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USGS2001

Cruise Report; RV Moana Wave cruise M1-01-GM; the bathymetry and acoustic backscatter of the mid shelf to upper slope off Panama City, Florida, northeastern Gulf of Mexico; September 3, through October 12, 2001, Panama City, FL to Panama City, FL

A zone of deep-water reefs is thought to extend from the mid and outer shelf south of Mississippi and Alabama to at least the northwestern Florida shelf off Panama City, Florida (Figure 1, 67kb). The reefs off Mississippi and Alabama are found in water depths of 60 to 120 m (Ludwick and Walton, 1957; Gardner et al., in press) and were the focus of a multibeam echosounder (MBES) mapping survey by the U.S. Geological Survey (USGS) in 2000 (Gardner et al., 2000; in press). If this deep-water-reef trend does exist along the northwestern Florida shelf, then it is critical to determine the accurate geomorphology and type of the reefs that occur because of their importance as benthic habitats for fisheries. Precisely georeferenced high-resolution mapping of bathymetry is a fundamental first step in the study of areas suspected to be critical habitats. Morphology is thought to be critical to defining the distribution of dominant demersal plankton/planktivores communities. Fish faunas of shallow hermatypic reefs have been well studied, but those of deep ahermatypic reefs have been relatively ignored. The ecology of deep-water ahermatypic reefs is fundamentally different from hermatypic reefs because autochthonous intracellular symbiotic zooxanthellae (the carbon source for hermatypic corals) do not form the base of the trophic web in ahermatypic reefs. Instead, exogenous plankton, transported to the reef by currents, serves as the primary carbon source. Thus, one of the principle uses of the morphology data will be to identify whether any reefs found are hermatypic or ahermatypic in origin. Community structure and trophodynamics of demersal fishes of the outer continental of the northeastern Gulf of Mexico presently are the focus of a major USGS reseach project. A goal of the project is to answer questions concerning the relative roles played by morphology and surficial geology in controling biological differentiation. Deep-water reefs are important because they are fish havens, key spawning sites, and are critical early larval and juvenile habitats for economically important sport/food fishes. It is known that deep-water reefs function as a key source for re-population (via seasonal and ontogenetic migration) of heavily impacted inshore reefs. The deep-water reefs south of Mississippi and Alabama support a lush fauna of ahermatypic hard corals, soft corals, black corals, sessile crinoids and sponges, that together form a living habitat for a well-developed fish fauna. The fish fauna comprises typical Caribbean reef fishes and Carolinian shelf fishes, plus epipelagic fishes, and a few deep-sea fishes. The base of the megafaunal invertebrate food web is plankton, borne by essentially continuous semi-laminar currents generated by eddies, spawned off the Loop Current, that periodically travel across the shelf edge. A few, sidescan-sonar surveys have been made of areas locally identified as Destin Pinnacles, Steamboat Lumps Marine Reserve (Koenig et al., 2000; Scanlon, et al., 2000; 2001), Twin Ridges (Briere, et al., 2000; Scanlon, et al., 2000), and Madison-Swanson Marine Reserve (Koenig et al., 2000; Scanlon, et al., 2000; 2001). However, no quantitative and little qualitative information about the geomorphology and surficial geology can be gained from these data. Existing bathymetry along the northwestern Florida shelf suggests the existence of areas of possible isolated deep-water reefs. NOAA bathymetric maps NOS NH16-9 and NG16-12 show geomorphic expressions that hint of the presence of reefs in isolated areas rather than in a continuous zone. There has been no systematic, high-resolution bathymetry collected in this area, prior to this cruise. After the successful mapping of the deep-water reefs on the Mississippi and Alabama shelf (Gardner et al., 2000; in press), a partnership composed of the USGS, Minerals Management Service, and NOAA was formed to continue the deep-reef mapping to the northwest Florida mid shelf and upper slope. This cruise is the first fruit of that partnership.

Florida↗

USGS1911

The geology of the Lake Superior region

The Lake Superior region is a part of the southern margin of the great pre-Cambrian shield of northern North America. It is bordered and overlapped on the south by Paleozoic rocks of the Mississippi Valley and on the southwest by Cretaceous deposits. The pre-Cambrian rocks of the area, which may be divided into a considerable number of lithologic and time units, contain the great iron and copper deposits by which the region is most widely known. The great development of the mineral industry in this region has afforded the geologist unusual opportunity for study, as it has not only made the region more accessible but has justified larger expenditures for geologic study than would otherwise have been made. This fortunate combination of a field containing an exceptionally full record of a little-known part of the geologic column with the means of studying it has warranted the study of the pre-Cambrian with a degree of detail that has been practicable in but few other significant pre-Cambrian regions.

Lake Superior↗

USGS2013

Computed statistics at streamgages, and methods for estimating low-flow frequency statistics and development of regional regression equations for estimating low-flow frequency statistics at ungaged locations in Missouri

The weather and precipitation patterns in Missouri vary considerably from year to year. In 2008, the statewide average rainfall was 57.34 inches and in 2012, the statewide average rainfall was 30.64 inches. This variability in precipitation and resulting streamflow in Missouri underlies the necessity for water managers and users to have reliable streamflow statistics and a means to compute select statistics at ungaged locations for a better understanding of water availability. Knowledge of surface-water availability is dependent on the streamflow data that have been collected and analyzed by the U.S. Geological Survey for more than 100 years at approximately 350 streamgages throughout Missouri. The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, computed streamflow statistics at streamgages through the 2010 water year, defined periods of drought and defined methods to estimate streamflow statistics at ungaged locations, and developed regional regression equations to compute selected streamflow statistics at ungaged locations. Streamflow statistics and flow durations were computed for 532 streamgages in Missouri and in neighboring States of Missouri. For streamgages with more than 10 years of record, Kendall’s tau was computed to evaluate for trends in streamflow data. If trends were detected, the variable length method was used to define the period of no trend. Water years were removed from the dataset from the beginning of the record for a streamgage until no trend was detected. Low-flow frequency statistics were then computed for the entire period of record and for the period of no trend if 10 or more years of record were available for each analysis. Three methods are presented for computing selected streamflow statistics at ungaged locations. The first method uses power curve equations developed for 28 selected streams in Missouri and neighboring States that have multiple streamgages on the same streams. Statistical estimates on one of these streams can be calculated at an ungaged location that has a drainage area that is between 40 percent of the drainage area of the farthest upstream streamgage and within 150 percent of the drainage area of the farthest downstream streamgage along the stream of interest. The second method may be used on any stream with a streamgage that has operated for 10 years or longer and for which anthropogenic effects have not changed the low-flow characteristics at the ungaged location since collection of the streamflow data. A ratio of drainage area of the stream at the ungaged location to the drainage area of the stream at the streamgage was computed to estimate the statistic at the ungaged location. The range of applicability is between 40- and 150-percent of the drainage area of the streamgage, and the ungaged location must be located on the same stream as the streamgage. The third method uses regional regression equations to estimate selected low-flow frequency statistics for unregulated streams in Missouri. This report presents regression equations to estimate frequency statistics for the 10-year recurrence interval and for the N-day durations of 1, 2, 3, 7, 10, 30, and 60 days. Basin and climatic characteristics were computed using geographic information system software and digital geospatial data. A total of 35 characteristics were computed for use in preliminary statewide and regional regression analyses based on existing digital geospatial data and previous studies. Spatial analyses for geographical bias in the predictive accuracy of the regional regression equations defined three low-flow regions with the State representing the three major physiographic provinces in Missouri. Region 1 includes the Central Lowlands, Region 2 includes the Ozark Plateaus, and Region 3 includes the Mississippi Alluvial Plain. A total of 207 streamgages were used in the regression analyses for the regional equations. Of the 207 U.S. Geological Survey streamgages, 77 were located in Region 1, 120 were located in Region 2, and 10 were located in Region 3. Streamgages located outside of Missouri were selected to extend the range of data used for the independent variables in the regression analyses. Streamgages included in the regression analyses had 10 or more years of record and were considered to be affected minimally by anthropogenic activities or trends. Regional regression analyses identified three characteristics as statistically significant for the development of regional equations. For Region 1, drainage area, longest flow path, and streamflow-variability index were statistically significant. The range in the standard error of estimate for Region 1 is 79.6 to 94.2 percent. For Region 2, drainage area and streamflow variability index were statistically significant, and the range in the standard error of estimate is 48.2 to 72.1 percent. For Region 3, drainage area and streamflow-variability index also were statistically significant with a range in the standard error of estimate of 48.1 to 96.2 percent. Limitations on the use of estimating low-flow frequency statistics at ungaged locations are dependent on the method used. The first method outlined for use in Missouri, power curve equations, were developed to estimate the selected statistics for ungaged locations on 28 selected streams with multiple streamgages located on the same stream. A second method uses a drainage-area ratio to compute statistics at an ungaged location using data from a single streamgage on the same stream with 10 or more years of record. Ungaged locations on these streams may use the ratio of the drainage area at an ungaged location to the drainage area at a streamgage location to scale the selected statistic value from the streamgage location to the ungaged location. This method can be used if the drainage area of the ungaged location is within 40 to 150 percent of the streamgage drainage area. The third method is the use of the regional regression equations. The limits for the use of these equations are based on the ranges of the characteristics used as independent variables and that streams must be affected minimally by anthropogenic activities.

Missouri↗

USGS1924

The composition of the river and lake waters of the United States

In the summer of 1903 the late Richard B. Dole, chemist of the water-resources branch of the United States Geological Survey, began a systematic investigation of the composition of the river and lake waters of the United States. His plan, which developed gradually, was to have analyses made of the different waters in such a manner as to give the average composition of each one for an entire year. For a few waters, such completeness was impracticable, the analyses covered only part of a year, but even in these waters the data obtained were of much value. As a rule, samples of each water were collected day by day. They were then mixed in sets of ten and analyzed, so that for each river or lake from 34 to 37 analyses were made. For the Mississippi above New Orleans composite analyses were made in sets of seven, giving 52 analyses from which to compute the average. For the Great Lakes, however, only monthly samples were taken, for the reason that their waters vary so little in composition that greater elaboration was not necessary. Some of the larger rivers were treated even more thoroughly; their average composition was determined at more than one point – the Mississippi at six points. For some rivers the analyses cover two years of collection, and for the data, received from a contributor not connected with the Geological Survey, three years.

Professional Paper↗

USGS2009

Channel, floodplain, and wetland responses to floods and overbank sedimentation, 1846-2006, Halfway Creek Marsh, Upper Mississippi Valley, Wisconsin

Conversion of upland forest and prairie vegetation to agricultural land uses, following Euro-American settlement in the Upper Mississippi River System, led to accelerated runoff and soil erosion that subsequently transformed channels, floodplains, and wetlands on bottomlands. Halfway Creek Marsh, at the junction of Halfway Creek and the Mississippi River on Wisconsin's western border, is representative of such historical transformation. This marsh became the focus of a 2005-2006 investigation by scientists from the U.S. Geological Survey, the University of Wisconsin- Madison, and the U.S. Environmental Protection Agency, who used an understanding of the historical transformation to help managers identify possible restoration alternatives for Halfway Creek Marsh. Field-scale topographic surveys and sediment cores provided data for reconstructing patterns and rates of historical overbank sedimentation in the marsh. Information culled from historical maps, aerial photographs, General Land Offi ce Survey notes, and other historical documents helped establish the timing of anthropogenic disturbances and document changes in channel patterns. Major human disturbances, in addition to agricultural land uses, included railroad and road building, construction of artifi cial levees, drainage alterations, and repeated dam failures associated with large floods. A volume of approximately 1,400,000 m 3 , involving up to 2 m of sandy historical overbank deposition, is stored through the upper and lower marshes and along the adjacent margins of Halfway Creek and its principal tributary, Sand Lake Coulee. The estimated overbank sedimentation rate for the entire marsh is ??3,000 m 3 yr- 1 for the recent period 1994-2006. In spite of reduced surface runoff and soil erosion in recent years, this recent sedimentation rate still exceeds by ??4 times the early settlement (1846-1885) rate of 700 m 3 yr- 1 , when anthropogenic acceleration of upland surface runoff and soil erosion was beginning. The highest rate of historical bottomland sedimentation occurred from 1919 to 1936, when the estimated overbank sedimentation rate was 20,400 m 3 yr- 1 . This rate exceeded by nearly 30 times the 1846-1886 rate. Artifi cial levees were constructed along the upper reach of Halfway Creek in the marsh during the early twentieth century to restrict fl ooding on the adjacent bottomlands. Anomalously high overbank sedimentation rates subsequently occurred on the fl oodplain between the levees, which also facilitated more effi cient transport of sediment into the lower marsh bottomland. Although overbank sedimentation rates dropped after 1936, corresponding to the widespread adoption of soil-conservation and agricultural best-management practices, the continuation of anomalously high overbank sedimentation between the levees led to increased bank heights and development of a relatively deep channel. The deep cross-section morphology is commonly mistaken as evidence of channel incision; however, this morphology actually resulted from excessive overbank sedimentation. The historical metamorphosis of the Halfway Creek channel and riparian wetlands underscores the importance of understanding the long-term history of channel and fl oodplain evolution when restoration of channels and riparian wetlands are under consideration. Sedimentation patterns and channel morphology for Halfway Creek Marsh probably are representative of other anthropogenically altered riparian wetlands in the Upper Mississippi River System and similar landscapes elsewhere.

Special Paper of the Geological Society of America↗

USGS1963

Studies of fluid inclusions; [Part] 2, Freezing data and their interpretation

Aqueous and non-aqueous inclusions in 84 samples of various minerals from a wide range of geologic environments were studied with the freezing stage in order to gain an insight into the range of concentrations and compositions of fluid inclusions . Inclusions in most Mississippi Valley-type ore minerals contain highly concentrated saline solutions, showing freezing temperatures between -23.4° and -10.5° C; minerals from ore deposits of more typically hydrothermal affiliations mainly show temperatures of -9.4° to nearly 0° C; and inclusions in quartz crystals from sedimentary, metamorphic, and igneous rock environments show a wide range of freezing temperatures. Inclusions in pegmatite minerals in particular vary over a wide range, from the most concentrated solutions found in any inclusion (> 40% salts) to fairly dilute solutions (< 5% salts). Most inclusions in quartz from Swiss Alpine-type veins, and from Brazilian quartz veins and pegmatites, show freezing temperatures in the range -8.5° to - 2 .5°, and considerable free C02. Other geologic environments sampled include Colombian emerald, pegmatitic topaz and fluorite, the Triassic traprock zeolite assemblage, and sedimentary halite beds. Not all the phenomena exhibited by inclusions at low temperature are completely understood at present but several crystalline hydrate phases, such as NaCl-2H,0 and CO,-5%H,0 (structural formula 8C02-46H20), are shown to be stable in inclusions of appropriate composition even at temperatures above 0° C, and probably exist in the inclusions in natural rocks in polar regions. More significantly, the formation and recognition of such phases aid in establishing the gross composition of individual inclusions far too small for chemical analysis. The data obtained are useful in a variety of ways, such as: discriminating among gas, liquid, and supercritical fluid , and among liquid water, liquid oil, and liquid C02 in inclusions ; improving precision of the pressure corrections applied to inclusion filling temperature determinations; proving the general lack of leakage into or out of inclusions ; estimating the minimum pressure at the time of deposition of certain samples; verifying the lack of extraneous solid crystallization nuclei in the inclusions and hence their formation from exceedingly quiet, clean solutions; determining the total equivalent NaCl concentrations and some information concerning the composition of the fluids from which ores have formed; and determining changes in the composition of the fluids bathing a single crystal during its growth, and at certain times throughout its history.

Economic Geology↗

USGS1979

Aeromagnetic map and associated depth map of the Upper Mississippi Embayment region

The purpose of these maps is to present recently compiled aeromagnetic data and associated depth estimates to magnetic basement in the upper Mississippi embayment region. This area is one of the most seismically active regions in the eastern United States. In 1974, the U.S. Geological Survey initiated magnetic surveys to delineate major geologic or tectonic features that may be responsible for the geration or control of seismic energy.

Upper Mississippi Embayment Region↗

USGS1955

Geology and zinc-lead deposits in the Durango area, Dubuque County, Iowa

Geologic investigations were begun in Iowa to appraise; (1) the possible occurrence of zinc ore in strata that elsewhere in the Upper Mississippi Valley zinc-lead district have been the principal sites of zinc concentration; and (2) lead ore of the type known as "crevice deposits," which were mined so extensively during the 19th century in Dubuque County, Iowa, but have been mined very little since 1910.

Iowa↗

USGS2013

Documenting the stages and streamflows associated with the 2011 activation of the New Madrid Floodway, Missouri

The U.S. Geological Survey initiated a substantial effort in the summer of 2011 to measure and document the record-setting floods of the Mississippi and Ohio Rivers, including the reach in and near the New Madrid Floodway. The activation of the floodway, which had not occurred since 1937, provided a rare opportunity to collect a unique dataset describing a flood wave downstream from a levee breach as well as the flow through a large floodway. A total of 42 submersible pressure transducers collected time series of water levels while crews collected hundreds of depth, velocity, and streamflow measurements at selected locations in and near the floodway throughout the period from late April to late June. These data are presented in this chapter.

Missouri↗

USGS2007

Nutrients discharged to the Mississippi River from eastern Iowa watersheds, 1996-1997

The introduction of nutrients from chemical fertilizer, animal manure, wastewater, and atmospheric deposition to the eastern Iowa environment creates a large potential for nutrient transport in watersheds. Agriculture constitutes 93 percent of all land use in eastern Iowa. As part of the U.S. Geological Survey National Water Quality Assessment Program, water samples were collected (typically monthly) from six small and six large watersheds in eastern Iowa between March 1996 and September 1997. A Geographic Information System (GIS) was used to determine land use and quantify inputs of nitrogen and phosphorus within the study area. Streamliow from the watersheds is to the Mississippi River. Chemical fertilizer and animal manure account for 92 percent of the estimated total nitrogen and 99.9 percent of the estimated total phosphorus input in the study area. Total nitrogen and total phosphorus loads for 1996 were estimated for nine of the 12 rivers and creeks using a minimum variance unbiased estimator model. A seasonal pattern of concentrations and loads was observed. The greatest concentrations and loads occur in the late spring to early summer in conjunction with row-crop fertilizer applications and spring nmoff and again in the late fall to early winter as vegetation goes into dormancy and additional fertilizer is applied to row-crop fields. The three largest rivers in eastern Iowa transported an estimated total of 79,000 metric tons of total nitrogen and 6,800 metric tons of total phosphorus to the Mississippi River in 1996. The estimated mass of total nitrogen and total phosphorus transported to the Mississippi River represents about 19 percent of all estimated nitrogen and 9 percent of all estimated phosphorus input to the study area.

Iowa↗

USGS2018

Geochemistry and mineralogy of late Quaternary loess in the upper Mississippi River valley, USA: Provenance and correlation with Laurentide Ice Sheet history

The midcontinent of North America contains some of the thickest and most extensive last-glacial loess deposits in the world, known as Peoria Loess. Peoria Loess of the upper Mississippi River valley region is thought to have had temporally varying glaciogenic sources resulting from inputs of sediment to the Mississippi River from different lobes of the Laurentide Ice Sheet. Here, we explore a new method of determining loess provenance using K/Rb and K/Ba values (in K-feldspars and micas) in loess from a number of different regions in North America. Results indicate that K/Rb and K/Ba values can distinguish loess originating from diverse geologic terrains in North America. Further, different loess bodies that are known to have had the same source sediments (using other criteria) have similar K/Rb and K/Ba values. We also studied three thick loess sections in the upper Mississippi River valley region. At each site, the primary composition of the loess changed over the course of the last glacial period, and K/Rb and K/Ba values parallel changes in carbonate mineral content and clay mineralogy. We thus confirm conclusions of earlier investigators that loess composition changed as a result of the shifting dominance of different lobes of the Laurentide Ice Sheet and the changing course of the Mississippi River. We conclude that K/Rb and K/Ba values are effective, robust, and rapid indicators of loess provenance that can be applied to many regions of the world.

Quaternary Science Reviews↗

USGS1975

Drainage areas for Illinois streams

Drainage areas were tabulated for all streams in Illinois which drain over 100 square miles. at sites where streamflow data have been collected, and at other selected locations. Areas were planimetered on U.S. Geological Survey topographic quadrangle maps and balanced to known areas taken from Smithsonian Geographical Tables of areas of quadrilaterals of the earth's surface (procedures and standards recommended by Subcommittee on Hydrology, Federal Inter-Agency River Basin Committee). Streams are tabulated in sequence; first, the Ohio River basin, followed by the St. Lawrence River basin, and finally, the Mississippi River basin. Streams are listed in downstream order, starting at the headwaters; the rank of the stream system within each basin is indicated by indention. At sites where streamflow data had been collected, previously assigned U.S. Geological Survey eight-digit numbers are used. These numbers, which describe unique sites, increase in downstream order. All locations are identified by reference to a town, land-line location, topographic quadrangle, and county at the point where the drainage area was determined. An alphabetical index is provided.

Illinois↗

USGS2011

Bank erosion of navigation canals in the western and central Gulf of Mexico

Erosion of navigation canal banks is a direct cause of land loss, but there has been little quantitative analysis to determine why certain major canals exhibit faster widening rates (indicative of erosion) than others in the coastal zones of Texas, Louisiana, Mississippi, and Alabama. We hypothesize that navigation canals exhibit varying rates of erosion based on soil properties of the embankment substrate, vegetation type, geologic region (derived from digital versions of state geologic maps), and the presence or absence of canal bank armaments (that is, rock rip-rap, concrete bulkheads, or other shoreline protection structures). The first objective of this project was to map the shoreline position and substrate along both banks of the navigation canals, which were digitized from 3 different time periods of aerial photography spanning the years of 1978/79 to 2005/06. The second objective was to quantify the erosion rates of the navigation canals in the study area and to determine whether differences in erosion rates are related to embankment substrate, vegetation type, geologic region, or soil type. To measure changes in shoreline position over time, transects spaced at 50-m (164-ft) intervals were intersected with shorelines from all three time periods, and an annual rate of change was calculated for each transect. Mean annual rates of shoreline change ranged from 1.75 m/year (5.74 ft/year) on the west side of the Atchafalaya River, La., where there was shoreline advancement or canal narrowing, to -3.29 m/year (-10.79 ft/year) on the south side of the Theodore Ship Channel, Ala., where there was shoreline retreat or erosion. Statistical analysis indicated that there were significant differences in shoreline retreat rates according to geologic region and marsh vegetation type, and a weak relationship with soil organic content. This information can be used to better estimate future land loss rates associated with navigation canals and to prioritize the location of restoration and erosion mitigation efforts. Combining all canals together, our results also showed that canal erosion rates have slowed in recent years, with an average canal widening rate of -0.99 m/year (-3.25 ft/year) for the 1996/98-2005/06 time period compared to -1.71 m/year (-5.61 ft/year) for the earlier 1978/79-1996/98 time period. Future research could focus on obtaining detailed vessel traffic information for individual canals, which is likely a factor that influences canal bank erosion rates.

Open-File Report↗

USGS2010

Coastal Change on Gulf Islands National Seashore during Hurricane Gustav: West Ship, East Ship, Horn, and Petit Bois Islands

INTRODUCTION Hurricane Gustav made landfall on September 1, 2008, near Cocodrie, Louisiana, as a category 2 storm, with maximum sustained winds near 170 km/hr. Hurricane-force winds, with speeds in excess of 119 km/hr, extended along 270 km of the Louisiana coastline, from Marsh Island to the central barrier islands. Tropical-storm-force winds (speeds > 63 km/hr) were felt across the coasts of Mississippi and Alabama. Within this area of high wind and associated storm surge and waves lie the Mississippi barrier islands of West Ship, East Ship, Horn, and Petit Bois, part of the National Park Service (NPS) Gulf Islands National Seashore (GUIS). These east-west trending islands form a barrier between the Mississippi Sound to the north and the Gulf of Mexico to the south. The islands are generally less than 1 km wide with dune elevations ranging generally between 2 and 3 m, but reaching 6 m on Horn Island. The interaction of waves and currents with the low, sandy beaches forces a range of dynamic responses, such as dune erosion, overwash deposition, spit elongation, and island breaching. The passage of strong hurricanes (such as Camille in 1969 and Katrina in 2005), combined with a background signal of long-term shoreline retreat, has caused significant coastal changes on the Mississippi barrier islands, presenting management challenges for State and Federal officials, including NPS resource managers. At the request of the NPS, the U.S. Geological Survey (USGS) has processed, analyzed, and interpreted pre- and post-Hurricane-Gustav lidar topographic data for West Ship, East Ship, Horn, and Petit Bois. These data and analyses can be used to better assess the storm vulnerability of portions of GUIS by characterizing the magnitude and spatial variability of hurricane-induced coastal changes, such as shoreline retreat, dune erosion, and beach volume change. This information will provide park managers with a greater understanding of the long-term evolution of these islands, which are frequently impacted by coastal storms. The purpose of this report is to summarize the methods used and observations made during a study of the effects of Hurricane Gustav on the coastal morphology of four island in GUIS.

Open-File Report↗

USGS2022

Water-surface profile maps for the Mississippi River near Prairie Island, Minnesota, 2019

Digital water-surface profile maps for a 14-mile reach of the Mississippi River near Prairie Island, Minnesota, from the confluence of the St. Croix River at Prescott, Wisconsin, to upstream from the U.S. Army Corps of Engineers Lock and Dam No. 3 (U.S. Army Corps of Engineers National Inventory of Dams number MN00595) in Welch, Minnesota, were created by the U.S. Geological Survey (USGS) in cooperation with the Prairie Island Indian Community in the State of Minnesota. The water-surface profile maps depict estimates of the areal extent and depth of water inundation corresponding to selected water levels (stages) at the USGS streamgage Mississippi River at Prescott, Wisconsin (USGS station number 05344500). Current conditions for estimating near-real-time areas of inundation by use of USGS streamgage information may be obtained from the National Water Information System on the internet at https://doi.org/10.5066/F7P55KJN . In this study, water-surface profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated by using the most current stage-discharge relations at the USGS streamgage Mississippi River at Prescott, Wisconsin (USGS station number 05344500). The hydraulic model was then used to determine four water-surface profiles for stream stages at 37.00, 39.00, 40.00, and 41.00 feet (ft) referenced to the streamgage datum and ranging from bankfull to approximately 2 ft below the highest recorded stage at the streamgage, which is 43.11 ft. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from light detection and ranging data having a 0.35-ft vertical and 1.97-ft root mean square error horizontal resolution) in order to delineate the area inundated at each stage. The combination of maps provided in this report and real-time stage data from the upstream USGS streamgage provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures as well as for post flood recovery efforts.

Minnesota↗

USGS1884

Report of the United States Geological Survey of the Territories Volume III: The vertebrata of the tertiary formations of the West Book I

I send herewith a report on the Tertiary Faunae of the United States as represented by collections made in various Territories and States west of the Mississippi River, embraced within the boundaries of your survey. The explorations from which the collections have been derived cover portions of the States and Territories included between British America on the north, the western boundaries of Minnesota and Missouri on the east; the northern borders of the Indian Territory and Arizona, and the middle of New Mexico on the south; and the Sierra Nevada on the west. The amount of material which I have procured through these explorations is large, and is but partially represented in the following pages. I trust that you will find the results a useful contribution to the records of your Geological Survey and to the science to which you have devoted your life ; and that you may find in this report some compensation for the arduous official duties which have recently withdrawn you to some degree from your chosen field of research.

Report↗

USGS2008

Digital surfaces and thicknesses of selected hydrogeologic units within the Mississippi Embayment Regional Aquifer Study (MERAS)

Digital surfaces of selected Tertiary and younger age hydrogeologic units within the Mississippi embayment aquifer system were created using more than 2,600 geophysical logs for an area that covers approximately 70,000 square miles and encompasses parts of eight states. The digital surfaces were developed to define and display the hydrogeologic framework for the Mississippi Embayment Regional Aquifer Study (MERAS). The digital surfaces also provide a foundation of the selected hydrogeologic units for development of a steady-state and transient regional ground-water flow model of the Mississippi embayment aquifer system from the top of the Midway confining unit upwards to land surface. The ground-water flow model is under development as part of the U.S. Geological Survey Ground-Water Resources Program. Using a Geographic Information System, nine digital surfaces of the tops of selected hydrogeologic units were created using the Australian National University Digital Elevation Model method as an interpolation scheme. Thickness maps also were constructed using the Geographic Information System by calculating the difference between the altitude of the interpreted base of an overlying unit and the altitude of the interpreted top of an underlying unit. In general, the highest hydrogeologic unit altitudes are located along the eastern edge of the study area in the outcrop, and the lowest altitudes, in general, are located along the southern edge of the study area along the axis of the embayment. The Mississippi River Valley alluvial aquifer and the lower Claiborne aquifer are the thinnest aquifers of importance in the study area; the thickest aquifer of importance is the middle Claiborne aquifer.

Mississippi Embayment Regional Aquifer↗

USGS2014

Organic petrology of the Aptian-age section in the downdip Mississippi Interior Salt Basin, Mississippi, USA: Observations and preliminary implications for thermal maturation history

This study identifies a thermal maturity anomaly within the downdip Mississippi Interior Salt Basin (MISB) of southern Mississippi, USA, through examination of bitumen reflectance data from Aptian-age strata (Sligo Formation, Pine Island Shale, James Limestone, and Rodessa Formation). U.S. Geological Survey (USGS) reconnaissance investigations conducted in 2011–2012 examined Aptian-age thermal maturity trends across the onshore northern Gulf of Mexico region and indicated that the section in the downdip MISB is approaching the wet gas/condensate window (R o ~1.2%). A focused study in 2012–2013 used 6 whole core, one sidewall core, and 49 high-graded cutting samples (depth range of 13,000–16,500 ft [3962.4–5029.2 m] below surface) collected from 15 downdip MISB wells for mineralogy, fluid inclusion, organic geochemistry, and organic petrographic analysis. Based on native solid bitumen reflectance (R o generally > 0.8%; interpreted to be post-oil indigenous bitumens matured in situ), R o values increase regionally across the MISB from the southeast to the northwest. Thermal maturity in the eastern half of the basin (R o range 1.0 to 1.25%) appears to be related to present-day burial depth and shows a gradual increase with respect to depth. To the west, thermal maturity continues to increase even as the Aptian section shallows structurally on the Adams County High (R o range 1.4 to > 1.8%). After evaluating the possible thermal agents responsible for increasing maturity at shallower depths (i.e., igneous activity, proximity to salt, variations in regional heat flux, and uplift), we tentatively propose that either greater paleoheat flow or deeper burial coupled with uplift in the western part of the MISB could be responsible for the thermal maturity anomaly. Further research and additional data are needed to determine the cause(s) of the thermal anomaly.

International Journal of Coal Geology↗