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At least 1,261 records · Page 70Linked to original sources
USGS1955

Geology and beryl deposits of the Peerless pegmatite, Pennington County, South Dakota

The Peerless pegmatite, half a mile south of Keystone, Pennington County, S. Dak., has been a large source of scrap mica and beryl. Feldspar, amblygonite, tantalite-columbite, and cassiterite also have been recovered. The pegmatite is intrusive into Precambrian quartz-mica schist. Much of the schist contains staurolite and chlorite. Staurolite has been partly altered to mica, quartz, and chlorite, especially near pegmatite contacts. The pegmatite is generally discordant with the schist, but in many places secondary schistosity has been developed parallel to the contact. Tourmaline and muscovite, presumably introduced by pegmatitic solutions, are characteristic of the wall rock near discordant contacts. At the surface the pegmatite is tadpole-shaped and is 580 feet long and 360 feet wide. In cross-section the pegmatite has an anticlinal form that suggests control of the intrusion by fractures bearing N. 30°W. and dipping 45°NE. and SW. Dike-like apophyses extending from the main pegmatite have various attitudes. The Peerless pegmatite is a complex pegmatite consisting of seven zones, two replacement units, and two types of fracture-fillings. These are: Zone 1, quartz-muscovite-plagioclase pegmatite (border zone); Zone 2, albite-quartz-muscovite pegmatite (wall zone); Zone 3, cleavelandite-quartz-muscovite pegmatite (first intermediate zone); Zone 4, perthite-cleavelandite-quartz pegmatite (second intermediate zone); Zone 5, clevelandite-quartz pegmatite (third intermediate zone); Zones 6a and b, quartz-microcline pegmatite and quartz pegmatite (fourth intermediate zone); Zone 7, lithia mica-cleavelandite pegmatite (core); lithia mica-cleavelandite-quartz replacement unit; muscovite-cleavelandite replacement unit; quartz fracture-fillings; and tourmaline-quartz fracture-fillings. Zones 1 and 2 consist of alternating layers of different texture and mineralogy that are parallel to the contact. The layers contain differing proportions of quartz, plagioclase, muscovite, perthite, and accessory minerals. Sugary albite-quartz aggregates are important constituents of some layers. Layers of similar composition may occur two, three, or perhaps more times. The overall mineralogic composition of Zones 1 and 2 is similar to the composition of wall zones in many other Black Hills pegmatite, Zones 3 to 7 are in the normal sequence of zones in Black Hills pegmatites. The structural, textural, and mineralogic data confirm previously published evidence from other Black Hills pegmatites that indicates crystallization of a magma-like fluid from the wall inward. Repetition of layers in Zones 1 and 2 indicates changes in composition of the fluid at the crystallizing face. These changes may have been caused by addition of new material from below, by loss of material to the wall rocks, or by failure of convection to maintain equilibrium throughout the fluid in the pegmatite chamber. Zone 3 to 7 are in the normal sequence of zoned pegmatites that indicates crystallization from a restricted or nearly closed system. The lithia mica-cleavelandite replacement unit, which extends outward from the core, shows that in, the very late stages of crystallization a pneumatolytic or hydrothermal fluid escaped outward and replaced previously crystallized pegmatite. Accessory minerals of the pegmatite include tourmaline, beryl, apatite, amblygonite (variety, montebrasite), lithia mica, cassiterite, tantalite-columbite, garnet, spodumene, svanbergite, loellingite (?), vivianite (?), triploidite (?), dahllite, and vari-colored phosphate minerals of the lithiophilitetriphylite group and their alteration products. The chemical composition of the pegmatite has been determined by estimating the mineral, constitution of the various units and by calculating the tonnage of these units by use of successive geologic sections. The principal constituents are: SiO 2 (77.0 percent), Al 2 O 3 (13.7 percent), Na 2 O (5.0 percent), and K 2 O (1.7 percent). Chemical composition has also been determined for four subdivisions of the pegmatite: (A) Zones 1 and 2, (B) Zones 3 and 4, (C) Zone 5, and (D) Zones 6 and 7 and the replacement units. The content of Si0 2 increases and the content of Al 2 O 3 decreases from the outer pan of the pegmatite inward. Na 2 O forms only 0.4 percent of the inner subdivision (D), but 4 .7 to 6.5 percent of the other subdivisions. K 2 O forms 4.0 percent of subdivision (B), but only 0.7 to 1.3 percent of the other subdivisions. Zone 3, the principal minable unit, contains 1. 7 percent beryl and 28 percent scrap mica. Beryl also constitutes more than 1 percent of parts of the wall zone, especially albite-rich layers of the inner part of the unit in the upper part of the pegmatite. Beryl is a less important constituent of other units of the pegmatite. Potash feldspar is mined chiefly from Zone 4. Clevelandite that can be hand-cobbed and sold as soda-feldspar occurs in Zones 3, 4, and 5. Amblygomlte forms between 0.5 and 1.0 percent of Zone 5. Reserves of beryl, scrap mica, potash feldspar, and amblygonite are one to six times past production.

South Dakota↗
USGS1961

Geology and ground-water resources of Sumner County, Kansas

This report describes the geography, geology, and ground-water resources of Sumner County in south-central Kansas. The hydrologic and geologic data upon which this report is based were obtained in the field during the summers of 1955 and 1956. Records of 300 wells and 2 springs, chemical analyses of 219 water samples from wells and test holes and of 15 from streams, and logs of 362 wells and test holes are included in tables. Sumner County has an area of 1,183 square miles and lies in the Wellington Lowland and Arkansas River Lowlands of the Central Lowland physiographic province. It is drained by Arkansas River, Ninnescah River, and Chikaskia River and their tributaries. The land surface in general is a southeastward-sloping, gently rolling plain. The average annual precipitation at Wellington is about 31 inches. Wheat fanning is the principal industry of the county, and oil is the chief natural resource. The Wellington Formation, of Permian age, crops out in the eastern two-thirds of the county except where it is covered by Pleistocene deposits. The Ninnescah Shale (Permian) overlies the Wellington Formation and crops out in parts of the western third of the county. The Permian rocks yield small quantities of hard water to wells. Pleistocene sand and gravel deposits of Nebraskan age are present in the northwestern corner of the county and yield moderate quantities of good water to wells. Discontinuous deposits of Kansan or Illinoisan age, locally mantled by colluvium, forms terraces in southern and eastern Sumner County, and may yield moderate quantities of water. Wisconsinan terrace deposits and Recent alluvium along the major streams yield large quantities of water. Colluvium and dune sand are unimportant as sources of water but may facilitate recharge. Maps of Sumner County included in this report show the outcrop areas of the formations, geologic cross sections, the shape and slope of the water table, the locations of wells and test holes for which records are given, and the distribution of chloride in water samples. The ground-water reservoir is recharged principally from rain and snow that fall within the county, by percolation from streams and other surface bodies of water, and by underflow from adjacent areas. Water is discharged from the ground-water reservoir by seepage into streams, by transpiration and evaporation, by movement into adjacent areas, and by wells. Water is pumped from wells for domestic, stock, municipal, industrial, and irrigation use. Irrigation from wells is most extensive in the valley of Arkansas River, in which area further development is most probable. Chemical analyses of samples of water from Sumner County indicate that the quality varies greatly from place to place. Sulfate is common in water from the Wellington Formation and Ninnescah Shale. Water from Pleistocene deposits is generally suitable for most uses except in local areas where it contains excessive chloride.

Kansas Geological Survey Bulletin↗
USGS2002

Cooperative investigation of precision and accuracy in chemical analysis of silicate rocks

This is the preliminary report of the first extensive program ever organized to study the analysis of igneous rocks, a study sponsored by the United States Geological Survey, the Massachusetts Institute of Technology, and the Geophysical Laboratory of the Carnegie Institution of Washington. Large samples of two typical igneous rocks, a granite and a diabase, were carefully prepared and divided. Small samples (about 70 grams) of each were sent to 25 rock-analysis laboratories throughout the world; analyses of one or both samples were reported by 34 analysts in these laboratories. The results, which showed rather large discrepancies, are presented in histograms. The great discordance in results reflects the present unsatisfactory state of rock analysis. It is hoped that the ultimate establishment of standard samples and procedures will contribute to the improvement of quality of analyses. The two rock samples have also been thoroughly studied spectrographically and petrographically. Detailed reports of all the studies will be published.

Analytical Chemistry↗
USGS1981

Environmental geologic studies on the southeastern United States Atlantic Outer Continental Shelf, 1977-1978

This report is a summary of the second year of marine environmental research activities by the U.S. Geological Survey (USGS) on the southeaster U.S. Atlantic Continental Margin, in accordance with with Memorandum of Understanding (MOU) AA551-MU8-13 between the USGS and the Bureau of Land Management (BLM). The report covers studies whose fieldwork was conducted during the period from 1 October 1977 to 30 September 1978. The results of the first year of study are reported in Popenoe (1978a and b) and as U.S. Department of Commerce NTIS report PB 300-820. The purpose of these investigations is to provide basic geologic and oceanographic data to the BLM Outer Continental Shelf (OCS) Marine Environmental Studies Program in support of management decisions which relate to possible development of oil and gas resources of the continental shelf. The objectives of the USGS-BLM geologic research program for fiscal year 1978 (FY-78) were 1) to determine the sedimentation rates and processes on the upper slope and inner Blake Plateau; 2) to determine the distribution, areal extent, and vertical characteristics of geological features supportive of biological communities; 3) to monitor the transport of bottom sediment across the OCS, evaluate its possible effect on pollutant transfer along the seabed and the potential of sediment as a pollutant sink, determine the implications of erosion/deposition on pipeline emplacement, and aid the interpretation of chemical, biological, and physical data; 4) to determine the concentration levels of chosen trace metals and silica in three chemically defined fractions of the suspended particulate matter (seston); 5) to study the shelf edge and slope near areas of oil and gas interest, and the northern portion of the Blake Plateau for evidence of slope instability and other geologic hazards, and 6) to determine the depth and rate of sediment mixing caused by large storms and/or by benthic organisms and where possible to estimate the rate of active sediment accumulation.

Atlantic Outer Continental Shelf↗
USGS1992

Chemistry of the subalkalic silicic obsidians

Nonhydrated obsidians are quenched magmatic liquids that record in their chemical compositions details of the tectonic environment of formation and of the differentiation mechanisms that affected their subsequent evolution. This study attempts to analyze, in terms of geologic processes, the compositional variations in the subalkalic silicic obsidians (Si0 2 ≥70 percent by weight, molecular (Na 2 O+K 2 0)>Al 2 O 3 ). New major- and trace-element determinations of 241 samples and a compilation of 130 published major-element analyses are reported and interpreted. Obsidians from five different tectonic settings are recognized: (1) primitive island arcs, (2) mature island arcs, (3) continental margins, (4) continental interiors, and (5) oceanic extensional zones. Tectonomagmatic discrimination between these groups is successfully made on Nb-Ta, Nb-FeO t and Th-Hf-Ta plots, and compositional ranges and averages for each group are presented. The chemical differences between groups are related to the type of crust in which magmas were generated. With increasingly sialic (continental type) crust, the obsidians show overall enrichment in F, Be, Li, Mo, Nb, Rb, Sn, Ta, U, W, Zn, and the rare-earth elements, and depletion in Mg, Ca, Ba, Co, Sc, Sr, and Zr. They become more potassic, have higher Fe/Mg and F/Cl ratios, and lower Zr/Hf, Nb/Ta, and Th/U ratios. Higher values of total rare-earth elements are accompanied by light rare-earth-element enrichment and pronounced negative Eu anomalies. An attempt is made to link obsidian chemistry to genetic mechanlism. Two broad groups of rocks are distinguished: one generated where crystal-liquid processes dominated (CLPD types), which are the products of crustal anatexis, possibly under conditions of low halogen fugacity, ± crystal fractionation ± magma mixing; and a second group represented by rocks formed in the upper parts of large magma chambers by interplays of crystal fractionation, volatile transfer, magma mixing, and possibly various liquid-state differentiation mechanisms, or in other words a complex interaction of petrogenetic processes (CIPP types). Such rocks may also form by volatile-fluxed partial melting of the wallrocks, and subsequent mixing into the magma reservoir. Compositional ranges and averages for CLPD and CIPP obsidians are given. It is shown by analogy with well-documented, zoned ash-flow ruffs that obsidians fractionated by CIPP have very low Mg, P, Ba, and Sr contents, flat rare-earth-element patterns with extensive Eu anomalies, low K/Rb and Zr/Nb ratios, and relatively high Na 2 O/K 2 O ratios. There is, however, considerable compositional overlap between CLPD and CIPP obsidians. The effects of magma mixing, assimilation, and vapor-phase transport in producing compositional variations in the obsidians are briefly assessed. The geochemistry of the subalkalic silicic obsidians is described on an element-by-element basis, in order to provide a database for silicic magma compositions that will hopefully contribute to studies of granitic rocks. Attempts are also made to isolate the geochemical effects of tectonic environment and genetic mechanism for each element, by comparison with data from crystal-liquid equilibria-controlled systems, from ash-flow sheets zoned by CIPP, and from mixed-magma series. A final tabulation relates the complexities of obsidian geochemistry to all the tectonic and genetic variables.

Professional Paper↗
USGS2015

Context of ancient aqueous environments on Mars from in situ geologic mapping at Endeavour Crater

Using the Mars Exploration Rover Opportunity , we have compiled one of the first field geologic maps on Mars while traversing the Noachian terrain along the rim of the 22 km diameter Endeavour Crater (Latitude −2°16′33″, Longitude −5°10′51″). In situ mapping of the petrographic, elemental, structural, and stratigraphic characteristics of outcrops and rocks distinguishes four mappable bedrock lithologic units. Three of these rock units predate the surrounding Burns formation sulfate-rich sandstones and one, the Matijevic Formation, represents conditions on early Mars predating the formation of Endeavour Crater. The stratigraphy assembled from these observations includes several geologic unconformities. The differences in lithologic units across these unconformities record changes in the character and intensity of the Martian aqueous environment over geologic time. Water circulated through fractures in the oldest rocks over periods long enough that texturally and elementally significant alteration occurred in fracture walls. These oldest pre-Endeavour rocks and their network of mineralized and altered fractures were preserved by burial beneath impact ejecta and were subsequently exhumed and exposed. The alteration along joints in the oldest rocks and the mineralized veins and concentrations of trace metals in overlying lithologic units is direct evidence that copious volumes of mineralized and/or hydrothermal fluids circulated through the early Martian crust. The wide range in intensity of structural and chemical modification from outcrop to outcrop along the crater rim shows that the ejecta of large (>8 km in diameter) impact craters is complex. These results imply that geologic complexity is to be anticipated in other areas of Mars where cratering has been a fundamental process in the local and regional geology and mineralogy.

Journal of Geophysical Research E: Planets↗
USGS1991

Fluid inclusion gas chemistry as a potential minerals exploration tool: Case studies from Creede, CO, Jerritt Canyon, NV, Coeur d'Alene district, ID and MT, southern Alaska mesothermal veins, and mid-continent MVT's

Recent advances in instrumentation now permit quantitative analysis of gas species from individual fluid inclusions. Fluid inclusion gas data can be applied to minerals exploration empirically to establish chemical (gas composition) signatures of the ore fluids, and conceptually through the development of genetic models of ore formation from a framework of integrated geologic, geochemical, and isotopic investigations. Case studies of fluid inclusion gas chemistry from ore deposits representing a spectrum of ore-forming processes and environments are presented to illustrate both the empirical and conceptual approaches. We consider epithermal silver-gold deposits of Creede, Colorado, Carlin-type sediment-hosted disseminated gold deposits of Jerritt Canyon, Nevada, metamorphic silver-base-metal veins of the Coeur d'Alene district, Idaho and Montana, gold-quartz veins in accreted terranes of southern Alaska, and the mid-continent base-metal sulfide deposits of Mississippi Valley-Type (MVT's). Variations in gas chemistry determine the redox state of the ore fluids, provide compositional input for gas geothermometers, characterize ore fluid chemistry (e.g., CH 4 CO 2 , H 2 SSO 2 , CO 2 /H 2 S, organic-rich fluids, gas-rich and gas-poor fluids), identify magmatic, meteoric, metamorphic, shallow and deep basin fluids in ore systems, locate upwelling plumes of magmatic-derived volatiles, zones of boiling and volatile separation, interfaces between contrasting fluids, and important zones of fluid mixing. Present techniques are immediately applicable to exploration programsas empirical studies that monitor fluid inclusion gas threshold concentration levels, presence or absence of certain gases, or changes in gas ratios. We suggest that the greater contribution of fluid inclusion gas analysis is in the integrated and comprehensive chemical dimension that gas data impart to genetic models, and in the exploration concepts based on processes and environments of ore formation derived from these genetic models.

Journal of Geochemical Exploration↗
USGS1996

Age of supergene oxidation and enrichment in the Chilean porphyry copper province

Twenty-five samples of supergene alunite collected from deeply developed supergene profiles in porphyry copper deposits and prospects between latitudes 20 degrees and 27 degrees S in northern Chile yield K/Ar ages ranging from about 34 to 14 Ma. Therefore supergene oxidation and enrichment processes were active from the early Oligocene to the middle Miocene, a minimum of 20 m.y. Supergene activity at individual deposits lasted for at least 0.4 to 6.2 m.y. The early Oligocene supergene activity affected deposits in the Paleocene porphyry copper belt, whereas early and middle Miocene supergene processes are documented in the Early Cretaceous, Paleocene, and late Eocene to early Oligocene porphyry, copper belts. Middle Miocene oxidation also affected the oldest epithermal gold-silver deposits in the Maricunga belt farther east. Supergene activity commenced no less than 11 m.y. after generation of each porphyry copper deposit because of the time required to unroof the copper-bearing parts of the system. Supergene activity throughout northern Chile ceased at approximately 14 Ma. The geologic features of deposits and prospects and their morphotectonic positions, present latitudes, and present elevations display no obvious correlations with the supergene chronology. Exploration for major cumulative enrichment blankets should not be carried out either beneath thick sequences of piedmont gravels (+ or - ignimbrites) of Oligocene through middle Miocene age unless their accumulation is demonstrably late in the documented history of supergene activity, or in porphyry copper provinces, such as those of central Chile and northwestern Argentina, which formed after approximately 14 Ma. The uplift responsible for efficient cumulative copper enrichment is difficult to correlate convincingly with the brief pulses of compressive tectonism postulated for northern Chile and contiguous areas unless their effects were much more prolonged. Intensifying aridity is confirmed as the likely reason for the cessation of supergene activity in northern Chile, and tectonic uplift was its most probable cause. However, more fundamental global controls producing a period of chemical weathering followed by worldwide dessication also may have played a role.

Economic Geology↗
USGS2012

Quaternary geologic map of the Glasgow 1° x 2° quadrangle, Montana

The Glasgow quadrangle encompasses approximately 16,084 km 2 (6,210 mi 2 ). The northern boundary is the Montana/Saskatchewan (U.S./Canada) boundary. The quadrangle is in the Northern Plains physiographic province and it includes the Boundary Plateau, Peerless Plateau, and Larb Hills. The primary river is the Milk River. The map units are surficial deposits and materials, not landforms. Deposits that comprise some constructional landforms (for example, ground-moraine deposits, end-moraine deposits, and stagnation-moraine deposits, all composed of till) are distinguished for purposes of reconstruction of glacial history. Surficial deposits and materials are assigned to 23 map units on the basis of genesis, age, lithology or composition, texture or particle size, and other physical, chemical, and engineering characteristics. It is not a map of soils that are recognized in pedology or agronomy. Rather, it is a generalized map of soils recognized in engineering geology, or of substrata or parent materials in which pedologic or agronomic soils are formed. Glaciotectonic (ice-thrust) structures and deposits are mapped separately, represented by a symbol. The surficial deposits are glacial, ice-contact, glaciofluvial, alluvial, lacustrine, eolian, colluvial, and mass-movement deposits. Residuum, a surficial material, also is mapped. Till of late Wisconsin age is represented by three map units. Till of Illinoian age is also represented locally but is widespread in the subsurface. This map was prepared to serve as a database for compilation of a Quaternary geologic map of the United States and Canada (scale 1:1,000,000). Letter symbols for the map units are those used for the same units in the Quaternary Geologic Atlas of the United States map series.

Montana↗
USGS1973

Isotopic composition of oil-field brines from Kettleman North Dome, California, and their geologic implications

Deuterium and O 18 analyses were made on 25 formation-water samples from Miocene (Temblor Formation) and Eocene (McAdams Formation) reservoir rocks at Kettleman North Dome oil field, California, and on three surface water samples from Reef Ridge located about three miles to the west of the field. The δO 18 values obtained generally increase with depth and most probably are due to temperature controlled exchange reactions with carbonate cement and dissolved carbonate species. The δD values obtained seem to be controlled primarily by the membrane behavior of shales modifying the assumed original values. The contribution of isotopic exchange between water and clays cannot be evaluated at present. The isotopic data support the conclusions based on a detailed study of geology, hydrodynamics, and formation water geochemistry ( Kharaka , 1971) which indicate that: 1. The Temblor Formation waters are probably meteoric in origin concentrated chemically and isotopically by shale membranes, and 2. The McAdams Formation waters were most probably obtained by squeezing the original interstitial marine connate waters of deposition from the underlying Mesozoic sediments.

California↗
USGS2009

Uranium adsorption on weathered schist - Intercomparison of modeling approaches

Experimental data for uranium adsorption on a complex weathered rock were simulated by twelve modelling teams from eight countries using surface complexation (SC) models. This intercomparison was part of an international project to evaluate the present capabilities and limitations of SC models in representing sorption by geologic materials. The models were assessed in terms of their predictive ability, data requirements, number of optimised parameters, ability to simulate diverse chemical conditions and transferability to other substrates. A particular aim was to compare the generalised composite (GC) and component additivity (CA) approaches for modelling sorption by complex substrates. Both types of SC models showed a promising capability to simulate sorption data obtained across a range of chemical conditions. However, the models incorporated a wide variety of assumptions, particularly in terms of input parameters such as site densities and surface site types. Furthermore, the methods used to extrapolate the model simulations to different weathered rock samples collected at the same field site tended to be unsatisfactory. The outcome of this modelling exercise provides an overview of the present status of adsorption modelling in the context of radionuclide migration as practised in a number of countries worldwide.

Radiochimica Acta↗
USGS2015

Strategy to evaluate persistent contaminant hazards resulting from sea-level rise and storm-derived disturbances—Study design and methodology for station prioritization

Coastal communities are uniquely vulnerable to sea-level rise (SLR) and severe storms such as hurricanes. These events enhance the dispersion and concentration of natural and anthropogenic chemicals and pathogenic microorganisms that could adversely affect the health and resilience of coastal communities and ecosystems in coming years. The U.S. Geological Survey has developed a strategy to define baseline and post-event sediment-bound environmental health (EH) stressors (hereafter referred to as the Sediment-Bound Contaminant Resiliency and Response [SCoRR] strategy). A tiered, multimetric approach will be used to (1) identify and map contaminant sources and potential exposure pathways for human and ecological receptors, (2) define the baseline mixtures of EH stressors present in sediments and correlations of relevance, (3) document post-event changes in EH stressors present in sediments, and (4) establish and apply metrics to quantify changes in coastal resilience associated with sediment-bound contaminants. Integration of this information provides a means to improve assessment of the baseline status of a complex system and the significance of changes in contaminant hazards due to storm-induced (episodic) and SLR (incremental) disturbances. This report describes the purpose and design of the SCoRR strategy and the methods used to construct a decision support tool to identify candidate sampling stations vulnerable to contaminants that may be mobilized by coastal storms.

Connecticut, Delaware, District of Columbia, Maine↗
USGS1954

Stockton and Stanley Hill clay deposits, Kootenai County, Idaho

The Stockton and Stanley Hill deposits, Kootenai County, Idaho, are about 25 to 30 miles east of Spokane, Wash. During World War II, the areas were studied by the U. S. Geological Survey in cooperation with the U. S. Bureau of Mines. The Bureau of Mines hand-augered 162 holes and made chemical analyses of the samples for available alumina, and available ferric oxide, and measured the ignition loss. The deposit contains two types of clay: granite residual clay derived from the weathering of Cretaceous granite gneiss in place; and transported clays of the Latah formation derived from the weathered. debris of the granodiorite and older rocks. The Stockton deposits average more than 20 percent available alumina and less than 10 percent available ferric oxide. The deposits, therefore, could serve as a small source of low-grade high alumina clay. Clays containing more than 15 percent available alumina and less than 5 percent available ferric oxide would be suitable for many ceramic products and some may meet the requirements for high-heat or super-heat duties. Therefore, the Stockton and Stanley Hill clay deposits contain ceramic-grade clays.

Idaho↗
USGS1954

Stanford clay deposit, Latah County, Idaho

The Stanford clay deposit, Latah County, Idaho, is about 4 miles northwest of Deary, Idaho. During World War II, the area was studied by the U. S. Geological Survey in cooperation with the U. S. Bureau of Mines. The Bureau of Mines hand-augered 10 holes and made chemical analyses on the samples for available alumina and available ferric oxide, and also measured the ignition loss. The deposit contains three types of clay: granitic residual clay derived from the weathering of Cretaceous granodiorite in place; basaltic residual clay derived from the weathering of Tertiary Columbia River basalts in place; and transported clays of the Latah formation derived from the weathered debris of the granodiorite and older rocks. Only the transported clays are considered as a potential source of available alumina and ceramic-grade clay in the Stanford deposit. The Stanford deposit averages 24.8 percent available alumina and 2 percent available ferric oxide. Transported clays containing more than 15 percent available alumina and less than 5% percent available ferric oxide would be suitable for many ceramic products and some may meet the requirements of high-heat or super-heat duties. Therefore, the clays are usable for ceramic structural ware such as bricks, terra cotta, and drain tile.

Idaho↗
USGS1980

Preliminary map showing availability of water from glacial-drift aquifers in McHenry County, north-central North Dakota

This preliminary map is the first product of the ground-water resources study of McHenry County . This study is part of a statewide program to determine the location, extent, chemical quality, and hydrologic characteristics of the ground-water reservoirs (aquifers) in North Dakota. The study was made by the U.S. Geological Survey in cooperation with the North Dakota State Water Commission, the North Dakota Geological Survey, and the McHenry County Water Management District.

Open-File Report↗
USGS1981

Hydrology of Area 7, Eastern Coal Province, Ohio

The U.S. Geological Survey established 24 study areas in Eastern Appalachian Coal Province to appraise the hydrology and water resources from Alabama to Pennsylvania. Chemical, physical, biological, and streamflow data were collected from 138 synoptic sites in Area 7, eastern Ohio. The data are evaluated and presented in this report. Area 7 lies within the drainage basins of Muskingum Rivers and Duck and Willis Creeks in eastern Ohio. Walhounding, Tuscarawas, and Little Muskingum, and Muskingum Rivers and Wills and Duck Creeks are the major streams draining the study area. In Ohio, surface and subsurface coal mining has altered the environment. In areas where land has been reclaimed, the environmental stress expected to be temporary. Hydrologic problems related to coal mining are erosion and sedimentation which degrade water-quality. Based on available sediment data, suspended sediment concentration were highest in abandoned mine areas, followed by currently mined and reclaimed areas, and lowest in unmined areas. Low pH, high specific conductance, high concentrations of iron, sulfate and manganese, increased sediment yields, discoloration of streambeds, limited aquatic vegetation and animal life typify streams draining areas with abandoned mines. In abandoned mine areas, the specific conductance of water ranged from 800 to 2,300 micromhos; pH ranged from 2.8 to 5.8; dissolved-iron concentrations ranged from 1,000 to 85,000 micrograms per liter; dissolved-sulfate concentrations ranged from 14 to 1,200 milligrams per liter and dissolved-manganese concentration commonly exceeded 2,000 micrograms per liter. Red and yellow coloration on the streambeds were precipitates from the hydrolysis of iron, manganese, and sulfate minerals carried into the stream channel by increased sediment erosion from abandoned coal mines. Trace metal concentrations (arsenic, cadmium, chromium, cobalt, copper, lead, mercury, selenium, and zinc) were generally low. Degradation of fish habitat is illustrated by conceptual model of the aquatic biology related to water chemistry.

Open-File Report↗
USGS1982

Preliminary map showing availability of ground water from glacial-drift aquifers in Logan County, south-central North Dakota

This preliminary map is the first product of the ground-water resources study of Logan County, which has an area of 1,015 mi 2 (2,629 km 2 ) in south-central North Dakota (see location map). This study is part of a statewide program to determine the location, extent, chemical quality, and hydrologic characteristics of the ground-water reservoirs (aquifers) in North Dakota. The study was made by the U.S. Geological Survey in cooperation with the North Dakota State Water Commission, North Dakota Geological Survey, and Logan County Water Management District.

Open-File Report↗
USGS1981

Preliminary map showing availability of water from glacial-drift aquifers in Towner County, north-central North Dakota

This preliminary map is the first product of the ground-water resources study of Towner County, which has an area of 1,049 mi 2 (2,717 km 2 ) in north-central North Dakota (see location map). The study is part of a statewide program to determine the location, extent, chemical quality, and hydrologic characteristics of the ground-water reservoirs (aquifers) in North Dakota. The study was made by the U.S. Geological Survey in cooperation with the North Dakota State Water Commission, the North Dakota Geological Survey, and the Towner County Water Management District.

Open-File Report↗