may differ slightly from totals or percentages calculated individually.

Louisiana↗

USGS1997

Environmental geochemistry and sediment quality in Lake Pontchartrain: database development and review

This paper reports on preliminary results of a project to develop a comprehensive data base of chemical and environmental information on sediments from Lake Pontchartrain, Louisiana, and surrounding water bodies. The goal is to evaluate all data for reliability and comparability, and to make it widely accessible and useful to all users. Methods for processing heterogeneous, historical data follow previous methods employed in the Boston Harbor and Massachusetts Bay area. Data from 11 different data sets, encompassing about 900 total samples, have been entered to date. Questionable or anomalous data were noted in a minority of cases. Problems tend to follow distinct patterns and are relatively easy to identify. Hence, comparability of data has not proven to be the major obstacle to synthesis efforts that was anticipated in earlier years (NRC, 1989). Quality-controlled data sets show that the bulk of sediment samples in the more central parts of Lake Pontchartrain have values within normal background for heavy metals like Cu, Pb, and Zn. The same or lower concentrations were found in the vicinity of the Bonnet Carre Spillway, representing influx from the Mississippi River. Mean concentrations for Cu, Pb, and Zn were 17, 21, and 74 µg/g (total dissolution analyses), respectively. However, values as high as 267 µg/g Pb and comparable increases for other metal and organic contaminants are found in sediments within 2 km of the coastal strip of New Orleans. Additional sampling in such areas and in other inland coastal waterways is needed, since such levels are above the threshold for potential toxic effects on benthic organisms, according to effects-based screening criteria. The most contaminated sites, Bayou Trepagnier and Bayou Bonfouca, involve industrial areas where waste discharge has now been controlled or remediated, but where sediments may retain large concentrations of contaminants, e.g. tenths of a percent of Pb, Cr, and Zn or more for Bayou Trepagnier.

Louisiana↗

USGS2020

Fate and behavior tools related to inland spill response—Workshop on the U.S. Geological Survey’s role in Federal science support

Executive Summary There is a growing body of tools available for science support for determining the fate and behavior of industrial and agricultural chemicals that are rapidly injected (“spilled”) into aquatic environments. A 2-day roundtable-style workshop was held by the U.S. Geological Survey (USGS) in Middleton, Wisconsin, in December 2017 to describe and explore existing Federal science support for spill fate and behavior tools used for inland spills, ongoing and new fate and behavior studies, and science gaps in planning and response tools as part of the USGS Midcontinent Region’s efforts to include spill response as part of its strategic plans. A total of 28 attendees representing a variety of Federal, State, and regional entities presented on programs and tools used in various aspects of spill response. Most programs and tools discussed were for spills in riverine environments but tools and applications for spills in lakes, on land surfaces, in urban storm sewer networks, and groundwater also were discussed. A primary workshop focus was to facilitate communication and increase potential for future collaboration among agencies for inland spill science support. The role and need for more USGS science support within the inland spill community was discussed. Enhanced communication is needed within the USGS and the U.S. Department of the Interior science programs, as well as within and among other agencies that do emergency planning and response. A main conclusion of the workshop was that there are untapped resources of the USGS outlined in the agency’s science strategy that could strengthen science support for fate and behavior tools in inland areas, especially in the Upper Mississippi River, Ohio River, and Great Lakes Basins where large freshwater resources overlap with dense corridors of oil and hazardous substances, with transportation networks, and with large populations centers. Fate and behavior tools are being developed quickly for inland spill response by multiple Federal agencies in partnership with local and regional entities. Applicability of these tools ranges from planning and preparedness, to the early stages of spill response for protection of human life and property, and to the application of monitoring and models to assess the long-term consequences of spills. Key findings from the workshop, with an emphasis on potential further development of USGS science support, include the following: •The national and regional response to spills occurs within an established system that must be respected by all parties involved in spill response. The USGS’s role is to support spill responders who are physically working at a spill scene, deploying booms and using other efforts to contain and recover spilled materials. •The USGS has tools that have been used throughout spill response operations, from early response to recovery and restoration. Developing a more formal role for the USGS to participate in science support for inland spills on a consistent basis is a desired outcome. This will require the USGS to improve internal and external communication and would be best accomplished by assigning one or more coordinator positions within the agency to plan and oversee USGS spill-response efforts. More involvement of the USGS on National and Regional Response Teams, especially in the realm of the Science and Technology Subcommittees, will gofar in increasing external communication and integration of fate and behavior tools. •Rapid response to spills requires modeling and mapping of plumes and associated time-of-travel estimation for a range of stream sizes across the United States. Many existing models use USGS streamgage data and the USGS National Hydrography Dataset. Nearly all existing models would benefit from updated linkages to USGS StreamStats and its soon-to-be released time-of-travel estimates,real-time velocity, stream morphology, and slope data. Integrating USGS tools with those from other agencies could be done to better serve the larger spill response community. • A problem is that existing models to rapidly predict plume extent, as well as more followup/longer-term fate and transport models, can be unknown or unavailable to spill responders. Thus, creating and strengthening linkages among USGS scientists skilled at using these tools is needed to support spill response with the on-scene responders. • Research for inland spill fate and behavior done outside of an immediate spill response can assist with spill planning and preparedness by (1) revealing sites likely to experience spills in the future (high-risk sites) and (2) understanding how a spilled substance might behave under a range of environmental conditions. However, USGS research on this topic has been scarce and subject to funding availability. Examples include the 2010 Line 6B Spill release into the Kalamazoo River in Michigan, where the USGS provided science support for a variety of fate and behavior tools for stream and impoundment environments. A long-term research site in Bemidji, Minnesota, provides important insights into transformations and longevity of spilled oil in groundwater and groundwater-surface water interactions. • Linking stream models to other components of this inland environment, including groundwater, overland flow, and karst, is needed. Stream network data can be linked to underground conduits such as storm sewers and karst groundwater systems. Stream models can also be linked with geospatial data such as that contained in U.S. Environmental Protection Agency’s interactive mapping tools. • The USGS is uniquely qualified to collect water-quality data during spills in the United States because of its many geographically dispersed water science centers, its knowledge and preparedness for flood measurement and documentation, and its cadre of skilled water-quality employees. Rapid-deployment gages, used for floods, could also be used for spills if they included spill-specific sensors. Coordinated expertise at USGS water and environmental science centers can be used for monitoring spill effects and for assessing risk to water quality and ecological communities. • Scientists at the USGS have proven capable of providing science coordination and technical assistance within the Incident Command Structure at the request of the lead on-scene coordinator. This external coordination, as well as internal communication within USGS Water, Hazards, and Ecosystems Mission Areas, could be improved by establishing and naming a USGS spills coordinator. Scott Morlock, Jo Ellen Hinck, and Faith Fitzpatrick are currently (2017) serving in informal coordination roles in addition to their traditional duties.

Open-File Report↗

USGS1999

U.S. Geological Survey Toxic Substances Hydrology Program: Proceedings of the technical meeting, Charleston, South Carolina, March 8-12, 1999: Volume 1 (Part A)

This report contains papers presented at the seventh Technical Meeting of the U.S. Geological Survey (USGS), Toxic Substances Hydrology (Toxics) Program. The meeting was held March 8-12, 1999, in Charleston, South Carolina. Toxics Program Technical Meetings are held periodically to provide a forum for presentation and discussion of results of recent research activities. The objectives of these meetings are to: Present recent research results to essential stakeholders, Encourage synthesis and integrated interpretations among scientists with different expertise who are working on a contamination issue, and Promote exchange of ideas among scientists working on different projects and issues within the Toxics Program. The Proceedings is published in three volumes. Volume 1 contains papers that report on results of research on contamination from hard-rock mining. Results include research on contamination from hard rock mining in arid southwest alluvial basins, research on hard rock mining in mountainous terrain, and progress from the USGS Abandoned Mine Lands Initiative. This Initiative is designed to develop a watershed-based approach to characterize and remediate contamination from abandoned mine lands and transfer technologies to Federal land management agencies and stakeholders. Volume 2 contains papers on contamination of hydrologic systems and related ecosystems. The papers discuss research on the response of estuarine ecosystems to contamination from human activities. They include research on San Francisco Bay; mercury contamination of aquatic ecosystems; and investigation of the occurrence, distribution, and fate of agricultural chemicals in the Mississippi River Basin. This volume also contains results on development and reconnaissance testing of new methods to detect emerging contaminants in environmental samples. Volume 3 contains papers on subsurface contamination from point sources. The papers discuss research on: hydrocarbons and fuel oxygenates at gasoline release sites; ground-water contamination by crude oil; complex contaminant mixtures from treated wastewater discharges; waste disposal and subsurface transport of contaminants in arid environments; ground water and surface water affected by municipal landfill leachate; natural attenuation of chlorinated solvents; and characterizing flow and transport in fractured rock aquifers. In all, the more than 175 papers contained in this proceedings reflect the contributions of more than 350 scientists who are co-authors. These scientists are from across the USGS, as well as from universities, other Federal and State agencies, and industry.

Water-Resources Investigations Report↗

USGS1999

U.S. Geological Survey Toxic Substances Hydrology Program: Proceedings of the technical meeting, Charleston, South Carolina, March 8-12, 1999: Volume 2 (Part B)

This report contains papers presented at the seventh Technical Meeting of the U.S. Geological Survey (USGS), Toxic Substances Hydrology (Toxics) Program. The meeting was held March 8-12, 1999, in Charleston, South Carolina. Toxics Program Technical Meetings are held periodically to provide a forum for presentation and discussion of results of recent research activities. The objectives of these meetings are to: Present recent research results to essential stakeholders, Encourage synthesis and integrated interpretations among scientists with different expertise who are working on a contamination issue, and Promote exchange of ideas among scientists working on different projects and issues within the Toxics Program. The Proceedings is published in three volumes. Volume 1 contains papers that report on results of research on contamination from hard-rock mining. Results include research on contamination from hard rock mining in arid southwest alluvial basins, research on hard rock mining in mountainous terrain, and progress from the USGS Abandoned Mine Lands Initiative. This Initiative is designed to develop a watershed-based approach to characterize and remediate contamination from abandoned mine lands and transfer technologies to Federal land management agencies and stakeholders. Volume 2 contains papers on contamination of hydrologic systems and related ecosystems. The papers discuss research on the response of estuarine ecosystems to contamination from human activities. They include research on San Francisco Bay; mercury contamination of aquatic ecosystems; and investigation of the occurrence, distribution, and fate of agricultural chemicals in the Mississippi River Basin. This volume also contains results on development and reconnaissance testing of new methods to detect emerging contaminants in environmental samples. Volume 3 contains papers on subsurface contamination from point sources. The papers discuss research on: hydrocarbons and fuel oxygenates at gasoline release sites; ground-water contamination by crude oil; complex contaminant mixtures from treated wastewater discharges; waste disposal and subsurface transport of contaminants in arid environments; ground water and surface water affected by municipal landfill leachate; natural attenuation of chlorinated solvents; and characterizing flow and transport in fractured rock aquifers. In all, the more than 175 papers contained in this proceedings reflect the contributions of more than 350 scientists who are co-authors. These scientists are from across the USGS, as well as from universities, other Federal and State agencies, and industry.

Water-Resources Investigations Report↗

USGS1999

U.S. Geological Survey Toxic Substances Hydrology Program: Proceedings of the technical meeting, Charleston, South Carolina, March 8-12, 1999: Volume 3 (Part C)

This report contains papers presented at the seventh Technical Meeting of the U.S. Geological Survey (USGS), Toxic Substances Hydrology (Toxics) Program. The meeting was held March 8-12, 1999, in Charleston, South Carolina. Toxics Program Technical Meetings are held periodically to provide a forum for presentation and discussion of results of recent research activities. The objectives of these meetings are to: Present recent research results to essential stakeholders, Encourage synthesis and integrated interpretations among scientists with different expertise who are working on a contamination issue, and Promote exchange of ideas among scientists working on different projects and issues within the Toxics Program. The Proceedings is published in three volumes. Volume 1 contains papers that report on results of research on contamination from hard-rock mining. Results include research on contamination from hard rock mining in arid southwest alluvial basins, research on hard rock mining in mountainous terrain, and progress from the USGS Abandoned Mine Lands Initiative. This Initiative is designed to develop a watershed-based approach to characterize and remediate contamination from abandoned mine lands and transfer technologies to Federal land management agencies and stakeholders. Volume 2 contains papers on contamination of hydrologic systems and related ecosystems. The papers discuss research on the response of estuarine ecosystems to contamination from human activities. They include research on San Francisco Bay; mercury contamination of aquatic ecosystems; and investigation of the occurrence, distribution, and fate of agricultural chemicals in the Mississippi River Basin. This volume also contains results on development and reconnaissance testing of new methods to detect emerging contaminants in environmental samples. Volume 3 contains papers on subsurface contamination from point sources. The papers discuss research on: hydrocarbons and fuel oxygenates at gasoline release sites; ground-water contamination by crude oil; complex contaminant mixtures from treated wastewater discharges; waste disposal and subsurface transport of contaminants in arid environments; ground water and surface water affected by municipal landfill leachate; natural attenuation of chlorinated solvents; and characterizing flow and transport in fractured rock aquifers. In all, the more than 175 papers contained in this proceedings reflect the contributions of more than 350 scientists who are co-authors. These scientists are from across the USGS, as well as from universities, other Federal and State agencies, and industry.

Water-Resources Investigations Report↗

USGS1988

Seismic stratigraphy of the Mississippi-Alabama shelf and upper continental slope

The Mississippi-Alabama shelf and upper continental slope contain relatively thin Upper Pleistocene and Holocene deposits. Five stages of shelf evolution can be identified from the early Wisconsinan to present. The stages were controlled by glacioeustatic or relative sea-level changes and are defined by the stratigraphic position of depositional and erosional episodes. The stratigraphy was identified on seismic profiles by means of geomorphic pattern, high-angle clinoform progradational deposits, buried stream entrenchments, planar conformities, and erosional unconformities. The oldest stage (stage 1) of evolution occurred during the early Wisconsinan lowstand; the subaerially exposed shelf was eroded to a smooth seaward-sloping surface. This paleosurface is overlain by a thin (< 10 m) drape of transgressive deposits (stage 2). Stage 3 occurred in three phases as the late Wisconsinan sea retreated: (1) fluvial channel systems eroded across the shelf, (2) deposited a thick (90 m) shelf-margin delta, and (3) contemporaneously deposited sediments on the upper slope. Stage 4 included the rapid Holocene sea-level rise that deposited a relatively thin transgressive facies over parts of the shelf. The last major depositional episode (stage 5) was the progradation of the St. Bernard delta over the northwestern and central parts of the area. A depositional hiatus has occurred since the St. Bernard progradation. These Upper Quaternary shelf and slope deposits provide models for analogous deposits in the geologic record. Primarily, they are examples of cyclic sedimentation caused by changes in sea level and may be useful in describing short-term, sandy depositional episodes in prograding shelf and slope sequences.

Marine Geology↗

USGS2003

Correlation of climate cycles in middle Mississippi Valley loess and Greenland ice

Two complete late Wisconsin loess successions in the middle Mississippi River Valley reveal 39 and 41 alternating paleosol A- and C-horizons. Striking changes in soil color, iron content, and carbonate content define four major and two minor paleosol A-horizon complexes, which were interpreted to represent Wisconsin interstadials 1, 2, 3, 4, and semiinterstadials 1.5 and 2.5, respectively. The timing of Wisconsin interstadials matches that of corresponding Greenland interstadials. Midcontinent loess and Greenland ice records as well as rates of atmospheric 14 C production have periodicities in common, suggesting a solar influence. Only a persistent heat and moisture supply could produce prominent paleosol complexes near the continental ice margin. This record suggests that El Niño–Southern Oscillation variability has amplified solar forcing, and resultant tropical heat and moisture transport played a significant role in millennial- and centennial-scale climate cycles during the late Wisconsin glaciation over the Northern Hemisphere.

Geology↗

USGS2014

Pesticide trends in major rivers of the United States, 1992-2010

This report is part of a series of pesticide trend assessments led by the National Water-Quality Assessment Program of the U.S. Geological Survey. This assessment focuses on major rivers of various sizes throughout the United States that have large watersheds with a range of land uses, changes in pesticide use, changes in management practices, and natural influences typical of the regions being drained. Trends were assessed at 59 sites for 40 pesticides and pesticide degradates during each of three overlapping periods: 1992–2001, 1997–2006, and 2001–10. In addition to trends in concentration, trends in agricultural-use intensity (agricultural use) were also assessed at 57 of the sites for 35 parent compounds with agricultural uses during the same three periods. The SEAWAVE-Q model was used to analyze trends in concentration, and parametric survival regression for interval-censored data was used to assess trends in agricultural use. All trends are provided in downloadable electronic files. A subset of 39 sites was chosen to represent non-nested, generally independent basins for a national analysis of pesticide and agricultural-use trends for the most prevalent pesticides (15 pesticides and 2 degradation products). Graphical and numerical results are presented to provide a national overview of concentration and use trends. As another perspective on understanding pesticide concentration trends in large rivers in relation to multiple tributary watersheds, this report also presents a detailed assessment of concentration and use trends for simazine, metolachlor, atrazine, deethylatrazine, and diazinon for a set of 17 nested sites in the Mississippi River Basin (including the Ohio and Missouri River Basins), for the second and third trend periods. Pesticides strongly dominated by agricultural use—cyanazine, metolachlor, atrazine, and alachlor—had widespread agreement between concentration trends and agricultural-use trends. Pesticides with substantial use in agricultural and urban applications—simazine, tebuthiuron, Dacthal, pendimethalin, chlorpyrifos, malathion, diazinon, fipronil, carbofuran, and carbaryl—had concentration trends that were mostly explained by a combination of agricultural-use trends and concentration trends in urban streams that were evaluated in a separate companion study. The importance of the urban stream trends for explaining concentration trends in major rivers indicates the significance of nonagricultural uses of some pesticides to concentrations in major rivers despite the much smaller area of urban land use compared to agriculture. Deethylatrazine, a degradate of atrazine, was the only pesticide compound assessed that had frequent occurrences during 1997–2006 and 2001–10 of concentration trends in the opposite direction of use trends (atrazine use). The nested analysis for the Mississippi River indicates that most trends observed in the largest rivers—multiple Mississippi River sites, the Ohio River, and the Missouri River—are consistent with streamflow contributions and concentration trends observed at tributary sites. Streamflow (incorporated into the trend model and shown in the nested basin analysis), trends in agricultural use of pesticides (quantified in this report), and urban use of pesticides (represented by concentration trends in a companion study of urban streams) are all important influences on pesticide concentrations in streams and rivers. Consideration of these influences is vital to understanding trends in pesticide concentrations.

Scientific Investigations Report↗

USGS1989

Constraints from fluid inclusions on sulfide precipitation mechanisms and ore fluid migration in the Viburnum Trend lead district, Missouri

Measurements on fluid inclusions in hydrothermal dolomite cements place constraints on sulfide precipitation mechanisms and on the thermal-hydrologic processes which formed the Viburnum Trend Mississippi Valley-type lead district. Homogenization temperatures and freezing point depressions were determined for fluid inclusions in Bonneterre Dolomite-hosted dolomite cements in mine samples, as well as drill core from up to 13 km outside of the district. A well-defined cathodoluminescent zonation distinguishes dolomite growth zones in the Vi-burnurn Trend as older or younger than main-stage mineralization (octahedral galena) and facilitates correlation with other dolomites outside the Viburnum Trend.Homogenization temperatures and salinities in samples from mines are not systematically different from those of samples outside of the district. Medians of homogenization temperature distributions differ by not more than 25 degrees C, so that a temperature gradient, if present, should not have exceeded approximately 25 degrees C within the study area. These observations are interpreted to indicate that the Viburnum Trend was not strongly thermally anomalous with respect to surrounding country rock and that fluid flow occurred on a broad scale through not only the Lamotte Sandstone but through the overlying Cambrian carbonates as well.The absence of a significant, recognizable decrease in temperature either vertically within the section or east-west across the district, coupled with the minor amount of silica in the district, argues against cooling as a primary cause of sulfide precipitation. Fluids whose primary aquifer was the Lamotte Sandstone, predominantly a quartz arenite, should have been in equilibrium with quartz. Quartz in the Viburnum Trend occurs as a minor, drusy, vug-lining phase, but the district lacks the intense silicification found in other Mississippi Valley-type districts such as Tri-State (Oklahoma, Kansas, Missouri). Quartz solubility is strongly temperature dependent and, under equilibrium conditions, a decrease of 10 degrees C or more should have precipitated at least as many moles of silica as galena (assuming a galena solubility of between 1 and 10 ppm). Clearly this is not the case, as galena is far more abundant than quartz in the Viburnum Trend.Ice final-melting temperatures (T m ) in fluid inclusions generally range from -14 degrees to -27 degrees C for primary dolomite-hosted inclusions. Using these T m values and cation ratios for the inclusion fluids, absolute concentrations for the individual cations and chloride were calculated using the thermochemical model of Spencer et al. (1990). The corresponding high but variable salinities, 3.9 to 5.9 chloride molality, are evidence for the presence of more than one distinct fluid during mineralization.In a reduced sulfur mineralization model with Pb carried as chloride complexes, dilution is also a possible sulfide precipitation mechanism. The difference in Pb solubility (for an equal quantity of reduced sulfur) in the extremes of the chloride concentration range, 3.9 vs. 5.9 molal, reaches 1 ppm only for pH values below approximately 4.5. Accepting 1 ppm as a minimum metal concentration for a viable ore-forming fluid, dilution only appears capable of precipitating sulfides in a fluid with pH near the lower limit of values considered geologically reasonable or attainable.Dolomite cements hosting warm (approximately 105 degrees -125 degrees C) saline fluid inclusions are ubiquitous in the porous dolomitic facies of the Bonneterre Dolomite. Based on stratigraphic reconstructions, however, it is unlikely that the Bonneterre was buried deeper than 1.5 km. The distribution of warm inclusions beyond the Viburnum Trend district implies that fluid migration was regional in scale. Fluid inclusion temperatures inconsistent with typical basement heat-flow-controlled geothermal gradients (25 degrees -35 degrees C/km) may be explained by long-distance migration of warm, basin-derived brines. Elevated temperatures observed in fluid inclusions at shallow stratigraphic depths are consistent with a gravity flow hydrologic system characterized by rapid flow rates and the capacity for advective heat transport.

Economic Geology↗