Experimental and field data are used to extend the utility of conodonts as semi-quantitative thermal indices into the regimes of regional and contact metamorphism, as well as hydrothermal alteration. An Arrhenius plot of data from induced conodont color alteration by pyrolysis in air at 1 atm was used to generate the geologic temperatures for conodont color-alteration indices (CAI) above 300 °C, that is, for CAI values of 5½ through 8. Such CAI values occur in very low- to medium-grade, regionally metamorphosed, contact-metamorphosed, and hydrothermally altered rocks. The uniformity or variability of CAI values within a sample, together with conodont texture, can help to distinguish grades and environments of metamorphism, particularly in metacarbonate sequences. Induced CAI by pyrolysis in a water-methane mixture at ½ kbar results in retardation of CAI and in a disparate mixture of both low and high CAI values within each experimental sample. In this system, color-alteration processes, above a CAI of 2 to 3, seem to change from predominantly carbonization to predominantly loss of organic matter, presumably by oxidation and volatilization of oxides. These experiments approximate the type of CAI mixture characteristically found in conodonts recovered from hydrothermally altered rocks. These data indicate that CAI values of 6 to 8 cannot be used to assess precise temperatures of hydrothermally altered rocks but may serve as useful indicators of potential mineralization.
","language":"English","publisher":"Geological Society of America","doi":"10.1130/0016-7606(1987)99<471:CCATAA>2.0.CO;2","usgsCitation":"Rejebian, V., Harris, A., and Huebner, J., 1987, Conodont color and textural alteration: An index to regional metamorphism, contact metamorphism, and hydrothermal alteration: Geological Society of America Bulletin, v. 99, no. 4, p. 471-479, https://doi.org/10.1130/0016-7606(1987)99<471:CCATAA>2.0.CO;2.","productDescription":"9 p.","startPage":"471","endPage":"479","numberOfPages":"9","costCenters":[],"links":[{"id":225565,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"99","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f9d1e4b0c8380cd4d7c8","contributors":{"authors":[{"text":"Rejebian, V.A.","contributorId":15352,"corporation":false,"usgs":true,"family":"Rejebian","given":"V.A.","email":"","affiliations":[],"preferred":false,"id":367969,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Harris, A. G.","contributorId":39791,"corporation":false,"usgs":true,"family":"Harris","given":"A. G.","affiliations":[],"preferred":false,"id":367970,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Huebner, J.S.","contributorId":41422,"corporation":false,"usgs":true,"family":"Huebner","given":"J.S.","email":"","affiliations":[],"preferred":false,"id":367971,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70014108,"text":"70014108 - 1987 - Isotopic composition of pyrite: Relationship to organic matter type and iron availability in some North American cretaceous shales","interactions":[],"lastModifiedDate":"2023-11-17T01:04:56.721853","indexId":"70014108","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1214,"text":"Chemical Geology: Isotope Geoscience Section","active":true,"publicationSubtype":{"id":10}},"title":"Isotopic composition of pyrite: Relationship to organic matter type and iron availability in some North American cretaceous shales","docAbstract":"The S isotope composition of pyrite in Cretaceous shales from the Western Interior of North America is related to organic C abundance, kerogen type and Fe availability. Both calcareous and noncalcareous rocks show a correlation between S and C, but noncalcareous rocks are relatively enriched in S with a higher S/C ratio. This higher ratio probably shows that pyrite formation was Fe limited in the calcareous rocks. Organic-carbon-rich noncalcareous shales accumulated slowly beneath anoxic bottom waters. The anoxic bottom waters allowed hydrogen-rich organic matter to be preserved. Such shales have a narrow range of 34S-depleted sulfide and have Fe/S ratios like stoichiometric pyrite, suggesting that pyrite formation in organic-rich shales was also limited by Fe availability. Conversely, organic-poor shales commonly accumulated at comparatively high rates, contain hydrogen-poor and refractory organic matter, and have a wide range of pyrite-S isotopic compositions. These organic-poor shales contain post-sulfidic authigenic minerals such as siderite and have excess reactive Fe rather than pyrite stoichiometry. Evidently Fe played a large role in early diagenesis and determined the course of post-sulfidic diagenesis. Fe availability was, however, mainly controlled by provenance, by the rates of sediment accumulation, and by the oxygen content of the depositional environment.
Atitlán caldera has been the site of several silicic eruptions within the last 150,000 years, following a period of basalt/andesite volcanism. The silicic volcanism began with 5–10 km3 of rhyodacites, erupted as plinian fall and pyroclastic flows, about 126,000 yr. B.P. At 85,000 yr. B.P. 270–280 km3 of compositionally distinct rhyolite was erupted in the Los Chocoyos event which produced widely dispersed, plinian fall deposits and widespread, mobile pyroclastic flows. In the latter parts of this eruption rhyodacite and minor dacite were erupted which compositionally resembled the earliest silicic magmas of the Atitlán center. As a result of this major eruption, the modern Atitlán (III) caldera formed. Following this event, rhyodacites were again erupted in smaller (5–13 km3) volumes, partly through the lake, and mafic volcanism resumed, forming three composite volcanoes within the caldera. The bimodal mafic/silicic Atitlán volcanism is similar to that which has occurred elsewhere in the Guatemalan Highlands, but is significantly more voluminous. Mafic lavas are thought to originate in the mantle, but rise, intrude and underplate the lower crust and partly escape to the surface. Eventually, silicic melts form in the crust, possibly partly derived from underplated basaltic material, rise, crystallize and erupt. The renewed mafic volcanism could reflect either regional magmato-tectonic adjustment after the large silicic eruption or the onset of a new cycle.
","language":"English","publisher":"Elsevier","doi":"10.1016/0377-0273(87)90054-0","issn":"03770273","usgsCitation":"Rose, W.I., Newhall, C.G., Bornhorst, T.J., and Self, S., 1987, Quaternary silicic pyroclastic deposits of Atitlán Caldera, Guatemala: Journal of Volcanology and Geothermal Research, v. 33, no. 1-3, p. 57-80, https://doi.org/10.1016/0377-0273(87)90054-0.","productDescription":"24 p.","startPage":"57","endPage":"80","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":487243,"rank":1,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://doi.org/10.1016/0377-0273(87)90054-0","text":"External Repository"},{"id":226201,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"33","issue":"1-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a92d9e4b0c8380cd80aaf","contributors":{"authors":[{"text":"Rose, William I. Jr.","contributorId":71556,"corporation":false,"usgs":true,"family":"Rose","given":"William","suffix":"Jr.","email":"","middleInitial":"I.","affiliations":[],"preferred":false,"id":367601,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Newhall, Christopher G.","contributorId":25557,"corporation":false,"usgs":true,"family":"Newhall","given":"Christopher","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":367602,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bornhorst, Theodore J.","contributorId":68375,"corporation":false,"usgs":true,"family":"Bornhorst","given":"Theodore","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":367600,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Self, Stephen","contributorId":29060,"corporation":false,"usgs":true,"family":"Self","given":"Stephen","affiliations":[],"preferred":false,"id":367603,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70014819,"text":"70014819 - 1987 - Stable isotope compositions of fossil mollusks from southern California: Evidence for a cool last interglacial ocean.","interactions":[],"lastModifiedDate":"2024-01-26T01:26:57.26798","indexId":"70014819","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1796,"text":"Geology","active":true,"publicationSubtype":{"id":10}},"title":"Stable isotope compositions of fossil mollusks from southern California: Evidence for a cool last interglacial ocean.","docAbstract":"Stable isotope compositions have been determined for modern mullusks and fossil mollusks collected from uplifted marine terraces at three localities in southern California. By using a paleoclimatic model that decouples the temperature and ice-volume signals in ocean water, ocean-water temperatures off southern California are estimated to have been −3.8 °C at ∼85 ka, −3.0 °C at ∼107 ka, and −2.2 °C at ∼125 ka relative to present temperature. These results indicate rather cool conditions during the peak of the last interglacial stage at 125 ka and conflict with results from terrace faunal studies that suggest water temperatures were warm or warmer than at present.
A geochemical survey of the Sherbrooke and Lewiston 1° × 2° quadrangles was conducted from 1979 to 1982 by the U.S. Geological Survey as part of the Conterminous United States Mineral Assessment Program. The area covers about 23,000 km2. The region is characterized by a temperate climate, abundant rainfall, and dense forests. The topography ranges from rolling and subdued to mountainous. Bedrock is generally covered by glacial deposits, lakes, and bogs. The bedrock includes metamorphic and plutonic rocks ranging in age from Precambrian to Cretaceous. Known mineral deposits within the area include massive-sulfide deposits, Cu-Mo porphyry deposits, minor base-metal vein deposits, minor Sn-bearing vein deposits, and minor Be-bearing skarn deposits.
","language":"English","publisher":"Elsevier","doi":"10.1016/0375-6742(87)90074-4","issn":"03756742","usgsCitation":"Nowlan, G., Canney, F., Howd, F.H., and Domenico, J.A., 1987, Regional geochemical studies in parts of Maine, New Hampshire and Vermont, U.S.A.: Journal of Geochemical Exploration, v. 29, no. 1-3, p. 129-150, https://doi.org/10.1016/0375-6742(87)90074-4.","productDescription":"22 p.","startPage":"129","endPage":"150","numberOfPages":"22","costCenters":[],"links":[{"id":225278,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"29","issue":"1-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a4dae4b0e8fec6cdbca7","contributors":{"authors":[{"text":"Nowlan, G.A.","contributorId":99131,"corporation":false,"usgs":true,"family":"Nowlan","given":"G.A.","affiliations":[],"preferred":false,"id":369368,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Canney, F. C.","contributorId":24790,"corporation":false,"usgs":true,"family":"Canney","given":"F. C.","affiliations":[],"preferred":false,"id":369366,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Howd, F. H.","contributorId":52965,"corporation":false,"usgs":true,"family":"Howd","given":"F.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":369367,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Domenico, J. A.","contributorId":12028,"corporation":false,"usgs":true,"family":"Domenico","given":"J.","middleInitial":"A.","affiliations":[],"preferred":false,"id":369365,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70014259,"text":"70014259 - 1987 - Convergent tectonics and coastal upwelling: a history of the Peru continental margin ( Pacific).","interactions":[],"lastModifiedDate":"2018-01-08T12:47:04","indexId":"70014259","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1582,"text":"Episodes","active":true,"publicationSubtype":{"id":10}},"title":"Convergent tectonics and coastal upwelling: a history of the Peru continental margin ( Pacific).","docAbstract":"Late in 1986, scientists on the ODP drillship JOIDES Resolution confirmed that the upper slope of the Peruvian margin consists of continental crust whereas the lower slope comprises an accretionary complex. An intricate history of horizontal and vertical movements can be detected, and the locations of ancient centers of upwelling appear to have varied, partly due to tectonic movements of the margin. In this review of Leg 112, the 3 scientific leaders on this cruise discuss their results. -from Journal Editor","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Episodes","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"07053797","usgsCitation":"von Huene, R.E., Suess, E., and Emeis, K., 1987, Convergent tectonics and coastal upwelling: a history of the Peru continental margin ( Pacific).: Episodes, v. 10, no. 2, p. 87-93.","startPage":"87","endPage":"93","numberOfPages":"7","costCenters":[],"links":[{"id":225564,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"10","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fbd8e4b0c8380cd4dfda","contributors":{"authors":[{"text":"von Huene, Roland E. 0000-0003-1301-3866 rvonhuene@usgs.gov","orcid":"https://orcid.org/0000-0003-1301-3866","contributorId":191070,"corporation":false,"usgs":true,"family":"von Huene","given":"Roland","email":"rvonhuene@usgs.gov","middleInitial":"E.","affiliations":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true},{"id":7065,"text":"USGS emeritus","active":true,"usgs":false}],"preferred":false,"id":367967,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Suess, E.","contributorId":77667,"corporation":false,"usgs":true,"family":"Suess","given":"E.","email":"","affiliations":[],"preferred":false,"id":367968,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Emeis, K.C.","contributorId":47920,"corporation":false,"usgs":true,"family":"Emeis","given":"K.C.","affiliations":[],"preferred":false,"id":367966,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70014256,"text":"70014256 - 1987 - Pressure-composition relations for coexisting gases and liquids and the critical points in the system NaCl-H2O at 450, 475, and 500°C","interactions":[],"lastModifiedDate":"2015-06-02T12:31:14","indexId":"70014256","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","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":"Pressure-composition relations for coexisting gases and liquids and the critical points in the system NaCl-H2O at 450, 475, and 500°C","docAbstract":"Pressure-temperature-composition (P, T, x) relations for the co-existing vapor and liquid phases in the system NaCl-H2O were determined experimentally at 450, 475, and 500°C. Data for each isotherm includeP-x relations near the critical point and extend to the three-phase assemblage vapor-liquid-halite on the vapor side. On the liquid side the P-x data range from the critical point to the room-temperature halite saturation point (~25 wt.% NaCl). Critical pressures were calculated from measured pressures and compositions and classical theory. The results generally support the few data points of Urusova (1974, 1975) and Ölander and Liander (1950) but differ markedly from the extensive data of Sourirajan andKennedy (1962).
","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7037(87)90289-4","issn":"00167037","usgsCitation":"Rosenbauer, R.J., and Bischoff, J.L., 1987, Pressure-composition relations for coexisting gases and liquids and the critical points in the system NaCl-H2O at 450, 475, and 500°C: Geochimica et Cosmochimica Acta, v. 51, no. 9, p. 2349-2354, https://doi.org/10.1016/0016-7037(87)90289-4.","productDescription":"6 p.","startPage":"2349","endPage":"2354","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":225500,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"51","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a8b5fe4b0c8380cd7e225","contributors":{"authors":[{"text":"Rosenbauer, Robert J. brosenbauer@usgs.gov","contributorId":204,"corporation":false,"usgs":true,"family":"Rosenbauer","given":"Robert","email":"brosenbauer@usgs.gov","middleInitial":"J.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":367952,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bischoff, James L. jbischoff@usgs.gov","contributorId":1389,"corporation":false,"usgs":true,"family":"Bischoff","given":"James","email":"jbischoff@usgs.gov","middleInitial":"L.","affiliations":[],"preferred":true,"id":367951,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70014254,"text":"70014254 - 1987 - Geology and origin of the Death Valley uranium deposit, Seward Peninsula, Alaska","interactions":[],"lastModifiedDate":"2017-07-03T23:04:45","indexId":"70014254","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","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":"Geology and origin of the Death Valley uranium deposit, Seward Peninsula, Alaska","docAbstract":"A uranium deposit discovered in 1977 in western Alaska, by means of airborne radiometric data, is the largest known in Alaska on the basis of industry reserve estimates. At about latitude 65 degrees N, it is the most northerly known sandstone-type uranium deposit in the world. The deposit lies in Eocene continental sandstone near the eastern end of the Seward Peninsula, in the southern end of a graben that extends northward into the Death Valley depositional basin.The deposit is apparently of epigenetic and supergene origin. The uranium was derived from the Cretaceous granite of the Darby pluton that forms part of the western side of Death Valley. Uranium from primary mineralization is in the subsurface in a marginal facies of the Tertiary sedimentary basin where nearshore coarse clastic rocks are interbedded with coal and lacustrine clay. Primary mineralization occurred when uranium-bearing oxidizing ground water moved downdip from the pluton eastward through transmissive clastic beds or on the surface. Uranium was deposited where the coal or other carbonaceous material produced a reducing environment in arkosic host rocks. The supergene enrichment is related to a soil horizon at the present ground surface. The most common uranium mineral is meta-autunite, but cofflnite has been identified in the primary deposits. The host rocks for the primary deposits were partly covered by basalt flows that issued from nearby vents. Some of the basalt is highly altered, and some basalt float from the supergene zone has alteration rinds that are enriched in uranium.Extensive exploratory drilling took place from 1979 to 1981. The average grade of the potential ore is 0.27 percent U 3 O 8 and the average thickness is 3 m. The calculated reserves are 1,000,000 lbs U 3 O 8 ; additional drilling would probably add to this figure.
","language":"English","publisher":"Society of Economic Geologists","doi":"10.2113/gsecongeo.82.6.1558","issn":"00130109","usgsCitation":"Dickinson, K.A., Cunningham, K.D., and Ager, T.A., 1987, Geology and origin of the Death Valley uranium deposit, Seward Peninsula, Alaska: Economic Geology, v. 82, no. 6, p. 1558-1574, https://doi.org/10.2113/gsecongeo.82.6.1558.","productDescription":"17 p.","startPage":"1558","endPage":"1574","costCenters":[],"links":[{"id":225498,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","otherGeospatial":"Seward Peninsula","volume":"82","issue":"6","noUsgsAuthors":false,"publicationDate":"1987-10-01","publicationStatus":"PW","scienceBaseUri":"505a1451e4b0c8380cd549d1","contributors":{"authors":[{"text":"Dickinson, Kendell A.","contributorId":55430,"corporation":false,"usgs":true,"family":"Dickinson","given":"Kendell","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":367946,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Cunningham, Kenneth D.","contributorId":99707,"corporation":false,"usgs":true,"family":"Cunningham","given":"Kenneth","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":367947,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ager, Thomas A. 0000-0002-5029-7581 tager@usgs.gov","orcid":"https://orcid.org/0000-0002-5029-7581","contributorId":736,"corporation":false,"usgs":true,"family":"Ager","given":"Thomas","email":"tager@usgs.gov","middleInitial":"A.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":367945,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70014253,"text":"70014253 - 1987 - DIGITAL CARTOGRAPHY OF THE PLANETS: NEW METHODS, ITS STATUS, AND ITS FUTURE.","interactions":[],"lastModifiedDate":"2012-03-12T17:19:30","indexId":"70014253","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3052,"text":"Photogrammetric Engineering and Remote Sensing","active":true,"publicationSubtype":{"id":10}},"title":"DIGITAL CARTOGRAPHY OF THE PLANETS: NEW METHODS, ITS STATUS, AND ITS FUTURE.","docAbstract":"A system has been developed that establishes a standardized cartographic database for each of the 19 planets and major satellites that have been explored to date. Compilation of the databases involves both traditional and newly developed digital image processing and mosaicking techniques, including radiometric and geometric corrections of the images. Each database, or digital image model (DIM), is a digital mosaic of spacecraft images that have been radiometrically and geometrically corrected and photometrically modeled. During compilation, ancillary data files such as radiometric calibrations and refined photometric values for all camera lens and filter combinations and refined camera-orientation matrices for all images used in the mapping are produced.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Photogrammetric Engineering and Remote Sensing","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00991112","usgsCitation":"Batson, R.M., 1987, DIGITAL CARTOGRAPHY OF THE PLANETS: NEW METHODS, ITS STATUS, AND ITS FUTURE.: Photogrammetric Engineering and Remote Sensing, v. 53, no. 9, p. 1211-1218.","startPage":"1211","endPage":"1218","numberOfPages":"8","costCenters":[],"links":[{"id":225497,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"53","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fd47e4b0c8380cd4e735","contributors":{"authors":[{"text":"Batson, R. M.","contributorId":76714,"corporation":false,"usgs":true,"family":"Batson","given":"R.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":367944,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70014250,"text":"70014250 - 1987 - Diagenesis and fluid flow in the San Juan Basin, New Mexico - regional zonation in the mineralogy and stable isotope composition of clay minerals in sandstone.","interactions":[],"lastModifiedDate":"2017-01-11T16:44:37","indexId":"70014250","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":732,"text":"American Journal of Science","active":true,"publicationSubtype":{"id":10}},"title":"Diagenesis and fluid flow in the San Juan Basin, New Mexico - regional zonation in the mineralogy and stable isotope composition of clay minerals in sandstone.","docAbstract":"The Westwater Canyon Member of the Upper Jurassic Morrison Formation is a relatively homogeneous, hydrologically continuous 100-m-thick sequence of massive fluvial sandstone, bounded above and below by relatively heterogeneous, hydrologically discontinuous units and has served as a primary conduit for fluids within this stratigraphic interval. Patterns of mineral-fluid reactions suggest a basinwide hydrologic regime in which warm, evolved fluids migrated up-dip from the center of the basin under the influence of a regional hydraulic head. -from Authors","language":"English","publisher":"American Journal of Science","doi":"10.2475/ajs.287.4.353","usgsCitation":"Whitney, C.G., and Northrop, H.R., 1987, Diagenesis and fluid flow in the San Juan Basin, New Mexico - regional zonation in the mineralogy and stable isotope composition of clay minerals in sandstone.: American Journal of Science, v. 287, no. 4, p. 353-382, https://doi.org/10.2475/ajs.287.4.353.","productDescription":"30 p.","startPage":"353","endPage":"382","numberOfPages":"30","costCenters":[],"links":[{"id":225433,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"287","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0093e4b0c8380cd4f7d0","contributors":{"authors":[{"text":"Whitney, C. Gene","contributorId":100350,"corporation":false,"usgs":true,"family":"Whitney","given":"C.","email":"","middleInitial":"Gene","affiliations":[],"preferred":false,"id":367939,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Northrop, H. R.","contributorId":40735,"corporation":false,"usgs":true,"family":"Northrop","given":"H.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":367940,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70014824,"text":"70014824 - 1987 - Computer simulations of large asteroid impacts into oceanic and continental sites--Preliminary results on atmospheric, cratering and ejecta dynamics","interactions":[],"lastModifiedDate":"2024-02-14T14:57:15.073617","indexId":"70014824","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2054,"text":"International Journal of Impact Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Computer simulations of large asteroid impacts into oceanic and continental sites--Preliminary results on atmospheric, cratering and ejecta dynamics","docAbstract":"Computer simulations have been completed that describe passage of a 10-km-diameter asteroid through the Earth's atmosphere and the subsequent cratering and ejecta dynamics caused by impact of the asteroid into both oceanic and continental sites. The asteroid was modeled as a spherical body moving vertically at 20 km/s with a kinetic energy of 2.6 × 1030 ergs (6.2 × 107 Mt ). Detailed material modeling of the asteroid, ocean, crustal units, sedimentary unit, and mantle included effects of strength and fracturing, generic asteroid and rock properties, porosity, saturation, lithostatic stresses, and geothermal contributions, each selected to simulate impact and geologic conditions that were as realistic as possible. Calculation of the passage of the asteroid through a U.S. Standard Atmosphere showed development of a strong bow shock wave followed by a highly shock compressed and heated air mass. Rapid expansion of this shocked air created a large low-density region that also expanded away from the impact area. Shock temperatures in air reached ∼20, 000K near the surface of the uplifting crater rim and were as high as ∼2000K at more than 30 km range and 10 km altitude. Calculations to 30 s showed that the shock fronts in the air and in most of the expanding shocked air mass preceded the formation of the crater, ejecta, and rim uplift and did not interact with them. As cratering developed, uplifted rim and target material were ejected into the very low density, shock-heated air immediately above the forming crater, and complex interactions could be expected. Calculations of the impact events showed equally dramatic effects on the oceanic and continental targets through an interval of 120 s. Despite geologic differences in the targets, both cratering events developed comparable dynamic flow fields and by ∼29s had formed similar-sized transient craters ∼39km deep and ∼62km across. Transient-rim uplift of ocean and crust reached a maximum altitude of nearly 40 km at ∼30s and began to decay at velocities of 500 m/s to develop large-tsunami conditions. After ∼30s, strong gravitational rebound drove both craters toward broad flat-floored shapes. At 120 s, transient crater diameters were ∼80km (continental) and ∼105km (oceanic) and transient depths were ∼27km; crater floors consisting of melted and fragmented hot rock were rebounding rapidly upward. By 60 s, the continental crater had ejected ∼2 × 1014t, about twice the mass ejected from the oceanic crater. By 120 s, ∼70, 000km3 (continental) and ∼90, 000km3 (oceanic) target material were excavated (no mantle) and massive ejecta blankets were formed around the craters. We estimate that in excess of ∼70% of the ejecta would finally lie within ∼3 crater diameters of the impact, and the remaining ejecta (∼1013t), including the vaporized asteroid, would be ejected into the atmosphere to altitudes as high as the ionosphere. Effects of secondary volcanism and return of the ocean over hot oceanic crater floor could also be expected to contribute substantial material to the atmosphere.
This synthesis links many seismic and tectonic processes at subduction zones, including great subduction earthquakes, to the sinking of subducted plate. Earthquake data and tectonic modeling for subduction zones indicate that the slab pull force is much larger than the ridge push force. Interactions between the forces that drive and resist plate motions cause spatially and temporally localized stresses that lead to characteristic earthquake activity, providing details on how subduction occurs. Compression is localized across a locked interface thrust zone, because both the ridge push and the slab pull forces are resisted there. The slab pull force increases with increasing plate age; thus because the slab pull force tends to bend subducted plate downward and decrease the force acting normal to the interface thrust zone, the characteristic maximum earthquake at a given interface thrust zone is inversely related to the age of the subducted plate. The 1960 Chile earthquake (Mw 9.5), the largest earthquake to occur in historic times, began its rupture at an interface bounding oceanic plate <30 m.y. old. However, this rupture initiation was associated with the locally oldest subducting lithosphere (weakest coupling); the rupture propagated southward along an interface bounding progressively younger oceanic lithosphere, terminating near the subducting Chile Rise. Prior to a great subduction earthquake, the sinking subducted slab will cause increased tension at depths of 50–200 km, with greatest tension near the shallow zone resisting plate subduction. Plate sinking not only leads to compressional stresses at a locked interface thrust zone but may load compressional stresses at plate depths of 260–350 km, provided that the shallow sinking occurs faster than the relaxation time of the deeper mantle. This explains K. Mogi's observations of M ≥ 7 thrust earthquakes at depths of 260–350 km, immediately downdip and within 3 years prior to five great, shallow earthquakes of northern Japan. The slab pull model explains the lower layer of double seismic zones as due to tension from the deeper, sinking plate and the upper layer as due to localized in-plate compression, as plate motion is resisted by the bounding mantle. Just downdip of the interface thrust zone, there occurs an aseismic 20°–50° dip increase of subducted plate. This slab bend reflects the summed slab pull force of deeper plate and probably is at the crustal basalt to eclogite phase change. Resistance to subduction provided by a continually developing slab bend may be an important factor in the size of slab pull force delivered to an interface thrust zone.
","language":"English","publisher":"Wiley","doi":"10.1029/RG025i001p00055","issn":"87551209","usgsCitation":"Spence, W., 1987, Slab pull and the seismotectonics of subducting lithosphere: Reviews of Geophysics, v. 25, no. 1, p. 55-69, https://doi.org/10.1029/RG025i001p00055.","productDescription":"15 p.","startPage":"55","endPage":"69","costCenters":[],"links":[{"id":480092,"rank":1,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://zenodo.org/record/1231450","text":"External Repository"},{"id":225368,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"25","issue":"1","noUsgsAuthors":false,"publicationDate":"2010-06-14","publicationStatus":"PW","scienceBaseUri":"505b912de4b08c986b31979f","contributors":{"authors":[{"text":"Spence, William","contributorId":27454,"corporation":false,"usgs":true,"family":"Spence","given":"William","affiliations":[],"preferred":false,"id":367929,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70014241,"text":"70014241 - 1987 - A model for tides and currents in the English Channel and southern North Sea","interactions":[],"lastModifiedDate":"2012-03-12T17:19:31","indexId":"70014241","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"A model for tides and currents in the English Channel and southern North Sea","docAbstract":"The amplitude and phase of 11 tidal constituents for the English Channel and southern North Sea are calculated using a frequency domain, finite element model. The governing equations - the shallow water equations - are modifed such that sea level is calculated using an elliptic equation of the Helmholz type followed by a back-calculation of velocity using the primitive momentum equations. Triangular elements with linear basis functions are used. The modified form of the governing equations provides stable solutions with little numerical noise. In this field-scale test problem, the model was able to produce the details of the structure of 11 tidal constituents including O1, K1, M2, S2, N2, K2, M4, MS4, MN4, M6, and 2MS6.","largerWorkTitle":"Advances in Water Resources","language":"English","issn":"03091708","usgsCitation":"Walters, R.A., 1987, A model for tides and currents in the English Channel and southern North Sea, in Advances in Water Resources, v. 10, no. 3, p. 138-148.","startPage":"138","endPage":"148","numberOfPages":"11","costCenters":[],"links":[{"id":225304,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"10","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e47de4b0c8380cd4666e","contributors":{"authors":[{"text":"Walters, Roy A.","contributorId":74877,"corporation":false,"usgs":true,"family":"Walters","given":"Roy","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":367923,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70014240,"text":"70014240 - 1987 - Ecological aspects of microorganisms inhabiting uranium mill tailings","interactions":[],"lastModifiedDate":"2012-03-12T17:19:31","indexId":"70014240","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2729,"text":"Microbial Ecology","active":true,"publicationSubtype":{"id":10}},"title":"Ecological aspects of microorganisms inhabiting uranium mill tailings","docAbstract":"Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques. Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereas Bacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the tailings. The results are placed in the context of the magnitude of uranium mill tailings in the United States, the hazards posed by the tailings, and how such hazards could be enhanced or diminished by microbial activities. Patterns in the composition of the microbial population are evaluated with respect to the ecological variables that influence microbial growth. ?? 1987 Springer-Verlag New York Inc.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Microbial Ecology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Springer-Verlag","doi":"10.1007/BF02013019","issn":"00953628","usgsCitation":"Miller, C., Landa, E.R., and Updegraff, D., 1987, Ecological aspects of microorganisms inhabiting uranium mill tailings: Microbial Ecology, v. 14, no. 2, p. 141-155, https://doi.org/10.1007/BF02013019.","startPage":"141","endPage":"155","numberOfPages":"15","costCenters":[],"links":[{"id":205618,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF02013019"},{"id":225303,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"14","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0545e4b0c8380cd50d21","contributors":{"authors":[{"text":"Miller, C.L.","contributorId":86788,"corporation":false,"usgs":true,"family":"Miller","given":"C.L.","email":"","affiliations":[],"preferred":false,"id":367921,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Landa, E. R.","contributorId":100002,"corporation":false,"usgs":true,"family":"Landa","given":"E.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":367922,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Updegraff, D.M.","contributorId":13251,"corporation":false,"usgs":true,"family":"Updegraff","given":"D.M.","email":"","affiliations":[],"preferred":false,"id":367920,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70014238,"text":"70014238 - 1987 - Suspended sediment and metals removal from urban runoff by a small lake","interactions":[],"lastModifiedDate":"2018-01-30T20:57:03","indexId":"70014238","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3718,"text":"Water Resources Bulletin","printIssn":"0043-1370","active":true,"publicationSubtype":{"id":10}},"title":"Suspended sediment and metals removal from urban runoff by a small lake","docAbstract":"A small lake in the Chicago Metropolitan Area was from 91 to 95 percent efficient in removing suspended sediment and from 76 to 94 percent efficient in removing copper, iron, lead, and zinc from urban runoff. Sediments accumulated in the lake in the form of an organic-rich mud at an average rate of 20 millimeters per year; this reduced lake storage and covered potential habitat for aquatic organisms. Copper, lead, and zinc concentrations were closely associated with suspended-sediment concentrations and with silt- and clay-sized fractions of lake sediment. Although concentrations of mercury and cadmium were near detection limits in runoff, measurable concentrations of these metals accumulated in the lake sediments.A small lake in the Chicago Metropolitan Area was from 91 to 95 percent efficient in removing suspended sediment and from 76 to 94 percent efficient in removing copper, iron, lead, and zinc from urban runoff. Sediments accumulated in the lake in the form of an organic-rich mud at an average rate of 20 millimeters per year; this reduced lake storage and covered potential habitat for aquatic organisms. Copper, lead, and zinc concentrations were closely associated with suspended sediment concentrations and with silt- and clay-sized fractions of lake sediment. Although concentrations of mercury and cadmium were near detection limits in runoff, measurable concentrations of these metals accumulated in the lake sediments.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Water Resources Bulletin","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"American Water Resources Association","doi":"10.1111/j.1752-1688.1987.tb00848.x","issn":"00431370","usgsCitation":"Striegl, R.G., 1987, Suspended sediment and metals removal from urban runoff by a small lake: Water Resources Bulletin, v. 23, no. 6, p. 985-996, https://doi.org/10.1111/j.1752-1688.1987.tb00848.x.","startPage":"985","endPage":"996","costCenters":[],"links":[{"id":225240,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":267766,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1752-1688.1987.tb00848.x"}],"volume":"23","issue":"6","noUsgsAuthors":false,"publicationDate":"2007-06-08","publicationStatus":"PW","scienceBaseUri":"505ba300e4b08c986b31faf4","contributors":{"authors":[{"text":"Striegl, Robert G. 0000-0002-8251-4659 rstriegl@usgs.gov","orcid":"https://orcid.org/0000-0002-8251-4659","contributorId":1630,"corporation":false,"usgs":true,"family":"Striegl","given":"Robert","email":"rstriegl@usgs.gov","middleInitial":"G.","affiliations":[{"id":36183,"text":"Hydro-Ecological Interactions Branch","active":true,"usgs":true},{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true},{"id":200,"text":"Coop Res Unit Seattle","active":true,"usgs":true}],"preferred":false,"id":367918,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70014690,"text":"70014690 - 1987 - The inventory and distribution of water on Mars","interactions":[],"lastModifiedDate":"2013-02-20T20:47:39","indexId":"70014690","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":661,"text":"Advances in Space Research","active":true,"publicationSubtype":{"id":10}},"title":"The inventory and distribution of water on Mars","docAbstract":"Terrain softening, fretted channels, debris flows, and closed depressions indicate that at least the upper 2 km of the cratered uplands at high latitudes (>30??) contain ice in amounts that exceed the porosity, estimated to be 10-20 percent. Theoretical studies, and lack of these features in the cratered uplands at low latitudes, suggest that the upper 1 km of the uplands at low latitudes is ice poor. However, valley networks indicate that water was present near the surface early in the planet's history, although in amounts smaller than at high latitudes. On the basis of these observations, the entire upper 1 km, planet-wide is estimated to have contained 75-125 meters of water at the end of heavy bombardment. From the volume of water needed to cut the circum-Chryse channels, and assuming uniform planet-wide distribution of water, the deep megaregolith is estimated to have contained at least 350 meters of water at the end of heavy bombardment, thereby giving a total minimum inventory of 425-475 meters planet-wide. Most of the water lost from the low latitude uplands by diffusion and in cutting the valley networks is now believed to be in the polar layered terrains. Most of the water involved in cutting the outflow channels is in the low-lying northern plains where a variety of features that have been attributed to ground ice is present. Since the end of heavy bombardment, a large fraction of the planet's surface has been overplated with water-poor volcanics, of which we have samples in the SNC meteorites. The younger volcanics have reacted extensively with the old volatile-rich basement. Part of the 10-20 bars of CO2 and 0.1 to 0.3 bars of N2 outgassed with the water was lost during heavy bombardment by impact erosion of the atmosphere and other processes. The remaining was fixed carbonates and nitrates and folded deep into the megaregolith during heavy bombardment. ?? 1987.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Advances in Space Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/0273-1177(87)90359-0","issn":"02731177","usgsCitation":"Carr, M.H., 1987, The inventory and distribution of water on Mars: Advances in Space Research, v. 7, no. 5, p. 85-94, https://doi.org/10.1016/0273-1177(87)90359-0.","startPage":"85","endPage":"94","numberOfPages":"10","costCenters":[],"links":[{"id":225270,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":267874,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0273-1177(87)90359-0"}],"volume":"7","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bad5de4b08c986b323b7e","contributors":{"authors":[{"text":"Carr, M. H.","contributorId":84727,"corporation":false,"usgs":true,"family":"Carr","given":"M.","email":"","middleInitial":"H.","affiliations":[{"id":131,"text":"Astrogeology Science Center","active":true,"usgs":true}],"preferred":false,"id":369011,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70014831,"text":"70014831 - 1987 - Natural-field and very low-frequency tipper profile interpretation of contacts","interactions":[],"lastModifiedDate":"2024-04-18T15:49:31.823669","indexId":"70014831","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1808,"text":"Geophysics","active":true,"publicationSubtype":{"id":10}},"title":"Natural-field and very low-frequency tipper profile interpretation of contacts","docAbstract":"Anomalous vertical magnetic field (tipper) profiles acquired using natural or very low-frequency (VLF) radio transmitter sources can be interpreted simply and rapidly for a number of geologic settings. The relations between computed numerical models, and outcropping dipping and buried vertical contacts are presented here in a series of interpretation charts. Use of the tipper phase in the analysis minimizes the effect of transmitter azimuth in the VLF case.Two examples illustrate the application to field data. An audiofrequency natural-field tipper profile over a conductive bed in a north-central Washington State metasedimentary sequence demonstrates the interpretation procedure for a dipping contact. VLF profiles over covered basement faults in Ontario demonstrate the application for a buried vertical contact. In both cases the quick results are in agreement with the much more laborious trial-and-error matching to two-dimensional models.
","language":"English","publisher":"Society of Exploration Geophysicists","doi":"10.1190/1.1442286","issn":"00168033","usgsCitation":"Labson, V.F., and Becker, A., 1987, Natural-field and very low-frequency tipper profile interpretation of contacts: Geophysics, v. 52, no. 12, p. 1697-1707, https://doi.org/10.1190/1.1442286.","productDescription":"11 p.","startPage":"1697","endPage":"1707","numberOfPages":"11","costCenters":[],"links":[{"id":225404,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"52","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6137e4b0c8380cd7184d","contributors":{"authors":[{"text":"Labson, Victor F. 0000-0003-1905-1820 vlabson@usgs.gov","orcid":"https://orcid.org/0000-0003-1905-1820","contributorId":326,"corporation":false,"usgs":true,"family":"Labson","given":"Victor","email":"vlabson@usgs.gov","middleInitial":"F.","affiliations":[{"id":349,"text":"International Water Resources Branch","active":true,"usgs":true}],"preferred":true,"id":369396,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Becker, Alex","contributorId":59567,"corporation":false,"usgs":true,"family":"Becker","given":"Alex","email":"","affiliations":[],"preferred":false,"id":369397,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70014237,"text":"70014237 - 1987 - Seismic stratigraphy and facies of continental slope and rise seaward of Baltimore Canyon Trough","interactions":[],"lastModifiedDate":"2023-01-17T15:57:28.522392","indexId":"70014237","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":701,"text":"American Association of Petroleum Geologists Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"Seismic stratigraphy and facies of continental slope and rise seaward of Baltimore Canyon Trough","docAbstract":"As part of a survey of the United States continental rise seaward of the northern Baltimore Canyon Trough, four major depositional sequences were mapped on a grid of 2,350 km of multichannel seismic reflection profiles. The sequences, which range in age from Jurassic (?) to Quaternary, record a gradual sedimentary buildup of fine-grained onlapping and slope-front fill. A broad wedge of Jurassic-age (?) sediment up to 5 km thick was deposited seaward of a conspicuous platform.
During the Cretaceous, the slope-rise transition became much gentler, and sequences are more blanket-like because the declivity seaward of the platform was smoothed and filled by fine-grained clastic sediments and thin-bedded limestones. The main constructional phase for the continental rise was during the Cenozoic, when a thick (0.1-2.4 km) wedge formed seaward of the shelf edge in response to major fluctuations in sea level and erosion of the gentle, ancestral continental slope.
The Cenozoic rise section can be subdivided into two main sequences separated by a conspicuous unconformity. The lower sequence is mostly a blanket (0.2-0.8 km thick) of Paleogene hemipelagic ooze and claystone. The sequence above the unconformity is a complex association of Neogene slump deposits, turbidites, hemipelagic clays, and channel fill that thickens seaward to 2.2 km under the middle continental rise. The final phase of rise construction was caused by widespread fluctuations in coastal onlap. These regressions resulted in deltaic outward-building on the shelf, extensive Pleistocene landward erosion of the slope, and the accumulation of a broad sedimentary apron on the rise.
","language":"English","publisher":"American Association of Petroleum Geologists","doi":"10.1306/703C7DF4-1707-11D7-8645000102C1865D","usgsCitation":"Schlee, J., and Hinz, K., 1987, Seismic stratigraphy and facies of continental slope and rise seaward of Baltimore Canyon Trough: American Association of Petroleum Geologists Bulletin, v. 71, no. 9, p. 1046-1067, https://doi.org/10.1306/703C7DF4-1707-11D7-8645000102C1865D.","productDescription":"22 p.","startPage":"1046","endPage":"1067","numberOfPages":"22","costCenters":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":225239,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"otherGeospatial":"Baltimore Canyon Trough","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -73.5,\n 40\n ],\n [\n -73.5,\n 38\n ],\n [\n -70,\n 38\n ],\n [\n -70,\n 40\n ],\n [\n -73.5,\n 40\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"71","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b8b65e4b08c986b3177d7","contributors":{"authors":[{"text":"Schlee, John S.","contributorId":99912,"corporation":false,"usgs":true,"family":"Schlee","given":"John S.","affiliations":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":false,"id":367916,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hinz, K.","contributorId":83273,"corporation":false,"usgs":true,"family":"Hinz","given":"K.","email":"","affiliations":[],"preferred":false,"id":367917,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70014236,"text":"70014236 - 1987 - Crystal structure and crystal chemistry of melanovanadite, a natural vanadium bronze.","interactions":[],"lastModifiedDate":"2012-03-12T17:19:31","indexId":"70014236","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":738,"text":"American Mineralogist","active":true,"publicationSubtype":{"id":10}},"title":"Crystal structure and crystal chemistry of melanovanadite, a natural vanadium bronze.","docAbstract":"The crystal structure of melanovanadite from Minas Ragra, Peru, has been determined in space group P1. The triclinic unit cell (non-standard) has a 6.360(2), b 18.090(9), c 6.276(2) A, alpha 110.18(4)o, beta 101.62(3)o, gamma 82.86(4)o. A subcell with b' = b/2 was found by crystal-structure analysis to contain CaV4O10.5H2O. The subcell has a layer structure in which the vanadate sheet consists of corner-shared tetrahedral VO4 and double square-pyramidal V2O8 groups, similar to that previously found in synthetic CsV2O5. Refinement of the full structure (R = 0.056) showed that the Ca atom, which half-occupies a general position in the subcell, is 90% ordered at one of these sites in the whole unit cell. Bond length-bond strength estimates indicate that the tetrahedra contain V5+, and the square pyramids, V4+.-J.A.Z.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"American Mineralogist","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"0003004X","usgsCitation":"Konnert, J., and Evans, H.T., 1987, Crystal structure and crystal chemistry of melanovanadite, a natural vanadium bronze.: American Mineralogist, v. 72, no. 5-6, p. 637-644.","startPage":"637","endPage":"644","numberOfPages":"8","costCenters":[],"links":[{"id":225238,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"72","issue":"5-6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fcfce4b0c8380cd4e56b","contributors":{"authors":[{"text":"Konnert, J.A.","contributorId":17640,"corporation":false,"usgs":true,"family":"Konnert","given":"J.A.","affiliations":[],"preferred":false,"id":367914,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Evans, H. T. Jr.","contributorId":41859,"corporation":false,"usgs":true,"family":"Evans","given":"H.","suffix":"Jr.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":367915,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70014832,"text":"70014832 - 1987 - CHANNEL EVOLUTION IN MODIFIED ALLUVIAL STREAMS.","interactions":[],"lastModifiedDate":"2012-03-12T17:19:36","indexId":"70014832","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3647,"text":"Transportation Research Record","active":true,"publicationSubtype":{"id":10}},"title":"CHANNEL EVOLUTION IN MODIFIED ALLUVIAL STREAMS.","docAbstract":"This study (a) assesses the channel changes and network trends of bed level response after modifications between 1959 and 1972 of alluvial channels in western Tennessee and (b) develops a conceptual model of bank slope development to qualitatively assess bank stability and potential channel widening. A six-step, semiquantitative model of channel evolution in disturbed channels was developed by quantifying bed level trends and recognizing qualitative stages of bank slope development. Development of the bank profile is defined in terms of three dynamic and observable surfaces: (a) vertical face (70 to 90 degrees), (b) upper bank (25 to 50 degrees), and (c) slough line (20 to 25 degrees).","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Transportation Research Record","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03611981","usgsCitation":"Simon, A., and Hupp, C.R., 1987, CHANNEL EVOLUTION IN MODIFIED ALLUVIAL STREAMS.: Transportation Research Record, no. 1151, p. 16-24.","startPage":"16","endPage":"24","numberOfPages":"9","costCenters":[],"links":[{"id":225405,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"1151","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f2cae4b0c8380cd4b38b","contributors":{"authors":[{"text":"Simon, Andrew","contributorId":78334,"corporation":false,"usgs":true,"family":"Simon","given":"Andrew","email":"","affiliations":[],"preferred":false,"id":369399,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hupp, Cliff R. 0000-0003-1853-9197 crhupp@usgs.gov","orcid":"https://orcid.org/0000-0003-1853-9197","contributorId":2344,"corporation":false,"usgs":true,"family":"Hupp","given":"Cliff","email":"crhupp@usgs.gov","middleInitial":"R.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true}],"preferred":true,"id":369398,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70014235,"text":"70014235 - 1987 - Rocks of the Thirtynine Mile volcanic field as possible sources of uranium for epigenetic deposits in central Colorado, USA.","interactions":[],"lastModifiedDate":"2012-03-12T17:19:36","indexId":"70014235","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3668,"text":"Uranium","active":true,"publicationSubtype":{"id":10}},"title":"Rocks of the Thirtynine Mile volcanic field as possible sources of uranium for epigenetic deposits in central Colorado, USA.","docAbstract":"The most likely volcanic source rock for uranium in epigenetic deposits of the Tallahassee Creek uranium district and nearby areas is the Wall Mountain Tuff. The widespread occurrence of the Tuff, its high apparent original uranium content, approx 11 ppm, and its apparent loss of uranium from devitrification and other alteration suggest its role in providing that element. An estimate of the original Th/U ratio is based on the present thorium and uranium contents of the basal vitrophyre of the Tuff from Castle Rock Gulch, Hecla Junction and other areas.-from Author","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Uranium","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","usgsCitation":"Dickinson, K.A., 1987, Rocks of the Thirtynine Mile volcanic field as possible sources of uranium for epigenetic deposits in central Colorado, USA.: Uranium, v. 4, no. 1, p. 43-65.","startPage":"43","endPage":"65","numberOfPages":"23","costCenters":[],"links":[{"id":226211,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"4","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aae1ae4b0c8380cd87017","contributors":{"authors":[{"text":"Dickinson, K. A.","contributorId":77528,"corporation":false,"usgs":true,"family":"Dickinson","given":"K.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":367913,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70014234,"text":"70014234 - 1987 - Submersible observations along the southern Juan de Fuca Ridge: 1984 Alvin program.","interactions":[],"lastModifiedDate":"2017-03-06T12:47:33","indexId":"70014234","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Submersible observations along the southern Juan de Fuca Ridge: 1984 Alvin program.","docAbstract":"In September 1984, the research submersible Alvin provided direct observations of three major hydrothermal vent areas along the southernmost segment of the Juan de Fuca Ridge (JFR). The submersible operations focused on specific volcanologie, structural, and hydrothermal problems that had been identified during the preceding 4 years of photographic, dredging, acoustic imaging, and geophysical studies along a 12-km-long section of the ridge. A continuously maintained (from 1981 to the present) net of seafloor-anchored acoustic transponders allowed the observations from Alvin to be directly tied to all previous U.S. Geological Survey data sets and National Oceanic and Atmospheric Administration water column surveys from 1984 to the present. The three vent areas studied are the largest of at least six areas identified by previous deep-towed camera surveys that lie within a deep cleft, which marks the axis of symmetry of the JFR in this region. The cleft appears to be the locus of eruption for this segment of the JFR. The vent areas, at least in part, are localized near what appear to be previous volcanic eruptive centers marked by extensive lava lake collapse features adjacent to the cleft at these sites. Each hydrothermal area has several active discharge sites, and sulfide deposits occur as clusters (15–100 m2) of small chimneys, individual large chimneys, or clusters of large branched chimneys. We review the dive program and present a brief synthesis of the geology of the vent sites together with sample and track line compilations.
","language":"English","publisher":"AGU Publications","doi":"10.1029/JB092iB11p11283","issn":"01480227","usgsCitation":"Normark, W.R., Morton, J.L., and Ross, S.L., 1987, Submersible observations along the southern Juan de Fuca Ridge: 1984 Alvin program.: Journal of Geophysical Research B: Solid Earth, v. 92, no. B11, p. 11283-11290, https://doi.org/10.1029/JB092iB11p11283.","productDescription":"8 p.","startPage":"11283","endPage":"11290","costCenters":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":226210,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"92","issue":"B11","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505b9d40e4b08c986b31d725","contributors":{"authors":[{"text":"Normark, William R.","contributorId":69570,"corporation":false,"usgs":true,"family":"Normark","given":"William","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":367912,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Morton, Janet L.","contributorId":37269,"corporation":false,"usgs":true,"family":"Morton","given":"Janet","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":367910,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ross, Stephanie L. 0000-0003-1389-4405 sross@usgs.gov","orcid":"https://orcid.org/0000-0003-1389-4405","contributorId":1024,"corporation":false,"usgs":true,"family":"Ross","given":"Stephanie","email":"sross@usgs.gov","middleInitial":"L.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":367911,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70014233,"text":"70014233 - 1987 - Cretaceous gastropods: contrasts between tethys and the temperate provinces","interactions":[],"lastModifiedDate":"2024-06-21T00:20:39.590569","indexId":"70014233","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2412,"text":"Journal of Paleontology","active":true,"publicationSubtype":{"id":10}},"title":"Cretaceous gastropods: contrasts between tethys and the temperate provinces","docAbstract":"During the Cretaceous Period, gastropod faunas show considerable differences in their evolution between the Tethyan Realm (tropical) and the Temperate Realms to the north and south. Like Holocene faunas, prosobranch gastropods constitute the dominant part of Cretaceous marine snail faunas. Entomotaeneata and opisthobranchs usually form all of the remainder. In Tethyan faunas the Archaeogastropoda form a consistent high proportion of total taxa but less than the Mesogastropoda throughout the period. In contrast, the Temperate faunas beginning in Albian times show a decline in percentages of archaeogastropod taxa and a significant increase in the Neogastropoda, until they constitute over 50 percent of the taxa in some faunas. The neogastropods never attain high diversity in the Cretaceous of the Tethyan Realm and are judged to be of Temperate Realm origin.
Cretaceous Tethyan gastropod faunas are closely allied to those of the “corallien fades” of the Jurassic and begin the period evolutionarily mature and well diversified. Greatest diversity in Tethys occurs in the lagoonal shales associated with the rudist or coral framework environments of the Cretaceous carbonate platforms. Their distribution was pan-tropical, extending in instances across the vast reaches of the Pacific. Three categories of Tethyan gastropods are analyzed. The first group consists of those of Jurassic ancestry. Except for the Nerineacea, these taxa are long ranging but evolutionarily conservative, showing only moderate diversification during the Cretaceous, and becoming extinct with the close of the era. The second group originates mainly during the Barremian and Aptian, reaches a climax in diversification during middle Cretaceous time, and usually declines during the latest Cretaceous, with most not lasting through the terminal event. The third group originates late in the Cretaceous and consists of taxa that manage to either survive the Cretaceous-Tertiary crisis or give rise to forms of prominence among Tertiary warm water faunas.
There is a trend among the Tethyan gastropod assemblages for increased provincialism with time. Early and middle Cretaceous taxa are especially widely distributed, but the latest Cretaceous is a time of restricted occurrence for many forms.
Temperate Realm gastropod faunas are less diverse than those of Tethys during the Early Cretaceous. Their source is among long lived, extra-Tethys groups, but is increased, especially during major phases of transgression, by immigrants from Tethys. They show a steady increase in diversity, primarily among the Mesogastropoda and Neogastropoda. This trend culminates in latest Cretaceous times when the gastropod assemblages of the clastic provinces of the inner shelf contain an abundance of taxa outstripping that of any other part of the Cretaceous of either realm.
Extinction at the Cretaceous-Tertiary boundary is much less pronounced in the Temperate Realm than in the Tethys. Among the Temperate Realm assemblages loss is of generic and species level taxa, unlike the extinction of the family Actaeonellidae or the superfamily Nerineacea and a host of less prominent groups in Tethys. In essence, by the late Maastrichtian, gastropod faunas of the Temperate Realm had attained a modern faunal aspect.
The present method of using constant secular variation rates to forecast magnetic components at a given site or to forecast spherical harmonic coefficients is known to be inaccurate. A new predictive method using trend and trigonometric functions fitted to known past values is used to extrapolate for a few years into the future. This provides an improvement over the usual linear extrapolation method. This method applied to the spherical harmonic coefficients (SHC) in the series of International Geomagnetic Reference Fields (IGRF) provides an analytic function for each SHC so that charts can be compiled for a few years in the future without using the idea of a constant secular variation. In this case, the trend and trigonometric functions utilize the same number of Fourier and trend coefficients as are now present in the IGRF models on which they are based so that they can completely replace the IGRF information.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB092iB07p06331","issn":"01480227","usgsCitation":"Alldredge, L., 1987, On predicting changes in the geomagnetic field: Journal of Geophysical Research Solid Earth, v. 92, no. B7, p. 6331-6338, https://doi.org/10.1029/JB092iB07p06331.","productDescription":"8 p.","startPage":"6331","endPage":"6338","numberOfPages":"8","costCenters":[],"links":[{"id":226208,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"92","issue":"B7","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505a6da5e4b0c8380cd7524b","contributors":{"authors":[{"text":"Alldredge, L.R.","contributorId":53457,"corporation":false,"usgs":true,"family":"Alldredge","given":"L.R.","email":"","affiliations":[],"preferred":false,"id":367908,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ]}