{"pageNumber":"1522","pageRowStart":"38025","pageSize":"25","recordCount":46677,"records":[{"id":70014276,"text":"70014276 - 1987 - GEOMETRIC PROCESSING OF DIGITAL IMAGES OF THE PLANETS.","interactions":[],"lastModifiedDate":"2012-03-12T17:19:28","indexId":"70014276","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":"GEOMETRIC PROCESSING OF DIGITAL IMAGES OF THE PLANETS.","docAbstract":"New procedures and software have been developed for geometric transformations of images to support digital cartography of the planets. The procedures involve the correction of spacecraft camera orientation of each image with the use of ground control and the transformation of each image to a Sinusoidal Equal-Area map projection with an algorithm which allows the number of transformation calculations to vary as the distortion varies within the image. When the distortion is low in an area of an image, few transformation computations are required, and most pixels can be interpolated. When distortion is extreme, the location of each pixel is computed. Mosaics are made of these images and stored as digital databases.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Photogrammetric Engineering and Remote Sensing","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00991112","usgsCitation":"Edwards, K., 1987, GEOMETRIC PROCESSING OF DIGITAL IMAGES OF THE PLANETS.: Photogrammetric Engineering and Remote Sensing, v. 53, no. 9, p. 1219-1222.","startPage":"1219","endPage":"1222","numberOfPages":"4","costCenters":[],"links":[{"id":225825,"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":"505a1453e4b0c8380cd549d7","contributors":{"authors":[{"text":"Edwards, Kathleen","contributorId":43833,"corporation":false,"usgs":true,"family":"Edwards","given":"Kathleen","email":"","affiliations":[],"preferred":false,"id":368011,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70014274,"text":"70014274 - 1987 - Analysis of two-color geodimeter measurements of deformation within the Long Valley caldera: June 1983 to October 1985","interactions":[],"lastModifiedDate":"2024-06-24T18:02:52.257541","indexId":"70014274","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","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":"Analysis of two-color geodimeter measurements of deformation within the Long Valley caldera: June 1983 to October 1985","docAbstract":"Line length changes from several baselines in a trilateration network within the Long Valley caldera clearly define a decrease in strain rate from June 1983 through October 1985. The data consist of more than 1600 length measurements on 23 baselines using a two-color geodimeter, which has a precision of 0.2 ppm of the line length. Initial measurements made during the summer of 1983 show extension rates were as high as 6 ppm/yr on some baselines. The rates subsequently decreased steadily, to less than 1 ppm/yr during the summer of 1985. Ih contrast, the strain rates on a few other baselines were less than 0.2 ppm/yr averaged over the 2.3-year interval. A model is constructed using these observations as well as yearly observations of a trilateration network within and near the caldera. The model contains two points of inflation located at 5 and 10 km beneath the resurgent dome of the caldera plus dextral slip on a fault plane within the south moat within an elastic half-space. To mimic the observed time dependence in the two-color geodimeter data, we conclude that the rates of both slip and inflation have steadily decreased over the survey interval. Because the two-color geodimeter network is closer to all three sources than the single-color geodimeter network, these data are important for defining the factor of 2–3 rate decrease of slip and inflation. Comparing our estimates of slip and inflation with similar estimates for the year prior to July 1983, we conclude that the rate decrease is probably a result of postseismic and postinflation relaxation following the earthquake swarm in the south moat in January 1983.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB092iB09p09423","issn":"01480227","usgsCitation":"Langbein, J., Linker, M., and Tupper, D., 1987, Analysis of two-color geodimeter measurements of deformation within the Long Valley caldera: June 1983 to October 1985: Journal of Geophysical Research Solid Earth, v. 92, no. B9, p. 9423-9442, https://doi.org/10.1029/JB092iB09p09423.","productDescription":"20 p.","startPage":"9423","endPage":"9442","numberOfPages":"20","costCenters":[],"links":[{"id":225823,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"92","issue":"B9","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"5059eb46e4b0c8380cd48d16","contributors":{"authors":[{"text":"Langbein, J.","contributorId":16990,"corporation":false,"usgs":true,"family":"Langbein","given":"J.","affiliations":[],"preferred":false,"id":368003,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Linker, M.","contributorId":23697,"corporation":false,"usgs":true,"family":"Linker","given":"M.","email":"","affiliations":[],"preferred":false,"id":368004,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Tupper, D.","contributorId":30376,"corporation":false,"usgs":true,"family":"Tupper","given":"D.","email":"","affiliations":[],"preferred":false,"id":368005,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70014269,"text":"70014269 - 1987 - Reassessment of the volkonskoite-chromian smectite nomenclature problem.","interactions":[],"lastModifiedDate":"2018-01-27T11:03:45","indexId":"70014269","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1245,"text":"Clays and Clay Minerals","onlineIssn":"1552-8367","printIssn":"0009-8604","active":true,"publicationSubtype":{"id":10}},"title":"Reassessment of the volkonskoite-chromian smectite nomenclature problem.","docAbstract":"The name volkonskoite was first used in 1830 to describe a bright blue-green, chromium-bearing clay material from the Okhansk region, west of the Ural Mountains, U.S.S.R. Since that time, the name has been applied to numerous members of the smectite group of clay minerals, although the reported chromium content has ranged from 1% to about 30% Cr2O3. The name has also been applied to some chromian chlorites. Because volkonskoite has been used for materials that differ not only in their chromium content but also in their basic structure, the species status of the mineral has been unclear.
To resolve this uncertainty, two specimens of volkonskoite from (1) Mount Efimiatsk, the type locality in the Soviet Union (USNM 16308) and (2) the Okhansk region in the Perm Basin, U.S.S.R. (USNM R4820), were examined by several mineralogical techniques. Neotype sample 16308 has the following structural formula:
(Ca0.11Mg0.11Fe2+0.03K0.02)(Cr1.18Mg0.78Fe3+0.29Ca0.02)(Si3.50Al0.51)O10(OH)2 ⋅3.64H2O.
Sample R4820 has the following structural formula:
(Ca0.25Mg0.05Fe2+0.01K0.03Mn0.01)(Cr1.07Mg0.75Fe3+0.35(Si3.59Al0.43)O10(OH)2 ⋅4.22H2O.
Mössbauer spectroscopy indicates that 91% and 98% of the iron is present as Fe3+ in samples 16308 and R4820, respectively. X-ray powder diffraction patterns of both samples have broad lines corresponding to minerals of the smectite group.
On the basis of these data, volkonskoite appears to be a dioctahedral member of the smectite group that contains chromium as the dominant cation in the octahedral layer. Smectites containing less than this amount of octahedral chromium should not be called volkonskoite, but should be named by chemical element adjectives, e.g., chromian montmorillonite, chromian nontronite.
","language":"English","publisher":"The Clay Mineral Society","doi":"10.1346/CCMN.1987.0350206","usgsCitation":"Foord, E.E., Starkey, H.C., Taggart, J.E., and Shawe, D., 1987, Reassessment of the volkonskoite-chromian smectite nomenclature problem.: Clays and Clay Minerals, v. 35, no. 2, p. 139-149, https://doi.org/10.1346/CCMN.1987.0350206.","productDescription":"10 p.","startPage":"139","endPage":"149","costCenters":[],"links":[{"id":225762,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"35","issue":"2","noUsgsAuthors":false,"publicationDate":"2024-04-02","publicationStatus":"PW","scienceBaseUri":"505a95c4e4b0c8380cd81c0b","contributors":{"authors":[{"text":"Foord, Eugene E.","contributorId":96319,"corporation":false,"usgs":true,"family":"Foord","given":"Eugene","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":367995,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Starkey, Harry C.","contributorId":175349,"corporation":false,"usgs":false,"family":"Starkey","given":"Harry","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":367993,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Taggart, Joseph E. Jr.","contributorId":66317,"corporation":false,"usgs":true,"family":"Taggart","given":"Joseph","suffix":"Jr.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":367994,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Shawe, Daniel R.","contributorId":91448,"corporation":false,"usgs":true,"family":"Shawe","given":"Daniel R.","affiliations":[],"preferred":false,"id":367992,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70014260,"text":"70014260 - 1987 - Conodont color and textural alteration: An index to regional metamorphism, contact metamorphism, and hydrothermal alteration","interactions":[],"lastModifiedDate":"2023-12-28T01:11:38.036502","indexId":"70014260","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1786,"text":"Geological Society of America Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"Conodont color and textural alteration: An index to regional metamorphism, contact metamorphism, and hydrothermal alteration","docAbstract":"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":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":70014229,"text":"70014229 - 1987 - Use of focal mechanisms to determine stress: A control study.","interactions":[],"lastModifiedDate":"2024-06-25T13:41:43.749612","indexId":"70014229","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","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":"Use of focal mechanisms to determine stress: A control study.","docAbstract":"To allow focal mechanisms to be inverted for the stress field requires a different inversion algorithm than for slickenside data because focal mechanisms do not represent fault slip data unless one can decide which nodal plane is the fault plane. If one can decide which nodal plane is the fault plane, then the focal mechanisms can be inverted with the slickenside inversion algorithm. This decision cannot always be made, so algorithms for inverting focal mechanisms for the stress field are studied. These algorithms either use both of the possible fault planes or attempt to choose the correct fault plane while determining the stress tensor. Simulated focal mechanisms are made from slickenside data and used to provide a control study for the focal mechanism inversion algorithms. The results of this control study show that focal mechanisms can be inverted to find the best stress tensor, but the resolution is decreased unless the fault planes can be picked a priori. The resolution can also be increased by including constraints on the magnitude of the tangential traction on the fault plane. Therefore, using focal mechanisms to study small variations in the stress field requires that other data (e.g., studies of the hypocenters, surface faulting, or structural information concerning the region) be introduced to pick which of the nodal planes is the fault plane. This study also introduces the method of bootstrap resampling to the statistics of this problem. The non-Gaussian nature of the data makes the nonparametric formulation of the bootstrap approach ideal for this problem.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB092iB01p00357","issn":"01480227","usgsCitation":"Michael, A., 1987, Use of focal mechanisms to determine stress: A control study.: Journal of Geophysical Research Solid Earth, v. 92, no. B1, p. 357-368, https://doi.org/10.1029/JB092iB01p00357.","productDescription":"12 p.","startPage":"357","endPage":"368","numberOfPages":"12","costCenters":[],"links":[{"id":226141,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"92","issue":"B1","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505bbf10e4b08c986b329931","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":367904,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70014225,"text":"70014225 - 1987 - Sedimentary processes on the northwestern Iberian continental margin viewed by long-range side-scan sonar and seismic data","interactions":[],"lastModifiedDate":"2017-03-03T11:40:12","indexId":"70014225","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2450,"text":"Journal of Sedimentary Petrology","active":true,"publicationSubtype":{"id":10}},"title":"Sedimentary processes on the northwestern Iberian continental margin viewed by long-range side-scan sonar and seismic data","docAbstract":"The effects of an eastern boundary current in the North Atlantic have been mapped from about 39° north latitude along the Iberian margin to as far north as 43°30![\"^prime\"](\"http://archives.datapages.com/data/sepm/journals/v55-58/misc/other/prime1.JPG\")
north latitude at the western margin of Galicia Bank. The geostrophic current has produced sediment drifts that are covered with bedforms. The sediment drifts are difficult to detect on Gloria long-range side-scan sonar data but are easily resolved on seismic-reflection records as anomalously thick accumulations of sediment banked against either buried or outcropping basement highs. The bedforms ornamenting the drift surfaces were subdivided into 1,000-m water-depth intervals, and their dimensions were tabulated. There are few bedforms in water depths less han 2,000 m, but from depths between 2,000 and 4,000 m they are numerous and have a mean wavelength of 695 m. Bedforms from depths greater than 4,000 m have a mean wavelength of 999 m. The different wavelengths from different water depths suggest two distinct and separated boundary flows. The wave heights of all bedforms found in water depths greater than 2,000 m are less than 10 m. In order to investigate the continuity of sediment drifting through geological time, the stratigraphic section drilled at DSDP Site 398 was reinterpreted and, using seismic-reflection profiles, was traced throughout the northern Iberian margin. Together, the lithostratigraphic and seismic data indicate that sediment drifting developed along this margin in the Eocene. The lithofacies of the Eocene section is t e oldest to have numerous layers of sand and silt. An unconformity separates the Eocene section from the latest Miocene-Pliocene section. The unconformity is interpreted to be the result of the initial pulses of Mediterranean outflow that followed the Messinian desiccation events. A second period of sediment drifting commenced during the Pliocene once the Mediterranean basin filled and the flow out of the Strait of Gibraltar resumed.
","language":"English","publisher":"The Society for Sedimentary Geology","doi":"10.1306/212F8B43-2B24-11D7-8648000102C1865D","issn":"00224472","usgsCitation":"Gardner, J., and Kidd, R., 1987, Sedimentary processes on the northwestern Iberian continental margin viewed by long-range side-scan sonar and seismic data: Journal of Sedimentary Petrology, v. 57, no. 3, p. 397-407, https://doi.org/10.1306/212F8B43-2B24-11D7-8648000102C1865D.","productDescription":"11 p.","startPage":"397","endPage":"407","costCenters":[],"links":[{"id":226074,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"57","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b8a34e4b08c986b3170af","contributors":{"authors":[{"text":"Gardner, James V.","contributorId":61769,"corporation":false,"usgs":true,"family":"Gardner","given":"James V.","affiliations":[],"preferred":false,"id":367895,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kidd, Robert B.","contributorId":63544,"corporation":false,"usgs":false,"family":"Kidd","given":"Robert B.","affiliations":[],"preferred":false,"id":367894,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70014219,"text":"70014219 - 1987 - Some effects of quiet geomagnetic field changes upon values used for main field modeling","interactions":[],"lastModifiedDate":"2013-02-13T13:27:25","indexId":"70014219","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3071,"text":"Physics of the Earth and Planetary Interiors","active":true,"publicationSubtype":{"id":10}},"title":"Some effects of quiet geomagnetic field changes upon values used for main field modeling","docAbstract":"The effects of three methods of data selection upon the assumed main field levels for geomagnetic observatory records used in main field modeling were investigated for a year of very low solar-terrestrial activity. The first method concerned the differences between the year's average of quiet day field values and the average of all values during the year. For H these differences were 2-3 gammas, for D they were -0.04 to -0.12???, for Z the differences were negligible. The second method of selection concerned the effects of the daytime internal Sq variations upon the daily mean values of field. The midnight field levels when the Sq currents were a minimum deviated from the daily mean levels by as much as 4-7 gammas in H and Z but were negligible for D. The third method of selection was designed to avoid the annual and semi-annual quiet level changes of field caused by the seasonal changes in the magnetosphere. Contributions from these changes were found to be as much as 4-7 gammas in quiet years and expected to be greater than 10 gammas in active years. Suggestions for improved methods of improved data selection in main field modeling are given. ?? 1987.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Physics of the Earth and Planetary Interiors","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/0031-9201(87)90144-0","issn":"00319201","usgsCitation":"Campbell, W., 1987, Some effects of quiet geomagnetic field changes upon values used for main field modeling: Physics of the Earth and Planetary Interiors, v. 48, no. 3-4, p. 193-199, https://doi.org/10.1016/0031-9201(87)90144-0.","startPage":"193","endPage":"199","numberOfPages":"7","costCenters":[],"links":[{"id":267335,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0031-9201(87)90144-0"},{"id":226007,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"48","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b929ae4b08c986b319fe6","contributors":{"authors":[{"text":"Campbell, W.H.","contributorId":30749,"corporation":false,"usgs":true,"family":"Campbell","given":"W.H.","email":"","affiliations":[],"preferred":false,"id":367877,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70014212,"text":"70014212 - 1987 - Modeling and analysis of direct-current electrical resistivity in the Durham Triassic basin, North Carolina","interactions":[],"lastModifiedDate":"2023-11-15T16:40:43.85911","indexId":"70014212","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1761,"text":"Geoexploration","active":true,"publicationSubtype":{"id":10}},"title":"Modeling and analysis of direct-current electrical resistivity in the Durham Triassic basin, North Carolina","docAbstract":"Sixty-two Schlumberger electrical soundings were made in the Durham Triassic basin in an effort to determine basin structural geometry, depth of the sedimentary layers, and spatial distribution of individual rock facies. A digital computer program was used to invert the sounding curves of apparent resistivity versus distance to apparent resistivity versus depth. The apparent-resistivity-versus-depth data from the computer-modeling program were used to construct a geoelectric model of the basin that is believed to accurately represent the subsurface geology of the basin. The largest depth to basement in the basin along a resistivity profile (geoelectric section) was determined to be 1,800 m. A resistivity decrease was observed on certain soundings from depths of 100 to 1,000 m; below a 1,000-m depth, apparent resistivity increased to the bottom of the basin. Resistivity values for basement rocks were greater than 1,000 ohm-m and less than 350 ohm-m for the sedimentary layers in the basin. The data suggest that the basin contains a system of step faults near its eastern boundary.
","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7142(87)90012-3","usgsCitation":"Brown, C.E., 1987, Modeling and analysis of direct-current electrical resistivity in the Durham Triassic basin, North Carolina: Geoexploration, v. 24, no. 6, p. 429-440, https://doi.org/10.1016/0016-7142(87)90012-3.","productDescription":"12 p.","startPage":"429","endPage":"440","numberOfPages":"12","costCenters":[],"links":[{"id":225880,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"North Carolina","otherGeospatial":"Durham basin","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -80.11054032257658,\n 34.81424858901997\n ],\n [\n -78.71952572597303,\n 35.63369969562967\n ],\n [\n -78.29487040818577,\n 36.369481295510155\n ],\n [\n -78.80312574155963,\n 36.15648733554863\n ],\n [\n -79.43844490827757,\n 35.6255443614009\n ],\n [\n -80.1172332811392,\n 35.01166900462569\n ],\n [\n -80.28442253553915,\n 34.81424671856449\n ],\n [\n -80.11054032257658,\n 34.81424858901997\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"24","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a5bd4e4b0c8380cd6f828","contributors":{"authors":[{"text":"Brown, C. Erwin","contributorId":96261,"corporation":false,"usgs":true,"family":"Brown","given":"C.","email":"","middleInitial":"Erwin","affiliations":[],"preferred":false,"id":367869,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70014211,"text":"70014211 - 1987 - Global petrologic variations on the moon: A ternary-diagram approach.","interactions":[],"lastModifiedDate":"2024-06-25T13:51:21.117715","indexId":"70014211","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","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":"Global petrologic variations on the moon: A ternary-diagram approach.","docAbstract":"A ternary-diagram approach for determination of global petrologic variations on the lunar surface is presented that incorporates valuable improvements in our previous method of using geochemical variation diagrams. This new approach uses a ternary diagram that is subdivided into equally spaced segments along each of its three sides and has a triangular area in its center. The segments are assigned distinct colors that cover the range of the visible spectrum. The apexes are assigned the three primary colors, and the center triangle, which represents equal proportions of the three apexes, is assigned the color gray. The apexes are assigned the average Fe and (Th/Ti)c (ratio normalized to chondrites) compositions of KREEP/Mg-suite rocks, mare basalts, and ferroan anorthosites. The composition of each picture element (pixel) within these Apollo orbital gamma ray databases is used to determine its position within the ternary diagram. The color corresponding to this ternary position is then placed on a classification map at that pixel's position within the orbital databases. Error databases produced for the Fe and (Th/Ti)c data were used to exclude pixels having high errors. The resultant classification map shows spatial transitions among petrologic units, allows direct determination of the relative proportions of each end-member composition in a pixel, and increases the geologic interpretability of these data over that of the individual elemental databases. The classification units correspond remarkably well to observed geologic units, when we consider the spatial resolution (100 km) of the gamma ray spectrometer. Our results are as follows: (1) The highlands contain large areas of relatively pure ferroan anorthosite. (2) The average composition of the upper lunar crust is represented by an “anorthositic gabbro” composition, which supports the “magma-ocean” hypothesis for lunar crustal genesis. (3) KREEP/Mg-suite rocks are a minor fraction of the upper lunar crust. (4) Within the farside highlands, areas of KREEP/Mg-suite rocks coincide mostly with areas of crustal thinning, which are probably areas of KREEP basalt extrusions or localized excavations of Mg-suite rocks or KREEP-rich rocks. (5) Portions of the east limb and farside highlands have considerable amounts of a mafic, chondritic Th/Ti component (like mare basalt) whose occurrences coincide with mapped concentrations of light plains that display dark-halo craters; the presence of this component supports the hypothesis that mare volcanism had occurred within this highland region before the end of final heavy bombardment.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB092iB04p0E387","issn":"01480227","usgsCitation":"Davis, P.A., and Spudis, P.D., 1987, Global petrologic variations on the moon: A ternary-diagram approach.: Journal of Geophysical Research Solid Earth, v. 92, no. B4, p. 387-395, https://doi.org/10.1029/JB092iB04p0E387.","productDescription":"9 p.","startPage":"387","endPage":"395","numberOfPages":"9","costCenters":[],"links":[{"id":480537,"rank":2,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"http://hdl.handle.net/2060/19870013974","text":"External Repository"},{"id":225879,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"92","issue":"B4","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505a2955e4b0c8380cd5a888","contributors":{"authors":[{"text":"Davis, P. A.","contributorId":74021,"corporation":false,"usgs":true,"family":"Davis","given":"P.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":367868,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Spudis, P. D.","contributorId":58719,"corporation":false,"usgs":true,"family":"Spudis","given":"P.","email":"","middleInitial":"D.","affiliations":[{"id":12445,"text":"Lunar and Planetary Institute","active":true,"usgs":false}],"preferred":false,"id":367867,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70014210,"text":"70014210 - 1987 - Relation of the spectroscopic reflectance of olivine to mineral chemistry and some remote sensing implications","interactions":[],"lastModifiedDate":"2024-06-25T14:09:18.175034","indexId":"70014210","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","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":"Relation of the spectroscopic reflectance of olivine to mineral chemistry and some remote sensing implications","docAbstract":"Using high-resolution visible and near-infrared diffuse spectral reflectance, we have systematically investigated apparent wavelength shifts as a function of mineral chemistry in the Fe/Mg olivine series from Fo11 to Fo91. The study also shows that trace amounts of nickel can be spectrally detected in the olivine structure. We show that significant compositional information can only be extracted at relatively high resolution, because the overall spectral characteristics of the olivines change only subtly as a function of the Fe/Mg ratio. Significant spectral variation as a function of grain size is also demonstrated, adding a further complication to the interpretation of remotely sensed data from olivine-rich surfaces. This laboratory study is expected to aid in the interpretation of remotely sensed data from both terrestrial and extraterrestrial bodies. Terrestrial applications may include the recognition of ultramafic, ultrabasic, and basaltic terrains which in themselves may have mineral potential. Among extraterrestrial applications, the asteroids are obvious candidates for further examination if instrumentation can provide the necessary wavelength coverage, resolution, and signal-to-noise ratio so that spectra can be compared to those laboratory data discussed here. Some permutations of Fe-Mg-Ni relations in olivines are discussed as they apply to the interpretation of asteroid surfaces and other extraterrestrial bodies.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB092iB11p11457","issn":"01480227","usgsCitation":"King, T.V., and Ridley, W., 1987, Relation of the spectroscopic reflectance of olivine to mineral chemistry and some remote sensing implications: Journal of Geophysical Research Solid Earth, v. 92, no. B11, p. 11457-11469, https://doi.org/10.1029/JB092iB11p11457.","productDescription":"13 p.","startPage":"11457","endPage":"11469","numberOfPages":"13","costCenters":[],"links":[{"id":225878,"rank":1,"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":"50e4a6b2e4b0e8fec6cdc280","contributors":{"authors":[{"text":"King, T. V. V.","contributorId":6192,"corporation":false,"usgs":true,"family":"King","given":"T.","email":"","middleInitial":"V. V.","affiliations":[],"preferred":false,"id":367865,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ridley, W.I.","contributorId":72122,"corporation":false,"usgs":true,"family":"Ridley","given":"W.I.","email":"","affiliations":[],"preferred":false,"id":367866,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70014209,"text":"70014209 - 1987 - Response of douglas fir (Pseudotsuga menziesii) to uraniferous groundwater in a small glaciated drainage, Northeastern Washington State","interactions":[],"lastModifiedDate":"2024-04-17T23:55:30.756546","indexId":"70014209","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2302,"text":"Journal of Geochemical Exploration","active":true,"publicationSubtype":{"id":10}},"title":"Response of douglas fir (Pseudotsuga menziesii) to uraniferous groundwater in a small glaciated drainage, Northeastern Washington State","docAbstract":"Douglas fir trees and associated soils were sampled from the slopes of a small (∼4 km2) drainage basin in northeastern Washington to investigate the biogeochemical response to locally uraniferous groundwater. Uranium is preferentially incorporated in needles and twigs compared to larger branches or the trunk. The U concentration in needle ash ranges from 0.2 to 5.8μg g−1 (ppm) and shows no correlation with the U concentration in associated soils. Rather, the distribution of anomalously uraniferous douglas fir (> 1.0μg g−1 U in needle ash) appears to be controlled by observed or readily inferred pathways of near-surface groundwater movement in the drainage. These pathways include: (1) general downslope movement of subsurface runoff; (2) increased flux of near-surface groundwater near the toe of an alluvial fan; and (3) emergence of uraniferous (100–150 ng ml−1 [ppb] groundwater in the vicinity of a slope spring. The data also indicate the presence of near-surface uraniferous groundwater along a structurally controlled zone that parallels the north-south strike of the valley, and that includes the slope spring. The results suggest that biogeochemical sampling may be used to supplement more direct, but more limited, measurements of groundwater quality and flow regime in areas of near-surface contaminated groundwater.
Douglas fir trees and associated soils were sampled from the slopes of a small (∼4 km2) drainage basin in northeastern Washington to investigate the biogeochemical response to locally uraniferous groundwater. Uranium is preferentially incorporated in needles and twigs compared to larger branches or the trunk. The U concentration in needle ash ranges from 0.2 to 5.8μg g−1 (ppm) and shows no correlation with the U concentration in associated soils. Rather, the distribution of anomalously uraniferous douglas fir (> 1.0μg g−1 U in needle ash) appears to be controlled by observed or readily inferred pathways of near-surface groundwater movement in the drainage. These pathways include: (1) general downslope movement of subsurface runoff; (2) increased flux of near-surface groundwater near the toe of an alluvial fan; and (3) emergence of uraniferous (100–150 ng ml−1 [ppb] groundwater in the vicinity of a slope spring. The data also indicate the presence of near-surface uraniferous groundwater along a structurally controlled zone that parallels the north-south strike of the valley, and that includes the slope spring. The results suggest that biogeochemical sampling may be used to supplement more direct, but more limited, measurements of groundwater quality and flow regime in areas of near-surface contaminated groundwater.
When regional geomagnetic charts for areas roughly the size of the United States were compiled by hand, some large local anomalies were displayed in the isomagnetic lines. Since the late nineteen sixties, when the compilation of charts using computers and mathematical models was started, most of the details available in the hand drawn regional charts have been lost. One exception to this is the Canadian magnetic declination chart for 1980. This chart was constructed using a 180 degree spherical harmonic model. It managed to show considerable detail, but even more detail might be useful. Suggestions are made about how more detail might be displayed in regional charts when adequate data are available.
","language":"English","publisher":"J-STAGE","doi":"10.5636/jgg.39.723","usgsCitation":"Alldredge, L., 1987, On regional geomagnetic charts: Journal of Geomagnetism & Geoelectricity, v. 39, no. 12, p. 723-738, https://doi.org/10.5636/jgg.39.723.","productDescription":"16 p.","startPage":"723","endPage":"738","numberOfPages":"16","costCenters":[],"links":[{"id":480535,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.5636/jgg.39.723","text":"Publisher Index Page"},{"id":226072,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"39","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6da8e4b0c8380cd7525e","contributors":{"authors":[{"text":"Alldredge, L.R.","contributorId":53457,"corporation":false,"usgs":true,"family":"Alldredge","given":"L.R.","email":"","affiliations":[],"preferred":false,"id":367745,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70014155,"text":"70014155 - 1987 - Evaluation of the stability of gas hydrates in Northern Alaska","interactions":[],"lastModifiedDate":"2023-09-21T15:26:40.006371","indexId":"70014155","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1264,"text":"Cold Regions Science and Technology","active":true,"publicationSubtype":{"id":10}},"title":"Evaluation of the stability of gas hydrates in Northern Alaska","docAbstract":"The factors which control the distribution of in situ gas hydrate deposits in colder regions such as Northern Alaska include; mean annual surface temperatures (MAST), geothermal gradients above and below the base of permafrost, subsurface pressures, gas composition, pore-fluid salinity and the soil condition. Currently existing data on the above parameters for the forty-six wells located in Northern Alaska were critically examined and used in calculations of depths and thicknesses of gas hydrate stability zones. To illustrate the effect of gas hydrate stability zones, calculations were done for a variable gas composition using the thermodynamic model of Holder and John (1982). The hydrostatic pressure gradient of 9.84 kPa/m (0.435 lbf/in2ft), the salinity of 10 parts per thousand (ppt) and the coarse-grained soil conditions were assumed. An error analysis was performed for the above parameters and the effect of these parameters on hydrate stability zone calculations were determined.
After projecting the hydrate stability zones for the forty-six wells, well logs were used to identify and to obtain values for the depth and thickness of hydrate zones. Of the forty-six wells, only ten wells showed definite evidence of the presence of gas hydrates.
","language":"English","publisher":"Elsevier","doi":"10.1016/0165-232X(87)90026-7","usgsCitation":"Kamath, A., Godbole, S.P., Ostermann, R.D., and Collett, T.S., 1987, Evaluation of the stability of gas hydrates in Northern Alaska: Cold Regions Science and Technology, v. 14, no. 2, p. 107-119, https://doi.org/10.1016/0165-232X(87)90026-7.","productDescription":"13 p.","startPage":"107","endPage":"119","numberOfPages":"13","costCenters":[],"links":[{"id":226069,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -162.35348507096748,\n 71.50417315803796\n ],\n [\n -163.3677789577233,\n 68.05690107968127\n ],\n [\n -145.36017551548042,\n 68.05690107968127\n ],\n [\n -145.36017551548042,\n 70.97000817935472\n ],\n [\n -162.35348507096748,\n 71.50417315803796\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"14","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0cf3e4b0c8380cd52d6c","contributors":{"authors":[{"text":"Kamath, A.","contributorId":41154,"corporation":false,"usgs":false,"family":"Kamath","given":"A.","email":"","affiliations":[],"preferred":false,"id":367734,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Godbole, S. P.","contributorId":23285,"corporation":false,"usgs":false,"family":"Godbole","given":"S.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":367733,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ostermann, R. D.","contributorId":42367,"corporation":false,"usgs":false,"family":"Ostermann","given":"R.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":367735,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Collett, T. S. 0000-0002-7598-4708","orcid":"https://orcid.org/0000-0002-7598-4708","contributorId":86342,"corporation":false,"usgs":true,"family":"Collett","given":"T.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":367736,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70014154,"text":"70014154 - 1987 - Heat capacity and thermodynamic properties of andradite garnet, Ca3Fe2Si3O12, between 10 and 1000 K and revised values for ΔfGom (298.15 K) of hedenbergite and wollastonite","interactions":[],"lastModifiedDate":"2015-06-02T12:37:12","indexId":"70014154","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":"Heat capacity and thermodynamic properties of andradite garnet, Ca3Fe2Si3O12, between 10 and 1000 K and revised values for ΔfGom (298.15 K) of hedenbergite and wollastonite","docAbstract":"The heat capacity of synthetic andradite garnet (Ca3Fe2Si3O12) was measured between 9.6 and 365.5 K by cryogenic adiabatic calorimetry and from 340 to 990 K by differential scanning calorimetry. At 298.15 KCop,m and Som are 351.9 ± 0.7 and 316.4 ± 2.0 J/(mol·K), respectively.
\nAndradite has a λ-peak in Cop,m with a maximum at 11.7 ± 0.2 K which is presumably associated with the antiferromagnetic ordering of the magnetic moments of the Fe3+ ions. The Gibbs free energy of formation,ΔfGom (298.15 K) of andradite is −5414.8 ± 5.5 kJ/mol and was obtained by combining our entropy and heat capacity data with the known breakdown of andradite to pseudowollastonite and hematite at ≈ 1410 to 1438 K. From a reexamination of the calcite + quartz = wollastonite equilibrium data we obtained ΔfHom(298.15 K) = − 1634.5 ± 1.8 kJ/mol for wollastonite.
\nBetween 300 and 1000 K the molar heat capacity of andradite can be represented by the equation Cop,m = 809.24 - 7.025 × 10−2T− 7.403 × 103T−0.5 − 6.789 × 105T−2. We have also used our thermochemical data for andradite to estimate the Gibbs free energy of formation of hedenbergite (CaFeSi2O6) for which we obtained ΔfGom (298.15 K) = −2674.3 ± 5.8 kJ/mol.
","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7037(87)90271-7","issn":"00167037","usgsCitation":"Robie, R.A., Bin, Z., Hemingway, B., and Barton, M.D., 1987, Heat capacity and thermodynamic properties of andradite garnet, Ca3Fe2Si3O12, between 10 and 1000 K and revised values for ΔfGom (298.15 K) of hedenbergite and wollastonite: Geochimica et Cosmochimica Acta, v. 51, no. 8, p. 2219-2224, https://doi.org/10.1016/0016-7037(87)90271-7.","productDescription":"6 p.","startPage":"2219","endPage":"2224","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":226006,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"51","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2ff2e4b0c8380cd5d233","contributors":{"authors":[{"text":"Robie, Richard A.","contributorId":92235,"corporation":false,"usgs":true,"family":"Robie","given":"Richard","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":367731,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bin, Zhao","contributorId":72938,"corporation":false,"usgs":true,"family":"Bin","given":"Zhao","email":"","affiliations":[],"preferred":false,"id":367732,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hemingway, Bruce S.","contributorId":13689,"corporation":false,"usgs":true,"family":"Hemingway","given":"Bruce S.","affiliations":[],"preferred":false,"id":367729,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Barton, Mark D.","contributorId":6166,"corporation":false,"usgs":true,"family":"Barton","given":"Mark","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":367730,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70014146,"text":"70014146 - 1987 - Analysis of Shuttle Multispecral Infrared Radiometer measurements of the western Saudi Arabian shield.","interactions":[],"lastModifiedDate":"2017-08-30T08:20:14","indexId":"70014146","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":"Analysis of Shuttle Multispecral Infrared Radiometer measurements of the western Saudi Arabian shield.","docAbstract":"During the November 12–14, 1981, mission of the space shuttle Columbia, the Shuttle Multispectral Infrared Radiometer (SMIRR) recorded radiances in ten channels along a 100 m wide groundtrack across the western Saudi Arabian shield. The ten channels are located in the 0.5 to 2.4 μm region, with five positioned between 2.0 and 2.40 μm for measuring absorption features that are diagnostic of OH‐bearing and
CO3‐bearing\">CO3‐bearing minerals. This exceptionally well exposed area consists of late Proterozoic metamorphic, intermediate to silicic intrusive, and interlayered clastic sedimentary and intermediate silicic volcanic rocks that have not been studied previously using SMIRR data. Plots or traces of unnormalized SMIRR channel ratios were examined before field studies to locate areas with high spectral contrast, especially in the 2.0 μm to 2.40 μm channels. Reflectance spectra were measured in the laboratory for rock and soil samples collected in these areas, and the mineralogic causes of the main absorption features were determined using X‐ray diffraction. Laboratory SMIRR spectra were produced by convolving the ten SMIRR filters with the laboratory spectra. Then, normalized SMIRR reflectance spectra were generated along the groundtrack using normalization coefficients calculated for a field sample representing a uniform, low‐spectral contrast area. Field evaluation shows that unnormalized SMIRR ratio traces are useful, even without specific mineralogic information, for distinguishing rocks that are characterized by Al‐OH, Mg‐OH, and/or
CO3\">CO3\">CO3, Fe3+\">Fe3+, and Fe2+ absorption features. Analysis of field samples permits suites of minerals causing absorption features to be identified. However, specific mineral identification cannot be achieved consistently using the SMIRR ratio traces or normalized SMIRR spectra, because the Al‐OH and Mg‐OH absorption features can be caused by more than one of the minerals commonly present. The normalized SMIRR spectra are especially useful for identifying subtle Al‐OH and Mg‐OH absorption features that are difficult to identify in the unnormalized ratio traces and for comparing the relative intensities of absorption features. Al‐OH absorption is related to muscovite, smectite, illite, and kaolinite, whereas Mg‐OH absorption is caused by chlorite, amphibole, and biotite. The principal sources of error in using SMIRR spectral measurements for identifying mineral groups along the orbit 27 groundtrack are inaccuracies in field location and lithologic heterogeneity that is not represented adequately by field samples. Calibration errors may account for systematic albedo and absorption intensity differences between calculated laboratory SMIRR spectra and normalized SMIRR spectra. SMIRR instrument noise and atmospheric factors appear to be less important sources of error. However, as higher spectral and spatial resolution systems are developed for mineral identification, radiometric precision and atmospheric factors will become more important.
The Ranger and Jabiluka uranium deposits are the largest in the Alligator Rivers uranium field, which contains at least 20 percent of the world's low-cost uranium reserves. Ore occurs in early Proterozoic metasediments, below an unconformity with sandstones of the 1.65-b.y.-old Kombolgie Formation. This study has used U-Pb isotope data from a large number of whole-rock drill core samples with a variety of mineral assemblages and textures. Ranger samples indicate a well-defined age of 1,737 + or - 20 m.y., consistent with earlier suggestions of the antiquity of this deposit. This age is distinctly pre-Kombolgie, so the Ranger deposit cannot have been formed by processes requiring its presence. The age is consistent, however, with mineralization related to heating associated with either the emplacement of early postmetamorphic granites, or possibly, with intrusion of the nearby Oenpelli Dolerite. In contrast, data for the least-altered Jabiluka ores yield a concordia intercept age of 1,437 + or - 40 m.y.--significantly younger than the Ranger age and also younger than the Kombolgie Formation. This age may correspond to a regional thermal event, as indicated both by mafic dikes of roughly this age and a zircon lower intercept age from a nearby granite-gneiss. Thus our data indicate that there must be at least three distinct periods of major U mineralization in the Alligator Rivers uranium field (including the previously determined approximately 900-m.y. age of the Nabarlek deposit), despite the fact that all of the deposits share strong similarities in their host rock, mineralogy, alteration, and geologic setting.Both Ranger and Jabiluka reflect a common, profound isotopic disturbance at about 400 to 600 m.y. This disturbance, which was especially pronounced at Jabiluka, may correspond to the development of basins and associated basalt flows to the west and southwest, as suggested by Crick et al. (1980).
","language":"English","publisher":"Society of Economic Geologists","doi":"10.2113/gsecongeo.82.4.857","issn":"03610128","usgsCitation":"Ludwig, K., Grauch, R., Nutt, C., Nash, J., Frishman, D., and Simmons, K.R., 1987, Age of uranium mineralization at the Jabiluka and Ranger deposits, Northern Territory, Australia: New U-Pb isotope evidence: Economic Geology, v. 82, no. 4, p. 857-874, https://doi.org/10.2113/gsecongeo.82.4.857.","productDescription":"18 p.","startPage":"857","endPage":"874","numberOfPages":"18","costCenters":[],"links":[{"id":225492,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"82","issue":"4","noUsgsAuthors":false,"publicationDate":"1987-07-01","publicationStatus":"PW","scienceBaseUri":"5059e8f3e4b0c8380cd47fd9","contributors":{"authors":[{"text":"Ludwig, K.R.","contributorId":97112,"corporation":false,"usgs":true,"family":"Ludwig","given":"K.R.","email":"","affiliations":[{"id":218,"text":"Denver Federal Center","active":false,"usgs":true}],"preferred":false,"id":367651,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Grauch, R. I. 0000-0002-1763-0813","orcid":"https://orcid.org/0000-0002-1763-0813","contributorId":107698,"corporation":false,"usgs":true,"family":"Grauch","given":"R. I.","affiliations":[],"preferred":false,"id":367652,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Nutt, C.J.","contributorId":52577,"corporation":false,"usgs":true,"family":"Nutt","given":"C.J.","email":"","affiliations":[],"preferred":false,"id":367649,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Nash, J. T.","contributorId":31751,"corporation":false,"usgs":true,"family":"Nash","given":"J. T.","affiliations":[],"preferred":false,"id":367648,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Frishman, D.","contributorId":14959,"corporation":false,"usgs":true,"family":"Frishman","given":"D.","affiliations":[],"preferred":false,"id":367647,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Simmons, K. R.","contributorId":68771,"corporation":false,"usgs":true,"family":"Simmons","given":"K.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":367650,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70014120,"text":"70014120 - 1987 - Pressure sensitivity of low permeability sandstones","interactions":[],"lastModifiedDate":"2024-05-13T14:48:01.033687","indexId":"70014120","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2419,"text":"Journal of Petroleum Science and Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Pressure sensitivity of low permeability sandstones","docAbstract":"Detailed core analysis has been carried out on 32 tight sandstones with permeabilities ranging over four orders of magnitude (0.0002 to 4.8 mD at 5000 psi confining pressure). Relationships between gas permeability and net confining pressure were measured for cycles of loading and unloading. For some samples, permeabilities were measured both along and across bedding planes. Large variations in stress sensitivity of permeability were observed from one sample to another. The ratio of permeability at a nominal confining pressure of 500 psi to that at 5000 psi was used to define a stress sensitivity ratio. For a given sample, confining pressure vs permeability followed a linear log-log relationship, the slope of which provided an index of pressure sensitivity. This index, as obtained for first unloading data, was used in testing relationships between stress sensitivity and other measured rock properties. Pressure sensitivity tended to increase with increase in carbonate content and depth, and with decrease in porosity, permeability and sodium feldspar. However, scatter in these relationships increased as permeability decreased. Tests for correlations between pressure sensitivity and various linear combinations of variables are reported. Details of pore structure related to diagenetic changes appears to be of much greater significance to pressure sensitivity than mineral composition.
","language":"English","publisher":"Elsevier","doi":"10.1016/0920-4105(87)90015-5","issn":"09204105","usgsCitation":"Kilmer, N., Morrow, N., and Pitman, J.K., 1987, Pressure sensitivity of low permeability sandstones: Journal of Petroleum Science and Engineering, v. 1, no. 1, p. 65-81, https://doi.org/10.1016/0920-4105(87)90015-5.","productDescription":"17 p.","startPage":"65","endPage":"81","numberOfPages":"17","costCenters":[{"id":241,"text":"Eastern Energy Resources Science Center","active":true,"usgs":true}],"links":[{"id":225360,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"1","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a8b5ce4b0c8380cd7e21c","contributors":{"authors":[{"text":"Kilmer, N.H.","contributorId":35475,"corporation":false,"usgs":true,"family":"Kilmer","given":"N.H.","email":"","affiliations":[],"preferred":false,"id":367637,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Morrow, N.R.","contributorId":98888,"corporation":false,"usgs":true,"family":"Morrow","given":"N.R.","email":"","affiliations":[],"preferred":false,"id":367639,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Pitman, Janet K. 0000-0002-0441-779X jpitman@usgs.gov","orcid":"https://orcid.org/0000-0002-0441-779X","contributorId":767,"corporation":false,"usgs":true,"family":"Pitman","given":"Janet","email":"jpitman@usgs.gov","middleInitial":"K.","affiliations":[{"id":164,"text":"Central Energy Resources Science Center","active":true,"usgs":true},{"id":241,"text":"Eastern Energy Resources Science Center","active":true,"usgs":true}],"preferred":true,"id":367638,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70014119,"text":"70014119 - 1987 - Analysis of broadband seismograms from selected IASPEI events","interactions":[],"lastModifiedDate":"2013-02-13T13:19:31","indexId":"70014119","displayToPublicDate":"1987-01-01T00:00:00","publicationYear":"1987","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3071,"text":"Physics of the Earth and Planetary Interiors","active":true,"publicationSubtype":{"id":10}},"title":"Analysis of broadband seismograms from selected IASPEI events","docAbstract":"Broadband seismograms of body waves that are flat to displacement and velocity in the frequency range from 0.01 to 5.0 Hz can now be routinely obtained for most earthquakes of magnitude greater than about 5.5. These records are obtained either directly or through multichannel deconvolution of waveforms from digitally recording seismograph stations. In contrast to data from conventional narrowband seismographs, broadband records have sufficient frequency content to define the source-time functions of body waves, even for shallow events for which the source functions of direct and surface-reflected phases may overlap. Broadband seismograms for selected IASPEI events are systematically analysed to identify depth phases and the presence of subevents. The procedure results in improved estimates of focal depth, identification of subevents in complex earthquakes, and better resolution of focal mechanisms. We propose that it is now possible for reporting agencies, such as the National Earthquake Information Center, to use broadband digital waveforms routinely in the processing of earthquake data. ?? 1987.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Physics of the Earth and Planetary Interiors","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/0031-9201(87)90069-0","issn":"00319201","usgsCitation":"Choy, G.L., and Engdahl, E., 1987, Analysis of broadband seismograms from selected IASPEI events: Physics of the Earth and Planetary Interiors, v. 47, no. C, p. 80-92, https://doi.org/10.1016/0031-9201(87)90069-0.","startPage":"80","endPage":"92","numberOfPages":"13","costCenters":[],"links":[{"id":267328,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0031-9201(87)90069-0"},{"id":225359,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"47","issue":"C","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059eb0ce4b0c8380cd48b98","contributors":{"authors":[{"text":"Choy, G. L. 0000-0002-0217-5555","orcid":"https://orcid.org/0000-0002-0217-5555","contributorId":78322,"corporation":false,"usgs":true,"family":"Choy","given":"G.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":367636,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Engdahl, E.R.","contributorId":22906,"corporation":false,"usgs":true,"family":"Engdahl","given":"E.R.","email":"","affiliations":[],"preferred":false,"id":367635,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70014098,"text":"70014098 - 1987 - Source of lead and mineralizing brines for rossie-type Pb-Zn veins in the Frontenac axis area, New York ( USA).","interactions":[],"lastModifiedDate":"2018-10-22T08:57:53","indexId":"70014098","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":"Source of lead and mineralizing brines for rossie-type Pb-Zn veins in the Frontenac axis area, New York ( USA).","docAbstract":"Veins composed mainly of calcite and some galena, sphalerite, fluorite, and other minerals are widespread in the Frontenac axis area of New York and Ontario. In New York, the veins (Fig. 1) occur mainly west and northwest of Gouverneur (Brown, 1983). The veins, mined in the 1800s for lead, were first described by Emmons (1838). Smyth (1903) called these the \"Rossie lead veins,\" a name now used locally for all veins of this type. Similar veins in southeastern Ontario were described by Uglow (1916) and Sangster (1970).
\nThe steeply dipping veins are aligned along extensional fractures in metamorphic rocks of the Grenville Complex and in Paleozoic sedimentary rocks, including the Potsdam Sandstone of Late Cambrian age, and limestones as young as Middle Ordovician. However, the age of emplacement of Rossie veins is unknown. The veins are mineralogically simple, consisting of calcite (~95%) with minor and approximately equal amounts of sphalerite and galena, and sparse fluorite, barite, celestite, and chalcopyrite (Brown, 1983). Paragenetically early minerals are crushed and granulated; later undeformed minerals fill open spaces (Fig. 2). Sandstone dikes that originated from either the overlying Potsdam Sandstone or stratigraphically higher arenaceous rocks cut into the Rossie veins and occupy all available space. Their unstratified nature suggests that sand was intruded under high hydraulic pressure during tectonic events that reopened the veins. Most veins are vertical and narrow (1-3 cm wide) and those that were mined are as much as 1.7 m wide. The veins trend mainly northwest-southeast but have a local east-west orientation. The fractures and veins show evidence of strike-slip faulting with a right-lateral offset due to late reactivation of north-east-trending faults that originally formed during the Proterozoic Grenville orogeny. Relatively rare inclined veins, termed gash veins (Brown, 1983), occur in proximity to some of the regional northeast-trending faults. These veins contain open spaces lined with large, undeformed crystals of calcite (~90%) and green fluorite (~5%). The minerals of the northeast-trending gash veins, which dip to the northwest, are believed to be paragenetically late results of the same mineralization and tectonic event that produced the Rossie veins. For example, the green fluorite in the gash veins is similar in color and occurrence to small fluorite crystals in vugs in the vertical Rossie veins. Associated with the fluorite in both occurrences is coarse crystalline calcite containing tiny tetrahedra of chalcopyrite aligned along crystallographic planes.
\nThe present study of fluid inclusions and lead isotopes was done to understand better the nature and possible source of the mineralizing solutions for both vertical and gash veins and the possible origin of the lead and zinc mineralization. Large deposits of essentially syngenetic sphalerite with minor to trace galena occur in the Proterozoic rocks of this region (e.g., Balmat-Edwards, New York). Although none of these deposits are known in the immediate vicinity of Rossie veins, the possibility that Rossie veins contain remobilized metals from these older deposits was considered.
","language":"English","publisher":"Society of Economic Geologists, Inc.","doi":"10.2113/gsecongeo.82.2.489","issn":"03610128","usgsCitation":"Ayuso, R., Foley, N.K., and Brown, C.E., 1987, Source of lead and mineralizing brines for rossie-type Pb-Zn veins in the Frontenac axis area, New York ( USA).: Economic Geology, v. 82, no. 2, p. 489-491, https://doi.org/10.2113/gsecongeo.82.2.489.","productDescription":"3 p.","startPage":"489","endPage":"491","numberOfPages":"3","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":245,"text":"Eastern Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"links":[{"id":226002,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"New York","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -76,\n 44\n ],\n [\n -76,\n 45\n ],\n [\n -75,\n 45\n ],\n [\n -75,\n 44\n ],\n [\n -76,\n 44\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"82","issue":"2","noUsgsAuthors":false,"publicationDate":"1987-04-01","publicationStatus":"PW","scienceBaseUri":"505b9331e4b08c986b31a358","contributors":{"authors":[{"text":"Ayuso, Robert","contributorId":96350,"corporation":false,"usgs":true,"family":"Ayuso","given":"Robert","email":"","affiliations":[],"preferred":false,"id":367566,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Foley, Nora K. 0000-0003-0124-3509 nfoley@usgs.gov","orcid":"https://orcid.org/0000-0003-0124-3509","contributorId":4010,"corporation":false,"usgs":true,"family":"Foley","given":"Nora","email":"nfoley@usgs.gov","middleInitial":"K.","affiliations":[{"id":245,"text":"Eastern Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"preferred":true,"id":367565,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Brown, C. Erwin","contributorId":96261,"corporation":false,"usgs":true,"family":"Brown","given":"C.","email":"","middleInitial":"Erwin","affiliations":[],"preferred":false,"id":367567,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
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