A new photoclinometric technique for extraction of topographic data from single planetary images is presented that overcomes many previous limitations of photoclinometry. The procedure fully compensates for oblique viewing geometry prevalent in spacecraft images. Albedo variations have been one of the most serious obstacles in the application of photoclinometry to planetary surfaces. This problem is overcome in the topographic solution by simultaneously utilizing brightness data from a pair of profiles; both segments are assumed to have the same topographic and albedo variations along their lengths. Profile directions are chosen where the orientation of downslope or upslope is obvious, thus resolving a major ambiguity in photoclinometry. This requirement is particularly easy to satisfy for craters and not very difficult for many irregular features. An additional procedure is presented that eliminates even the requirement of topographic symmetry along the pair of profiles. If two profiles have the same relief but their shapes are very different, another method can be used in an iterative process to derive topographic profiles; however, this procedure does, require that the albedo not vary along the profiles. Test results indicate that both procedures have an accuracy and precision of approximately 2° for slopes of typical bowl-shaped craters, which translates to approximately 5% for depths.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB089iB11p09449","issn":"01480227","usgsCitation":"Davis, P.A., and Soderblom, L., 1984, Modeling crater topography and albedo from monoscopic Viking orbiter images: 1. Methodology: Journal of Geophysical Research Solid Earth, v. 89, no. B11, p. 9449-9457, https://doi.org/10.1029/JB089iB11p09449.","productDescription":"9 p.","startPage":"9449","endPage":"9457","numberOfPages":"9","costCenters":[],"links":[{"id":480212,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/jb089ib11p09449","text":"Publisher Index Page"},{"id":222041,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"89","issue":"B11","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505a5bebe4b0c8380cd6f8ce","contributors":{"authors":[{"text":"Davis, P. A.","contributorId":74021,"corporation":false,"usgs":true,"family":"Davis","given":"P.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":364636,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Soderblom, L.A. 0000-0002-0917-853X","orcid":"https://orcid.org/0000-0002-0917-853X","contributorId":6139,"corporation":false,"usgs":true,"family":"Soderblom","given":"L.A.","affiliations":[],"preferred":false,"id":364635,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70012873,"text":"70012873 - 1984 - A Model of Regional Ground-Water Flow in Secondary-Permeability Terrane","interactions":[],"lastModifiedDate":"2024-03-21T12:11:24.86057","indexId":"70012873","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3825,"text":"Groundwater","active":true,"publicationSubtype":{"id":10}},"title":"A Model of Regional Ground-Water Flow in Secondary-Permeability Terrane","docAbstract":"The ground-water flow system in the Lower Susquehanna River Basin in Pennsylvania and Maryland can be considered as one complex unconfined aquifer in which secondary porosity and permeability are the dominant influences on the occurrence and flow of ground water. The degree of development of secondary porosity and permeability in the various lithologies of the lower basin determines the aquifer characteristics of each lithology. Based on qualitative evidence, the use of a porous-media model was assumed to be appropriate on a regional scale and a finite-difference ground-water flow model was constructed for the lower basin.
The conceptual model of ground-water flow in the lower basin incorporates the major features of the flow system. Through the use of two layers, 21 hydrogeologic units, and five topographic settings, the conceptual model was systematically reduced to arrive at a simplified conceptual model. Further reduction produced a numerical model representation of the conceptual model, in which the essential features of the lower-basin flow system were quantified for input into the numerical model.
The model was calibrated under both steady-state and transient conditions, and was used to evaluate the water-supply potential of the 21 hydrogeologic units. The carbonate units have the greatest potential for ground-water development and the Triassic sedimentary and crystalline units have the least potential. A total ground-water yield potential of about 900 million gallons per day could be obtained from the lower basin with a consequent 50-percent reduction of base flow in streams.
Mesozoic structural domes are developed in an older Proterozoic crystalline basement of granitic to granodioritic foliate metaplutonic rocks in the Halloran Hills, southeastern California. Isotopic analyses of whole rocks and mineral separates from these rocks by U-Th-Pb, Rb-Sr, and Ar-Ar techniques yield a complex pattern of discordance that is the result of a fairly simple geologic history. Individual mineral isotopic systems have variably equilibrated with each other in response to Mesozoic regional metamorphism and locally to later heating during Mesozoic batholith emplacement.
Discordant U-Th-Pb zircon data indicate that the granitic core rocks are 1,710 Ma and that one dioritic phase may be slightly older. Rb-Sr whole-rock model dates scatter about 1,700 Ma Rb-Sr amphibole–whole-rock and U-Th-Pb amphibole dates are also Proterozoic. Potassium feldspars retain a 207Pb/206Pb signature of their Proterozoic age. Ar-Ar amphibole spectra from the flank of the main dome reveal disturbed dates of 1,450 Ma to 1,100 Ma, and the dates become younger toward the structurally deeper core of the dome.
All remaining isotopic determinations yield Mesozoic or younger dates for mineral–whole-rock systems. Rb-Sr whole-rock–apatite–feldspar–biotite analyses show nonequilibration of strontium isotopes, with resultant mineral pair dates from 4 foliate plutonic rocks ranging from 200 to 50 Ma. No single metamorphic age is indicated by the Rb-Sr data. Rb-Sr whole-rock–biotite dates are consistently younger than any other determinations and may be reduced by weathering or gain of nonradiogenic strontium from ground water.
U-Pb sphene and apatite analyses from rocks that yield 1,710-Ma zircon dates are nearly concordant at 140 Ma. An amphibole from the structurally deepest rocks of the main dome that yield 140- to 150-Ma U-Pb sphene dates has an Ar-Ar plateau date of 144 Ma. The U-Pb sphene and Ar-Ar amphibole analyses are believed to be the best age estimate for the end of the highest-temperature phase of regional metamorphism. Th-Pb sphene and apatite dates and Ar-Ar biotite dates cluster at 90 ± 5 Ma as a consequence of regional cooling during Late Cretaceous time following extensive Mesozoic plutonism in the region at 97 to 90 Ma.
We interpret the discordant mineral date patterns to have resulted from metamorphism of ∼1,700-Ma plutonic rocks during the Jurassic (≥ 140–50 Ma) and subsequent uplift and cooling to ∼200 °C at about 90 Ma. On the basis of this study, the isotope dating systems ranked in decreasing order of resistance to resetting are: U-Th-Pb zircon (concordia intercept) ≥ Rb-Sr whole rock ∼Rb-Sr amphibole ∼U-Th-Pb amphibole ∼Pb-Pb whole rock > Ar-Ar amphibole ≥ Rb-Sr sphene ≥ U-Pb sphene and apatite > Rb-Sr plagioclase-potassium feldspar-apatite > Th-Pb sphene and apatite ∼Ar-Ar biotite ∼U-Pb feldspars > Rb-Sr biotite.
A simple numerical model for estimating a phreatic surface in an earthen dam is presented. The numerical approach is based upon the Complex Variable Boundary Element Method (CVBEM). By expanding the CVBEM approximation geometric functions into a first order Taylor series, the unknown phreatic surface location geometrics can be approximated without iteration by solving a single matrix system. The developed technique provides for the numerical solution of the inverse problem of locating the phreatic surface coordinates. A comparison of results produced from this simple approach to results produced from a finite element analog and an iterative CVBEM analog for an example problem is presented.
","language":"English","publisher":"Elsevier","doi":"10.1016/0309-1708(84)90044-7","usgsCitation":"Hromadka, T., 1984, A simple model of a phreatic surface through an earth dam: Advances in Water Resources, v. 7, no. 3, p. 141-143, https://doi.org/10.1016/0309-1708(84)90044-7.","productDescription":"3 p.","startPage":"141","endPage":"143","numberOfPages":"3","costCenters":[],"links":[{"id":225807,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"7","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e590e4b0c8380cd46e24","contributors":{"authors":[{"text":"Hromadka, T. V. II","contributorId":76464,"corporation":false,"usgs":true,"family":"Hromadka","given":"T. V.","suffix":"II","affiliations":[],"preferred":false,"id":367234,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70013946,"text":"70013946 - 1984 - Chemical equilibration of the Earth's core and upper mantle","interactions":[],"lastModifiedDate":"2024-03-19T16:17:30.433759","indexId":"70013946","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":"Chemical equilibration of the Earth's core and upper mantle","docAbstract":"The oxygen fugacity (fO2) of the Earth's upper mantle appears to lie somewhat above that of the iron-wüstite buffer, its fO2 is assumed to have been similar to the present value at the time of core formation. In the upper mantle, the Fe-rich liquid protocore that would form under such conditions of fO2 at elevated temperatures would lie predominantly in the system Fe-S-O. Distribution coefficients for Co, Cu, Ni, Ir, Au, Ir, W, Re, Mo, Ag and Ga between such liquids and basalt are known and minimum values are known for Ge. From these coefficients, upper mantle abundances for the above elements can be calculated by assuming cosmic abundances for the whole Earth and equilibrium between the Fe-S-O protocore and upper mantle. These calculated abundances are surprisingly close to presently known upper mantle abundances; agreements are within a factor of 5, except for Cu, W, and Mo. Therefore, siderophile element abundances in the upper mantle based on known distribution coefficients do not demand a late-stage meteoritic bombardment, and a protocore formed from the upper mantle containing S and O seems likely.
As upper mantle abundances fit a local equilibrium model, then either the upper mantle has not been mixed with the rest of the mantle since core formation, or else partition coefficients between protocore and mantle were similar for the whole mantle regardless of
No abstract available.
","language":"English","publisher":"American Chemical Society","doi":"10.1021/es00121a011","issn":"0013936X","usgsCitation":"Helz, G., Sugam, R., and Sigleo, A., 1984, Chemical modifications of estuarine water by a power plant using continuous chlorination: Environmental Science & Technology, v. 18, no. 3, p. 192-199, https://doi.org/10.1021/es00121a011.","productDescription":"8 p.","startPage":"192","endPage":"199","costCenters":[],"links":[{"id":225675,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Maryland","otherGeospatial":"Chalk Point, Patuxent River Estuary","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -76.6894216239552,\n 38.54009215508728\n ],\n [\n -76.68876775337405,\n 38.54064195044876\n ],\n [\n -76.68765617338566,\n 38.541319599414265\n ],\n [\n -76.68750905250512,\n 38.54156252862094\n ],\n [\n -76.68647920633981,\n 38.54124288475791\n ],\n [\n -76.68603784369716,\n 38.54137074247362\n ],\n [\n -76.68546570693861,\n 38.54253423724242\n ],\n [\n -76.68409257871835,\n 38.54507851735954\n ],\n [\n -76.68628304516541,\n 38.54565384460639\n ],\n [\n -76.68695326251115,\n 38.54569219959231\n ],\n [\n -76.68844081808322,\n 38.545896759173075\n ],\n [\n -76.68907834190026,\n 38.54605017847658\n ],\n [\n -76.68930719660338,\n 38.54606296340344\n ],\n [\n -76.69386794390728,\n 38.54681727008369\n ],\n [\n -76.69419487919812,\n 38.54649764957517\n ],\n [\n -76.6913178486407,\n 38.54441368903153\n ],\n [\n -76.69043512335593,\n 38.54367214249143\n ],\n [\n -76.68968317218757,\n 38.54308401393581\n ],\n [\n -76.68966682542295,\n 38.54165202864817\n ],\n [\n -76.68973221248142,\n 38.54065473633787\n ],\n [\n -76.68958509160035,\n 38.539977081108304\n ],\n [\n -76.6894216239552,\n 38.54009215508728\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"18","issue":"3","noUsgsAuthors":false,"publicationDate":"2002-05-01","publicationStatus":"PW","scienceBaseUri":"5059f580e4b0c8380cd4c279","contributors":{"authors":[{"text":"Helz, G.R.","contributorId":96823,"corporation":false,"usgs":true,"family":"Helz","given":"G.R.","email":"","affiliations":[],"preferred":false,"id":367214,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sugam, R.","contributorId":107864,"corporation":false,"usgs":true,"family":"Sugam","given":"R.","email":"","affiliations":[],"preferred":false,"id":367215,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sigleo, A.C.","contributorId":20899,"corporation":false,"usgs":true,"family":"Sigleo","given":"A.C.","email":"","affiliations":[],"preferred":false,"id":367213,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70013939,"text":"70013939 - 1984 - Geochemistry of tholeiitic and alkalic lavas from the Koolau Range, Oahu, Hawaii: Implications for Hawaiian volcanism","interactions":[],"lastModifiedDate":"2020-10-01T18:41:29.620455","indexId":"70013939","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":"Geochemistry of tholeiitic and alkalic lavas from the Koolau Range, Oahu, Hawaii: Implications for Hawaiian volcanism","docAbstract":"Lavas of the post-erosional, alkalic Honolulu Volcanics have significantly lower 87Sr/86Sr and higher 143Nd/144Nd than the older and underlying Koolau tholeiites which form the Koolau shield of eastern Oahu, Hawaii. Despite significant compositional variation within lavas forming the Honolulu Volcanics, these lavas are isotopically (Sr, Nd, Pb) very similar which contrasts with the isotopic heterogeneity of the Koolau tholeiites. Among Hawaiian tholeiitic suites, the Koolau lavas are geochemically distinct because of their lower iron contents and Sr and Nd isotopic ratios which range to bulk earth values. These geochemical data preclude simple models such as derivation of the Honolulu Volcanics and Koolau tholeiites from a common source by different degrees of melting or by mixing of two geochemically distinct sources. There may be no genetic relationship between the origin and evolution of these two lava suites; however, the trend shown by Koolau Range lavas of increasing 143Nd/144Nd and decreasing 87Sr/86Sr with decreasing eruption age and increasing alkalinity also occurs at Haleakala, East Molokai and Kauai volcanoes. A complex mixing model proposed for Haleakala lavas can account for the variations in Sr and Nd isotopic ratios and incompatible element abundances found in lavas from the Koolau Range. This model may reflect mixing and melting processes occurring during ascent of relatively enriched mantle through relatively depleted MORB-related lithosphere. Although two isotopically distinct components may be sufficient to explain Sr and Nd isotopic variations at individual Hawaiian volcanoes, more than two isotopically distinct materials are required to explain variations of Sr, Nd and Pb isotopic ratios in all Hawaiian lavas.
The Gossan Lead district is a 28-km-long, northeast-trending belt of discontinuous massive sulfide deposits in the Blue Ridge province of southwestern Virginia. The deposits, hosted by the Ashe Formation of late Proterozoic age, consist of strata-bound lenses and layers of massive pyrrhotite, minor chalcopyrite, sphalerite, and pyrite, and rare arsenopyrite and galena. Deposits were mined principally in the Iron Ridge and Betty Baker segments, respectively, at the southwestern and northeastern ends of the belt. Detailed mapping of the Gossan Howard, Huey, and Bumbarger pits in the Iron Ridge segment indicates that the deposits occur at one horizon and have been variously folded and brecciated after sulfide deposition. The Gossan Howard consists of a single, gently dipping lens of sulfide. The Huey deposit is complexly folded and locally contains tectonically thickened ore. The Bumbarger deposit is a lens as much as 40 m thick--the thickest known in the district. This deposit contains abundant coarse breccia fragments of wall rock around which the massive sulfide has flowed (during deformation and metamorphism), probably thickening the original deposit significantly. In the northeastern part of the district, drill holes intersect several sulfide layers that possibly are structurally repeated.The Ashe Formation in the district is a sequence of metasedimentary rocks and local conformable lenses of amphibolite and actinolite-chlorite schist. The metasedimentary rocks include metapelite, quartz-feldspar granofels (metagraywacke), and minor quartzite and carbonaceous schist, and are interpreted as marine turbidites. The amphibolites and other mafic rocks have chemical compositions similar to low Ti tholeiitic basalt, with a high Y/Nb (>10) and high average contents of Co (40 ppm), Cr (403 ppm), Ni (211 ppm), and V (247 ppm). Immobile trace element signatures (Ti-Y-Zr; Th-Hf-Ta; Ti-Cr) suggest a magmatic affinity with midocean ridge basalt (MORB); rare earth elements (REE) have low abundance levels (10X-15X chondrite), broadly flat patterns [(La/Yb) N = 0.7-1.1], and a slight depletion in the light elements similar to midocean ridge basalts. An amphibolite from a much higher stratigraphic level, south of the district, differs significantly from the mafic rocks closer to the sulfide zone in having the chemical signature of a transitional, slightly alkalic tholeiite with high TiO 2 (3.87 wt %), Fe 2 O 3 (16.4 wt %), and P 2 O 5 (0.56 wt %), low Y/Nb (3.3), and a highly fractionated rare earth element distribution [(La/Yb) N = 3.9] similar to continental basalt.Some silicate wall rocks of the deposits are mineralogically and chemically unusual, and differ substantially from the clastic metasediments of the Ashe Formation. Such rocks are composed mainly or wholly of plagioclase feldspar, biotite, chlorite, muscovite, or spessartine-rich garnet. The unusual lithologies form local strata-bound lenses in the footwall and/or hanging wall of the deposits, typically within 10 m of massive sulfide. The plagioclase rocks (3.4-7.6 wt % Na 2 O) consist largely of granoblastic albite-oligoclase (Ab (sub 78-90) ) with minor quartz and biotite; rare earth elements are highly fractionated [(La/Yb) N = 6.8-7.1] and their patterns resemble those of the quartz-feldspar granofels (metagraywacke) from the district.The biotite schists, locally monomineralic, have FeO/(FeO + MgO) = 0.5 and contain high phosphorus (1 wt % P 2 O 5 ) and fluorine (0.5 wt % F), present in fluorapatite. The chlorite schist is essentially all ripidolite; rare earth elements are highly fractionated, and have a large negative Eu anomaly. The spessartine-rich rocks (6.3-8.9 wt % MnO) are in places interlayered with the other unusual wall rocks and consist of abundant Mn-rich garnet (Sp 50 Al 23 Gr 19 Py 8 ) and minor quartz, plagioclase, pyrrhotite, and biotite. The distinctive mineralogy and chemistry of these rocks suggest that they represent metamorphosed alteration zones and/or intermixed chemical and clastic sediments.The sulfide deposits are interpreted as syngenetic in origin but modified in form by deformation which accompanied metamorphism. The great length of the mineralized district parallel to the regional strike and the flyschoid (turbidite) nature of the host rocks suggest that sedimentation and initial sulfide deposition took place in a deep, elongate marine basin or graben overlying a crustal rift zone. A rift underlying the sedimentary pile is consistent with the occurrence of mafic metavolcanic rocks of midocean ridge basalt affinity and could also have served as the feeder system for a line of hydrothermal vents on the sea floor that generated the sulfide deposits.
","language":"English","publisher":"Society of Economic Geologists","doi":"10.2113/gsecongeo.79.7.1483","issn":"03610128","usgsCitation":"Gair, J., and Slack, J.F., 1984, Deformation, geochemistry, and origin of massive sulfide deposits, Gossan lead district, Virginia: Economic Geology, v. 79, no. 7, p. 1483-1520, https://doi.org/10.2113/gsecongeo.79.7.1483.","productDescription":"38 p.","startPage":"1483","endPage":"1520","numberOfPages":"38","costCenters":[],"links":[{"id":219973,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"79","issue":"7","noUsgsAuthors":false,"publicationDate":"1984-11-01","publicationStatus":"PW","scienceBaseUri":"5059fe4de4b0c8380cd4ec63","contributors":{"authors":[{"text":"Gair, J. E.","contributorId":50891,"corporation":false,"usgs":true,"family":"Gair","given":"J. E.","affiliations":[],"preferred":false,"id":365846,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Slack, J. F.","contributorId":75917,"corporation":false,"usgs":true,"family":"Slack","given":"J.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":365847,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013274,"text":"70013274 - 1984 - Mineralogy and chemistry of massive sulfide deposits from the Juan de Fuca Ridge","interactions":[],"lastModifiedDate":"2024-01-03T01:16:04.658224","indexId":"70013274","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":"Mineralogy and chemistry of massive sulfide deposits from the Juan de Fuca Ridge","docAbstract":"Six hydrothermal vent sites and associated benthic communities were located in the axial valley of the southern Juan de Fuca Ridge using transponder-navigated bottom photography. The hydrothermal deposits form ledges and shallow mounds within a central zone characterized by a linear bathymetric depression and numerous collapse features. The flat valley floor adjacent to the central zone consists of ferrobasalt lobate flows and sheet flows; sediment cover is minimal. Vent sites are characterized by concentrations of tube worms, clams, benthic siphonophores, and several unidentified fauna.
Two types of massive sulfide were dredged from one of the vent sites. Type A samples are angular slabs of dark gray Zn-rich sulfide with interlayers and a thin, partly oxidized crust of Fe sulfide. These layered sulfide aggregates appear to be fragments of a sulfide wall enclosing an active hydrothermal vent. The outer sulfide wall is composed mainly of colloform Fe sulfide and Fe-poor sphalerite deposited under lower-temperature conditions whereby sea water and hydrothermal fluid mix above the discharge point. With continued sulfide deposition, the wall inhibits mixing of sea water and hydrothermal fluid. Inside the wall, the intensifying hydrothermal system deposits a higher-temperature assemblage of granular Fe-rich sphalerite, wurtzite, pyrite, and minor Cu-Fe sulfide. The zonation in wurtzite from Fe-rich cores to Fe-poor rims may result from a late-stage cooling of the hydrothermal fluid and(or) a change in fluid chemistry. The sulfide wall grows outward where a rupture in it permits the escape of high-temperature fluid and then deposition of a secondary shell over the breakthrough point. As temperature increases, earlier-formed minerals dissolve, and Zn, Fe, and Pb migrate toward the outer sulfide wall. Tube worms flourished in the outer wall of type A samples, and abandoned tube structures served as conduits for the late-stage hydrothermal fluids.
Type B sulfide samples are subrounded, spongy-textured fragments composed almost entirely of dendritic aggregates of pale, Fe-poor colloform sphalerite and opaline silica. This type of sulfide is deposited in open space by moderate- to low-temperature fluid discharging at a slow but variable rate; the fluid becomes increasingly oxidizing, resulting in late-stage deposition of hematite, barite, and sulfur. Type B samples show little evidence of burrowing animals; this type of sulfide may be deposited in settings peripheral to sites of focused discharge.
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":70013929,"text":"70013929 - 1984 - Hydrothermal minerology of research drill hole Y-3, Yellowstone National Park, Wyoming","interactions":[],"lastModifiedDate":"2020-09-02T14:53:05.613161","indexId":"70013929","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Hydrothermal minerology of research drill hole Y-3, Yellowstone National Park, Wyoming","docAbstract":"The approximate paragenetic sequence of hydrothermal minerals in the Y-3 U. S. Geological Survey research diamond-drill hole in Lower Geyser Basin, Yellowstone National Park, Wyoming, is: hydrothermal chalcedony, hematite, pyrite, quartz, clay minerals (smectite and mixed-layer illite-smectite), calcite, chlorite, fluorite, pyrite, quartz, zeolite minerals (analcime, dachiardite, laumontite, stilbite, and yugawaralite), and clay minerals (smectite and mixed-layer illite-smectite). A few hydrothermal minerals that were identified in drill core Y-3 (lepidolite, aegirine, pectolite, and truscottite) are rarely found in modern geothermal areas. The alteration minerals occur primarily as vug and fracture fillings that were deposited from cooling thermal water. Refs.","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Transactions - Geothermal Resources Council","largerWorkSubtype":{"id":12,"text":"Conference publication"},"conferenceTitle":"Geothermal Energy: Bet on It! Geothermal Resources Council 1984 Annual Meeting","conferenceLocation":"Reno, NV, USA","language":"English","publisher":"Geothermal Resources Council","publisherLocation":"Davis, CA, USA","usgsCitation":"Bargar, K.E., and Beeson, M.H., 1984, Hydrothermal minerology of research drill hole Y-3, Yellowstone National Park, Wyoming, in Transactions - Geothermal Resources Council, v. 8, Reno, NV, USA, p. 111-117.","productDescription":"7 p.","startPage":"111","endPage":"117","numberOfPages":"7","costCenters":[],"links":[{"id":225414,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Wyoming","otherGeospatial":"Yellowstone National Park","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -111.016845703125,\n 43.84245116699039\n ],\n [\n -109.302978515625,\n 43.84245116699039\n ],\n [\n -109.302978515625,\n 44.972570682240644\n ],\n [\n -111.016845703125,\n 44.972570682240644\n ],\n [\n -111.016845703125,\n 43.84245116699039\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2e8ee4b0c8380cd5c662","contributors":{"authors":[{"text":"Bargar, Keith E.","contributorId":9643,"corporation":false,"usgs":true,"family":"Bargar","given":"Keith","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":367185,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Beeson, Melvin H. mbeeson@usgs.gov","contributorId":5017,"corporation":false,"usgs":true,"family":"Beeson","given":"Melvin","email":"mbeeson@usgs.gov","middleInitial":"H.","affiliations":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"preferred":true,"id":367184,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013921,"text":"70013921 - 1984 - Laboratory studies of volcanic jets","interactions":[],"lastModifiedDate":"2024-06-27T16:07:41.067511","indexId":"70013921","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":6453,"text":"Journal of Geophysical Research Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Laboratory studies of volcanic jets","docAbstract":"The study of the fluid dynamics of violent volcanic eruptions by laboratory experiment is described, and the important fluid-dynamic processes that can be examined in laboratory models are discussed in detail. In preliminary experiments, pure gases are erupted from small reservoirs. The gases used are Freon 12 and Freon 22, two gases of high molecular weight and high density that are good analogs of heavy and particulate-laden volcanic gases; nitrogen, a moderate molecular weight, moderate density gas for which the thermodynamic properties are well known; and helium, a low molecular weight, lowdensity gas that is used as a basis for comparison with the behavior of the heavier gases and as an analog of steam, the gas that dominates many volcanic eruptions. Transient jets erupt from the reservoir into the laboratory upon rupture of a thin diaphragm at the exit of a convergent nozzle. The gas accelerates from rest in the reservoir to high velocity in the jet. Reservoir pressures and geometries are such that the fluid velocity in the jets is initially supersonic and later decays to subsonic. The measured reservoir pressure decreases as the fluid expands through repetitively reflecting rarefaction waves, but for the conditions of these experiments, a simple steady-discharge model is sufficient to explain the pressure decay and to predict the duration of the flow. Density variations in the flow field have been visualized with schlieren and shadowgraph photography. The observed structure of the jet is correlated with the measured pressure history. The starting vortex generated when the diaphragm ruptures becomes the head of the jet. Though the exit velocity is sonic, the flow head in the helium jet decelerates to about one-third of sonic velocity in the first few nozzle diameters, the nitrogen head decelerates to about three-fourths of sonic velocity, while Freon maintains nearly sonic velocity. The impulsive acceleration of reservoir fluid into the surrounding atmosphere produces a compression wave. The strength of this wave depends primarily on the sound speed of the fluid in the reservoir but also, secondarily with opposite effect, on the density: helium produces a relatively strong atmospheric shock while the Freons do not produce any optically observable wave front. Well-formed N waves are detected with a microphone far from the reservoir. Barrel shocks, Mach disks, and other familiar features of steady underexpanded supersonic jets form inside the jet almost immediately after passage of the flow head. These features are maintained until the pressure in the reservoir decays to sonic conditions. At low pressures the jets are relatively structureless. Gas-particle jets from volcanic eruptions may behave as pseudogases if particle concentrations and mass and momentum exchange between the components are sufficiently small. The sound speed of volcanic pseudogases can be as large as 1000 m s−1 or as small as a few tens of meters per second depending on the mass loading and initial temperature. Fluids of high sound speed produce stronger atmospheric shock waves than do those of low sound speed. Therefore eruption of a hot gas lightly laden with particulates should produce a stronger shock than eruption of a cooler or heavily laden fluid. An empirical expression suggests that the initial velocity of the head of supersonic volcanic jets is controlled by the sound speed and the ratio of the density of the erupting fluid to that of the atmosphere. The duration of gas or pseudogas eruptions is controlled by the sound speed of the fluid and the ratio of reservoir volume to vent area.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB089iB10p08253","issn":"01480227","usgsCitation":"Kieffer, S.W., and Sturtevant, B., 1984, Laboratory studies of volcanic jets: Journal of Geophysical Research Solid Earth, v. 89, no. B10, p. 8253-8268, https://doi.org/10.1029/JB089iB10p08253.","productDescription":"16 p.","startPage":"8253","endPage":"8268","numberOfPages":"16","costCenters":[],"links":[{"id":480209,"rank":2,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://resolver.caltech.edu/CaltechAUTHORS:20141029-163731844","text":"External Repository"},{"id":225286,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"89","issue":"B10","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505a4118e4b0c8380cd652b9","contributors":{"authors":[{"text":"Kieffer, S. W.","contributorId":19186,"corporation":false,"usgs":true,"family":"Kieffer","given":"S.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":367168,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sturtevant, B.","contributorId":48318,"corporation":false,"usgs":true,"family":"Sturtevant","given":"B.","email":"","affiliations":[],"preferred":false,"id":367169,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013919,"text":"70013919 - 1984 - Spilled oil and infaunal activity - Modification of burrowing behavior and redistribution of oil","interactions":[],"lastModifiedDate":"2012-03-12T17:19:29","indexId":"70013919","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2664,"text":"Marine Environmental Research","active":true,"publicationSubtype":{"id":10}},"title":"Spilled oil and infaunal activity - Modification of burrowing behavior and redistribution of oil","docAbstract":"A series of experiments in Willapa Bay, Washington, indicates the degree to which the presence of spilled oil modifies the burrowing behavior of infauna and the extent to which the animals redistribute oil into intertidal sediment. Small amounts of North Slope crude oil introduced at low tide directly into burrow openings (mostly made by the crustacean Callianassa) resulted in a limited and temporary reduction in the number of burrow openings. In contrast, a layer of oil-saturated sand 1 cm thick buried about 5 cm below the sediment surface sharply reduced the number of burrow openings. After a year, the few new burrows penetrated only the margins of the experimental plot, and bioturbation below the buried oil-saturated sand layer declined dramatically. The experiments suggest that small amounts of oil temporarily stranded by tides in themselves have no long-range effect on burrowing behavior. The fauna, however, are capable of introducing measurable amounts of oil into the subsurface, where it is retained long after the rest of the stranded oil had washed away. A buried layer of oil-saturated sand greatly reduces infaunal activity; the oil presents an effective barrier that can persist for years. The oil incorporated into the sediment from burrow openings showed evidence of degradation after 7 months. In contrast the layer of buried oil remained essentially undergraded after a period of two years, even though oil in lower concentrations above the layer was degraded after a period of one year. This variation in degree of degradation of the buried oil, as well as the heterogeneity of oil distribution wherever the oil has been incorporated from the surface, emphasises the importance of careful sampling in any attempt to locate or monitor the presence of spilled oil in the substrate.In a series of experiments in Willapa Bay, Washington, small amounts of North Slope crude oil introduced at low tide directly into burrow openings resulted in a limited and temporary reduction in the number of burrow openings. In contrast, a layer of oil-saturated sand 1 cm thick buried about 5 cm below the sediment surface sharply reduced the number of burrow openings. After a year, the few new burrows penetrated only the margins of the experimental plot, and bioturbation below the buried oil-saturated sand layer declined dramatically. The experiments suggest that small amounts of oil temporarily stranded by tides in themselves have no long-range effect on burrowing behavior. The oil incorporated into the sediment from burrow openings showed evidence of degradation after 17 months. In contrast, the layer of buried oil remained essentially undegraded after a period of two years. Refs.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine Environmental Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/0141-1136(84)90026-6","issn":"01411136","usgsCitation":"Clifton, H., Kvenvolden, K., and Rapp, J.B., 1984, Spilled oil and infaunal activity - Modification of burrowing behavior and redistribution of oil: Marine Environmental Research, v. 11, no. 2, p. 111-136, https://doi.org/10.1016/0141-1136(84)90026-6.","startPage":"111","endPage":"136","numberOfPages":"26","costCenters":[],"links":[{"id":205616,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0141-1136(84)90026-6"},{"id":225284,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"11","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b95c4e4b08c986b31b0f1","contributors":{"authors":[{"text":"Clifton, H.E.","contributorId":44151,"corporation":false,"usgs":true,"family":"Clifton","given":"H.E.","affiliations":[],"preferred":false,"id":367164,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kvenvolden, K.A.","contributorId":80674,"corporation":false,"usgs":true,"family":"Kvenvolden","given":"K.A.","email":"","affiliations":[],"preferred":false,"id":367165,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rapp, J. B.","contributorId":28987,"corporation":false,"usgs":true,"family":"Rapp","given":"J.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":367163,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70013255,"text":"70013255 - 1984 - Ferromanganese nodules from MANOP Sites H, S, and R-Control of mineralogical and chemical composition by multiple accretionary processes","interactions":[],"lastModifiedDate":"2024-03-19T16:16:08.308122","indexId":"70013255","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":"Ferromanganese nodules from MANOP Sites H, S, and R-Control of mineralogical and chemical composition by multiple accretionary processes","docAbstract":"The chemical composition of ferromanganese nodules from the three nodule-bearing MANOP sites in the Pacific can be accounted for in a qualitative way by variable contributions of distinct accretionary processes. These accretionary modes are:
(1) hydrogenous, i.e., direct precipitation or accumulation of colloidal metal oxides in seawater,
(2) oxic diagenesis which refers to a variety of ferromanganese accretion processes occurring in oxic sediments; and
(3) suboxic diagenesis which results from reduction of Mn+4 by oxidation of organic matter in the sediments. Geochemical evidence suggests processes (1) and (2) occur at all three MANOP nodule-bearing sites, and process (3) occurs only at the hemipelagic site, H, which underlies the relatively productive waters of the eastern tropical Pacific.
A normative model quantitatively accounts for the variability observed in nearly all elements. Zn and Na, however, are not well explained by the three end-member model, and we suggest that an additional accretionary process results in greater variability in the abundances of these elements. Variable contributions from the three accretionary processes result in distinct top-bottom compositional differences at the three sites. Nodule tops from H are enriched in Ni, Cu, and Zn, instead of the more typical enrichments of these elements in nodule bottoms. In addition, elemental correlations typical of most pelagic nodules are reversed at site H.
The three accretionary processes result in distinct mineralogies. Hydrogenous precipitation produces δMnO2. Oxic diagenesis, however, produces Cu-Ni-rich todorokite, and suboxic diagenesis results in an unstable todorokite which transforms to a 7 Å phase (“birnessite”) upon dehydration. The presence of Cu and Ni as charge-balancing cations influence the stability of the todorokite structure. In the bottoms of H nodules, which accrete dominantly by suboxic diagenesis, Na+ and possibly Mn+2 provide much of the charge balance for the todorokite structure.
Limited growth rate data for H nodules suggest suboxic accretion is the fastest of the three processes, with rates at least 200 mm/106 yr. Oxic accretion is probably 10 times slower and hydrogenous 100 times slower. Since these rates predict more suboxic component in bulk nodules than is calculated by the normative analysis, we propose that suboxic accretion is a non-steady-state process. Variations in surface water productivity cause pulses of particulate flux to the sea floor which result in transient Mn reduction in the surface sediments and reprecipitation on nodule surfaces.
","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7037(84)90186-8","issn":"00167037","usgsCitation":"Dymond, J., Lyle, M., Finney, B., Piper, D., Murphy, K., Conard, R., and Pisias, N., 1984, Ferromanganese nodules from MANOP Sites H, S, and R-Control of mineralogical and chemical composition by multiple accretionary processes: Geochimica et Cosmochimica Acta, v. 48, no. 5, p. 931-949, https://doi.org/10.1016/0016-7037(84)90186-8.","productDescription":"19 p.","startPage":"931","endPage":"949","numberOfPages":"19","costCenters":[],"links":[{"id":220526,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"48","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0f87e4b0c8380cd53937","contributors":{"authors":[{"text":"Dymond, J.","contributorId":98461,"corporation":false,"usgs":true,"family":"Dymond","given":"J.","email":"","affiliations":[],"preferred":false,"id":365653,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lyle, M.","contributorId":40344,"corporation":false,"usgs":true,"family":"Lyle","given":"M.","email":"","affiliations":[],"preferred":false,"id":365649,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Finney, B.","contributorId":72125,"corporation":false,"usgs":true,"family":"Finney","given":"B.","affiliations":[],"preferred":false,"id":365651,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Piper, D.Z.","contributorId":34154,"corporation":false,"usgs":false,"family":"Piper","given":"D.Z.","email":"","affiliations":[],"preferred":false,"id":365648,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Murphy, K.","contributorId":89865,"corporation":false,"usgs":false,"family":"Murphy","given":"K.","email":"","affiliations":[],"preferred":false,"id":365652,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Conard, R.","contributorId":63531,"corporation":false,"usgs":true,"family":"Conard","given":"R.","email":"","affiliations":[],"preferred":false,"id":365650,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Pisias, N.","contributorId":25290,"corporation":false,"usgs":true,"family":"Pisias","given":"N.","affiliations":[],"preferred":false,"id":365647,"contributorType":{"id":1,"text":"Authors"},"rank":7}]}} ,{"id":70013916,"text":"70013916 - 1984 - The Piedmont landscape of Maryland: a new look at an old problem.","interactions":[],"lastModifiedDate":"2013-03-13T15:42:00","indexId":"70013916","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1425,"text":"Earth Surface Processes and Landforms","active":true,"publicationSubtype":{"id":10}},"title":"The Piedmont landscape of Maryland: a new look at an old problem.","docAbstract":"Both equilibrium and episodic erosion features can be recognized in the modern landscape. An equilibrium condition is suggested by adjustment of first and second order streams to rock structure and lithology, entrenchment of some streams against gneiss domes, altitudinal zonation of rock types around gneiss domes, correlation of lithology with overburden thickness on uplands, etc. The long-term episodic character of erosion is suggested by clastic wedges on the adjacent Coastal Plain, an upland of low relief that truncates non-carbonate rocks of different lithologies, isovolumetric chemical weathering of alumino-silicate rocks, clastic deposition in marble valleys, and weathering profile truncation by modern drainage. The upland surface preserved in the eastern Piedmont developed by the Late Cretaceous. In the interval from the Late Cretaceous to the Late Miocene, low input of terrigenous sediments to the Coastal Plain, dominance of marine sedimentation, and spotty evidence of saprolite formation on crystalline rocks, suggest that the Maryland Piedmont was an area of low relief undergoing intense weathering. Incised valleys were formed during a cycle of erosion probably initiated in the Late Miocene and extensive colluvial sediments were deposited on hillslopes by periglacial processes during the Pleistocene.-after Authors","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Earth Surface Processes and Landforms","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Wiley","doi":"10.1002/esp.3290090107","usgsCitation":"Costa, J.E., and Cleaves, E., 1984, The Piedmont landscape of Maryland: a new look at an old problem.: Earth Surface Processes and Landforms, v. 9, no. 1, p. 59-74, https://doi.org/10.1002/esp.3290090107.","startPage":"59","endPage":"74","numberOfPages":"16","costCenters":[],"links":[{"id":226256,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":269257,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/esp.3290090107"}],"volume":"9","issue":"1","noUsgsAuthors":false,"publicationDate":"2006-07-18","publicationStatus":"PW","scienceBaseUri":"505ba883e4b08c986b321c9f","contributors":{"authors":[{"text":"Costa, J. E.","contributorId":28977,"corporation":false,"usgs":true,"family":"Costa","given":"J.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":367157,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Cleaves, E.T.","contributorId":41148,"corporation":false,"usgs":true,"family":"Cleaves","given":"E.T.","email":"","affiliations":[],"preferred":false,"id":367158,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013143,"text":"70013143 - 1984 - Uranium mineralization in response to regional metamorphism at Lilljuthatten, Sweden","interactions":[],"lastModifiedDate":"2024-01-08T23:59:30.282543","indexId":"70013143","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1472,"text":"Economic Geology","active":true,"publicationSubtype":{"id":10}},"title":"Uranium mineralization in response to regional metamorphism at Lilljuthatten, Sweden","docAbstract":"Analyses of six mineralized and five nonmineralized whole-rock drill core samples from the uranium deposit at Lilljuthatten yield a lead-lead isochron age of 420 + or - 1 m.y. This age corresponds to the last stage of the Caledonian Orogeny. None of the isotopic systems examined have completely retained the intrusive age of the Olden Granite, but data for several systems suggest an age of approximately 1,650 m.y. Indications that Caledonian hydrothermal activity strongly affected most of the Olden Granite. A model for the genesis of the ore deposit is proposed as follows: (1) derivation of a highly evolved granite by partial melting of crustal materials about 1,650 m.y. ago; (2) pervasive hydrothermal alteration and fracturing of the granite in response to the Caledonian Orogeny approximately 420 m.y. ago; (3) mobilization of uranium and lead in response to circulation of heated fluids; (4) precipitation of these elements in open fractures; and (5) recent modification of the Caledonian uranium distribution as a result of exposure to near-surface conditions.
","language":"English","publisher":"Society of Economic Geologists","doi":"10.2113/gsecongeo.79.3.509","issn":"03610128","usgsCitation":"Stuckless, J., and Troeng, B., 1984, Uranium mineralization in response to regional metamorphism at Lilljuthatten, Sweden: Economic Geology, v. 79, no. 3, p. 509-528, https://doi.org/10.2113/gsecongeo.79.3.509.","productDescription":"20 p.","startPage":"509","endPage":"528","numberOfPages":"20","costCenters":[],"links":[{"id":220516,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"79","issue":"3","noUsgsAuthors":false,"publicationDate":"1984-05-01","publicationStatus":"PW","scienceBaseUri":"505bbdc2e4b08c986b3291e5","contributors":{"authors":[{"text":"Stuckless, J. S.","contributorId":6060,"corporation":false,"usgs":true,"family":"Stuckless","given":"J. S.","affiliations":[],"preferred":false,"id":365392,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Troeng, B.","contributorId":56373,"corporation":false,"usgs":true,"family":"Troeng","given":"B.","email":"","affiliations":[],"preferred":false,"id":365393,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70014022,"text":"70014022 - 1984 - Optimization of electrothermal atomization parameters for simultaneous multielement atomic absorption spectrometry","interactions":[],"lastModifiedDate":"2023-03-10T17:01:58.649487","indexId":"70014022","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":761,"text":"Analytical Chemistry","active":true,"publicationSubtype":{"id":10}},"title":"Optimization of electrothermal atomization parameters for simultaneous multielement atomic absorption spectrometry","docAbstract":"The effect of the acid matrix, the measurement mode (height or area), the atomizer surface (unpyrolyzed and pyrolyzed graphite), the atomization mode (from the wall or from a platform), and the atomization temperature on the simultaneous electrothermal atomization of Co, Cr, Cu, Fe, Mn, Mo, Ni, V, and Zn was examined. The 5% HNO3 matrix gave rise to severe irreproducibility using a pyrolyzed tube unless the tube was properly \"prepared\". The 5% HCl matrix did not exhibit this problem, and no problems were observed with either matrix using an unpyrolized tube or a pyrolyzed platform. The 5% HCl matrix gave better sensitivities with a pyrolyzed tube but the two matrices were comparable for atomization from a platform. If Mo and V are to be analyzed with the other seven elements, a high atomization temperature (2700??C or greater) is necessary regardless of the matrix, the measurement mode, the atomization mode, or the atomizer surface. Simultaneous detection limits (peak height with pyrolyzed tube atomization) were comparable to those of conventional atomic absorption spectrometry using electrothermal atomization above 280 nm. Accuracies and precisions of ??10-15% were found in the 10 to 120 ng mL-1 range for the analysis of NBS acidified water standards.","language":"English","publisher":"ACS Publications","doi":"10.1021/ac00265a014","usgsCitation":"Harnly, J.M., and Kane, J., 1984, Optimization of electrothermal atomization parameters for simultaneous multielement atomic absorption spectrometry: Analytical Chemistry, v. 56, no. 1, p. 48-54, https://doi.org/10.1021/ac00265a014.","productDescription":"7 p.","startPage":"48","endPage":"54","numberOfPages":"7","costCenters":[],"links":[{"id":225866,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"56","issue":"1","noUsgsAuthors":false,"publicationDate":"2002-05-01","publicationStatus":"PW","scienceBaseUri":"505a6ef2e4b0c8380cd7589f","contributors":{"authors":[{"text":"Harnly, J. M.","contributorId":22492,"corporation":false,"usgs":false,"family":"Harnly","given":"J.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":367397,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kane, Jean S.","contributorId":66544,"corporation":false,"usgs":true,"family":"Kane","given":"Jean S.","affiliations":[],"preferred":false,"id":367398,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013902,"text":"70013902 - 1984 - Transitional paleointensities from Kauai, Hawaii, and geomagnetic reversal models","interactions":[],"lastModifiedDate":"2012-06-22T01:01:40","indexId":"70013902","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2312,"text":"Journal of Geophysical Research","active":true,"publicationSubtype":{"id":10}},"title":"Transitional paleointensities from Kauai, Hawaii, and geomagnetic reversal models","docAbstract":"Previously presented paleointensity results from an R-N transition zone in Kauai, Hawaii, show that field intensity dropped from 0. 431 Oe to 0. 101 Oe while the field remained within 30 degree of the reversed axial dipole direction. A recovery in intensity and the main directional change followed this presumably short period of low field strength. As the reversal neared completion, the field has an intensity of 0. 217 Oe while still 40 degree from the final direction. The relationship of paleointensity to field direction during the early part of the reversal thus differs from that toward the end, a feature that only some reversal models are consistent with. For example, a model in which a standing nondipole component persists through the dipole reversal predicts only symmetric intensity patterns. In contrast, zonal flooding models generate suitably complex field behavior if multiple flooding schemes operate during a single reversal or if the flooding process is itself asymmetric.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Geophysical Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1029/JB089iB12p10341","issn":"01480227","usgsCitation":"Bogue, S.W., and Coe, R.S., 1984, Transitional paleointensities from Kauai, Hawaii, and geomagnetic reversal models: Journal of Geophysical Research, v. 89, no. B12, p. 10341-10354, https://doi.org/10.1029/JB089iB12p10341.","startPage":"10341","endPage":"10354","numberOfPages":"14","costCenters":[],"links":[{"id":225990,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":257786,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/JB089iB12p10341","linkFileType":{"id":5,"text":"html"}}],"volume":"89","issue":"B12","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505bb712e4b08c986b327045","contributors":{"authors":[{"text":"Bogue, Scott W.","contributorId":20476,"corporation":false,"usgs":true,"family":"Bogue","given":"Scott","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":367130,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Coe, Robert S.","contributorId":20477,"corporation":false,"usgs":true,"family":"Coe","given":"Robert","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":367131,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013716,"text":"70013716 - 1984 - Regional investigations of soil and overburden analysis and plant uptake of metals","interactions":[],"lastModifiedDate":"2012-03-12T17:18:39","indexId":"70013716","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2754,"text":"Minerals and the Environment","active":true,"publicationSubtype":{"id":10}},"title":"Regional investigations of soil and overburden analysis and plant uptake of metals","docAbstract":"Regional studies on the bioavailability of metals at native and disturbed sites were conducted over the past seven years by the USGS. The work was concentrated in the Fort Union, Powder River, and Green River coal resource regions where measures of extractable metals in soils were found to have limited use in predicting metal levels in plants. Correlations between Cu, Fe, and Zn in plants and extractable (DTPA, EDTA, and oxalate) or total levels in native A- and C-horizons of soil were occasionally significant. A simple linear model is generally not adequate, however, in estimating element uptake by plants. Prediction capabilities were improved when a number of soil chemical and physical parameters were included as independent variables in a stepwise linear multiple regression analysis; however, never more than 54% of the total variability in the data was explained by the equations for these metals. Soil pH was the most important variable relating soil chemistry to plant chemistry. This relation was always positive and apparently a response to soil levels of metal carbonates and not Fe and Mn oxides. Studies that compared the metal uptake by rehabilitation species to extractable (DTPA) metal levels in mice soils produced similar results. ?? 1984 Science and Technology Letters.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Minerals and the Environment","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Kluwer Academic Publishers","doi":"10.1007/BF02043989","issn":"01427245","usgsCitation":"Gough, L.P., 1984, Regional investigations of soil and overburden analysis and plant uptake of metals: Minerals and the Environment, v. 6, no. 3, p. 105-110, https://doi.org/10.1007/BF02043989.","startPage":"105","endPage":"110","numberOfPages":"6","costCenters":[],"links":[{"id":204982,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF02043989"},{"id":219875,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"6","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a534e4b0e8fec6cdbd7f","contributors":{"authors":[{"text":"Gough, L. P.","contributorId":64198,"corporation":false,"usgs":true,"family":"Gough","given":"L.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":366698,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70013891,"text":"70013891 - 1984 - Interpretation of gravity data in a complex volcano-tectonic setting, southwestern Nevada","interactions":[],"lastModifiedDate":"2024-06-27T16:10:06.855058","indexId":"70013891","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":6453,"text":"Journal of Geophysical Research Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Interpretation of gravity data in a complex volcano-tectonic setting, southwestern Nevada","docAbstract":"This regional gravity study, based on an irregular 2-km data grid, was conducted during the past few years at Yucca Mountain, southern Nye County, Nevada, as part of a program to locate a suitable repository for high-level nuclear waste. About 100 surface rock samples, three borehole gamma-gamma logs, and one borehole gravity study provide excellent density control. A nearly linear increase in density of 0.26 g/cm3 per kilometer of depth is indicated in the thick tuff sequences that underlie the mountain. Isostatic and 2.0-g/cm3 Bouguer corrections were applied to the observed gravity values to remove regional gradients and topographic effects, respectively. The Bare Mountain gravity high, with an isostatic anomaly maximum of 48 mGal, is connected with a greater gravity high over the Funeral Mountains, to the southwest; together, these highs result from a continuous block of dense, metamorphosed Precambrian and Paleozoic rocks that stretches across much of the Walker Lane from the east edge of Death Valley to Bare Mountain. The Calico Hills gravity high appears more likely to originate from a northeast trending buried ridge of Paleozoic rocks that extends southwestward beneath Busted Butte, 5 km southeast of the proposed repository, where two- and three-dimensional modeling indicates that the pre-Cenozoic rocks lie less than 1000 m beneath the surface. Tuff, at least 4000 m thick, fills a large steep-sided depression in the pretuff rocks beneath Yucca Mountain and Crater Flat. The gravity low and the thick tuff section lie within a large collapse area that includes the Crater Flat-Timber Mountain-Silent Canyon caldera complexes. Gravity lows in Crater Flat itself are interpreted to coincide with the source areas of the Prow Pass Member, the Bullfrog Member, and the Tram Member of the Crater Flat Tuff; these source areas add nearly 350 km2 to the previously recognized extent of the local caldera complexes. Southward extension of the broad gravity low associated with Crater Flat into the Amargosa Desert is evidence for sector graben-type collapse segments related to the formation of the Timber Mountain caldera and superimposed on the other volcanic and extensional structures within Crater Flat.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB089iB12p10193","issn":"01480227","usgsCitation":"Snyder, D.B., and Carr, W.J., 1984, Interpretation of gravity data in a complex volcano-tectonic setting, southwestern Nevada: Journal of Geophysical Research Solid Earth, v. 89, no. B12, p. 10193-10206, https://doi.org/10.1029/JB089iB12p10193.","productDescription":"14 p.","startPage":"10193","endPage":"10206","numberOfPages":"14","costCenters":[],"links":[{"id":225858,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"89","issue":"B12","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505a37d1e4b0c8380cd611bd","contributors":{"authors":[{"text":"Snyder, David B.","contributorId":13380,"corporation":false,"usgs":true,"family":"Snyder","given":"David","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":367103,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Carr, W. J.","contributorId":9245,"corporation":false,"usgs":true,"family":"Carr","given":"W.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":367102,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013889,"text":"70013889 - 1984 - Modification of δ D values in eastern Nevada granitoid rocks spatially related to thrust faults","interactions":[],"lastModifiedDate":"2015-06-05T13:52:58","indexId":"70013889","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":"Modification of δ D values in eastern Nevada granitoid rocks spatially related to thrust faults","docAbstract":"Stable isotope data have been determined for 13 Mesozoic and Tertiary plutons in eastern Nevada and nearby Utah. In the southern Snake Range of eastern Nevada, where relations are best exposed and have been most intensively studied, δD, δ 18O, and apparent K-Ar ages depend on proximity to the Snake Range decollement. Where stresses resulting from late movement on the decollement have caused cataclasis of Oligocene (37 Ma) granitoid rock, δ 18O, δD, and K-Ar age values as low as −2.5‰, −155‰, and 18 Ma, respectively, have been determined. Where there has been no cataclasis, δ 18O values of Jurassic, Cretaceous, and Oligocene granitoid rocks are apparently unaffected, but both δD values and K-Ar ages have been modified for distances of tens of meters below the decollement.
\nResults similar to those in the southern Snake Range have been observed in other eastern Nevada granitoid rocks spatially related to regional thrust faults, as in the Kern Mountains, the Toana Range, and the northern Egan Range. In each of these areas cataclasis or deformation of granitoid rocks has resulted in lowered δ 18O, δD, and K-Ar age values. Where there has been no cataclasis or deformation, δ 18O values are unaffected, but both δD and K-Ar age values have been lowered by stresses resulting from postcrystallization movement along overlying thrust faults.
\nMany of the plutons discussed have not been deeply eroded, and spatially related thrust faults crop out. Where thrust faults are not in evidence and the granitoid rocks give δD values lower than about −130‰ along with spuriously low K-Ar age results, modification of the δD and K-Ar age values may have been caused by stresses related to late movement along an overlying (now eroded) thrust fault.
","language":"English","publisher":"Springer","doi":"10.1007/BF00380174","issn":"00107999","usgsCitation":"Lee, D.E., Friedman, I., and Gleason, J., 1984, Modification of δ D values in eastern Nevada granitoid rocks spatially related to thrust faults: Contributions to Mineralogy and Petrology, v. 88, no. 3, p. 288-298, https://doi.org/10.1007/BF00380174.","productDescription":"11 p.","startPage":"288","endPage":"298","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":225803,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":205655,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00380174"}],"volume":"88","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5cace4b0c8380cd6fe7f","contributors":{"authors":[{"text":"Lee, D. E.","contributorId":96705,"corporation":false,"usgs":true,"family":"Lee","given":"D.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":367089,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Friedman, Irving","contributorId":90664,"corporation":false,"usgs":true,"family":"Friedman","given":"Irving","email":"","affiliations":[],"preferred":false,"id":367088,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gleason, J.D.","contributorId":27072,"corporation":false,"usgs":true,"family":"Gleason","given":"J.D.","email":"","affiliations":[],"preferred":false,"id":367087,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70013886,"text":"70013886 - 1984 - Chemical determination of particulate nitrogen in San Francisco Bay. Nitrogen: chlorophyll a ratios in plankton","interactions":[],"lastModifiedDate":"2023-10-12T16:20:13.93668","indexId":"70013886","displayToPublicDate":"1984-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1587,"text":"Estuarine, Coastal and Shelf Science","active":true,"publicationSubtype":{"id":10}},"displayTitle":"Chemical determination of particulate nitrogen in San Francisco Bay. Nitrogen: chlorophyll a ratios in plankton","title":"Chemical determination of particulate nitrogen in San Francisco Bay. Nitrogen: chlorophyll a ratios in plankton","docAbstract":"Particulate nitrogen (PN) and chlorophyll a (Chla) were measured in the northern reach of San Francisco Bay throughout 1980. The PN values were calculated as the differences between unfiltered and filtered (0·4 μm) samples analyzed using the UV-catalyzed peroxide digestion method. The Chla values were measured spectrophotometrically, with corrections made for phaeopigments. The plot of all