Depositional controls on peat-forming environments which produce thick (>10m) coal beds can be inferred from relationships between coal bed geometry, maceral composition and associated lithologies. Study of these relationships within sedimentary sequences associated with the Wyodak-Anderson (Palaeocene) and the Felix (Eocene) sub-bituminous coal beds in the Powder River Basin, Wyoming, USA suggests two modes of fluvially controlled peat accumulation. The Wyodak-Anderson peat is interpreted to have formed in restricted parts of the floodplain that were separated by deposits of contemporaneous, anastomosed channels. The channels and associated sediments maintained their position through time because they were confined by thick deposits of raised Wyodak-Anderson peat. In contrast, the Felix coal bed is interpreted to have formed as a raised but widespread peat on an abandoned platform of meander-belt sands.
The purpose of this paper is to compare and contrast two different fluvial depositional settings that produced anomalously thick (>10m) coal deposits in the intermontane Powder River Basin of Wyoming, USA. These models may be useful as predictive tools for coal exploration and production.
","language":"English","publisher":"Geological Society of London","doi":"10.1144/gsjgs.145.4.0613","usgsCitation":"Warwick, P.D., and Stanton, R.W., 1988, Depositional models for two Tertiary coal-bearing sequences in the Powder River Basin, Wyoming, USA: Journal of the Geological Society, v. 145, no. 4, p. 613-620, https://doi.org/10.1144/gsjgs.145.4.0613.","productDescription":"8 p.","startPage":"613","endPage":"620","costCenters":[],"links":[{"id":226079,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Wyoming","otherGeospatial":"Powder River Basin","volume":"145","issue":"4","noUsgsAuthors":false,"publicationDate":"2022-06-06","publicationStatus":"PW","scienceBaseUri":"5059fec7e4b0c8380cd4ef0a","contributors":{"authors":[{"text":"Warwick, Peter D. 0000-0002-3152-7783 pwarwick@usgs.gov","orcid":"https://orcid.org/0000-0002-3152-7783","contributorId":762,"corporation":false,"usgs":true,"family":"Warwick","given":"Peter","email":"pwarwick@usgs.gov","middleInitial":"D.","affiliations":[{"id":241,"text":"Eastern Energy Resources Science Center","active":true,"usgs":true}],"preferred":false,"id":368065,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Stanton, Ronald W.","contributorId":37386,"corporation":false,"usgs":true,"family":"Stanton","given":"Ronald","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":368064,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70014298,"text":"70014298 - 1988 - Three-dimensional gravity modeling of the geologic structure of Long Valley caldera","interactions":[],"lastModifiedDate":"2024-06-05T15:48:18.183909","indexId":"70014298","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","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":"Three-dimensional gravity modeling of the geologic structure of Long Valley caldera","docAbstract":"A 48-mGal gravity low coincides with Long Valley caldera and is mainly attributed to low-density caldera fill. Gravity measurements by Unocal Geothermal have been integrated with U.S. Geological Survey data, vastly improving gravity station coverage throughout the caldera. A strong regional gravity trend is mainly attributed to isostasy. A “best fitting” (based on regional control of basement densities) Airy-Heiskanen isostatic model was used for the regional correction. A three-dimensional, multiple-unit gravity modeling program with iterative capabilities was developed to model the residual gravity. The density structure of Long Valley caldera and vicinity was modeled with 22 discrete density units, most of which were based on geologic units. Information from drill hole lithologies, surface geology, and structural geology interpretations constrain the model. Some important points revealed by the three-dimensional gravity modeling are that (1) the volume of ejected magma associated with the Bishop Tuff eruption is greater than previously thought, (2) the caldera structure is strongly influenced by precaldera topography and the extensions of major, active faults, (3) the main west ring fracture is coincident with the Inyo Domes-Mono Craters fracture system, (4) a relatively low-density region probably underlies the caldera, and (5) a silicic magma chamber may underlie Devils Postpile.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB093iB11p13237","issn":"01480227","usgsCitation":"Carle, S.F., 1988, Three-dimensional gravity modeling of the geologic structure of Long Valley caldera: Journal of Geophysical Research Solid Earth, v. 93, no. B11, p. 13237-13250, https://doi.org/10.1029/JB093iB11p13237.","productDescription":"14 p.","startPage":"13237","endPage":"13250","costCenters":[],"links":[{"id":226080,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"93","issue":"B11","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505bb32ce4b08c986b325c1c","contributors":{"authors":[{"text":"Carle, S. F.","contributorId":72808,"corporation":false,"usgs":true,"family":"Carle","given":"S.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":368066,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70014333,"text":"70014333 - 1988 - An Angus/Argo study of the neovolcanic zone along the East Pacific rise from the Clipperton fracture zone to 12°N","interactions":[],"lastModifiedDate":"2015-06-02T11:47:38","indexId":"70014333","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1742,"text":"Geo-Marine Letters","active":true,"publicationSubtype":{"id":10}},"title":"An Angus/Argo study of the neovolcanic zone along the East Pacific rise from the Clipperton fracture zone to 12°N","docAbstract":"Still photographs and video images collected along the Neovolcanic Zone of the East Pacific Rise from 10°15′N to 11°53′N show that recent volcanic sheet flows, possibly less than 100 years old, are superimposed on an older sediment-laden pillow terrane. This recent activity is restricted to a narrow zone that crosses two topographic highs at 10°55′N and 11°26′N and diminishes along-axis away from these highs. The association of recent sheet flows with older flows and collapse structures on the overlapping spreading centers at 11°45′N supports the evolutionary model for the occurrence and evolution of overlapping spreading centers by MacDonald and others (1986, 1988).
","language":"English","publisher":"Springer","doi":"10.1007/BF02326089","issn":"02760460","usgsCitation":"Uchupi, E., Schwab, W.C., Ballard, R.D., Cheminee, J., Francheteau, J., Hekinian, R., Blackman, D., and Sigurdsson, H., 1988, An Angus/Argo study of the neovolcanic zone along the East Pacific rise from the Clipperton fracture zone to 12°N: Geo-Marine Letters, v. 8, no. 3, p. 131-138, https://doi.org/10.1007/BF02326089.","productDescription":"8 p.","startPage":"131","endPage":"138","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":487232,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://digitalcommons.uri.edu/gsofacpubs/2436","text":"External Repository"},{"id":225633,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":205641,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF02326089"}],"volume":"8","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e9d0e4b0c8380cd48495","contributors":{"authors":[{"text":"Uchupi, E.","contributorId":10074,"corporation":false,"usgs":true,"family":"Uchupi","given":"E.","affiliations":[],"preferred":false,"id":368140,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Schwab, W. C.","contributorId":78740,"corporation":false,"usgs":true,"family":"Schwab","given":"W.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":368146,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ballard, Richard D.","contributorId":40729,"corporation":false,"usgs":true,"family":"Ballard","given":"Richard","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":368143,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Cheminee, J.L.","contributorId":79633,"corporation":false,"usgs":true,"family":"Cheminee","given":"J.L.","affiliations":[],"preferred":false,"id":368147,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Francheteau, Jean","contributorId":34262,"corporation":false,"usgs":false,"family":"Francheteau","given":"Jean","email":"","affiliations":[],"preferred":false,"id":368141,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Hekinian, R.","contributorId":44273,"corporation":false,"usgs":true,"family":"Hekinian","given":"R.","email":"","affiliations":[],"preferred":false,"id":368144,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Blackman, D.K.","contributorId":59962,"corporation":false,"usgs":true,"family":"Blackman","given":"D.K.","email":"","affiliations":[],"preferred":false,"id":368145,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Sigurdsson, Haraldur","contributorId":35079,"corporation":false,"usgs":true,"family":"Sigurdsson","given":"Haraldur","email":"","affiliations":[],"preferred":false,"id":368142,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70014334,"text":"70014334 - 1988 - Precursory seismic quiescence: A preliminary assessment of the hypothesis","interactions":[],"lastModifiedDate":"2012-03-12T17:19:30","indexId":"70014334","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3209,"text":"Pure and Applied Geophysics PAGEOPH","active":true,"publicationSubtype":{"id":10}},"title":"Precursory seismic quiescence: A preliminary assessment of the hypothesis","docAbstract":"Numerous cases of precursory seismic quiescence have been reported in recent years. Some investigators have interpreted these observations as evidence that seismic quiescence is a somewhat reliable precursor to moderate or large earthquakes. However, because failures of the pattern to predict earthquakes may not, in general, be reported, and because numerous earthquakes are not preceded by quiescence, the validity and reliability of the quiescence precursor have not been established. We have analyzed the seismicity rate prior to, and in the source region of, 37 shallow earthquakes (M 5.3-7.0) in central California and Japan for patterns of rate fluctuation, especially precursory quiescence. Nonuniformity in rate for these pre-mainshock sequences is relatively high, and numerous intervals with significant (p<0.10) extrema in rate are observed in some of the sequences. In other sequences, however, the rate remains within normal limits up to the time of the mainshock. Overall, in terms of an observational basis for intermediate-term earthquake prediction, no evidence is found in the cases studied for a systematic, widespread or reliable pattern of quiescence prior to the mainshocks. In earthquake sequences comprising full seismic cycles for 5 sets of (M 3.7-5.1) repeat earthquakes on the San Andreas fault near Bear Valley, California, the seismicity rates are found to be uniform. A composite of the estimated rate fluctuations for the sequences, normalized to the length of the seismic cycle, reveals a weak pattern of a low rate in the first third of the cycle, and a high rate in the last few months. While these observations are qualitative, they may represent weak expressions of physical processes occurring in the source region over the seismic cycle. Re-examination of seismicity rate fluctuations in volumes along the creeping section of the San Andreas fault specified by Wyss and Burford (1985) qualitatively confirms the existence of low-rate intervals in volumes 361, 386, 382, 372 and 401. However, only the quiescence in volume 386 is found by the present study to be statistically significant. ?? 1988 Birkha??user Verlag.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Pure and Applied Geophysics PAGEOPH","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Birkha??user-Verlag","doi":"10.1007/BF00879004","issn":"00334553","usgsCitation":"Reasenberg, P., and Matthews, M., 1988, Precursory seismic quiescence: A preliminary assessment of the hypothesis: Pure and Applied Geophysics PAGEOPH, v. 126, no. 2-4, p. 373-406, https://doi.org/10.1007/BF00879004.","startPage":"373","endPage":"406","numberOfPages":"34","costCenters":[],"links":[{"id":205648,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00879004"},{"id":225699,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"126","issue":"2-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a814ce4b0c8380cd7b463","contributors":{"authors":[{"text":"Reasenberg, P.A.","contributorId":19959,"corporation":false,"usgs":true,"family":"Reasenberg","given":"P.A.","email":"","affiliations":[],"preferred":false,"id":368148,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Matthews, M.V.","contributorId":70920,"corporation":false,"usgs":true,"family":"Matthews","given":"M.V.","email":"","affiliations":[],"preferred":false,"id":368149,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70014397,"text":"70014397 - 1988 - The hydrothermal system at Newberry Volcano, Oregon","interactions":[],"lastModifiedDate":"2024-06-05T15:31:30.70872","indexId":"70014397","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","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":"The hydrothermal system at Newberry Volcano, Oregon","docAbstract":"Results of recent geological and geophysical studies at Newberry Volcano have been incorporated into conceptual and numerical models of a magma-based hydrothermal system. Numerical simulations begin with emplacement of a small magma body, the presumed source of silicic eruptions at Newberry that began about 10,000 B.P., into a thermal regime representing 100,000 years of cooling of a large underlying intrusion. Simulated flow patterns and thermal histories for three sets of hypothetical permeability values are compatible with data from four geothermal drill holes on the volcano. Meteoric recharge cools the caldera-fill deposits, but thermal water moving up a central conduit representing a permeable volcanic vent produces temperatures close to those observed in drill holes within the caldera. Meteoric recharge from the caldera moves down the flanks and creates a near-isothermal zone that extends several hundred meters below the water table, producing temperature profiles similar to those observed in drill holes on the flanks. The temperatures observed in drill holes on the flanks are not influenced by the postulated Holocene magma body. The elevated temperature gradients measured in the lower portions of these holes may be related to the cumulative effect of older intrusions. The models also indicate that meteoric recharge to the deep hydrothermal system probably originates within or near the caldera. Relatively low fluid velocities at depth suggest that at least a significant fraction of the thermal fluid may be very old.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB093iB09p10149","issn":"01480227","usgsCitation":"Sammel, E., Ingebritsen, S.E., and Mariner, R.H., 1988, The hydrothermal system at Newberry Volcano, Oregon: Journal of Geophysical Research Solid Earth, v. 93, no. B9, p. 10149-10162, https://doi.org/10.1029/JB093iB09p10149.","productDescription":"14 p.","startPage":"10149","endPage":"10162","numberOfPages":"14","costCenters":[],"links":[{"id":225831,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"93","issue":"B9","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505baccee4b08c986b32375c","contributors":{"authors":[{"text":"Sammel, E.A.","contributorId":59480,"corporation":false,"usgs":true,"family":"Sammel","given":"E.A.","affiliations":[],"preferred":false,"id":368309,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ingebritsen, S. E.","contributorId":8078,"corporation":false,"usgs":true,"family":"Ingebritsen","given":"S.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":368308,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mariner, Robert H.","contributorId":81075,"corporation":false,"usgs":true,"family":"Mariner","given":"Robert","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":368310,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70014418,"text":"70014418 - 1988 - Effects of three-dimensional velocity structure on the seismicity of the 1984 Morgan Hill, California, aftershock sequence","interactions":[],"lastModifiedDate":"2023-10-28T00:03:13.198919","indexId":"70014418","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1135,"text":"Bulletin of the Seismological Society of America","onlineIssn":"1943-3573","printIssn":"0037-1106","active":true,"publicationSubtype":{"id":10}},"title":"Effects of three-dimensional velocity structure on the seismicity of the 1984 Morgan Hill, California, aftershock sequence","docAbstract":"A three-dimensional velocity model for the area surrounding the 24 April 1984 Morgan Hill earthquake has been developed by simultaneously inverting local earthquake and refraction arrival-time data. This velocity model corresponds well to the surface geology of the region, predominantly showing a low-velocity region associated with the sedimentary sequence to the southwest of the Madrone Springs fault. This low-velocity sequence extends to a depth of approximately 5 km. Previously constructed geologic cross-sections for this region had suggested that these sediments extended to a depth of less than 2 km. Relocation of 2,179 hypocenters with the three-dimensional velocity model did not show great differences when compared to locations done with a one-dimensional velocity model with station corrections. In both cases, the Calaveras fault is steep but has a noticeable dip to the northeast and the seismicity does not intersect the surface along the trace of the Calaveras fault in the southern half of the rupture zone. The greatest differences between the two sets of locations was that the locations using the three-dimensional velocity model were deeper, and fewer earthquakes were located within the low-velocity region. The focal mechanisms were also determined for 946 earthquakes using both the one-dimensional and three-dimensional earth models. Both earth models yield similar focal mechanisms for these earthquakes.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA0780031199","usgsCitation":"Michael, A., 1988, Effects of three-dimensional velocity structure on the seismicity of the 1984 Morgan Hill, California, aftershock sequence: Bulletin of the Seismological Society of America, v. 78, no. 3, p. 1199-1221, https://doi.org/10.1785/BSSA0780031199.","productDescription":"23 p.","startPage":"1199","endPage":"1221","numberOfPages":"23","costCenters":[],"links":[{"id":422213,"rank":2,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.geoscienceworld.org/ssa/bssa/article/78/3/1199/102327/Effects-of-three-dimensional-velocity-structure-on"},{"id":226221,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -121.76463433600294,\n 37.421031586189955\n ],\n [\n -121.76463433600294,\n 36.94800385988415\n ],\n [\n -121.0560161719405,\n 36.94800385988415\n ],\n [\n -121.0560161719405,\n 37.421031586189955\n ],\n [\n -121.76463433600294,\n 37.421031586189955\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"78","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a080ce4b0c8380cd5194f","contributors":{"authors":[{"text":"Michael, A.J. 0000-0002-2403-5019","orcid":"https://orcid.org/0000-0002-2403-5019","contributorId":52192,"corporation":false,"usgs":true,"family":"Michael","given":"A.J.","affiliations":[],"preferred":false,"id":368358,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70014455,"text":"70014455 - 1988 - Vapor-dominated zones within hydrothermal systems: Evolution and natural state","interactions":[],"lastModifiedDate":"2024-06-05T14:53:15.43716","indexId":"70014455","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","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":"Vapor-dominated zones within hydrothermal systems: Evolution and natural state","docAbstract":"Three conceptual models illustrate the range of hydrothermal systems in which vapor-dominated conditions are found. The first model (model I) represents a system with an extensive near-vaporstatic vapor-dominated zone and limited liquid throughflow and is analogous to systems such as The Geysers, California. Such systems can evolve within low-permeability barriers without changes in boundary conditions or rock properties, given an adequate supply of heat. Their scarcity in nature may be due to the need for a long-lived, potent heat source and for a low-permeability aureole that remains intact for significant lengths of time. Models II and III represent systems with significant liquid throughflow and include steam-heated discharge features at higher elevations and high-chloride springs at lower elevations, connected to and fed by a single circulation system at depth. In model II, as in model I, the vapor-dominated zone has a near-vaporstatic vertical pressure gradient and is generally underpressured with respect to local hydrostatic pressure. The vapor-dominated zone in model III is quite different, in that phase separation takes place at pressures close to local hydrostatic and the overall pressure gradient is near hydrostatic. A relatively large number of high-temperature systems in regions of moderate to great topographic relief are similar to either model II or model III; however, in most cases there are insufficient data to establish a single preferred model.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB093iB11p13635","issn":"01480227","usgsCitation":"Ingebritsen, S.E., and Sorey, M., 1988, Vapor-dominated zones within hydrothermal systems: Evolution and natural state: Journal of Geophysical Research Solid Earth, v. 93, no. B11, p. 13635-13655, https://doi.org/10.1029/JB093iB11p13635.","productDescription":"21 p.","startPage":"13635","endPage":"13655","costCenters":[],"links":[{"id":225776,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"93","issue":"B11","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505bc120e4b08c986b32a461","contributors":{"authors":[{"text":"Ingebritsen, S. E.","contributorId":8078,"corporation":false,"usgs":true,"family":"Ingebritsen","given":"S.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":368433,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sorey, M.L.","contributorId":73185,"corporation":false,"usgs":true,"family":"Sorey","given":"M.L.","affiliations":[],"preferred":false,"id":368434,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013693,"text":"70013693 - 1988 - Crustal contributions to arc magmatism in the Andes of Central Chile","interactions":[],"lastModifiedDate":"2012-03-12T17:18:32","indexId":"70013693","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","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":"Crustal contributions to arc magmatism in the Andes of Central Chile","docAbstract":"Fifteen andesite-dacite stratovolcanoes on the volcanic front of a single segment of the Andean arc show along-arc changes in isotopic and elemental ratios that demonstrate large crustal contributions to magma genesis. All 15 centers lie 90 km above the Benioff zone and 280??20 km from the trench axis. Rate and geometry of subduction and composition and age of subducted sediments and seafloor are nearly constant along the segment. Nonetheless, from S to N along the volcanic front (at 57.5% SiO2) K2O rises from 1.1 to 2.4 wt %, Ba from 300 to 600 ppm, and Ce from 25 to 50 ppm, whereas FeO*/MgO declines from >2.5 to 1.4. Ce/Yb and Hf/Lu triple northward, in part reflecting suppression of HREE enrichment by deep-crustal garnet. Rb, Cs, Th, and U contents all rise markedly from S to N, but Rb/Cs values double northward - opposite to prediction were the regional alkali enrichment controlled by sediment subduction. K/Rb drops steeply and scatters greatly within many (biotite-free) andesitic suites. Wide diversity in Zr/Hf, Zr/Rb, Ba/Ta, and Ba/La within and among neighboring suites (which lack zircon and alkali feldspar) largely reflects local variability of intracrustal (not slab or mantle) contributions. Pb-isotope data define a limited range that straddles the Stacey-Kramers line, is bracketed by values of local basement rocks, in part plots above the field of Nazca plate sediment, and shows no indication of a steep (mantle+sedimentary) Pb mixing trend. 87Sr/86Sr values rise northward from 0.7036 to 0.7057, and 143Nd/144Nd values drop from 0.5129 to 0.5125. A northward climb in basal elevation of volcanic-front edifices from 1350 m to 4500 m elevation coincides with a Bougueranomaly gradient from -95 to -295 mgal, interpreted to indicate thickening of the crust from 30-35 km to 50-60 km. Complementary to the thickening crust, the mantle wedge beneath the front thins northward from about 60 km to 30-40 km (as slab depth is constant). The thick northern crust contains an abundance of Paleozoic and Triassic rocks, whereas the proportion of younger arc-intrusive basement increases southward. Primitive basalts are unknown anywhere along the arc. Base-level isotopic and chemical values for each volcano are established by blending of subcrustal and deep-crustal magmas in zones of melting, assimilation, storage and homogenization (MASH) at the mantle-crust transition. Scavenging of mid-to upper-crustal silicic-alkalic melts and intracrustal AFC (prominent at the largest center) can subsequently modify ascending magmas, but the base-level geochemical signature at each center reflects the depth of its MASH zone and the age, composition, and proportional contribution of the lowermost crust. ?? 1988 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/BF00372365","issn":"00107999","usgsCitation":"Hildreth, W., and Moorbath, S., 1988, Crustal contributions to arc magmatism in the Andes of Central Chile: Contributions to Mineralogy and Petrology, v. 98, no. 4, p. 455-489, https://doi.org/10.1007/BF00372365.","startPage":"455","endPage":"489","numberOfPages":"35","costCenters":[],"links":[{"id":205032,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00372365"},{"id":220388,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"98","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fcdae4b0c8380cd4e47e","contributors":{"authors":[{"text":"Hildreth, W. 0000-0002-7925-4251","orcid":"https://orcid.org/0000-0002-7925-4251","contributorId":100487,"corporation":false,"usgs":true,"family":"Hildreth","given":"W.","affiliations":[],"preferred":false,"id":366655,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Moorbath, S.","contributorId":49516,"corporation":false,"usgs":true,"family":"Moorbath","given":"S.","email":"","affiliations":[],"preferred":false,"id":366654,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70174356,"text":"70174356 - 1988 - System considerations in numerical modeling of estuarine problems, in Niki, H., and Kawahara, M., eds., computational methods in flow analysis","interactions":[],"lastModifiedDate":"2016-07-26T16:37:41","indexId":"70174356","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"System considerations in numerical modeling of estuarine problems, in Niki, H., and Kawahara, M., eds., computational methods in flow analysis","docAbstract":"No abstract available
","largerWorkType":{"id":24,"text":"Conference Paper"},"largerWorkTitle":"Proceedings, international conference on computational method in flow analysis","conferenceTitle":"International conference on computational method in flow analysis","conferenceLocation":"Okayama, Japan","language":"English","usgsCitation":"Cheng, R.T., and Burau, J., 1988, System considerations in numerical modeling of estuarine problems, in Niki, H., and Kawahara, M., eds., computational methods in flow analysis, in Proceedings, international conference on computational method in flow analysis, Okayama, Japan, p. 1025-1032.","productDescription":"8 p.","startPage":"1025","endPage":"1032","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":552,"text":"San Francisco Bay-Delta","active":false,"usgs":true},{"id":5079,"text":"Pacific Regional Director's Office","active":true,"usgs":true}],"links":[{"id":324974,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5780cebfe4b08116168223cb","contributors":{"authors":[{"text":"Cheng, R. T.","contributorId":23138,"corporation":false,"usgs":false,"family":"Cheng","given":"R.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":641998,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Burau, J.R. 0000-0002-5196-5035","orcid":"https://orcid.org/0000-0002-5196-5035","contributorId":7307,"corporation":false,"usgs":true,"family":"Burau","given":"J.R.","affiliations":[],"preferred":false,"id":641999,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":28201,"text":"wri884004 - 1988 - Simulation of three lahars in the Mount St Helens area, Washington using a one-dimensional, unsteady-state streamflow model","interactions":[],"lastModifiedDate":"2023-03-21T18:57:07.538832","indexId":"wri884004","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":342,"text":"Water-Resources Investigations Report","code":"WRI","active":false,"publicationSubtype":{"id":5}},"seriesNumber":"88-4004","title":"Simulation of three lahars in the Mount St Helens area, Washington using a one-dimensional, unsteady-state streamflow model","docAbstract":"A one-dimensional, unsteady-state, open-channel model was used to analytically reproduce three lahar events. Factors contributing to the success of the modeling were: (1) the lahars were confined to a channel, (2) channel roughness was defined by field information, and (3) the volume of the flow remained relatively unchanged for the duration of the peak. Manning 's 'n ' values used in computing conveyance in the model were subject to the changing rheology of the debris flow and were calculated from field cross-section information (velocities used in these calculations were derived from super-elevation or run-up formulas). For the events modeled in this exercise, Manning 's 'n ' calculations ranged from 0.020 to 0.099. In all lahar simulations, the rheology of the flow changed in a downstream direction during the course of the event. Chen's 'U ', the mudflow consistency index, changed approximately an order of magnitude for each event. The ' u ' values ranged from 5-2,260 kg/m for three events modeled. The empirical approach adopted in this paper is useful as a tool to help predict debris-flow behavior, but does not lead to understanding the physical processes of debris flows.
","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/wri884004","usgsCitation":"Laenen, A., and Hansen, R.P., 1988, Simulation of three lahars in the Mount St Helens area, Washington using a one-dimensional, unsteady-state streamflow model: U.S. Geological Survey Water-Resources Investigations Report 88-4004, iv, 20 p., https://doi.org/10.3133/wri884004.","productDescription":"iv, 20 p.","costCenters":[{"id":518,"text":"Oregon Water Science Center","active":true,"usgs":true}],"links":[{"id":414481,"rank":3,"type":{"id":36,"text":"NGMDB Index Page"},"url":"https://ngmdb.usgs.gov/Prodesc/proddesc_46936.htm","linkFileType":{"id":5,"text":"html"}},{"id":159612,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/wri/1988/4004/report-thumb.jpg"},{"id":57039,"rank":2,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/wri/1988/4004/report.pdf","linkFileType":{"id":1,"text":"pdf"}}],"country":"United States","state":"Washington","otherGeospatial":"Mount St. Helens area","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -123,\n 46.5\n ],\n [\n -123,\n 46\n ],\n [\n -122,\n 46\n ],\n [\n -122,\n 46.5\n ],\n [\n -123,\n 46.5\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4afee4b07f02db697729","contributors":{"authors":[{"text":"Laenen, Antonius","contributorId":107673,"corporation":false,"usgs":true,"family":"Laenen","given":"Antonius","email":"","affiliations":[],"preferred":false,"id":199385,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hansen, R. P.","contributorId":106538,"corporation":false,"usgs":true,"family":"Hansen","given":"R.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":199384,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013668,"text":"70013668 - 1988 - Compositional evolution of the zoned calcalkaline magma chamber of Mount Mazama, Crater Lake, Oregon","interactions":[],"lastModifiedDate":"2018-10-24T13:23:57","indexId":"70013668","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","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":"Compositional evolution of the zoned calcalkaline magma chamber of Mount Mazama, Crater Lake, Oregon","docAbstract":"The climactic eruption of Mount Mazama has long been recognized as a classic example of rapid eruption of a substantial fraction of a zoned magma body. Increased knowledge of eruptive history and new chemical analyses of ∼350 wholerock and glass samples of the climactic ejecta, preclimactic rhyodacite flows and their inclusions, postcaldera lavas, and lavas of nearby monogenetic vents are used here to infer processes of chemical evolution of this late Pleistocene — Holocene magmatic system. The 6845±50 BP climactic eruption vented ∼50 km3of magma to form: (1) rhyodacite fall deposit; (2) welded rhyodacite ignimbrite; and (3) lithic breccia and zoned ignimbrite, these during collapse of Crater Lake caldera. Climactic ejecta were dominantly homogeneous rhyodacite (70.4±0.3% SiO2), followed by subordinate andesite and cumulate scoriae (48–61% SiO2). The gap in wholerock composition reflects mainly a step in crystal content because glass compositions are virtually continuous. Two types of scoriae are distinguished by different LREE, Rb, Th, and Zr, but principally by a twofold contrast in Sr content: High-Sr (HSr) and low-Sr (LSr) scoriae. HSr scoriae were erupted first. Trace element abundances indicate that HSr and LSr scoriae had different calcalkaline andesite parents; basalt was parental to some mafic cumulate scoriae. Parental magma compositions reconstructed from scoria wholerock and glass data are similar to those of inclusions in preclimactic rhyodacites and of aphyric lavas of nearby monogenetic vents.
Preclimactic rhyodacite flows and their magmatic inclusions give insight into evolution of the climactic chamber. Evolved rhyodacite flows containing LSr andesite inclusions were emplaced between ∼30000 and ∼25000 BP. At 7015±45 BP, the Llao Rock vent produced a zoned rhyodacite pumice fall, then rhyodacite lava with HSr andesite inclusions. The Cleetwood rhyodacite flow, emplaced immediately before the climactic eruption and compositionally identical to climactic rhyodacite (volatile-free), contains different HSr inclusions from Llao Rock. The change from LSr to HSr inclusions indicates replenishment of the chamber with andesite magma, perhaps several times, in the latest Pleistocene to early Holocene.
Modeling calculations and wholerock-glass relations suggest than: (1) magmas were derived mainly by crystallization differentiation of andesite liquid; (2) evolved preclimactic rhyodacite probably was derived from LSr andesite; (3) rhyodacites contain a minor component of partial melt from wall rocks, and (4) climactic and compositionally similar rhyodacites probably formed by mixing of evolved rhyodacite with HSr derivative liquid(s) after replenishment of the chamber with HSr andesite magma. Density considerations permit a model for growth and evolution of the chamber in which andesite recharge magma ponded repeatedly between cumulates and rhyodacite magma. Convective cooling of this andesite resulted in rapid crystallization and upward escape of buoyant derivative liquid which mixed with overlying, convecting rhyodacite. The evolved rhyodacites were erupted early in the chamber's history and(or) near its margins. Postcaldera andesite lavas may be hybrids composed of LSr cumulates mixed with remnant climactic rhyodacite. Younger postcaldera rhyodacite probably formed by fractionation of similar andesite and assimilation of partial melts of wallrocks.
Uniformity of climactic rhyodacite suggests homogeneous silicic ejecta from other volcanoes resulted from similar replenishment-driven convective mixing. Calcalkaline pluton compositions and their internal zonation can be interpreted in terms of the Mazama system frozen at various times in its history.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Contributions to Mineralogy and Petrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Springer-Verlag","doi":"10.1007/BF00402114","issn":"00107999","usgsCitation":"Bacon, C., and Druitt, T.H., 1988, Compositional evolution of the zoned calcalkaline magma chamber of Mount Mazama, Crater Lake, Oregon: Contributions to Mineralogy and Petrology, v. 98, no. 2, p. 224-256, https://doi.org/10.1007/BF00402114.","productDescription":"33 p.","startPage":"224","endPage":"256","numberOfPages":"33","costCenters":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"links":[{"id":219994,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":204996,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00402114"}],"country":"United States","state":"Oregon","otherGeospatial":"Mount Mazama, Crater Lake","volume":"98","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f937e4b0c8380cd4d4db","contributors":{"authors":[{"text":"Bacon, C. R. 0000-0002-2165-5618","orcid":"https://orcid.org/0000-0002-2165-5618","contributorId":21522,"corporation":false,"usgs":true,"family":"Bacon","given":"C. R.","affiliations":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"preferred":false,"id":366595,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Druitt, T. H.","contributorId":60662,"corporation":false,"usgs":true,"family":"Druitt","given":"T.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":366596,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70014404,"text":"70014404 - 1988 - Measurement, characterization, and prediction of strong ground motion","interactions":[],"lastModifiedDate":"2012-03-12T17:19:29","indexId":"70014404","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Measurement, characterization, and prediction of strong ground motion","docAbstract":"A number of predictive relationships derived from regression analysis of strong-motion data are available for horizontal peak acceleration, velocity, and response spectral values. Theoretical prediction of ground motion calls for stochastic source models because source heterogeneities control the amplitude of ground motion at most, if not all, frequencies of engineering interest. Theoretical methods have been developed for estimation of ground-motion parameters and simulation of ground-motion time series. These methods are particularly helpful for regions such, as eastern North America where strong-motion data are sparse. The authors survey the field, first reviewing developments in ground-motion measurement and data processing. The authors then consider the choice of parameters for characterizing strong ground motion and describe the wave-types involved in strong ground motion and the factors affecting ground-motion amplitudes. They conclude by describing methods for predicting ground motion.","largerWorkTitle":"Geotechnical Special Publication","conferenceTitle":"Earthquake Engineering and Soil Dynamics II - Recent Advances in Ground-Motion Evaluation: Proceedings of the Specialty Conference","conferenceDate":"27 June 1988 through 30 June 1988","conferenceLocation":"Park City, UT, USA","language":"English","publisher":"Publ by ASCE","publisherLocation":"New York, NY, United States","issn":"08950563","usgsCitation":"Joyner, W., and Boore, D.M., 1988, Measurement, characterization, and prediction of strong ground motion, in Geotechnical Special Publication, no. n, Park City, UT, USA, 27 June 1988 through 30 June 1988, p. 43-102.","startPage":"43","endPage":"102","numberOfPages":"60","costCenters":[],"links":[{"id":225955,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"n","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5323e4b0c8380cd6c8d3","contributors":{"authors":[{"text":"Joyner, William","contributorId":94444,"corporation":false,"usgs":true,"family":"Joyner","given":"William","affiliations":[],"preferred":false,"id":368329,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Boore, David M. boore@usgs.gov","contributorId":2509,"corporation":false,"usgs":true,"family":"Boore","given":"David","email":"boore@usgs.gov","middleInitial":"M.","affiliations":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"preferred":false,"id":368328,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":44852,"text":"wri884057 - 1988 - Areal variation in recharge to and discharge from the Floridan aquifer system in Florida","interactions":[],"lastModifiedDate":"2023-03-20T20:22:24.794333","indexId":"wri884057","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":342,"text":"Water-Resources Investigations Report","code":"WRI","active":false,"publicationSubtype":{"id":5}},"seriesNumber":"88-4057","title":"Areal variation in recharge to and discharge from the Floridan aquifer system in Florida","docAbstract":"This report is a revision and update of existing recharge maps of the Floridan aquifer system to include quantitative information derived from Regional Aquifer Systems Analysis models as well as other recent information and also includes information on discharge from the system. The report represents predevelopment conditions with inset map that describes the change in recharge resulting from development. Recharge is greater in areas where the Floridan is unconfined, poorly confined, or the overlying confining layer is breached by sinkholes, such as is commonly found in the area extending from Tallahassee to Tampa. Discharge from the Floridan is dominated by spring flow. Spring flow is common in the area between Tallahassee and Tampa. Offshore discharge by upward leakage and submarine springs also is an important component of the flow system. Little inflow or outflow occurs from the Floridan in large areas of Florida, including south Florida and the extreme panhandle. The principal factors affecting recharge to the Florida aquifer system are the thickness and hydraulic conductivity of the overlying confining bed. Other factors of importance include the vertical hydraulic gradient, water available for recharge, and aquifer transmissivity.
","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/wri884057","usgsCitation":"Aucott, W.R., 1988, Areal variation in recharge to and discharge from the Floridan aquifer system in Florida: U.S. Geological Survey Water-Resources Investigations Report 88-4057, 1 Plate: 39.90 x 35.35 inches, https://doi.org/10.3133/wri884057.","productDescription":"1 Plate: 39.90 x 35.35 inches","costCenters":[],"links":[{"id":161613,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":414380,"rank":3,"type":{"id":36,"text":"NGMDB Index Page"},"url":"https://ngmdb.usgs.gov/Prodesc/proddesc_46980.htm","linkFileType":{"id":5,"text":"html"}},{"id":274634,"rank":2,"type":{"id":17,"text":"Plate"},"url":"https://pubs.usgs.gov/wri/1988/4057/plate-1.pdf","linkFileType":{"id":1,"text":"pdf"}}],"country":"United States","state":"Florida","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -87.81898559997501,\n 30.9788108343064\n ],\n [\n -87.81898559997501,\n 24.90908840831331\n ],\n [\n -79.66372299066961,\n 24.90908840831331\n ],\n [\n -79.66372299066961,\n 30.9788108343064\n ],\n [\n -87.81898559997501,\n 30.9788108343064\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4abce4b07f02db67323e","contributors":{"authors":[{"text":"Aucott, Walter R.","contributorId":90275,"corporation":false,"usgs":true,"family":"Aucott","given":"Walter","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":230554,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70014406,"text":"70014406 - 1988 - The growth of geological structures by repeated earthquakes 1. Conceptual framework","interactions":[],"lastModifiedDate":"2024-06-05T15:19:17.418175","indexId":"70014406","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","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":"The growth of geological structures by repeated earthquakes 1. Conceptual framework","docAbstract":"In many places, earthquakes with similar characteristics have been shown to recur. If this is common, then relatively small deformations associated with individual earthquake cycles should accumulate over time to create geological structures. Following this paradigm, we show that existing models developed to describe leveling line changes associated with the seismic cycle can be adapted to explain geological features associated with a fault. In these models an elastic layer containing the fault overlies a viscous half-space with a different density. Fault motion associated with an earthquake results in immediate deformation followed by a long period of readjustment as stresses relax in the viscous layer and isostatic equilibrium is restored. Deformation is also caused as a result of the loading and unloading due to sediment deposition and erosion. In this paper, the parameters that control the growth of dip-slip structures are identified. We find that the flexural rigidity of the crust (or the apparent elastic thickness) provides the main control of the width of a structure. The loading due to erosion and deposition of sediment determines the ratio of uplift to subsidence between the two sides of the fault. The flexure due to sediment load is much more important in this respect than whether the fault is normal or reverse in character. We find that, in general, real structures are associated with apparent elastic thicknesses of 4 km or less and thus with very low flexural rigidities.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB093iB11p13307","issn":"01480227","usgsCitation":"King, G., Stein, R., and Rundle, J.B., 1988, The growth of geological structures by repeated earthquakes 1. Conceptual framework: Journal of Geophysical Research Solid Earth, v. 93, no. B11, p. 13307-13318, https://doi.org/10.1029/JB093iB11p13307.","productDescription":"12 p.","startPage":"13307","endPage":"13318","costCenters":[],"links":[{"id":226021,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"93","issue":"B11","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505baca8e4b08c986b323644","contributors":{"authors":[{"text":"King, G.C.P.","contributorId":18510,"corporation":false,"usgs":true,"family":"King","given":"G.C.P.","email":"","affiliations":[],"preferred":false,"id":368334,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Stein, R.S.","contributorId":8875,"corporation":false,"usgs":true,"family":"Stein","given":"R.S.","email":"","affiliations":[],"preferred":false,"id":368332,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rundle, J. B.","contributorId":17766,"corporation":false,"usgs":false,"family":"Rundle","given":"J.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":368333,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70013241,"text":"70013241 - 1988 - Molecular composition and mobility of torbanite precursors: Implications for the structure of coal","interactions":[],"lastModifiedDate":"2023-12-16T00:57:07.285115","indexId":"70013241","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1506,"text":"Energy & Fuels","active":true,"publicationSubtype":{"id":10}},"title":"Molecular composition and mobility of torbanite precursors: Implications for the structure of coal","docAbstract":"Coorongite, a torbanite precursor found in South Australia, and algal residues derived from Botryococcus braunii and other algae have been examined by solid-state 13C NMR techniques. The majority of carbon in these materials is present as (CH2)n. However, variable-temperature studies show that a considerable proportion of the alkyl chains have unusual dipolar-dephasing behavior and are more mobile than in rigid solids. It is suggested that these mobile structures contribute to the so-called \"guest phases\" in coal. The data are also consistent with a vascular and algal model of coal. ?? 1988 American Chemical Society.","language":"English","publisher":"American Chemical Society","doi":"10.1021/ef00011a012","issn":"08870624","usgsCitation":"Wilson, M.A., Batts, B., and Hatcher, P.G., 1988, Molecular composition and mobility of torbanite precursors: Implications for the structure of coal: Energy & Fuels, v. 2, no. 5, p. 668-672, https://doi.org/10.1021/ef00011a012.","productDescription":"5 p.","startPage":"668","endPage":"672","numberOfPages":"5","costCenters":[],"links":[{"id":220298,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"2","issue":"5","noUsgsAuthors":false,"publicationDate":"2002-05-01","publicationStatus":"PW","scienceBaseUri":"505a5cfee4b0c8380cd700af","contributors":{"authors":[{"text":"Wilson, M. A.","contributorId":107649,"corporation":false,"usgs":false,"family":"Wilson","given":"M.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":365614,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Batts, B.D.","contributorId":15757,"corporation":false,"usgs":true,"family":"Batts","given":"B.D.","email":"","affiliations":[],"preferred":false,"id":365612,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hatcher, Patrick G.","contributorId":93625,"corporation":false,"usgs":true,"family":"Hatcher","given":"Patrick","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":365613,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70014453,"text":"70014453 - 1988 - Coastal geomorphology of arctic Alaska","interactions":[],"lastModifiedDate":"2012-03-12T17:19:31","indexId":"70014453","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3519,"text":"Technical Council on Cold Regions Engineering Monograph","active":true,"publicationSubtype":{"id":10}},"title":"Coastal geomorphology of arctic Alaska","docAbstract":"The treeless, tundra-plain of northern Alaska merges with the Arctic Ocean along a coastal area characterized by low tundra bluffs, and sparse coastal and delta dunes. Coastal engineering projects that aggrade or degrade permafrost will alter the geomorphology and rates of coastal processes by changing coastal stability. Similarly, projects that modify the ice environment (artificial islands) or the coastal configuration (causeways) will cause nature to readjust to the new process regime, resulting in modification of the coast. In this paper the authors describe the coastal geomorphology from Barrow to the Canadian border. In addition, they provide a general outline and extensive references of the major coastal processes operating in this environment that will be useful on coastal environments elsewhere in the Arctic.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Technical Council on Cold Regions Engineering Monograph","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","isbn":"0872626393; 0872626393","usgsCitation":"Barnes, P.W., Rawlinson, S.E., and Reimnitz, E., 1988, Coastal geomorphology of arctic Alaska: Technical Council on Cold Regions Engineering Monograph, p. 3-30.","startPage":"3","endPage":"30","numberOfPages":"28","costCenters":[],"links":[{"id":225774,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f782e4b0c8380cd4cb63","contributors":{"authors":[{"text":"Barnes, Peter W.","contributorId":6042,"corporation":false,"usgs":true,"family":"Barnes","given":"Peter","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":368427,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rawlinson, Stuart E.","contributorId":99708,"corporation":false,"usgs":true,"family":"Rawlinson","given":"Stuart","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":368429,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Reimnitz, Erk","contributorId":17963,"corporation":false,"usgs":true,"family":"Reimnitz","given":"Erk","email":"","affiliations":[],"preferred":false,"id":368428,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70014410,"text":"70014410 - 1988 - Sr and Nd isotopic variations in ferromanganese crusts from the Central Pacific: Implications for age and source provenance","interactions":[],"lastModifiedDate":"2024-04-03T16:21:48.833884","indexId":"70014410","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","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":"Sr and Nd isotopic variations in ferromanganese crusts from the Central Pacific: Implications for age and source provenance","docAbstract":"Isotopic analyses of two hydrogenetic ferromanganese (Fe-Mn) crusts from volcanic edifices in the central Pacific Ocean reveal systematic variations in
Descriptive and grade/tonnage models have recently been built for many types of deposits. Such models consist of descriptions of mineralogy, host rocks, ore textures, controls, alteration, geochemical signatures, age, and tectonic settings, together with statistical models of grades, tonnages, and contained metal of deposits of each type. The models are used to identify areas that may contain undiscovered deposits of given types, to convey to non-geologists an idea of the importance of such deposits, and to test and refine classifications of mineral deposits.
Descriptive and grade/tonnage models have recently been built for five types of primary tin deposits: rhyolite-hosted such as in Mexico; hydrothermal lodes such as in Cornwall, England, and the Herberton district, Queensland; replacement (or exhalative?) such as Renison Bell, Tasmania; skarn such as at Lost River, Alaska; and greisen such as in the Erzgebirge. Analyses of frequency distributions of tonnage, contained metal, tin grades and the relationships between these variables show that the deposits fall into four well-defined domains that have definite geological characteristics. Rhyolite-hosted, or Mexican, deposits contain a median of 4 t of tin and have a median grade of 0.4% Sn. Hydrothermal lode deposits have the highest grades. Half of such deposits have grades over 1.0% Sn, and the majority contain more than 1,000 t Sn. Large hydrothermal vein deposits contain more than 50,000 t Sn. Replacement (or exhalative?) deposits contain the largest amount of tin (median = 40,000 t). They are only of slightly lower grade (median = 0.80% Sn) than the hydrothermal lodes. Greisen or stockwork deposits have larger tonnages than replacement deposits, but contain less tin (median = 25,000 t).They are also of much lower grade (median = 0.3% Sn). Though grades and tonnages are available for only four skarn deposits, they appear to be more like greisen deposits than replacement deposits when compared using grades, tonnage and contained tin.
Although these individual models of primary tin deposits must be regarded as preliminary because of the relatively small number of deposits upon which they are built, they clearly demonstrate differences among types and provide basic information that can be useful in making decisions about exploration strategy, land classification, and tin supply.
","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Geology of tin deposits in Asia and the Pacific","language":"English","publisher":"Springer","doi":"10.1007/978-3-642-72765-8_4","usgsCitation":"Menzie, W., Reed, B., and Singer, D.A., 1988, Models of grades and tonnages of some lode tin deposits, chap. of Geology of tin deposits in Asia and the Pacific, p. 73-88, https://doi.org/10.1007/978-3-642-72765-8_4.","productDescription":"16 p.","startPage":"73","endPage":"88","costCenters":[{"id":312,"text":"Geology, Minerals, Energy, and Geophysics Science Center","active":true,"usgs":true}],"links":[{"id":354465,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5b15af92e4b092d9651e2330","contributors":{"authors":[{"text":"Menzie, W. D.","contributorId":52916,"corporation":false,"usgs":true,"family":"Menzie","given":"W. D.","affiliations":[],"preferred":false,"id":736462,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Reed, B.L.","contributorId":29434,"corporation":false,"usgs":true,"family":"Reed","given":"B.L.","email":"","affiliations":[],"preferred":false,"id":736463,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Singer, Donald A. dsinger@usgs.gov","contributorId":5601,"corporation":false,"usgs":true,"family":"Singer","given":"Donald","email":"dsinger@usgs.gov","middleInitial":"A.","affiliations":[],"preferred":true,"id":736464,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70013694,"text":"70013694 - 1988 - On low-frequency errors of uniformly modulated filtered white-noise models for ground motions","interactions":[],"lastModifiedDate":"2013-03-13T15:23:09","indexId":"70013694","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1434,"text":"Earthquake Engineering and Structural Dynamics","active":true,"publicationSubtype":{"id":10}},"title":"On low-frequency errors of uniformly modulated filtered white-noise models for ground motions","docAbstract":"Low-frequency errors of a commonly used non-stationary stochastic model (uniformly modulated filtered white-noise model) for earthquake ground motions are investigated. It is shown both analytically and by numerical simulation that uniformly modulated filter white-noise-type models systematically overestimate the spectral response for periods longer than the effective duration of the earthquake, because of the built-in low-frequency errors in the model. The errors, which are significant for low-magnitude short-duration earthquakes, can be eliminated by using the filtered shot-noise-type models (i. e. white noise, modulated by the envelope first, and then filtered).","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Earthquake Engineering and Structural Dynamics","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Wiley","doi":"10.1002/eqe.4290160307","issn":"03756297","usgsCitation":"Safak, E., and Boore, D.M., 1988, On low-frequency errors of uniformly modulated filtered white-noise models for ground motions: Earthquake Engineering and Structural Dynamics, v. 16, no. 3, p. 381-388, https://doi.org/10.1002/eqe.4290160307.","startPage":"381","endPage":"388","numberOfPages":"8","costCenters":[],"links":[{"id":220389,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":269244,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/eqe.4290160307"}],"volume":"16","issue":"3","noUsgsAuthors":false,"publicationDate":"2006-12-18","publicationStatus":"PW","scienceBaseUri":"505a69e6e4b0c8380cd73f74","contributors":{"authors":[{"text":"Safak, Erdal","contributorId":73984,"corporation":false,"usgs":true,"family":"Safak","given":"Erdal","email":"","affiliations":[],"preferred":false,"id":366657,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Boore, David M. boore@usgs.gov","contributorId":2509,"corporation":false,"usgs":true,"family":"Boore","given":"David","email":"boore@usgs.gov","middleInitial":"M.","affiliations":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"preferred":false,"id":366656,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70014412,"text":"70014412 - 1988 - Contrasting serpentinization processes in the eastern Central Alps","interactions":[],"lastModifiedDate":"2012-03-12T17:19:29","indexId":"70014412","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","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":"Contrasting serpentinization processes in the eastern Central Alps","docAbstract":"Stable isotope compositions have been determined for serpentinites from between Davos (Arosa-Platta nappe, Switzerland) and the Valmalenco (Italy). ??D and ??18O values (-120 to -60 and 6-10???, respectively) in the Arosa-Platta nappe indicate that serpentinization took place on the continent at relatively low temperatures in the presence of limited amounts of metamorphic fluids that contained a component of meteoric water. One sample of chrysotile has a ??18O value of 13??? providing evidence of high W/R ratios and low formation temperature of lizardite-chrysotile in this area. In contrast, relatively high ??D values (-42 to -34???) and low ??18O values (4.4-7.4???) for serpentine in the eastern part of the Valmalenco suggest a serpentinization process that took place at moderate temperatures in fluids that were dominated by ocean water. The antigorite in the Valmalenco is the first reported example of continental antigorite with an ocean water signature. An amphibole sample from a metasomatically overprinted contact zone to metasediments (??D=-36???) indicates that the metasomatic event also took place in the presence of ocean water. Lower ??D values (-93 to -60???) of serpentines in the western part of the Valmalenco suggest a different alteration history possibly influenced by fluids associated with contact metamorphism. Low water/rock ratios during regional metamorphism (and metasomatism) have to be assumed for both regions. ?? 1988 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/BF00371940","issn":"00107999","usgsCitation":"Burkhard, D., and O’Neil, J.R., 1988, Contrasting serpentinization processes in the eastern Central Alps: Contributions to Mineralogy and Petrology, v. 99, no. 4, p. 498-506, https://doi.org/10.1007/BF00371940.","startPage":"498","endPage":"506","numberOfPages":"9","costCenters":[],"links":[{"id":480015,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"http://hdl.handle.net/2027.42/47349","text":"External Repository"},{"id":205684,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00371940"},{"id":226152,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"99","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fa7ce4b0c8380cd4db0b","contributors":{"authors":[{"text":"Burkhard, D.J.M.","contributorId":19716,"corporation":false,"usgs":true,"family":"Burkhard","given":"D.J.M.","email":"","affiliations":[],"preferred":false,"id":368347,"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":368348,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013647,"text":"70013647 - 1988 - Late Wisconsinan-Holocene paleogeography of Delaware Bay; a large coastal plain estuary","interactions":[],"lastModifiedDate":"2024-09-30T22:36:12.525238","indexId":"70013647","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2667,"text":"Marine Geology","active":true,"publicationSubtype":{"id":10}},"title":"Late Wisconsinan-Holocene paleogeography of Delaware Bay; a large coastal plain estuary","docAbstract":"Analyses of an extensive grid of seismic reflection profiles along with previously published core data and modern sedimentary environment information from surrounding coastal areas permit an outline of the paleogeography of the large Delaware Bay estuary during the last transgression of sea level. During late Wisconsinan times, the Delaware River system eroded a dendritic drainage pattern into the gravelly and muddy sands of Tertiary and younger age beneath the southern half of the lower bay area. This system included the trunk valley of the ancestral river and a large tributary valley formed by the convergence of secondary streams along the Delaware coast. The evolution of the estuary from this drainage system proceeded as follows: (1) When local relative sea level was at -50 m, the head of the tide reached the present bay-mouth area. (2) At -40 m (possibly 15,000-12,000 yrs ago), the trunk valley of the drainage system was a tidal river that extended more than 30 km up the bay, and a small contiguous inlet existed at the bay mouth. (3) At -30 m (approximately 11,000-10,000 yrs ago), the estuary comprised two narrow passages formed by the drowning of the main and tributary river valleys, and the bay-mouth inlet was 5-6 km wide. (4) At -20 m (between 8000 and 7000 yrs ago), the two passages of the estuary were joined, except for a series of small islands on top of a low intervening ridge, and the inlet channel was 11 km wide. (5) At -10 m (between 6000 and 5000 yrs ago), the estuary was nearly continuous and encompassed about 60% of the present lower bay area. Thin, coarse-grained fluvial deposits accumulated initially within the main channels of the former drainage system as base level was elevated by rising sea level. During the subsequent development of the estuary, clayey silts were deposited rapidly beneath the nontidal estuarine depocenter (turbidity maximum) as it migrated through the bay area, and organic muds accumulated in tidal wetlands that occupied the mouths of tributaries and small marginal embayments. As the fetch and tidal prism of the estuary increased, narrow barrier and headland beaches, composed of fine to coarse sands, were formed locally along the bay shorelines. In the later stages of development, sediment scour, reworking and transport became the dominant processes within the open estuary. Data from this study demonstrate the great temporal and spatial variability of sedimentary deposits within large drowned river-valley estuaries and outline a model that can be used to interpret ancient estuarine strata. ?? 1988.","language":"English","publisher":"Elsevier","doi":"10.1016/0025-3227(88)90055-2","issn":"00253227","usgsCitation":"Knebel, H., Fletcher, C., and Kraft, J., 1988, Late Wisconsinan-Holocene paleogeography of Delaware Bay; a large coastal plain estuary: Marine Geology, v. 83, no. 1-4, p. 115-133, https://doi.org/10.1016/0025-3227(88)90055-2.","productDescription":"19 p.","startPage":"115","endPage":"133","numberOfPages":"19","costCenters":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":220550,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Delaware, New Jersey","otherGeospatial":"Delaware Bay","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -75.48161565019512,\n 39.348130187297784\n ],\n [\n -75.48161565019512,\n 38.74867521775795\n ],\n [\n -74.8564927492127,\n 38.74867521775795\n ],\n [\n -74.8564927492127,\n 39.348130187297784\n ],\n [\n -75.48161565019512,\n 39.348130187297784\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"83","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4543e4b0c8380cd67182","contributors":{"authors":[{"text":"Knebel, H.J.","contributorId":79092,"corporation":false,"usgs":true,"family":"Knebel","given":"H.J.","affiliations":[],"preferred":false,"id":366550,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fletcher, C.H. III","contributorId":85721,"corporation":false,"usgs":true,"family":"Fletcher","given":"C.H.","suffix":"III","email":"","affiliations":[],"preferred":false,"id":366551,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kraft, J.C.","contributorId":69300,"corporation":false,"usgs":true,"family":"Kraft","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":366549,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70013645,"text":"70013645 - 1988 - On-line estimation of nonlinear physical systems","interactions":[],"lastModifiedDate":"2012-03-12T17:18:27","indexId":"70013645","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2700,"text":"Mathematical Geology","active":true,"publicationSubtype":{"id":10}},"title":"On-line estimation of nonlinear physical systems","docAbstract":"Recursive algorithms for estimating states of nonlinear physical systems are presented. Orthogonality properties are rediscovered and the associated polynomials are used to linearize state and observation models of the underlying random processes. This requires some key hypotheses regarding the structure of these processes, which may then take account of a wide range of applications. The latter include streamflow forecasting, flood estimation, environmental protection, earthquake engineering, and mine planning. The proposed estimation algorithm may be compared favorably to Taylor series-type filters, nonlinear filters which approximate the probability density by Edgeworth or Gram-Charlier series, as well as to conventional statistical linearization-type estimators. Moreover, the method has several advantages over nonrecursive estimators like disjunctive kriging. To link theory with practice, some numerical results for a simulated system are presented, in which responses from the proposed and extended Kalman algorithms are compared. ?? 1988 International Association for Mathematical Geology.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Mathematical Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Kluwer Academic Publishers-Plenum Publishers","doi":"10.1007/BF00918881","issn":"08828121","usgsCitation":"Christakos, G., 1988, On-line estimation of nonlinear physical systems: Mathematical Geology, v. 20, no. 2, p. 111-133, https://doi.org/10.1007/BF00918881.","startPage":"111","endPage":"133","numberOfPages":"23","costCenters":[],"links":[{"id":205038,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00918881"},{"id":220495,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"20","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6e1ae4b0c8380cd754bc","contributors":{"authors":[{"text":"Christakos, G.","contributorId":87685,"corporation":false,"usgs":true,"family":"Christakos","given":"G.","email":"","affiliations":[],"preferred":false,"id":366545,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70014425,"text":"70014425 - 1988 - Icebergs rework shelf sediments to 500 m off Antarctica","interactions":[],"lastModifiedDate":"2024-01-24T12:32:57.237036","indexId":"70014425","displayToPublicDate":"1988-01-01T00:00:00","publicationYear":"1988","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1796,"text":"Geology","active":true,"publicationSubtype":{"id":10}},"title":"Icebergs rework shelf sediments to 500 m off Antarctica","docAbstract":"Icebergs and sea ice rework the sediments of high-latitude shelves, producing modern diamicts (ice-keel turbates) unrelated to glacial proximity. Off Antarctica, sidescan sonar data indicate the presence of ice-gouge features formed by the physical interaction between ice keels and the sea bed. These are recognized as incisions a few metres deep and tens of metres wide, in water depths up to 500 m. On the submarine bank tops and slopes off Wilkes Land and in the Weddell Sea, subcircular depressions 30 to 150 m in diameter, a washboard pattern, and hummocky bed features also represent iceberg-resting sites. The freshness of sea-bed morphology, nearby Holocene sediment ponding, and active hydraulic sedimentary processes indicate that the sea floor is being reworked by iceberg keels. Tabular iceberg drafts in excess of 330 m have been measured, and modeling studies suggest that nontabular iceberg drafts of 500 m are possible. We conclude that a modern ice-keel turbate deposit in the form of a poorly stratified diamicton is probably widespread on that part (54%) of the Antarctic shelf less than 500 m deep.