Undisrupted periphyton communities from a N‐rich (NO3− = 63 µmol L−1) and pristine (NO3− = 2.9 µmol L−1) stream were assayed for denitrifying activity (acetylene‐blockage technique) in 40‐L chambers incubated at in situ temperature and nutrient concentrations. Nitrous oxide formation associated with periphyton from the N‐rich stream was immediate and linear (52.1 µmol N2O m−2 h−1) in the dark, anaerobic chamber (50 kPa C2H2). In the corresponding light, aerobic chamber (50 kPa C2H2), N2O production was inhibited by 82% (9.3 µmol N2O m−2 h−1). Nitrous oxide formation was not associated with periphyton from the pristine stream incubated in situ, either with or without NO3− amendment.
Denitrification estimates made with undisrupted periphyton communities at in situ temperature and nutrient concentrations (40‐L chambers) were less variable than estimates made with periphyton “scrapings” in small flasks (room temperature). The calculated diel periphyton‐associated denitrification rate based on a 14‐h light‐10‐h dark day was 651 µmol N2O m−2 d−1. The data suggest denitrification within periphyton mats may contribute toward removal of NO3− from N‐rich fluvial environments.
","language":"English","publisher":"Wiley","doi":"10.2134/jeq1984.00472425001300040002x","issn":"00472425","usgsCitation":"Duff, J., Triska, F., and Oremland, R., 1984, Denitrification associated with stream periphyton: Chamber estimates from undisrupted communities: Journal of Environmental Quality, v. 13, no. 4, p. 514-518, https://doi.org/10.2134/jeq1984.00472425001300040002x.","productDescription":"5 p.","startPage":"514","endPage":"518","numberOfPages":"5","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":220045,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"13","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fe98e4b0c8380cd4edfb","contributors":{"authors":[{"text":"Duff, J.H.","contributorId":60377,"corporation":false,"usgs":true,"family":"Duff","given":"J.H.","email":"","affiliations":[],"preferred":false,"id":366311,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Triska, F.J.","contributorId":69560,"corporation":false,"usgs":true,"family":"Triska","given":"F.J.","email":"","affiliations":[],"preferred":false,"id":366312,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Oremland, R.S.","contributorId":97512,"corporation":false,"usgs":true,"family":"Oremland","given":"R.S.","email":"","affiliations":[],"preferred":false,"id":366313,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70013727,"text":"70013727 - 1984 - Hydrogen isotope systematics of submarine basalts","interactions":[],"lastModifiedDate":"2024-03-19T16:20:38.259739","indexId":"70013727","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1759,"text":"Geochimica et Cosmochimica Acta","active":true,"publicationSubtype":{"id":10}},"title":"Hydrogen isotope systematics of submarine basalts","docAbstract":"The D/H ratios and water contents in fresh submarine basalts from the Mid-Atlantic Ridge, the East Pacific Rise, and Hawaii indicate that the primary D/H ratios of many submarine lavas have been altered by processes including (1) outgassing, (2) addition of seawater at magmatic temperature, and (3) low-temperature hydration of glass. Decreases in δD and H2O+ from exteriors to interiors of pillows are explained by outgassing of water whereas inverse relations between δD and H2O+ in basalts from the Galapagos Rise and the FAMOUS Area are attributed to outgassing of CH4 and H2. A good correlation between δD values and H2O is observed in a suite of submarine tholeiites dredged from the Kilauea East Rift Zone where seawater (added directly to the magma), affected only the isotopic compositions of hydrogen and argon. Analyses of some glassy rims indicate that the outer millimeter of the glass can undergo lowtemperature hydration by hydroxyl groups having δD values as low as −100.
δD values vary with H2O contents of subaerial transitional basalts from Molokai, Hawaii, and subaerial alkali basalts from the Society Islands, indicating that the primary δD values were similar to those of submarine lavas.
Extrapolations to possible unaltered δD values and H2O contents indicate that the primary δD values of most thoteiite and alkali basalts are near −80 ± 5: the weight percentages of water are variable, 0.15–0.35 for MOR tholeiites, about 0.25 for Hawaiian tholeiites, and up to 1.1 for alkali basalts. The primary δD values of −80 for most basalts are comparable to those measured for deep-seated phlogopites. These results indicate that hydrogen, in marked contrast to other elements such as Sr, Nd, Pb, and O, has a uniform isotopic composition in the mantle. This uniformity is best explained by the presence of a homogeneous reservoir of hydrogen that has existed in the mantle since the very early history of the Earth.
","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7037(84)90392-2","issn":"00167037","usgsCitation":"Kyser, T., and O’Neil, J.R., 1984, Hydrogen isotope systematics of submarine basalts: Geochimica et Cosmochimica Acta, v. 48, no. 10, p. 2123-2133, https://doi.org/10.1016/0016-7037(84)90392-2.","productDescription":"11 p.","startPage":"2123","endPage":"2133","numberOfPages":"11","costCenters":[],"links":[{"id":220112,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"48","issue":"10","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a334ee4b0c8380cd5eec7","contributors":{"authors":[{"text":"Kyser, T.K.","contributorId":25585,"corporation":false,"usgs":true,"family":"Kyser","given":"T.K.","email":"","affiliations":[],"preferred":false,"id":366733,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"O’Neil, J. R.","contributorId":69633,"corporation":false,"usgs":true,"family":"O’Neil","given":"J.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":366734,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70009978,"text":"70009978 - 1984 - The occurrence and behavior of radium in saline formation water of the U.S. Gulf Coast region","interactions":[],"lastModifiedDate":"2013-01-21T08:39:44","indexId":"70009978","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1213,"text":"Chemical Geology","active":true,"publicationSubtype":{"id":10}},"title":"The occurrence and behavior of radium in saline formation water of the U.S. Gulf Coast region","docAbstract":"Radium has been measured in deep saline formation waters produced from a variety of U.S. Gulf Coast subsurface environments, including oil reservoirs, gas reservoirs and water-producing geopressured aquifers. A strong positive correlation has been found between formation-water salinity and Ra activity, resulting from the interaction of formation water with aquifer matrix. Ra isotopes enter the fluid phase after being produced by the decay of parent elements U and Th, which are located at sites on and within the solid matrix. Processes that are belived to be primarily responsible for transferring Ra from matrix to formation water are chemical leaching and alpha-particle recoil. Factors controlling the observed salinity-Ra relationship may be one or a combination of the following factors: (a) ion exchange; (b) increased solubility of matrix silica surrounding Ra atoms, coupled with a salinity-controlled rate of reequilibration of silica between solution and quartz grains; and (c) the equilibration of Ra in solution with detrial barite within the aquifer. No difference was found in the brine-Ra relation in water produced from oil or gas wells and water produced from wells penetrating only water-bearing aquifers, although the relation was more highly correlated for water-bearing aquifers than hydrocarbon-containing reservoirs. ?? 1984.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Chemical Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/0009-2541(84)90186-4","issn":"00092541","usgsCitation":"Kraemer, T.F., and Reid, D., 1984, The occurrence and behavior of radium in saline formation water of the U.S. Gulf Coast region: Chemical Geology, v. 46, no. 2, p. 153-174, https://doi.org/10.1016/0009-2541(84)90186-4.","startPage":"153","endPage":"174","numberOfPages":"22","costCenters":[],"links":[{"id":266106,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0009-2541(84)90186-4"},{"id":219659,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"46","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bae31e4b08c986b323f48","contributors":{"authors":[{"text":"Kraemer, T. F.","contributorId":63400,"corporation":false,"usgs":true,"family":"Kraemer","given":"T.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":357575,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Reid, D.F.","contributorId":27188,"corporation":false,"usgs":true,"family":"Reid","given":"D.F.","email":"","affiliations":[],"preferred":false,"id":357574,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70009980,"text":"70009980 - 1984 - Radioisotope dilution analyses of geological samples using 236U and 229Th","interactions":[],"lastModifiedDate":"2013-03-06T19:12:42","indexId":"70009980","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2907,"text":"Nuclear Instruments and Methods In Physics Research","active":true,"publicationSubtype":{"id":10}},"title":"Radioisotope dilution analyses of geological samples using 236U and 229Th","docAbstract":"The use of 236U and 229Th in alpha spectrometric measurements has some advantages over the use of other tracers and measurement techniques in isotope dilution analyses of most geological samples. The advantages are: (1) these isotopes do not occur in terrestrial rocks, (2) they have negligible decay losses because of their long half lives, (3) they cause minimal recoil contamination to surface-barrier detectors, (4) they allow for simultaneous determination of the concentration and isotopic composition of uranium and thorium in a variety of sample types, and (5) they allow for simple and constant corrections for spectral inferences, 0.5% of the 238U activity is subtracted for the contribution of 235U in the 236U peak and 1% of the 229Th activity is subtracted from the 230Th activity. Disadvantages in using 236U and 229Th are: (1) individual separates of uranium and thorium must be prepared as very thin sources for alpha spectrometry, (2) good resolution in the spectrometer system is required for thorium isotopic measurements where measurement times may extend to 300 h, and (3) separate calibrations of the 236U and 229Th spike solution with both uranium and thorium standards are required. The use of these tracers in applications of uranium-series disequilibrium studies has simplified the measurements required for the determination of the isotopic composition of uranium and thorium because of the minimal corrections needed for alpha spectral interferences. ?? 1984.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Nuclear Instruments and Methods In Physics Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/0167-5087(84)90711-7","issn":"01675087","usgsCitation":"Rosholt, J., 1984, Radioisotope dilution analyses of geological samples using 236U and 229Th: Nuclear Instruments and Methods In Physics Research, v. 223, no. 2-3, p. 572-576, https://doi.org/10.1016/0167-5087(84)90711-7.","startPage":"572","endPage":"576","numberOfPages":"5","costCenters":[],"links":[{"id":219661,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":268836,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0167-5087(84)90711-7"}],"volume":"223","issue":"2-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a93fde4b0c8380cd81135","contributors":{"authors":[{"text":"Rosholt, J.N.","contributorId":37749,"corporation":false,"usgs":true,"family":"Rosholt","given":"J.N.","email":"","affiliations":[],"preferred":false,"id":357577,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70013389,"text":"70013389 - 1984 - SHUTTLE IMAGING RADAR PROVIDES FRAMEWORK FOR SUBSURFACE GEOLOGIC EXPLORATION IN EGYPT AND SUDAN.","interactions":[],"lastModifiedDate":"2012-03-12T17:18:36","indexId":"70013389","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"SHUTTLE IMAGING RADAR PROVIDES FRAMEWORK FOR SUBSURFACE GEOLOGIC EXPLORATION IN EGYPT AND SUDAN.","docAbstract":"Shuttle Imaging Radar provides a pictorial framework to guide exploration for mineral resources (potential placers), groundwater sources, and prehistoric archaeological sites in the Western Desert of Egypt and Sudan. Documented penetration by the SIR-A signal of dry surficial sediment to depths of a meter or more revealed bedrock geologic features and networks of former stream valleys otherwise concealed beneath windblown sand, alluvium, and colluvial deposits. 'Radar units' mapped on SIR-A images according to relative brightness and degree of mottling correspond to subsurface geologic and topographic features identified in more than 50 test pits. Petrologic examination of pit samples confirms that a variety of depositional environments existed in this now hyper-arid region before it was mantled by windblown sand sheets and dunes. Wet sand was discovered in two buried valleys shown on the radar images and located in the field with the aid of co-registered maps and Landsat images, and a satellite navigation device. Buried valleys whose streams once traversed mineralized zones are potential sites of placers (gold, tin).","conferenceTitle":"Proceedings of the International Symposium on Remote Sensing of Environment, Third Thematic Conference: Remote Sensing for Exploration Geology.","conferenceLocation":"Colorado Springs, CO, USA","language":"English","publisher":"Environmental Research Inst of Michigan","publisherLocation":"Ann Arbor, MI, USA","usgsCitation":"Breed, C.S., McCauley, J., and Schaber, G.G., 1984, SHUTTLE IMAGING RADAR PROVIDES FRAMEWORK FOR SUBSURFACE GEOLOGIC EXPLORATION IN EGYPT AND SUDAN., Proceedings of the International Symposium on Remote Sensing of Environment, Third Thematic Conference: Remote Sensing for Exploration Geology., Colorado Springs, CO, USA.","startPage":"949","costCenters":[],"links":[{"id":219916,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aaf4ce4b0c8380cd874eb","contributors":{"authors":[{"text":"Breed, Carol S.","contributorId":100904,"corporation":false,"usgs":true,"family":"Breed","given":"Carol","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":365957,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McCauley, John F.","contributorId":54973,"corporation":false,"usgs":true,"family":"McCauley","given":"John F.","affiliations":[],"preferred":false,"id":365956,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Schaber, Gerald G.","contributorId":12511,"corporation":false,"usgs":true,"family":"Schaber","given":"Gerald","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":365955,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70013338,"text":"70013338 - 1984 - Paleohydrological methods and some examples from Swedish fluvial environments. II - River meanders","interactions":[],"lastModifiedDate":"2023-12-19T00:51:04.459307","indexId":"70013338","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1767,"text":"Geografiska Annaler, Series A","active":true,"publicationSubtype":{"id":10}},"title":"Paleohydrological methods and some examples from Swedish fluvial environments. II - River meanders","docAbstract":"Empirical relations are developed between river-meander features and water-discharge characteristics for 19 reaches along Swedish rivers. In these relations, either average channel width or average radius of curvature of meander arcs can be used to estimate average annual peak discharge and average daily discharge. By accepting certain assumptions, the relations can be applied to other meandering Swedish rivers, present or ancient. The Öster-Dalälven River near Mora is used as an example.
Very low Ti basalts and green glass samples from the moon show high Lu/Hf ratios and low Hf concentrations. Low-Ti lunar basalts show high and variable Lu/Hf ratios and higher Hf concentrations, whereas high-Ti lunar basalts show low Lu/Hf ratios and high Hf concentrations. KREEP basalts have constant Lu/Hf ratios and high but variable Hf concentrations. Using the Lu-Hf behavior as a constraint, we propose a model for the mare basalts evolution. This constraint requires extensive crystallization of the primary lunar magma ocean prior to formation of the lunar mare basalt sources and the KREEP basalts. Mare basalts are produced by the melting of the cumulate rocks, and KREEP basalts represent the residual liquid of the magma ocean.
Lu and Hf concentrations and the Hf isotopic data of lunar rocks suggest that assimilation cannot be accepted as a major process to explain the diversity of the lunar mare basalts. The urKREEP hypothesis is also unnecessary. Both high- and low-Ti basalts show enough iron enrichment to be regarded as melting products of the last stage cumulate rocks from the lunar magma ocean. The KREEP basalts are also rich in iron and may be regarded as the final, residual liquid left after the crystallization of the major portion of the primary lunar magma ocean.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB089iS02p0B445","usgsCitation":"Fujimaki, H., and Tatsumoto, M., 1984, Lu-Hf constraints on the evolution of lunar basalts: Journal of Geophysical Research Solid Earth, v. 89, no. S02, p. B445-B458, https://doi.org/10.1029/JB089iS02p0B445.","productDescription":"14 p.","startPage":"B445","endPage":"B458","numberOfPages":"14","costCenters":[],"links":[{"id":502537,"rank":2,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://tohoku.repo.nii.ac.jp/records/5255","text":"External Repository"},{"id":219795,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"89","issue":"S02","noUsgsAuthors":false,"publicationDate":"2012-09-21","publicationStatus":"PW","scienceBaseUri":"505a4a80e4b0c8380cd68e03","contributors":{"authors":[{"text":"Fujimaki, Hirokazu","contributorId":27607,"corporation":false,"usgs":true,"family":"Fujimaki","given":"Hirokazu","email":"","affiliations":[],"preferred":false,"id":365828,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tatsumoto, Mistunobu","contributorId":24637,"corporation":false,"usgs":true,"family":"Tatsumoto","given":"Mistunobu","email":"","affiliations":[],"preferred":false,"id":365827,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013333,"text":"70013333 - 1984 - Fluid heterogeneity during granulite facies metamorphism in the Adirondacks: stable isotope evidence","interactions":[],"lastModifiedDate":"2012-03-12T17:18:16","indexId":"70013333","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1336,"text":"Contributions to Mineralogy and Petrology","active":true,"publicationSubtype":{"id":10}},"title":"Fluid heterogeneity during granulite facies metamorphism in the Adirondacks: stable isotope evidence","docAbstract":"The preservation of premetamorphic, whole-rock oxygen isotope ratios in Adirondack metasediments shows that neither these rocks nor adjacent anorthosites and gneisses have been penetrated by large amounts of externally derived, hot CO2-H2O fluids during granulite facies metamorphism. This conclusion is supported by calculations of the effect of fluid volatilization and exchange and is also independently supported by petrologic and phase equilibria considerations. The data suggest that these rocks were not an open system during metamorphism; that fluid/rock ratios were in many instances between 0.0 and 0.1; that externally derived fluids, as well as fluids derived by metamorphic volatilization, rose along localized channels and were not pervasive; and thus that no single generalization can be applied to metamorphic fluid conditions in the Adirondacks. Analyses of 3 to 4 coexisting minerals from Adirondack marbles show that isotopic equilibrium was attained at the peak of granulite and upper amphibolite facies metamorphism. Thus the isotopic compositions of metamorphic fluids can be inferred from analyses of carbonates and fluid budgets can be constructed. Carbonates from the granulite facies are on average, isotopically similar to those from lower grade or unmetamorphosed limestones of the same age showing that no large isotopic shifts accompanied high grade metamorphism. Equilibrium calculations indicate that small decreases in ??18O, averaging 1 permil, result from volatilization reactions for Adirondack rock compositions. Additional small differences between amphibolite and granulite facies marbles are due to systematic lithologie differences. The range of Adirondack carbonate ??18O values (12.3 to 27.2) can be explained by the highly variable isotopic compositions of unmetamorphosed limestones in conjunction with minor 18O and 13C depletions caused by metamorphic volatilization suggesting that many (and possibly most) marbles have closely preserved their premetamorphic isotopic compositions. Such preservation is particularly evident in instances of high ??18O calcites (25.0 to 27.2), low ??18O wollastonites (-1.3 to 3.5), and sharp gradients in ??18O (18 permil/15m between marble and anorthosite, 8 permil/25 m in metasediments, and 6 permil/1 m in skarn). Isotopic exchange is seen across marble-anorthosite and marble-granite contacts only at the scale of a few meters. Small (<5 m) marble xenoliths are in approximate exchange equilibrium with their hosts, but for larger xenoliths and layers of marble there is no evidence of exchange at distances greater than 10 m from meta-igneous contacts. ?? 1984 Springer-Verlag.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Contributions to Mineralogy and Petrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Springer-Verlag","doi":"10.1007/BF00371706","issn":"00107999","usgsCitation":"Valley, J., and O’Neil, J.R., 1984, Fluid heterogeneity during granulite facies metamorphism in the Adirondacks: stable isotope evidence: Contributions to Mineralogy and Petrology, v. 85, no. 2, p. 158-173, https://doi.org/10.1007/BF00371706.","startPage":"158","endPage":"173","numberOfPages":"16","costCenters":[],"links":[{"id":204979,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00371706"},{"id":219847,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"85","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a126fe4b0c8380cd542d1","contributors":{"authors":[{"text":"Valley, J.W.","contributorId":28741,"corporation":false,"usgs":true,"family":"Valley","given":"J.W.","email":"","affiliations":[],"preferred":false,"id":365829,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"O’Neil, J. R.","contributorId":69633,"corporation":false,"usgs":true,"family":"O’Neil","given":"J.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":365830,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013426,"text":"70013426 - 1984 - U. S. GEOLOGICAL SURVEY MARINE-MINERALS RESEARCH.","interactions":[],"lastModifiedDate":"2012-03-12T17:18:28","indexId":"70013426","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"U. S. GEOLOGICAL SURVEY MARINE-MINERALS RESEARCH.","docAbstract":"Summary form only given. The US Exclusive Economic Zone is an area approximately one and two-thirds the size of the land area of the United States. In this frontier area, US Geological Survey (USGS) research in marine minerals is aimed at three objectives: (1) defining geologic settings of potential mineral resources; (2) understanding the processes by which seafloor nonliving resources form; and (3) estimating the resource potential. Potential resources of primary interest are cobalt-rich manganese seafloor crusts, polymetallic sulfides in hydrothermal vent areas on the seafloor, and heavy-mineral placer deposits. Research activities include studies of manganese-crust samples from oceanographic-institution archives and a USGS research cruise through the central and southern Pacific. Preliminary results confirm that cobalt is concentrated by as much as 2. 5% in the manganese crusts at water depths of 1000-2600 m; further research on the precipitation processes and patterns of crust formation will be needed to understand the origin, occurrence patterns, and resource potential of these crusts. Research cruises have revealed a zone of polymetallic sulfide vent deposits a few hundred meters long in the Juan de Fuca spreading center.","largerWorkTitle":"Oceans Conference Record (IEEE)","conferenceTitle":"Oceans '84 Conference & Exposition, Conference Record: Industry, Government, Education, Designs for the Future.","conferenceLocation":"Washington, DC, USA","language":"English","publisher":"IEEE","publisherLocation":"New York, NY, USA","issn":"01977385","usgsCitation":"Offield, 1984, U. S. GEOLOGICAL SURVEY MARINE-MINERALS RESEARCH., in Oceans Conference Record (IEEE), Washington, DC, USA.","startPage":"481","costCenters":[],"links":[{"id":220428,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb9e8e4b08c986b327eca","contributors":{"authors":[{"text":"Offield","contributorId":127918,"corporation":true,"usgs":false,"organization":"Offield","id":535138,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70013317,"text":"70013317 - 1984 - Uplift and submarine formation of some Melanesian porphyry copper deposits: Stable isotope evidence","interactions":[],"lastModifiedDate":"2023-12-10T21:59:19.772362","indexId":"70013317","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1427,"text":"Earth and Planetary Science Letters","active":true,"publicationSubtype":{"id":10}},"title":"Uplift and submarine formation of some Melanesian porphyry copper deposits: Stable isotope evidence","docAbstract":"Hydrogen and oxygen isotope analyses of sericites and kaolinites from four young porphyry copper deposits (Ok Tedi (1.2 Ma) and Yandera (6.5 Ma), Papua New Guinea; Koloula (1.5 Ma), Solomon Islands; and Waisoi (<5 Ma), Fiji) indicate that the fluids from which these minerals precipitated were of mixed magmatic and non-magmatic sources. The non-magmatic component of the fluid from the island arc deposits (Koloula, Waisoi) was ocean water.
For Ok Tedi, the non-magmatic component was a meteoric water with an isotopic composition different from that of the present meteoric water in the region. The isotopic signature of the former meteoric water is consistent with a surface elevation of 200 m a.s.l. or less at the time of mineralization. The deposit was later exposed and supergene kaolinitization commenced at approximately 1200 m a.s.l. Uplift and erosion has continued to the present at which time the elevation of the exposed deposit is 1800 m a.s.l. This rate of uplift is consistent with that known from other geological evidence. If the rate of uplift were approximately constant during the last 1.2 Ma, the age of supergene enrichment can be dated at approximately 0.4 Ma B.P.
Similarly, influx of meteoric water at Yandera occurred when the ground surface above the deposit was at an elevation of approximately 600 m a.s.l. The deposit's present elevation is 1600 m a.s.l. In this case a total uplift of approximately 2.2 km is indicated, with removal of 1.2 km of overburden by erosion.
","language":"English","publisher":"Elsevier","doi":"10.1016/0012-821X(84)90163-8","issn":"0012821X","usgsCitation":"Chivas, A., O’Neil, J.R., and Katchan, G., 1984, Uplift and submarine formation of some Melanesian porphyry copper deposits: Stable isotope evidence: Earth and Planetary Science Letters, v. 68, no. 2, p. 326-334, https://doi.org/10.1016/0012-821X(84)90163-8.","productDescription":"9 p.","startPage":"326","endPage":"334","numberOfPages":"9","costCenters":[],"links":[{"id":220476,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"68","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbd26e4b08c986b328ee9","contributors":{"authors":[{"text":"Chivas, A.R.","contributorId":16573,"corporation":false,"usgs":true,"family":"Chivas","given":"A.R.","affiliations":[],"preferred":false,"id":365805,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"O’Neil, J. R.","contributorId":69633,"corporation":false,"usgs":true,"family":"O’Neil","given":"J.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":365806,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Katchan, G.","contributorId":101009,"corporation":false,"usgs":true,"family":"Katchan","given":"G.","email":"","affiliations":[],"preferred":false,"id":365807,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70013527,"text":"70013527 - 1984 - Paleogeographic controls of coal accumulation, Cretaceous Blackhawk Formation and Star Point Sandstone, Wasatch Plateau, Utah","interactions":[],"lastModifiedDate":"2024-01-03T01:08:52.826988","indexId":"70013527","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1786,"text":"Geological Society of America Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"Paleogeographic controls of coal accumulation, Cretaceous Blackhawk Formation and Star Point Sandstone, Wasatch Plateau, Utah","docAbstract":"Analysis of sequences, associations, and relationships of facies in the Upper Cretaceous Blackhawk Formation and Star Point Sandstone in the Wasatch Plateau, Utah, leads to inferences regarding the paleogeographic controls affecting the accumulation of coals in delta–barrier-island complexes. Progradation, lateral shifting, and abandonment of these complexes created four major landward-thinning tongues of the upper sandstone bed of the Star Point Sandstone that extend into the lowermost Blackhawk Formation. Each tongue of the Star Point Sandstone trends northwest to southeast, subparallel to the general orientation of the Late Cretaceous paleoshoreline, and represents accretion-ridge, distributary-channel, and mouth-bar sandstones. The accretion-ridge or barrier-island sandstones grade landward into coastwise lagoonal and back-barrier swamp deposits, which, in turn, merge with bayhead deposits of short-headed streams. These deposits grade laterally into delta-plain deposits that consist of major distributary channels which crosscut the coastwise lagoons. Two coal populations were formed in this paleogeographic setting: delta-plain and back-barrier coals. Delta-plain coals formed as thin to thick, discontinuous bodies. Back-barrier coals are thicker and more laterally continuous. They parallel depositional strike and accumulated in swamps on surfaces of infilled lagoons. Here, the swamps were sites of accumulation of thick coals and were influenced by abandonment of associated deltaic barrier-island complexes. Successive offlap events resulted in accumulation of the Hiawatha coal, not as a single continuous bed, but as a series of discontinuous, related coal bodies.
No abstract available.
","language":"English","publisher":"American Chemical Society","doi":"10.1021/es00128a003","issn":"0013936X","usgsCitation":"Roy, W.R., Griffin, R.A., Dickerson, D.R., Schuller, R., and Martin, S., 1984, Illinois basin coal fly ashes. 1. Chemical characterization and solubility: Environmental Science & Technology, v. 18, no. 10, p. 734-739, https://doi.org/10.1021/es00128a003.","productDescription":"6 p.","startPage":"734","endPage":"739","costCenters":[],"links":[{"id":220377,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Illinois, Indiana, Kentucky, Missouri, Tennessee","otherGeospatial":"Illinois Basin","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -91.06012768821296,\n 41.166245344052385\n ],\n [\n -90.9440178593725,\n 41.121500116943594\n ],\n [\n -90.9440178593725,\n 40.89289489107543\n ],\n [\n -90.92778901209066,\n 40.72912010111139\n ],\n [\n -91.31187173110142,\n 40.48681483692641\n ],\n [\n -91.43629289359946,\n 40.270347713477605\n ],\n [\n -91.40924481479573,\n 39.87294278034287\n ],\n [\n -91.1387640267598,\n 39.652549533294945\n ],\n [\n -90.77091015503088,\n 39.347835170685215\n ],\n [\n -90.64648899253415,\n 39.062791086107296\n ],\n [\n -90.52747744579932,\n 38.929806618914085\n ],\n [\n -90.22453896319907,\n 38.51196980400155\n ],\n [\n -90.26781588928463,\n 38.39335092164919\n ],\n [\n -90.22453896319907,\n 38.19380256842274\n ],\n [\n -89.99192548548808,\n 37.9553270932186\n ],\n [\n -89.93782932788064,\n 37.81015933850318\n ],\n [\n -89.67275815560535,\n 37.43310405088404\n ],\n [\n -89.42932544637313,\n 37.29121578228303\n ],\n [\n -88.92082156486563,\n 37.14905941763121\n ],\n [\n -88.60165423498253,\n 36.991472046111994\n ],\n [\n -88.17970420564616,\n 36.562512121596555\n ],\n [\n -88.02282534858573,\n 36.506005910920805\n ],\n [\n -87.67660993989925,\n 36.40157833183379\n ],\n [\n -87.35744261001717,\n 36.41028599937843\n ],\n [\n -87.16810605839174,\n 36.31444800050697\n ],\n [\n -86.86645392231121,\n 36.32276783221242\n ],\n [\n -86.24434810982882,\n 36.505609255668446\n ],\n [\n -85.9305903957067,\n 36.42294859242482\n ],\n [\n -85.66010960767079,\n 36.50995737525332\n ],\n [\n -85.5951942185421,\n 36.65330823364356\n ],\n [\n -85.43290574572042,\n 36.96947073370481\n ],\n [\n -85.21652111529193,\n 37.124905258477284\n ],\n [\n -85.26520765713813,\n 37.447703537571925\n ],\n [\n -85.2543884256169,\n 37.550706285737064\n ],\n [\n -85.4058576669167,\n 37.824684952934774\n ],\n [\n -85.47618267180663,\n 38.01245759958013\n ],\n [\n -85.73584422832006,\n 38.36262724324672\n ],\n [\n -85.80616923320935,\n 38.899312152341736\n ],\n [\n -85.91436154842425,\n 39.40271720766714\n ],\n [\n -86.20107118374202,\n 39.87761089297936\n ],\n [\n -86.67170775492455,\n 40.30799876146148\n ],\n [\n -86.96923662176421,\n 40.555060270139904\n ],\n [\n -87.52764859646277,\n 40.790516486373576\n ],\n [\n -87.8089486160199,\n 41.10513126288646\n ],\n [\n -88.16598325622765,\n 41.34924584788982\n ],\n [\n -88.70153521653886,\n 41.572216501900044\n ],\n [\n -89.0856179355503,\n 41.7298582522088\n ],\n [\n -89.42642372847553,\n 41.85085855627486\n ],\n [\n -89.79427760020445,\n 41.782319759132605\n ],\n [\n -90.21622762954019,\n 41.59244853977762\n ],\n [\n -90.44343149149056,\n 41.483120238130454\n ],\n [\n -90.68145458496214,\n 41.466907736457955\n ],\n [\n -90.84374305778383,\n 41.45879996498567\n ],\n [\n -90.924887294195,\n 41.430414782099774\n ],\n [\n -90.97898345180181,\n 41.44258138094605\n ],\n [\n -91.05471807245168,\n 41.42635874235265\n ],\n [\n -91.0763565354948,\n 41.345184741170044\n ],\n [\n -91.13045269310226,\n 41.24764220036627\n ],\n [\n -91.06012768821296,\n 41.166245344052385\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"18","issue":"10","noUsgsAuthors":false,"publicationDate":"2002-05-01","publicationStatus":"PW","scienceBaseUri":"505a386ce4b0c8380cd61576","contributors":{"authors":[{"text":"Roy, William R.","contributorId":45454,"corporation":false,"usgs":true,"family":"Roy","given":"William","middleInitial":"R.","affiliations":[],"preferred":false,"id":366362,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Griffin, R. A.","contributorId":46211,"corporation":false,"usgs":true,"family":"Griffin","given":"R.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":366363,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dickerson, D. R.","contributorId":66837,"corporation":false,"usgs":true,"family":"Dickerson","given":"D.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":366364,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Schuller, R.M.","contributorId":11760,"corporation":false,"usgs":true,"family":"Schuller","given":"R.M.","email":"","affiliations":[],"preferred":false,"id":366360,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Martin, S.M.C.","contributorId":14110,"corporation":false,"usgs":true,"family":"Martin","given":"S.M.C.","email":"","affiliations":[],"preferred":false,"id":366361,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70013194,"text":"70013194 - 1984 - Changing patterns of Pennsylvanian coal-swamp vegetation and implications of climatic control on coal occurrence","interactions":[],"lastModifiedDate":"2024-02-24T01:31:04.407339","indexId":"70013194","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2033,"text":"International Journal of Coal Geology","active":true,"publicationSubtype":{"id":10}},"title":"Changing patterns of Pennsylvanian coal-swamp vegetation and implications of climatic control on coal occurrence","docAbstract":"Improved regional and interregional stratigraphic correlations of Pennsylvanian strata permit comparisons of vegetational changes in Euramerican coal swamps. The coal-swamp vegetation is known directly from in situ coal-ball peat deposits from more than 65 coals in the United States and Europe. Interpretations of coal-swamp floras on the basis of coal-ball peat studies are extended to broader regional and stratigraphic patterns by use of coal palynology. Objectives of the quantitative analyses of the vegetation in relation to coal are to determine the botanical constituents at the peat stage and their environmental implications for plant growth and peat accumulation. Morphological and paleoecological analyses provide a basis for deducing freshwater regimes of coal swamps.
Changes in composition of Pennsylvanian coal-swamp vegetation are quire similar from one paralic coal region to another and show synchrony that is attributable to climate. Paleobotany and paleogeography of the Euramerican province indicate a moist tropical paleoclimate. Rainfall, runoff and evapotranspiration were the variable climatic controls in the distribution of coal-swamp vegetation, peat accumulation and coal resources. In relative terms of climatic wetness the Pennsylvanian Period is divisible into five intervals, which include two relatively drier intervals that developed during the Lower-Middle and Middle-Upper Pennsylvanian transitions. The climate during Early Pennsylvanian time was moderately wet and the median in moisture availability. Early Middle Pennsylvanian was drier, probably seasonally dry-wet; late Middle Pennsylvanian was the wettest in the Midcontinent; early Late Pennsylvanian was the driest; and late Late Pennsylvanian was probably the wettest in the Dunkard Basin. The five climatic intervals represent a general means of dividing coal resources within each region into groups with similar botanical constituents and environments of peat accumulation. Regional differences in basinal geology and climate were significant variables, but the synchronous control of paleoclimate was of primary importance.
Although free oscillations of the Earth may be computed by many different methods, numerous practical considerations have led us to use a Rayleigh-Ritz formulation with piecewise cubic Hermite spline basis functions. By treating the resulting banded matrix equation as a generalized algebraic eigenvalue problem, we are able to achieve great accuracy and generality and a high degree of automation at a reasonable cost.
","language":"English","publisher":"Elsevier","doi":"10.1016/0021-9991(84)90141-4","issn":"00219991","usgsCitation":"Buland, R.P., and Gilbert, F., 1984, Computation of free oscillations of the earth: Journal of Computational Physics, v. 54, no. 1, p. 95-114, https://doi.org/10.1016/0021-9991(84)90141-4.","productDescription":"20 p.","startPage":"95","endPage":"114","numberOfPages":"20","costCenters":[],"links":[{"id":219441,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"54","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f94be4b0c8380cd4d552","contributors":{"authors":[{"text":"Buland, Raymond P.","contributorId":69294,"corporation":false,"usgs":true,"family":"Buland","given":"Raymond","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":358575,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gilbert, F.","contributorId":60767,"corporation":false,"usgs":true,"family":"Gilbert","given":"F.","affiliations":[],"preferred":false,"id":358574,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70010303,"text":"70010303 - 1984 - Inter-pulse high-resolution gamma-ray spectra using a 14 MeV pulsed neutron generator","interactions":[],"lastModifiedDate":"2013-03-06T19:15:24","indexId":"70010303","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2907,"text":"Nuclear Instruments and Methods In Physics Research","active":true,"publicationSubtype":{"id":10}},"title":"Inter-pulse high-resolution gamma-ray spectra using a 14 MeV pulsed neutron generator","docAbstract":"A neutron generator pulsed at 100 s-1 was suspended in an artificial borehole containing a 7.7 metric ton mixture of sand, aragonite, magnetite, sulfur, and salt. Two Ge(HP) gamma-ray detectors were used: one in a borehole sonde, and one at the outside wall of the sample tank opposite the neutron generator target. Gamma-ray spectra were collected by the outside detector during each of 10 discrete time windows during the 10 ms period following the onset of gamma-ray build-up after each neutron burst. The sample was measured first when dry and then when saturated with water. In the dry sample, gamma rays due to inelastic neutron scattering, neutron capture, and decay were counted during the first (150 ??s) time window. Subsequently only capture and decay gamma rays were observed. In the wet sample, only neutron capture and decay gamma rays were observed. Neutron capture gamma rays dominated the spectrum during the period from 150 to 400 ??s after the neutron burst in both samples, but decreased with time much more rapidly in the wet sample. A signal-to-noise-ratio (S/N) analysis indicates that optimum conditions for neutron capture analysis occurred in the 350-800 ??s window. A poor S/N in the first 100-150 ??s is due to a large background continuum during the first time interval. Time gating can be used to enhance gamma-ray spectra, depending on the nuclides in the target material and the reactions needed to produce them, and should improve the sensitivity of in situ well logging. ?? 1984.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Nuclear Instruments and Methods In Physics Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/0167-5087(84)90159-5","issn":"01675087","usgsCitation":"Evans, L., Trombka, J., Jensen, D., Stephenson, W., Hoover, R.A., Mikesell, J., Tanner, A., and Senftle, F.E., 1984, Inter-pulse high-resolution gamma-ray spectra using a 14 MeV pulsed neutron generator: Nuclear Instruments and Methods In Physics Research, v. 219, no. 1, p. 233-242, https://doi.org/10.1016/0167-5087(84)90159-5.","startPage":"233","endPage":"242","numberOfPages":"10","costCenters":[],"links":[{"id":219442,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":268838,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0167-5087(84)90159-5"}],"volume":"219","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3ca3e4b0c8380cd62ee0","contributors":{"authors":[{"text":"Evans, L.G.","contributorId":107426,"corporation":false,"usgs":true,"family":"Evans","given":"L.G.","email":"","affiliations":[],"preferred":false,"id":358583,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Trombka, J.I.","contributorId":8985,"corporation":false,"usgs":true,"family":"Trombka","given":"J.I.","email":"","affiliations":[],"preferred":false,"id":358576,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Jensen, D.H.","contributorId":46684,"corporation":false,"usgs":true,"family":"Jensen","given":"D.H.","email":"","affiliations":[],"preferred":false,"id":358579,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Stephenson, W.A.","contributorId":76462,"corporation":false,"usgs":true,"family":"Stephenson","given":"W.A.","email":"","affiliations":[],"preferred":false,"id":358582,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Hoover, R. A.","contributorId":50287,"corporation":false,"usgs":true,"family":"Hoover","given":"R.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":358581,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Mikesell, J.L.","contributorId":46113,"corporation":false,"usgs":true,"family":"Mikesell","given":"J.L.","email":"","affiliations":[],"preferred":false,"id":358578,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Tanner, A.B.","contributorId":44155,"corporation":false,"usgs":true,"family":"Tanner","given":"A.B.","email":"","affiliations":[],"preferred":false,"id":358577,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Senftle, F. E.","contributorId":47788,"corporation":false,"usgs":true,"family":"Senftle","given":"F.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":358580,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70009966,"text":"70009966 - 1984 - Heating rates in furnace atomic absorption using the L'vov platform","interactions":[],"lastModifiedDate":"2020-03-09T19:44:03","indexId":"70009966","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3464,"text":"Spectrochimica Acta Part B: Atomic Spectroscopy","active":true,"publicationSubtype":{"id":10}},"title":"Heating rates in furnace atomic absorption using the L'vov platform","docAbstract":"Heating rate profiles for the furnace tube wall, the furnace atmosphere, and a L'vov platform were established for a range of conditions in a cyclically heated graphite atomizer. The tube wall profile was made by direct observation with a recording optical pyrometer. The sodium line reversal method was used to establish the heating rate of the furnace atmosphere, and appearance temperatures for a series metals of differing volatility was used to establish platform profiles. The tube wall heating rate was nearly linear at 2240°C s− until the desired temperature was reached after which the temperature remained constant. The furnace atmosphere reached a given temperature 0.2–0.4 s later than the tube wall through most of the atomize cycle. The platform lagged the tube wall 0.5–0.8 s. Under typical operating conditions the furnace atmosphere was 100–200°C cooler than the tube wall and at nearly constant temperature when the analyte vaporized from the platform. The L'vov platform causes the cyclically heated commercial furnace to approximate the behavior of a constant temperature furnace during atomization.