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USGS2023

Microfossils and biostratigraphy of the Upper Cretaceous Coon Creek Formation Lagerstätte, Mississippi Embayment, USA

The Upper Cretaceous Coon Creek Formation type-locality in McNairy County, Tennessee, is an exceptional marine invertebrate Lagerstätte that was deposited in a nearshore reentrant into the ancestral continent of Appalachia. Extensive taxonomic analysis of the macrofauna has been done for over 100 years. However, documentation of the microfossil component at the type-locality has largely been ignored. This paper provides analysis of calcareous microfossils (benthic and planktonic foraminifera, calcareous nannofossils and ostracods) and palynomorphs (pollen, spores, algal remains and dinoflagellates) for detailed age control and information regarding environment of deposition. The Coon Creek type-locality is late Campanian (76.8–76.0 Ma) in age and was deposited in 35–60 m water depths. Calcareous nannofossil assemblages suggest that there was an influence of colder water through time, possibly by a connection to the northern Western Interior Seaway. The complex interplay between currents of the Gulf of Mexico and the Western Interior Seaway, upwelling and runoff influenced the palaeoenvironment. Increased influx of freshwater palynomorphs near the top of the section suggests placement proximal to the palaeoshoreline and that weathering increased through time. Changes in the dinoflagellate assemblage may be linked to a mosasaur mass mortality event and the presence of a harmful algal bloom.

Tennessee↗

USGS1983

Reworked Hantkenina speciments at Little Stave Creek, Alabama

The Eocene-Oligocene boundary in Mississippi and Alabama has been traditionally placed between the Shubuta Member of the Yazoo Formation and the overlying Red Bluff Formation (or its carbonate facies equivalent, the Bumpnose Formation). Consequently, the presence of Eocene planktonic foraminifers in the Red Bluff and Bumpnose has long been attributed to reworking. To test the validity of this hypothesis, samples were collected on both sides of the boundary from the upper "Shubuta" and Bumpnose units at Little Stave Creek, Alabama, and were examined for both calcareous nannofossil and planktonic foraminiferal content. The calcereous nannofossil assemblage, preserved in the matrix from inside handpicked specimens of Hantkenina from both units, was demonstrably older than the calcareous nannofossil assemblage from the surrounding sediment. Thus, at least some of the Hantkenina specimens in both the "Shubuta" and Bumpnose are indeed reworked, which not only confirms the original hypothesis regarding reworking within the Red Bluff and Bumpnose, but also indicates that the last occurrence of Hantkenina , the "Shubuta"-Bumpnose contact, and the Eocene-Oligocene boundary in the U.S. Gulf Coast may not be equivalent.

Alabama↗

USGS2012

Transmissivity of the Upper Floridan aquifer in Florida and parts of Georgia, South Carolina, and Alabama

The Floridan aquifer system (FAS) covers an area of approximately 100,000 square miles in Florida and parts of Georgia, South Carolina, Alabama, and Mississippi. Groundwater wells for water supply were first drilled in the late 1800s and by the year 2000, the FAS was the primary source of drinking water for about 10 million people. One of the methods for assessing groundwater availability is the development of regional or subregional groundwater flow models of the aquifer system that can be used to develop water budgets spatially and temporally, as well as evaluate the groundwater resource change over time. Understanding the distribution of transmissivity within the FAS is critical to the development of groundwater flow models. The map presented herein differs from previously published maps of the FAS in that it is based on interpolation of 1,487 values of transmissivity. The transmissivity values in the dataset range from 8 to 9,000,000 feet squared per day (ft 2 /d) with the majority of the values ranging from 10,000 to 100,000 ft 2 /d. The wide range in transmissivity (6 orders of magnitude) is typical of carbonate rock aquifers, which are characterized by a wide range in karstification. Commonly, the range in transmissivity is greatest in areas where groundwater flow creates conduits in facies that dissolve more readily or areas of high porosity units that have interconnected vugs, with diameters greater than 0.1 foot. These are also areas where transmissivity is largest. Additionally, first magnitude springsheds and springs are shown because in these springshed areas, the estimates of transmissivity from interpolation may underestimate the actual range in transmissivity. Also shown is an area within the Gulf Trough in Georgia where high yielding wells are unlikely to be developed in the Upper Floridan aquifer. The interpolated transmissivity ranges shown on this map reflect the geologic structure and karstified areas. Transmissivity is large in the areas where the system is unconfined, such as west-central Florida and southwest Georgia just northwest of the Gulf Trough. Transmissivity is small along the Gulf Trough and Southwest Georgia Embayment (referred to as Apalachicola Embayment in some reports). Transmissivity is also small in the thin, updip part of the system near its northern boundary. Another area of large transmissivity coincides with the Southeast Georgia Embayment.

Alabama, Florida, Georgia, South Carolina↗

USGS1970

Comparative hydrogeology: An example of its use

As a start toward needed classifications of hydrogeologic settings, a type of setting is described. The setting includes areas where soluble materials are exposed to considerable recharge from precipitation and where both the topographic relief and permeability are inappreciable. Typical areas of this setting are (1) the Black Belt of the Coastal Plain of Alabama and Mississippi, underlain by chalk of the Selma Group, and (2) a 25-sq-mi area near Harrisburg, Cabarrus County, North Carolina, underlain by gabbro in the Piedmont province. Hydrologic conditions that may be inferred and that are easily discernible from this type of setting include: excessive evapotranspiration, low water-table gradient, water table near land surface, thin soils, ground-water movement being almost inappreciable, and the zone of movement being almost limited to a thin zone that includes the contact between the soil and rock, inappreciable ground-water discharge to streams leading, in turn, to a low base flow in streams, low drainage density, and subsurface water relatively high in dissolved mineral matter. Evaluation of the hydrogeologic setting described leads inductively into the undeveloped field of comparative hydrology, which represents a quick useful means of discerning the significance of processes and principles in particular environments. The setting reveals the significance of solution by subsurface water in developing some plains. Comparative hydrology, using the described setting and typical karst settings as examples, allows an advanced analysis of some pertinent factors.

Alabama, Mississippi, North Carolina↗

USGS1995

Water-quality and lake-stage data for Wisconsin lakes, water year 1994

The U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many yes rs, provide a data base for developing an improved understanding of the water quality of lakes\ To make these data available to interested parties outside the USGS, the data are published annually in this report series. The location of surface water-quality and lake-stage stations in Wisconsin for water year 1994 are shown in figure 1. A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends and which includes 9 of the 12 months. Thus the period October 1, 1993 through September 30, 1994, is called "water year 1994." The purpose of this report is to provide information about the physical, che-nical, and biological characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected includes measurements of lake stage and in-lake water quality. Graphs of Secchi depths, and total-phosphorus and chlorophyll-a concentrations versus time are included for lakes with two or more years of data. Descriptive information for each lake includes location of the lake, drainage area of the lake's watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published in two other volunres: "Water Resources Data-Wisconsin, 1994, St. Lawrence River Basin" (Volume 1) and "Water Resources Data-Wisconsin, 1994, Upper Mississippi River Basin" (Volume 2).

Wisconsin↗

USGS2019

The Zn–Pb mineralization of Florida Canyon, an evaporite-related Mississippi Valley-type deposit in Bongará district, northern Peru

The Florida Canyon evaporite-related Zn–Pb sulfide deposit, in northern Peru, is one of the largest Mississippi Valley-type (MVT) deposits in South America. Triassic carbonate and former evaporite-bearing rocks of the Pucará Group host the ore bodies that comprise two different styles: (i) predominantly stratabound ore associated with hydrocarbon-rich porous dolostones and evaporite dissolution breccias; and (ii) high-grade ore associated with evaporite breccias representing diapiric injections along faults. A dome structure that controls the location of the ore deposit was defined by drillhole spatial data; the dome likely resulted from halokinetic processes during Andean deformation. NNE-trending steeply dipping secondary faults linked to major NW structures appear to control the distribution of ore grades in the deposit. Mineralization post-dated hydrocarbon migration and accumulation. Strontium, carbon, and oxygen data isotopic signatures allow distinction between pre-and syn-mineralization carbonate stages. The sulfur isotopic composition of sulfides in the deposit suggests they precipitated as the result of mixing of a metal-rich fluid with resident hydrogen sulfide in the dome. Local thermochemical sulfate reduction (TSR) may have contributed to the reduced sulfur budget during mineralization.

Economic Geology↗

USGS2006

The Response of Suspended Sediment, Turbidity, and Velocity to Historical Alterations of the Missouri River

The heavy sediment load and large amounts of floating debris generated by the constantly caving banks of the Missouri River was documented in the first written description of the river by Father Jacques Marquette in 1673 as he approached the mouth of the Missouri River from the upper Mississippi River: '[We]' heard the noise of a rapid, into which we were about to run. I have seen nothing more dreadful. An accumulation of large and entire trees, branches, and floating islands, was issuing from the mouth of the river Pekitanoui (Missouri River), with such impetuosity that we could not without great danger risk passing through it. So great was its agitation that the water was so very muddy, and could not become clear.' However, large changes in suspended sediment and turbidity in the lower Missouri River below Gavins Point Dam have occurred in response to extensive structural changes that have been imposed on the Missouri River and its watershed during the last two centuries. Efforts to shape the channel, remove snags and sawyers, dredge shallows, and stabilize banks for navigation began as early as 1838 ( http://www.lewis-clark.org/ri_mo-snagboats.htm , Chittenden, 1903). However, bank stabilization efforts were sporadic and scattered in comparison to large scale changes that occurred after 1929. In the early 1930s the numerous small channels were combined into a single-fixed channel with 4,745 stone and wood-pile dikes, 3,371 dike extensions, streambank protection works on concave banks, man-made cutoffs, the closing of chutes with dikes, the removal of snags, and dredging (Keown and others, 1981). The resulting navigation channel was 6-ft (feet) deep by 200-ft wide and was expanded to 9 by 300 ft in the 1950s and early 1960s. Construction of six dams was started in 1933 and their reservoirs were filled by 1967. Three of these reservoirs are among the five largest in the United States. Nearly one-third of the Missouri River is now submerged below these massive reservoirs. Since 1967, hydrologic changes have been relatively minor. In the early 1970s, the U.S. Geological Survey (USGS) began the long-term, systematic collection of suspended-sediment and water-quality data that continues to the present (2006). Because changes in the channel configuration and hydrologic character of the river have been small compared to the changes before 1973, all samples collected after that time are referred to in this report as modern samples. These modern samples compose a large data set that are compared to samples collected before the pervasive hydrologic and channel-stabilizing changes that began in the early 1930s and to the qualitative and semiquantitative observations of the explorers in the early nineteenth century.

Circular↗

USGS2017

Evaluation of the Eureka Manta2 Water-Quality Multiprobe Sonde

Two Eureka Manta2 3.5 water-quality multiprobe sondes by Eureka Water Probes were tested at the U.S. Geological Survey (USGS) Hydrologic Instrumentation Facility (HIF) against known standards over the sonde operating temperatures to verify the manufacturer’s stated accuracy specifications for pH, specific conductance (SC) at 25 degrees Celsius (°C), dissolved oxygen (DO), and turbidity. The Manta2 sondes were evaluated for compliance with the USGS National Field Manual for the Collection of Water-Quality Data (NFM) criteria for continuous water-quality monitors, and for compliance with the manufacturer’s technical specifications. The Manta2 was also evaluated for its compliance to Serial Digital Interface at 1200 baud (SDI-12) version 1.3. The Manta2 met the NFM recommendations and manufacturer’s accuracy specifications for DO and turbidity at all values tested. The Manta2 pH sensors met the NFM recommendations and manufacturer’s accuracy specification for nominal pH values of 10 and lower. One of the two sensors was out of compliance by 1.2 units for pH 11.16 at 15 °C and by 0.25 unit for pH 10.78 at 40 °C. The Manta2 sensors were within the NFM recommendations for SC, except at 100 microsiemens (μS/cm) at 40 °C, where the SC sensor exceeded the test standard value by as much as 25 percent. One of two sensors was within manufacturer’s accuracy specifications at 25 °C for all the tested SC values, while the other SC sensor was outside the manufacturer’s accuracy specifications at 100 μS/cm, exceeding the test standard value by 9 percent. One of two sensors was outside the manufacturer’s accuracy specifications at 10,000 μS/cm at 15°C, exceeding the test standard value by 3 percent. One Manta2 passed SDI-12 compliance testing with a NR Systems SDI-12 Verifier. One Manta2 was field tested for 6 weeks at USGS station 02492620, National Space Technology Laboratories (NSTL) Station, Mississippi, on the Pearl River and showed overall good agreement with a well-maintained Hydrolab Datasonde 5X site sonde for water temperature, pH, and DO. Differences in SC values between the Manta2 and the site sonde were most likely due to differences in the deployment depth of the sondes.

Open-File Report↗

USGS2017

Effects of tow transit on the efficacy of the Chicago Sanitary and Ship Canal Electric Dispersal Barrier System

In 2016, the U.S. Fish and Wildlife Service, U.S. Geological Survey, and U.S. Army Corps of Engineers undertook a field study in the Chicago Sanitary and Ship Canal near Romeoville, Illinois to determine the influence of tow transit on the efficacy of the Electric Dispersal Barrier System (EDBS) in preventing the passage of juvenile fish (total length < 100 millimeters (mm)). Dual-frequency identification sonar data showed that large schools of juvenile fish (mean school size of 120 fish; n = 19) moved upstream and crossed the electric field of an array in the EDBS concurrent with downstream-bound (downbound) loaded tows in 89.5% of trials. Smaller schools of juvenile fish (mean school size of 98 fish; n = 15) moved downstream and crossed the electric field of an array in the EDBS concurrent with upstream-bound (upbound) loaded tows in 73.3% of trials. Observed fish passages through the EDBS were always opposite to the direction of tow movement, and not associated with propeller wash. These schools were not observed to breach the EDBS in the absence of a tow and showed no signs of incapacitation in the barrier during tow passage. Loaded tows transiting the EDBS create a return current of water flowing between the tow and the canal wall that typically travels opposite the direction of tow movement, and cause a decrease in the voltage gradient of the barrier of up to 88%. Return currents and decreases in voltage gradients induced by tow passage likely contributed to the observed fish passage through the EDBS. The efficacy of the EDBS in preventing the passage of small, wild fish is compromised while tows are moving across the barrier system. In particular, downbound tows moving through the EDBS create a pathway for the upstream movement of small fish, and therefore may increase the risk of transfer of invasive fishes from the Mississippi River Basin to the Great Lakes Basin.

Illinois↗

USGS2020

Missouri StreamStats—St. Louis County and the City of St. Louis urban application

To address a major limitation of the functionality of the Missouri statewide StreamStats application in the urban areas of St. Louis County and the City of St. Louis, Missouri, the U.S. Geological Survey, in cooperation with the Metropolitan St. Louis Sewer District, defined watershed boundaries and hydrography for the study area using high-resolution 3-meter digital elevation data derived from light detection and ranging sources, high-resolution 6-inch imagery, and storm sewer network geospatial data. The combined sanitary sewers, a part of the storm sewer network, were integrated into the open channel hydrography and elevation data using a new Arc Hydro stormwater tool developed to facilitate the incorporation of the combined sanitary sewer network into the StreamStats application. The combined sanitary sewer network was edited for connectivity and flow direction before integration into the Missouri-St. Louis StreamStats application. Inlet structures in the geospatial data were defined as HydroJunction features that allow for stormwater runoff to enter the combined sanitary sewer network. An Arc Hydro stormwater processing workflow and a sewershed delineation tool were developed to integrate the combined sanitary sewer network with the hydrographic dataset and digital elevation model in the study area. The StreamStats application developed for the study area provides various data exploration tools that can be used to examine the spatial data and to obtain general descriptive information and flow statistics at streamgages in the study area. Watersheds and sewersheds can be delineated and basin characteristics can be determined at any point on the open channel network or the combined sanitary sewer network in the study area. Peak-flow statistics can be computed at any point on the open channel network. A report summarizing the results is generated by the StreamStats application and can be downloaded and used in other software. The Missouri-St. Louis StreamStats application is limited to the area inside St. Louis County and the City of St. Louis and excludes locations on the main stem of the Mississippi, Missouri, and Meramec Rivers. The limitations of the Missouri-St. Louis StreamStats application include possible inaccuracies using regression equations for peak-flow statistics developed assuming natural flow conditions and topographically derived watersheds determined from a coarser resolution of data than is used in this application. Additionally, published regression equations for peak-flow statistics did not incorporate any pipe flow or sewershed delineations when they were developed, which limits the applicability of peak-flow statistics to basins based on primarily topographic delineation. Inaccuracies in resolution, completeness, location, or attribution of geospatial elevation data, hydrographic data, derived stream lines, derived watershed boundaries, and combined sanitary sewer data can limit the accuracy and functionality of the Missouri-St. Louis StreamStats application.

Missouri↗

USGS2015

Results from laboratory and field testing of nitrate measuring spectrophotometers

Five ultraviolet (UV) spectrophotometer nitrate analyzers were evaluated by the U.S. Geological Survey (USGS) Hydrologic Instrumentation Facility (HIF) during a two-phase evaluation. In Phase I, the TriOS ProPs (10-millimeter (mm) path length), Hach NITRATAX plus sc (5-mm path length), Satlantic Submersible UV Nitrate Analyzer (SUNA, 10-mm path length), and S::CAN Spectro::lyser (5-mm path length) were evaluated in the HIF Water-Quality Servicing Laboratory to determine the validity of the manufacturer's technical specifications for accuracy, limit of linearity (LOL), drift, and range of operating temperature. Accuracy specifications were met in the TriOS, Hach, and SUNA. The stock calibration of the S::CAN required two offset adjustments before the analyzer met the manufacturer's accuracy specification. Instrument drift was observed only in the S::CAN and was the result of leaching from the optical path insert seals. All tested models, except for the Hach, met their specified LOL in the laboratory testing. The Hach's range was found to be approximately 18 milligrams nitrogen per liter (mg-N/L) and not the manufacturer-specified 25 mg-N/L. Measurements by all of the tested analyzers showed signs of hysteresis in the operating temperature tests. Only the SUNA measurements demonstrated excessive noise and instability in temperatures above 20 degrees Celsius (°C). The SUNA analyzer was returned to the manufacturer at the completion of the Phase II field deployment evaluation for repair and recalibration, and the performance of the sensor improved significantly. In Phase II, the analyzers were deployed in field conditions at three diferent USGS sites. The measured nitrate concentrations were compared to discrete (reference) samples analyzed by the Direct UV method on a Shimadzu UV1800 bench top spectrophotometer, and by the National Environmental Methods Index (NEMI) method I-2548-11 at the USGS National Water Quality Laboratory. The first deployment at USGS site 0249620 on the East Pearl River in Hancock County, Mississippi, tested the ability of the TriOs ProPs (10-mm path length), Hach NITRATAX (5 mm), Satlantic SUNA (10 mm), and the S::CAN Spectro::lyser (5 mm) to accurately measure low-level (less than 2 mg-N/L) nitrate concentrations while observing the effect turbidity and colored dissolved organic matter (CDOM) would have on the analyzers' measurements. The second deployment at USGS site 01389005 Passaic River below Pompton River at Two Bridges, New Jersey, tested the analyzer's accuracy in mid-level (2-8 mg-N/L) nitrate concentrations. This site provided the means to test the analyzers' performance in two distinct matrices—the Passaic and the Pompton Rivers. In this deployment, three instruments tested in Phase I (TriOS, Hach, and SUNA) were deployed with the S::CAN Spectro::lyser (35 mm) already placed by the New Jersey Water Science Center (WSC). The third deployment at USGS site 05579610 Kickapoo Creek at 2100E Road near Bloomington, Illinois, tested the ability of the analyzers to measure high nitrate concentrations (greater than 8 mg-N/L) in turbid waters. For Kickapoo Creek, the HIF provided the TriOS (10 mm) and S::CAN (5 mm) from Phase I, and a SUNA V2 (5 mm) to be deployed adjacent to the Illinois WSC-owned Hach (2 mm). A total of 40 discrete samples were collected from the three deployment sites and analyzed. The nitrate concentration of the samples ranged from 0.3–22.2 mg-N/L. The average absolute difference between the TriOS measurements and discrete samples was 0.46 mg-N/L. For the combined data from the Hach 5-mm and 2-mm analyzers, the average absolute difference between the Hach samples and the discrete samples was 0.13 mg-N/L. For the SUNA and SUNA V2 combined data, the average absolute difference between the SUNA samples and the discrete samples was 0.66 mg-N/L. The average absolute difference between the S::CAN samples and the discrete samples was 0.63 mg-N/L.

Open-File Report↗

USGS1973

Changes in floodflow characteristics of a rectified channel caused by vegetation, Jackson, Mississippi

Extreme changes in velocity, stage, and Manning's roughness coefficient, n , were observed during the first year after canalization of Hanging Moss Creek at Jackson, Miss. Additional changes were observed during the following 8 years. The channel, constructed during the summer of 1963, had a 50-foot-wide bottom, 2:1 side slopes, and 12-foot depth. In March 1964, average velocities of 7.8 feet per second were measured at a 5 1/2-foot depth in the clean channel and Manning's n was computed to be 0.022. In October 1964 the average velocity was 3.2 fps at a 5 1/2-foot depth and Manning's n was 0.045. The channel was then lined with fairly thick vegetation consisting of small willows, weeds, and grass. In October 1970 (summer foliage existing) the average velocity was 2.0 fps at a 5 1/2-foot depth and Manning's n was 0.07. Willow trees, 8 to 10 feet high, then lined the channel. In March 1971 (barren foliage), Manning's n was 0.05. In March 1972 (barren foliage), Manning's n was increased to 0.07. These observations indicate that the commonly used values of Manning's n for channel rectification (0.02-0.03) are low and that the carrying capacity of earthen channels may be reduced 50 percent as a result of only 1 year's growth of vegetation and 70 percent as a result of 8 year's growth. The carrying capacity during summer foliage is approximately two-thirds the carrying capacity during barren winter foliage.

Mississippi↗

USGS1990

A dolomitized shelfedge hardground in the northern Gulf of Mexico

An elongated calcareous hardground occurs on the shelfedge northeast of the Mississippi Trough. High-resolution seismic reflection profiles show that the hardground is in 90-110 m of water, is 70-250 m wide, at least 2.3 km long, and of low relief (5-10 m). The hardground is composed of dolostone and coquinoid limestone, and exhibits a dead biofacies of nodular and encrusting calcium carbonate-secreting organisms that are significantly different from those forms living in the adjacent unconsolidated sediments. Cementation of the hardground substrate by primary dolomite was initiated during early diagenesis close to the sea floor and progressed by concretionary growth under an interstitial environment partially open to marine molecular fluxes. The bicarbonate necessary to form the dolomite came from an admixture of isotopically light thermogenic and sedimentary organic carbon sources and an isotopically heavier marine source. Exposed surfaces of the dolostone, which have been heavily bioeroded, are covered by an oxidized, goethite-rich, reddish-brown rind. The coquina is primarily composed of whole and fragmented mollusk shells and was deposited in a higher-energy environment than the precursor sediments of the dolostone. The hardground was preserved during the Holocene transgression because of its lithified nature and the top has been intermittently swept free of finer detritus by current action.

Alabama, Florida, Louisiana, Mississippi, Texas↗

USGS2006

Estimate of ground water in storage in the Great Lakes basin, United States, 2006

Hydrogeologic data from Regional Aquifer System Analyses (RASA) studies by the U.S. Geological Survey in the Great Lakes Basin, United States, during 1978-95, were compiled and used to estimate the total volume of water that is stored in the many aquifers of the basin. These studies focused on six regional aquifer systems: the Cambrian-Ordovician aquifer system in Wisconsin, Illinois, and Indiana; the Silurian- Devonian aquifers in Wisconsin, Michigan, Illinois, Indiana, and Ohio; the surficial aquifer system (aquifers of alluvial and glacial origin) found throughout the Great Lakes Basin; and the Pennsylvanian sandstone and carbonate-rock aquifers and the Mississippian sandstone aquifer in Michigan. Except for the surficial aquifers, all of these aquifer systems are capable of yielding substantial quantities of water and are not small aquifers with only local importance. Individual surficial aquifers, although small in comparison to the bedrock aquifers, collectively represent large potential sources of ground water and therefore have been treated as a regional system. Summation of ground-water volumes in the many regional aquifers of the basin indicates that about 1,340 cubic miles of water is in storage; of this, about 984 cubic miles is considered freshwater (that is, water with dissolved-solids concentration less than 1,000 mg/L). These volumes should not be interpreted as available in their entirety to meet water-supply needs; complete dewatering of any aquifer is environmentally undesirable. The amount of water that is considered available on the basis of water quality and environmental, economic, and legal constraints has not been determined. The effect of heavy pumping in the Chicago, Ill., and Milwaukee, Wis., areas, which has caused the regional ground-water divide in the Cambrian-Ordovician aquifer system to shift westward, has been included in the above estimates. This shift in the ground-water divide has increased the amount of water in storage in the deep-bedrock aquifers of the Great Lakes Basin by about 36 cubic miles; however, this water is removed by wells and, after use, is mostly discharged to the Mississippi River Basin rather than to the Great Lakes Basin. The corresponding decrease in ground-water storage that has resulted from lowering of the potentiometric surface due to this heavy pumping (0.059 cubic miles) is negligible compared to the total estimated storage.

Scientific Investigations Report↗

USGS2020

Characterization of the unconventional Tuscaloosa marine shale reservoir in southwestern Mississippi, USA: Insights from optical and SEM petrography

This study presents new optical petrography and electron microscopy data, interpreted in the context of previously published petrophysical, geochemical, and mineralogical data, to further characterize the Tuscaloosa marine shale (TMS) as an unconventional reservoir in southwestern Mississippi. The basal high resistivity zone has a higher proportion of Type II sedimentary organic matter than the overlying TMS, indicating it is more prone to oil generation. Optical petrography and electron microscopy reveal a heterogeneous clay matrix with ubiquitous pyrite grains, quartz, feldspar, glaucony, foraminifera, shell fragments, and rarer occurrences of apatite and crinoid fragments as well as liptinite, alginite, inertinite, and vitrinite. Our petrographic observations suggest that higher abundances of detrital quartz grains coupled with minimal authigenic cements result in higher porosity and permeability. However, the TMS is also more clay-rich than other unconventional shale oil and gas plays, which can impair the effectiveness of hydraulic fracture stimulation. Thin section observations reveal alternating clay and calcium carbonate laminae that are interpreted to reflect changes in sediment flux. Planktonic foraminifera indicate an overlying oxygenated water column while benthic inoceramid fragments and pervasive authigenic pyrite suggest anoxic or dysoxic bottom water conditions. Apatite fragments in thin section suggest mixing events and an influx of nutrient-rich sediments. Overall, these observations suggest that a variety of paleodepositional environments occurred in the TMS and the lithofacies diversity resulting from these small-scale depositional cycles makes it difficult to determinatively identify areas conducive to enhanced economic hydrocarbon recovery.

Mississippi, Lousianna↗

USGS1984

Shoreface translation and the Holocene stratigraphic record: Examples from Nova Scotia, the Mississippi Delta and eastern Australia

Classic descriptive models of barrier sedimentation have been developed with data from the Atlantic and Gulf coasts of the United States. These models are dominated by low to moderate rates of relative sea level (RSL) rise and wave energy. Barriers respond by landward recycling of sediment through the mechanism of shoreface retreat. Sedimentation processes on the central coast of New South Wales (N.S.W.), Australia, consist of rapid RSL rise in early Holocene times followed by a stillstand since 6500 B.P. Wave energy is relatively high year-round and sand sources for barrier formation are only found on the inner shelf. Barrier sedimentation on the central coast of N.S.W. exhibits a thick, composite sequence composed of a basal marine transgressive sand overlain by regressive beach and dune facies. The Louisiana coast surrounding the Mississippi delta is underlain by compacting deltaic muds which generate very rapid rates of RSL rise. The Louisiana coast experiences low wave energy punctuated by high-energy tropical and extra-tropical storm events. Barrier sediments accumulate from the erosion of deltaic headlands and undergo a transformation from subaerial barrier island systems to subaqueous shoals located on the inner shelf. Drumlins experience coastal erosion on the Eastern Shore of Nova Scotia and provide a sediment source for compartmented estuary mouth barriers. An ongoing, moderate rise of RSL results from the passage of a glacial forebulge. Wave energy is intermediate between Louisiana and N.S.W. and displays a seasonal pattern dominated by frequent winter storms. Coastal barrier sedimentation is episodic, consisting of a period of beach ridge progradation followed by barrier destruction and re-establishment further landward. The three contrasting sedimentary sequences found in examples from Louisiana, N.S.W. and Nova Scotia indicate that presently available sedimentation models from locations such as the middle Atlantic or Texas coasts of the United States may only represent well-documented regional case studies. A true generalised coastal sedimentation model is required which can identify the parameters controlling vertical and horizontal translation of the depositional surface and provide relationships between these parameters which quantitatively predict the genesis, distribution and geometry of coastal sedimentary facies.

Marine Geology↗

USGS2011

Trace and minor element variations and sulfur isotopes in crystalline and colloform ZnS: Incorporation mechanisms and implications for their genesis

Various models have been proposed to explain the formation mechanism of colloform sphalerite, but the origin is still under debate. In order to decipher influences on trace element incorporation and sulfur isotope composition, crystalline and colloform sphalerite from the carbonate-hosted Mississippi-Valley Type (MVT) deposit near Wiesloch, SW Germany, were investigated and compared to sphalerite samples from 52 hydrothermal vein-type deposits in the Schwarzwald ore district, SW Germany to study the influence of different host rocks, formation mechanisms and fluid origin on trace element incorporation. Trace and minor element incorporation in sphalerite shows some correlation to their host rock and/or origin of fluid, gangue, paragenetic minerals and precipitation mechanisms (e.g., diagenetic processes, fluid cooling or fluid mixing). Furthermore, crystalline sphalerite is generally enriched in elements like Cd, Cu, Sb and Ag compared to colloform sphalerite that mainly incorporates elements like As, Pb and Tl. In addition, sulfur isotopes are characterized by positive values for crystalline and strongly negative values for colloform sphalerite. The combination of trace element contents, typical minerals associated with colloform sphalerite from Wiesloch, sulfur isotopes and thermodynamic considerations helped to evaluate the involvement of sulfate-reducing bacteria in water-filled karst cavities. Sulfate-reducing bacteria cause a sulfide-rich environment that leads in case of a metal-rich fluid supply to a sudden oversaturation of the fluid with respect to galena, sphalerite and pyrite. This, however, exactly coincides with the observed crystallization sequence of samples involving colloform sphalerite from the Wiesloch MVT deposit.

Wiesloch↗

USGS2024

Water-quality trends in the Kansas River, Kansas, since enactment of the Clean Water Act, 1972–2020

The Clean Water Act was passed by Congress in 1972 to regulate pollution within the waters of the United States. The U.S. Geological Survey (USGS), in cooperation with the Kansas Department of Health and Environment (KDHE), the Kansas Water Office, the Nature Conservancy, the City of Lawrence, the City of Manhattan, the City of Olathe, the City of Topeka, WaterOne, and Evergy, compiled and analyzed historical streamflow and water-quality data collected by USGS and KDHE to characterize trends in water-quality constituents of interest because of their relation to water supply, drinking-water treatment, and sediment and nutrient transport, among others (total dissolved solids, chloride, ammonia, dissolved inorganic nitrogen [ammonia and nitrate plus nitrite], total nitrogen, orthophosphate, total phosphorus, total suspended solids, and fecal coliform bacteria) during mean- and low-flow conditions in the Kansas River since the passage of the Clean Water Act in 1972 through 2020. Trends in water-quality concentrations, or densities, and loads were analyzed using the Exploration and Graphics for RivER Trends R package and Weighted Regressions on Time, Discharge, and Season (WRTDS) model at upstream (Kansas River at Wamego, Kansas; USGS station 06887500) and downstream (Kansas River at De Soto, Kansas; USGS station 06892350) locations along the Kansas River using streamflow and water-quality data collected by the USGS and KDHE during 1972 through 2020. The Exploration and Graphics for RivER Trends Confidence Intervals R package and WRTDS bootstrap test estimated direction, uncertainty, and likelihood of trends in concentration and loads for each water-quality constituent of interest. Downward trends in concentration and load were observed for 5 of the 9 water-quality constituents at both sites during mean-flow conditions during the study period. During low-flow conditions, 7 of the 9 constituents exhibited downward trends, possibly reflecting reductions in point-source contributions to the Kansas River. Downward trends in ammonia, dissolved inorganic nitrogen, and total nitrogen during mean- and low-flow conditions were observed at both Kansas River sites, which were similar to patterns observed nationally. Upward trends were generally observed for orthophosphate and total phosphorus, which were similar to patterns observed at sites in the Mississippi River Basin. Downward trends, or no trend, were observed for chloride. Upward and downward trends were observed for total dissolved solids. Downward trends in total suspended solids and fecal coliform bacteria were observed at both sites, which were also similar to patterns observed nationally. The long-term trend analyses in this report are an essential step to understanding how water-quality conditions have changed in the Kansas River since the passage of the Clean Water Act.

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