The Grindstone Creek Section, Glenn County, Northern California is a sequence of hemipelagic mudstone, siltstone and sandstone interbedded with concretionary limestone and a few thin tuffs and bentonites. Two tuffs have been collected from a narrow interval of this sequence and subjected to mineralogical and isotopic analyses. U&z.sbnd;Pb isotopic analyses of zircon fractions from these volcanic horizons indicate an age of 137.1 + 1.6/−0.6 Ma. A detailed investigation has been conducted on the calcareous nannofossil stratigraphy of this section based on numerous samples with moderately preserved assemblages. The nannoflora is largely of Tethyan affinity, and allows direct correlation with the Berriasian stratotype section, with sections with published magnetostratigraphies and with a DSDP site drilled between known magnetic anomalies. The dated tuffs lie in the lower part of the upper BerriasianCretarhabdus angustiforatus Zone (Assipetra infracretacea Subzone) and within the narrow range ofRhagodiscus nebulosus. At three different sections, this subzone can be correlated with M-sequence Polarity Zones M16 and M16n. An independent magnetostratigraphic correlation is provided at DSDP Site 387, drilled between anomalies M15 and M16, where basal sediments containR. nebulosus. Buchia collected within a meter of the lower tuff lie within theB. uncitoides Zone which is Berriasian in age. The upper tuff level, which occurs 65 m above the lower tuff, is situated within the overlyingB. pacifica Zone. This zone had previously been correlated with the early Valanginian, but is clearly also partly of Berriasian age based on nannofossil stratigraphy. Our results allow an estimate of the age of the Berriasian-Valanginian and Jurassic-Cretaceous boundaries of 135.1 Ma and 141.1 Ma, respectively, and these fall within the range of, but differ significantiy from, several published time-scales.
The J-M Reef is an interval of disseminated sulfides in the Lower Banded series of the Stillwater Complex that is enriched in the platinum group elements (PGE). Palladium and Pt occur in solid solution in base-metal sulfides and as discrete PGE minerals. PGE minerals include sulfides, tellurides, arsenides, antimonides, bismuthides, and alloys with Fe, Sn, Hg, and Au. Several subpopulations can be delineated based on whole-rock chemical analyses for As, Bi, Cu, Hg, Pd, Pt, S, Sb and Te for samples collected from and adjacent to the J-M Reef. In general, samples from within the reef have higher Pt/Cu, Pd/Cu, Pd/Pt, Te/Bi and S/(Te+Bi) than those collected adjacent to the reef. Vertical compositional profiles through the reef suggest that Pd/Cu and Pt/Cu decrease systematically upsection from mineralized to barren rock. The majority of samples with elevated As, Sb and Hg occur adjacent to the reef, not within it, or in sulfide-poor rocks
Neither magma mixing nor fluid migration models readily explain why the minor quantities of sulfide minerals immediately adjacent to the sulfide-enriched layers that form the J-M Reef have different element ratios than the sulfide minerals that form the reef. If all the sulfides formed by exsolution during a magma mixing event and the modal proportion of sulfide now in the rocks are simply the result of mechanical processes that concentrated the sulfides into some layers and not others, then the composition of the sulfide would not be expected to be different. Models that rely upon ascending liquids or fluids are incompatible with the presence of sulfides that are not enriched in PGE immediately below or interlayered with the PGE-enriched sulfides layers. PGE-enriched postcumulus fluids should have reacted to the same extent with sulfides immediately outside the reef as within the reef.
","language":"English","publisher":"Elsevier","doi":"10.1016/0375-6742(90)90082-L","issn":"03756742","usgsCitation":"Zientek, M.L., Fries, T.L., and Vian, R., 1990, As, Bi, Hg, S, Sb, Sn and Te geochemistry of the J-M Reef, Stillwater Complex, Montana: Constraints on the origin of PGE-enriched sulfides in layered intrusions: Journal of Geochemical Exploration, v. 37, no. 1, p. 51-73, https://doi.org/10.1016/0375-6742(90)90082-L.","productDescription":"23 p.","startPage":"51","endPage":"73","numberOfPages":"23","costCenters":[],"links":[{"id":223359,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"37","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059edb3e4b0c8380cd49961","contributors":{"authors":[{"text":"Zientek, M. L.","contributorId":6118,"corporation":false,"usgs":true,"family":"Zientek","given":"M.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":373008,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fries, T. L.","contributorId":12053,"corporation":false,"usgs":true,"family":"Fries","given":"T.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":373009,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Vian, R.W.","contributorId":17376,"corporation":false,"usgs":true,"family":"Vian","given":"R.W.","email":"","affiliations":[],"preferred":false,"id":373010,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70015886,"text":"70015886 - 1990 - Results of seismological monitoring in the Cascade Range 1962-1989: earthquakes, eruptions, avalanches and other curiosities","interactions":[],"lastModifiedDate":"2012-03-12T17:18:45","indexId":"70015886","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1813,"text":"Geoscience Canada","active":true,"publicationSubtype":{"id":10}},"title":"Results of seismological monitoring in the Cascade Range 1962-1989: earthquakes, eruptions, avalanches and other curiosities","docAbstract":"Modern monitoring of seismic activity at Cascade Range volcanoes began at Longmire on Mount Rainier in 1958. Since then, there has been an expansion of the regional seismic networks in Washington, northern Oregon and northern California. Now, the Cascade Range from Lassen Peak to Mount Shasta in the south and Newberry Volcano to Mount Baker in the north is being monitored for earthquakes as small as magnitude 2.0, and many of the stratovolcanoes are monitored for non-earthquake seismic activity. This monitoring has yielded three major observations. First, tectonic earthquakes are concentrated in two segments of the Cascade Range between Mount Rainier and Mount Hood and between Mount Shasta and Lassen Peak, whereas little seismicity occurs between Mount Hood and Mount Shasta. Second, the volcanic activity and associated phenomena at Mount St. Helens have produced intense and widely varied seismicity. And third, at the northern stratovolcanoes, signals generated by surficial events such as debris flows, icequakes, steam emissions, rockfalls and icefalls are seismically recorded. Such records have been used to alert authorities of dangerous events in progress. -Authors","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geoscience Canada","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03150941","usgsCitation":"Weaver, C., Norris, R., and Jonientz-Trisler, C., 1990, Results of seismological monitoring in the Cascade Range 1962-1989: earthquakes, eruptions, avalanches and other curiosities: Geoscience Canada, v. 17, no. 3, p. 158-162.","startPage":"158","endPage":"162","numberOfPages":"5","costCenters":[],"links":[{"id":222819,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"17","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aab83e4b0c8380cd8689a","contributors":{"authors":[{"text":"Weaver, C.S.","contributorId":57874,"corporation":false,"usgs":true,"family":"Weaver","given":"C.S.","email":"","affiliations":[],"preferred":false,"id":372008,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Norris, R.D.","contributorId":45735,"corporation":false,"usgs":true,"family":"Norris","given":"R.D.","email":"","affiliations":[],"preferred":false,"id":372007,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Jonientz-Trisler, C.","contributorId":40081,"corporation":false,"usgs":true,"family":"Jonientz-Trisler","given":"C.","email":"","affiliations":[],"preferred":false,"id":372006,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":1000568,"text":"1000568 - 1990 - Improved method for sectioning pectoral spines of catfish for age determination","interactions":[],"lastModifiedDate":"2016-04-25T13:40:59","indexId":"1000568","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2299,"text":"Journal of Freshwater Ecology","active":true,"publicationSubtype":{"id":10}},"title":"Improved method for sectioning pectoral spines of catfish for age determination","docAbstract":"The Gulf of Maine, an embayment of the New England margin, is floored by shallow, glacially scoured basins that are partly filled with late Pleistocene and Holocene silt and clay containing 0.7 to 1.0 wt percent TiO 2 , chiefly in the form of silt-size rutile. Eleven basins in the gulf are estimated to contain 479 X 10 6 metric tons of TiO 2 (to a depth of 10 m) in the U.S. exclusive economic zone and 168 X 10 6 in Canada, based on analyses of surface sediment and of cores 10 to 20 m long. The U.S. annually consumes approximately 1 X 10 6 metric tons of TiO 2 , of which 73 percent is imported. The inferred amount of fine-grained TiO 2 in the basins is large, and we interpret it to be predominantly rutile; but no attempt has been made yet to mine and beneficiate the fine-grained ore.Sedimentary rocks of Nova Scotia, New Brunswick, and northern Maine contain fine-grained rutile crystals and have been the major source of the fine-grained sediment in the Gulf of Maine basins during and after the Wisconsinan glaciation. We conclude that much of the rutile in the Gulf of Maine mud formed diagenetically in poorly cemented Carboniferous and Triassic coarse-grained sedimentary rocks of Nova Scotia and New Brunswick after the dissolution of titanium-rich detrital minerals (ilmenite, ilmenomagnetite). Another major source of rutile is the generally finer grained Paleozoic sedimentary rocks of northern Maine (and possibly northwestern New Brunswick) which contain recycled diagenetic rutile that most likely originated in sandstones. Additional Wisconsinan sources of fine-grained, diagenetic TiO 2 probably include sedimentary rocks of inferred Triassic age that underlie the Gulf of Maine.The diagenesis of rutlie in coarse sedimentary rocks (especially arkose and graywacke) followed by erosion, segregation, and deposition (and including recycling of fine-grained rutile from shales) can serve as a model for predicting and prospecting for unconsolidated deposits of fine-grained TiO 2 .Gulf of Maine mud is comparable in TiO 2 content to typical shale. A determination of whether the fine-grained TiO 2 in shales primarily occurs as detrital titanium minerals from metamorphic and igneous sources or as recycled, diagenetic titanium oxides from sedimentary sources may assist in interpreting shale provenance and environment of deposition.
","language":"English","publisher":"Society of Economic Geologists","doi":"10.2113/gsecongeo.85.4.862","issn":"03610128","usgsCitation":"Valentine, P.C., and Commeau, J., 1990, Fine-grained rutile in the Gulf of Maine: Diagenetic origin, source rocks, and sedimentary environment of deposition: Economic Geology, v. 85, no. 4, p. 862-876, https://doi.org/10.2113/gsecongeo.85.4.862.","productDescription":"15 p.","startPage":"862","endPage":"876","costCenters":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":223225,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"85","issue":"4","noUsgsAuthors":false,"publicationDate":"1990-07-01","publicationStatus":"PW","scienceBaseUri":"505a1023e4b0c8380cd53b43","contributors":{"authors":[{"text":"Valentine, P. C.","contributorId":46505,"corporation":false,"usgs":true,"family":"Valentine","given":"P.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":371810,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Commeau, J.A.","contributorId":21549,"corporation":false,"usgs":true,"family":"Commeau","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":371809,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70015878,"text":"70015878 - 1990 - High-resolution reflectance spectra of Mars in the 2.3-μm region: evidence for the mineral scapolite","interactions":[],"lastModifiedDate":"2015-05-29T13:43:13","indexId":"70015878","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2312,"text":"Journal of Geophysical Research","active":true,"publicationSubtype":{"id":10}},"title":"High-resolution reflectance spectra of Mars in the 2.3-μm region: evidence for the mineral scapolite","docAbstract":"patially resolved reflectance spectra of Mars in the 2.2- to 2.4-μm spectral region were obtained in August 1988 using the NASA 3-m Infrared Telescope Facility. The spectra show weak absorption features due to Martian atmospheric carbon monoxide and a surface mineral. Both CO and the mineral absorptions are composed of overlapping narrow features, but in many locations, such as Hellas, Chryse, Eden, and Moab, the mineral absorptions are quite strong, at least 3 times stronger than at the most absorbing wavelengths of CO near 2.33 μm. Therefore CO complicates the analysis of the surface mineral but does not always overwhelm its signature. Model removal of the Martian atmospheric CO has been performed, and the remaining absorption bands are identified as scapolite. Relatively strong absorptions that match bands in the spectrum of scapolite and have little or no CO absorption interference are seen near 2.41, 2.39, and 2.29 μm. Absorption also occurs at the scapolite bands at 2.36 and 2.33 μm, but the analysis is complicated by uncertainty in the atmospheric CO removal at these wavelengths. Weaker scapolite bands are seen at 2.44 and 2.23 μm where there is virtually no atmospheric interference. The scapolite bands observed on Mars are due to HCO3− and HSO4− ions in the scapolite structure. The bicarbonate and bisulfate contents appear to vary with location: the scapolite in Hellas is more bisulfate-rich relative to that in the Chryse/Moab/Eden area. Other locations contain little (Arabia, Syrtis Major, Hellespontica, and Isidis) or no scapolite (e.g., Margaritifer, Ausonia, and Erythraeum). The calculated abundances are unconstrained because the amounts of HCO3− and HSO4− in the Martian scapolites as well as their grain sizes are not known. If the scapolites contain about 3 wt % of each, near the maximum possible, the scapolite abundances probably range from about 5 wt % scapolite at Eden and Hellas; 3–5% at Chryse, Moab, and Oxia Palus; 2–3% at Arabia, Syrtis Major, and Isidis; to less than 2% at Hellespontica, Syrtis Minor, and Margaritifer, assuming a relatively large grain size of 50–100 μm. If the characteristic grain sizes are smaller or the HCO3− and HSO4− contents are lower, the scapolite abundances required to match the observed band depths would be higher. The mineral bands are apparent in many of the Mars spectra measured, so it appears to be widely but not uniformly distributed. The newly observed fine structure also varies greatly in both depth and spectral detail with location on Mars. Thus there appears to be regional variations in composition. The mineral phases appear to reflect local or regional geology and are not primarily contained in the homogeneous, globally redistributed aeolian dust. Higher spectral resolution Martian spectra in the 2.3-μm region as well as at 3.9 μm are needed to confirm the scapolite identification and to constrain its abundance.
","language":"English","publisher":"AGU Publications","doi":"10.1029/JB095iB09p14463","issn":"01480227","usgsCitation":"Clark, R.N., Swayze, G.A., Singer, R.B., and Pollack, J.B., 1990, High-resolution reflectance spectra of Mars in the 2.3-μm region: evidence for the mineral scapolite: Journal of Geophysical Research, v. 95, no. B9, p. 14463-14480, https://doi.org/10.1029/JB095iB09p14463.","productDescription":"18 p.","startPage":"14463","endPage":"14480","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":479844,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/jb095ib09p14463","text":"Publisher Index Page"},{"id":223537,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"95","issue":"B9","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505a3114e4b0c8380cd5dbf4","contributors":{"authors":[{"text":"Clark, Roger N. 0000-0002-7021-1220 rclark@usgs.gov","orcid":"https://orcid.org/0000-0002-7021-1220","contributorId":515,"corporation":false,"usgs":true,"family":"Clark","given":"Roger","email":"rclark@usgs.gov","middleInitial":"N.","affiliations":[{"id":211,"text":"Crustal Geophysics and Geochemistry Science Center","active":true,"usgs":true}],"preferred":true,"id":371981,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Swayze, Gregg A. 0000-0002-1814-7823 gswayze@usgs.gov","orcid":"https://orcid.org/0000-0002-1814-7823","contributorId":518,"corporation":false,"usgs":true,"family":"Swayze","given":"Gregg","email":"gswayze@usgs.gov","middleInitial":"A.","affiliations":[{"id":211,"text":"Crustal Geophysics and Geochemistry Science Center","active":true,"usgs":true},{"id":309,"text":"Geology and Geophysics Science Center","active":true,"usgs":true}],"preferred":true,"id":371984,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Singer, Robert B.","contributorId":16166,"corporation":false,"usgs":true,"family":"Singer","given":"Robert","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":371983,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Pollack, James B.","contributorId":12616,"corporation":false,"usgs":true,"family":"Pollack","given":"James","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":371982,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70016056,"text":"70016056 - 1990 - Structural evidence for northeastward movement on the Chocolate Mountains Thrust, southeasternmost California","interactions":[],"lastModifiedDate":"2024-05-24T16:41:17.578949","indexId":"70016056","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2312,"text":"Journal of Geophysical Research","active":true,"publicationSubtype":{"id":10}},"title":"Structural evidence for northeastward movement on the Chocolate Mountains Thrust, southeasternmost California","docAbstract":"The Late Cretaceous Chocolate Mountains thrust of southeastern California and southwestern Arizona places a block of Proterozoic and Mesozoic continental crust over the late Mesozoic continental margin oceanic sedimentary and volcanic rocks of the regionally distinctive Orocopia Schist. The Chocolate Mountains thrust is interpreted as a thrust (burial, subduction) fault rather than a low-angle normal (exhumation, unroofing, uplift) fault. An important parameter required to understand the tectonic significance of the Chocolate Mountains and related thrusts is their sense of movement. The Chocolate Mountains thrust zone contains sparse to locally abundant mesoscopic asymmetric folds. Fabric relations, supported by regional geologic evidence, indicate that these folds are an integral part of and coeval with the thrust zone. On a lower hemisphere equal-area plot representing the orientation and sense of asymmetry of 80 thrust zone folds from 36 localities, spread over an area 60 by 10 km, Z folds plot northwest of and S folds plot southeast of a northeast-southwest striking vertical plane of overall monoclinic symmetry. The only sense of movement consistent with the collective asymmetry of the thrust zone folds is top to the northeast. Asymmetric microstructures studied at several localities also indicate top to the northeast movement. Paleomagnetic data suggest that the original sense of thrusting, prior to Neogene vertical axis tectonic rotation related to the San Andreas fault system, was northward. The essential point is that movement of the upper plate of the Chocolate Mountains thrust evidently was continentward. Continentward thrusting suggests a tectonic scenario in which an insular or peninsular microcontinental fragment collided with mainland southern California. The suture predicted by this model is elusive; but the Chocolate Mountains thrust and underlying Orocopia Schist themselves may represent the suture, at the present level of exposure. Alternative tectonic models involving subduction of the Orocopia Schist eastward beneath continental southern California circumvent the suture problem but are presently not supported by any direct structural evidence.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB095iB12p19953","issn":"01480227","usgsCitation":"Dillon, J.T., Haxel, G.B., and Tosdal, R., 1990, Structural evidence for northeastward movement on the Chocolate Mountains Thrust, southeasternmost California: Journal of Geophysical Research, v. 95, no. B12, p. 19953-19971, https://doi.org/10.1029/JB095iB12p19953.","productDescription":"19 p.","startPage":"19953","endPage":"19971","costCenters":[],"links":[{"id":223245,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"95","issue":"B12","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505b9be4e4b08c986b31d15d","contributors":{"authors":[{"text":"Dillon, J. T.","contributorId":72382,"corporation":false,"usgs":true,"family":"Dillon","given":"J.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":372441,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Haxel, G. B.","contributorId":71503,"corporation":false,"usgs":true,"family":"Haxel","given":"G.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":372440,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Tosdal, R. M.","contributorId":54982,"corporation":false,"usgs":true,"family":"Tosdal","given":"R. M.","affiliations":[],"preferred":false,"id":372439,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70016505,"text":"70016505 - 1990 - Reflected and mode-converted seismic waves within the shallow Aleutian subduction zone, southern Kenai Peninsula, Alaska","interactions":[],"lastModifiedDate":"2024-05-24T15:26:59.741501","indexId":"70016505","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","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":"Reflected and mode-converted seismic waves within the shallow Aleutian subduction zone, southern Kenai Peninsula, Alaska","docAbstract":"Pronounced secondary phases observed in local recordings of quarry shots and earthquakes on the southern Kenai Peninsula, Alaska, are identified as reflected P and S and converted S-to-P phases originating within four depth ranges: in the upper few kilometers of the Cook Inlet Tertiary basin, at midcrustal depths within the overthrust North American plate, at about 35 km depth near the top of the Wadati-Benioff seismic zone in proximity to the inferred interplate megathrust, and at about 5–10 km below the megathrust in the subducted Pacific plate. Beneath the landward margin of the accreted Chugach terrane, the mid-upper plate (MUP) discontinuity dips as steeply as 20°–30° to the west-northwest over the depth range 12–18 km. At shallower depths it flattens and possibly arches with the crest at about 10 km depth. Similar midcrustal reflectors have been imaged about 125 km to the southwest and about 350 km to the northeast along the structural trend of the Chugach terrane. The extensive reflectors may have a common origin, possible caused by the presence of underplated rocks. Relative amplitudes and polarities of the secondary phases originating at MUP depths provide few constraints on the nature of the discontinuity. It appears that the MUP discontinuity is seismically inactive and does not represent a brittle-ductile transition zone within the upper plate. The two converted S-to-P phases generated near the top of the subducted plate could indicate a low-velocity zone associated with subducted oceanic crust.
","largerWorkTitle":"American Geophysical Union","language":"English","doi":"10.1029/JB095iB05p06883","issn":"01480227","usgsCitation":"Stephens, C., Page, R., and Lahr, J., 1990, Reflected and mode-converted seismic waves within the shallow Aleutian subduction zone, southern Kenai Peninsula, Alaska: Journal of Geophysical Research Solid Earth, v. 95, no. B5, p. 6883-6897, https://doi.org/10.1029/JB095iB05p06883.","productDescription":"15 p.","startPage":"6883","endPage":"6897","numberOfPages":"15","costCenters":[],"links":[{"id":223379,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"95","issue":"B5","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"50e4a43be4b0e8fec6cdbad7","contributors":{"authors":[{"text":"Stephens, C.D.","contributorId":18752,"corporation":false,"usgs":true,"family":"Stephens","given":"C.D.","email":"","affiliations":[],"preferred":false,"id":373746,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Page, R.A.","contributorId":40197,"corporation":false,"usgs":true,"family":"Page","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":373748,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lahr, J.C.","contributorId":34892,"corporation":false,"usgs":true,"family":"Lahr","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":373747,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70016071,"text":"70016071 - 1990 - Recent uplift and hydrothermal activity at Tangkuban Parahu volcano, west Java, Indonesia","interactions":[],"lastModifiedDate":"2012-03-12T17:18:46","indexId":"70016071","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1109,"text":"Bulletin of Volcanology","active":true,"publicationSubtype":{"id":10}},"title":"Recent uplift and hydrothermal activity at Tangkuban Parahu volcano, west Java, Indonesia","docAbstract":"Tangkuban Parahu is an active stratovolcano located 17 km north of the city of Bandung in the province west Java, Indonesia. All historical eruptive activity at this volcano has been confined to a complex of explosive summit craters. About a dozen eruptions-mostly phreatic events- and 15 other periods of unrest, indicated by earthquakes or increased thermal activity, have been noted since 1829. The last magmatic eruption occurred in 1910. In late 1983, several small phreatic explosions originated from one of the summit craters. More recently, increased hydrothermal and earthquake activity occurred from late 1985 through 1986. Tilt measurements, using a spirit-level technique, have been made every few months since February 1981 in the summit region and along the south and east flanks of the volcano. Measurements made in the summit region indicated uplift since the start of these measurements through at least 1986. From 1981 to 1983, the average tilt rate at the edges of the summit craters was 40-50 microradians per year. After the 1983 phreatic activity, the tilt rate decreased by about a factor of five. Trilateration surveys across the summit craters and on the east flank of the volcano were conducted in 1983 and 1986. Most line length changes measured during this three-year period did not exceed the expected uncertainty of the technique (4 ppm). The lack of measurable horizontal strain across the summit craters seems to contradict the several years of tilt measurements. Using a point source of dilation in an elastic half-space to model tilt measurements, the pressure center at Tangkuban Parahu is located about 1.5 km beneath the southern part of the summit craters. This is beneath the epicentral area of an earthquake swarm that occurred in late 1983. The average rate in the volume of uplift from 1981 to 1983 was 3 million m3 per year; from 1983 to 1986 it averaged about 0.4 million m3 per year. Possible causes for this uplift are increased pressure within a very shallow magma body or heating and expansion of a confined aquifier. ?? 1990 Springer-Verlag.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Bulletin of Volcanology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Springer-Verlag","doi":"10.1007/BF00680317","issn":"02588900","usgsCitation":"Dvorak, J., Matahelumual, J., Okamura, A., Said, H., Casadevall, T.J., and Mulyadi, D., 1990, Recent uplift and hydrothermal activity at Tangkuban Parahu volcano, west Java, Indonesia: Bulletin of Volcanology, v. 53, no. 1, p. 20-28, https://doi.org/10.1007/BF00680317.","startPage":"20","endPage":"28","numberOfPages":"9","costCenters":[],"links":[{"id":223448,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":205370,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00680317"}],"volume":"53","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a9656e4b0c8380cd81f2d","contributors":{"authors":[{"text":"Dvorak, J.","contributorId":94042,"corporation":false,"usgs":true,"family":"Dvorak","given":"J.","email":"","affiliations":[],"preferred":false,"id":372477,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Matahelumual, J.","contributorId":21285,"corporation":false,"usgs":true,"family":"Matahelumual","given":"J.","affiliations":[],"preferred":false,"id":372474,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Okamura, A.T.","contributorId":70400,"corporation":false,"usgs":true,"family":"Okamura","given":"A.T.","email":"","affiliations":[],"preferred":false,"id":372475,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Said, H.","contributorId":9775,"corporation":false,"usgs":true,"family":"Said","given":"H.","email":"","affiliations":[],"preferred":false,"id":372473,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Casadevall, T. J.","contributorId":96680,"corporation":false,"usgs":true,"family":"Casadevall","given":"T.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":372478,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Mulyadi, D.","contributorId":88495,"corporation":false,"usgs":true,"family":"Mulyadi","given":"D.","affiliations":[],"preferred":false,"id":372476,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70015938,"text":"70015938 - 1990 - Stratigraphic, lithologic, and major element geochemical constraints on magmatic evolution at Lassen volcanic center, California","interactions":[],"lastModifiedDate":"2024-05-24T16:53:26.689232","indexId":"70015938","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","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":"Stratigraphic, lithologic, and major element geochemical constraints on magmatic evolution at Lassen volcanic center, California","docAbstract":"The Lassen volcanic center is the most recent of several long-lived volcanic centers in the southernmost Cascade Range. These centers have erupted products ranging from basaltic andesite to rhyolite and are superimposed on a background of regional basaltic to andesitic volcanism. The evolution of the Lassen volcanic center is described in three stages. Stages I and II comprise the Brokeoff volcano, and 80 km3 andesitic stratocone, active from 600 to 400 ka. Brokeoff volcano is compositionally equivalent to the regional basaltic andesite to andesite volcanism in the Lassen region and is the result of structurally controlled focusing of the diffuse regional mafic magmatism. Stage III comprises a silicic dome field and adjacent area of hybrid andesites and has a total volume of about 100 km3. Volcanism during stage III was episodic and is subdivided into four sequences of lithologically and temporally distinct lavas. Stage III began at 400 ka with a rhyolitic, caldera-forming pyroclastic eruption and chemically related lavas. Additional sequences of dacite erupted between 250–200 ka and 100–0 ka. Hybrid andesites erupted adjacent to the silicic dome field between 300 and 0 ka. Porphyritic andesite and dacite with high Al2O3, low TiO2, medium K2O and FeO/MgO ratios of 1.5–2.0 are the most abundant rock types in the Lassen volcanic center. However, the single most voluminous unit is sparsely phyric rhyolite pumice. In general, the lavas of Lassen volcanic center form a single coherent trend on major element variation diagrams and in pseudo-quaternary phase space, consistant with an origin either by fractional crystallization or magma mixing. In detail, however, the lack of systematic temporal change in silica and subtly crossing trends indicate a complex origin. A variety of statistically successful fractional crystallization models can be constructed that derive Brokeoff andesites from regional magmas. An important conclusion of the modeling is that if fractional crystallization is the process responsible for generation of Brokeoff andesite, then the parent magma must be low to medium K in geochemical affinity in order to explain the variation in K2O. However, although major element variation can be modeled by fractional crystallization, petrographic and stratigraphic evidence indicates that magma mixing is an important but subtle process in Brokeoff lavas and suggests that lavas evolved in small independent batches. Lavas erupted during stage III, while predominantly silicic, range from 53 to 75% SiO2. Disequilibrium mineral assemblages in the stage III lavas indicate that they are not directly derived from Brokeoff andesite by fractional crystallization. Mixing of silicic magma with regional mafic magma and disaggregation of andesitic quenched magmatic inclusions play dominant roles in the compositional diversity of stage III lavas.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB095iB12p19651","issn":"01480227","usgsCitation":"Clynne, M., 1990, Stratigraphic, lithologic, and major element geochemical constraints on magmatic evolution at Lassen volcanic center, California: Journal of Geophysical Research Solid Earth, v. 95, no. B12, p. 19651-19669, https://doi.org/10.1029/JB095iB12p19651.","productDescription":"19 p.","startPage":"19651","endPage":"19669","costCenters":[],"links":[{"id":222771,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"95","issue":"B12","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505b9970e4b08c986b31c411","contributors":{"authors":[{"text":"Clynne, M.A.","contributorId":90722,"corporation":false,"usgs":true,"family":"Clynne","given":"M.A.","affiliations":[],"preferred":false,"id":372124,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70016180,"text":"70016180 - 1990 - A comparison of two- and three-dimensional stochastic models of regional solute movement","interactions":[],"lastModifiedDate":"2012-03-12T17:18:46","indexId":"70016180","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3646,"text":"Transport in Porous Media","active":true,"publicationSubtype":{"id":10}},"title":"A comparison of two- and three-dimensional stochastic models of regional solute movement","docAbstract":"Recent models of solute movement in porous media that are based on a stochastic description of the porous medium properties have been dedicated primarily to a three-dimensional interpretation of solute movement. In many practical problems, however, it is more convenient and consistent with measuring techniques to consider flow and solute transport as an areal, two-dimensional phenomenon. The physics of solute movement, however, is dependent on the three-dimensional heterogeneity in the formation. A comparison of two- and three-dimensional stochastic interpretations of solute movement in a porous medium having a statistically isotropic hydraulic conductivity field is investigated. To provide an equitable comparison between the two- and three-dimensional analyses, the stochastic properties of the transmissivity are defined in terms of the stochastic properties of the hydraulic conductivity. The variance of the transmissivity is shown to be significantly reduced in comparison to that of the hydraulic conductivity, and the transmissivity is spatially correlated over larger distances. These factors influence the two-dimensional interpretations of solute movement by underestimating the longitudinal and transverse growth of the solute plume in comparison to its description as a three-dimensional phenomenon. Although this analysis is based on small perturbation approximations and the special case of a statistically isotropic hydraulic conductivity field, it casts doubt on the use of a stochastic interpretation of the transmissivity in describing regional scale movement. However, by assuming the transmissivity to be the vertical integration of the hydraulic conductivity field at a given position, the stochastic properties of the hydraulic conductivity can be estimated from the stochastic properties of the transmissivity and applied to obtain a more accurate interpretation of solute movement. ?? 1990 Kluwer Academic Publishers.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Transport in Porous Media","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Kluwer Academic Publishers","doi":"10.1007/BF00714626","issn":"01693913","usgsCitation":"Shapiro, A., and Cvetkovic, V., 1990, A comparison of two- and three-dimensional stochastic models of regional solute movement: Transport in Porous Media, v. 5, no. 1, p. 1-25, https://doi.org/10.1007/BF00714626.","startPage":"1","endPage":"25","numberOfPages":"25","costCenters":[],"links":[{"id":205377,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00714626"},{"id":223503,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"5","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e37be4b0c8380cd46066","contributors":{"authors":[{"text":"Shapiro, A.M. 0000-0002-6425-9607","orcid":"https://orcid.org/0000-0002-6425-9607","contributorId":88384,"corporation":false,"usgs":true,"family":"Shapiro","given":"A.M.","affiliations":[],"preferred":true,"id":372756,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Cvetkovic, V.D.","contributorId":52335,"corporation":false,"usgs":true,"family":"Cvetkovic","given":"V.D.","email":"","affiliations":[],"preferred":false,"id":372755,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70016229,"text":"70016229 - 1990 - Variations in fault slip and strain accumulation at Parkfield, California: Initial results using two-color geodimeter measurements 1984-1988","interactions":[],"lastModifiedDate":"2024-05-24T16:23:28.635268","indexId":"70016229","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","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":"Variations in fault slip and strain accumulation at Parkfield, California: Initial results using two-color geodimeter measurements 1984-1988","docAbstract":"Repeated length measurements of several geodetic baselines near Parkfield, California, have revealed significant variations in the local rates of shallow fault slip and strain. This network of baselines, surveyed several times each week, straddles the San Andreas fault in the transition zone between the creeping section to the northwest and the locked section to the southeast. The length measurements, characterized by a precision approaching 0.1 ppm, reveal large fluctuations in the rates of baseline extension. Principal mode analysis of the length change data indicates that the two largest components of the signal are (1) secular extensions and contractions consistent with surface slip on the main strand of the San Andreas fault, and (2) a large seasonal oscillation with no obvious spatial coherence. On most of these baselines, the second component appears to be in phase with seasonal rainfall. When data from the baselines with the largest amplitude of the seasonal signal are excluded, the remaining data can be modeled in terms of both spatial and temporal variations in surface slip, variations in the components of the changes in uniform strain, and the possible displacement of the central monument in this radial network. In parameterizing this model, the spatial variation of slip beneath the near surface is reflected by changes in shear strain. Although the computed secular shear is highly dependent upon the specified parameterization of surface slip, the data are consistent with the hypothesis that slip at intermediate depths lags behind the surface slip rate. However, the range in models that fit the data does not necessarily imply that there is a deficit in slip at depth relative to the surface. Comparison of the inferred values of surface slip from the model with the observed fault slip measured by very short baseline creep meters indicates close agreement in secular rates, but the short-term variations observed with the creep meters are either highly attenuated or nonexistent in the modeled slip since the modeled slip is a spatial average which smooths out possible short-wavelength variations in the surface slip for which the creep instruments are most sensitive. An interesting conclusion from the two-color data is that surface slip on the San Andreas fault appears to be spread over a 2-km-wide zone on the south flank of Middle Mountain but is confined to a very narrow zone to the south as the fault passes through the center of the network. This conclusion is dependent upon the assumption that a few critical monuments are stable and track tectonic displacements in the long term. Finally, the largest observed strain change is an extensional strain coincident with the Kettleman Hills earthquake M5.5 in August 1985.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB095iB03p02533","issn":"01480227","usgsCitation":"Langbein, J.O., Burford, R.O., and Slater, L., 1990, Variations in fault slip and strain accumulation at Parkfield, California: Initial results using two-color geodimeter measurements 1984-1988: Journal of Geophysical Research Solid Earth, v. 95, no. B3, p. 2533-2552, https://doi.org/10.1029/JB095iB03p02533.","productDescription":"20 p.","startPage":"2533","endPage":"2552","numberOfPages":"20","costCenters":[],"links":[{"id":223560,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"95","issue":"B3","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505bc17de4b08c986b32a5d0","contributors":{"authors":[{"text":"Langbein, J. O.","contributorId":39404,"corporation":false,"usgs":true,"family":"Langbein","given":"J.","email":"","middleInitial":"O.","affiliations":[],"preferred":false,"id":372911,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Burford, Robert O.","contributorId":52560,"corporation":false,"usgs":true,"family":"Burford","given":"Robert","middleInitial":"O.","affiliations":[],"preferred":false,"id":372912,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Slater, L.E.","contributorId":35063,"corporation":false,"usgs":true,"family":"Slater","given":"L.E.","email":"","affiliations":[],"preferred":false,"id":372910,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70015834,"text":"70015834 - 1990 - High temperature annealing of fission tracks in fluorapatite, Santa Fe Springs oil field, Los Angeles Basin, California","interactions":[],"lastModifiedDate":"2013-03-06T20:08:40","indexId":"70015834","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2067,"text":"International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements","active":true,"publicationSubtype":{"id":10}},"title":"High temperature annealing of fission tracks in fluorapatite, Santa Fe Springs oil field, Los Angeles Basin, California","docAbstract":"Annealing of fission tracks is a kinetic process dependent primarily on temperature and to a laser extent on time. Several kinetic models of apatite annealing have been proposed. The predictive capabilities of these models for long-term geologic annealing have been limited to qualitative or semiquantitative at best, because of uncertainties associated with (1) the extrapolation of laboratory observations to geologic conditions, (2) the thermal histories of field samples, and (3) to some extent, the effect of apatite composition on reported annealing temperatures. Thermal history in the Santa Fe Springs oil field, Los Angeles Basin, California, is constrained by an exceptionally well known burial history and present-day temperature gradient. Sediment burial histories are continuous and tightly constrained from about 9 Ma to present, with an important tie at 3.4 Ma. No surface erosion and virtually no uplift were recorded during or since deposition of these sediments, so the burial history is simple and uniquely defined. Temperature gradient (???40??C km-1) is well established from oil-field operations. Fission-track data from the Santa Fe Springs area should thus provide one critical field test of kinetic annealing models for apatite. Fission-track analysis has been performed on apatites from sandstones of Pliocene to Miocene age from a deep drill hole at Santa Fe Springs. Apatite composition, determined by electron microprobe, is fluorapatite [average composition (F1.78Cl0.01OH0.21)] with very low chlorine content [less than Durango apatite; sample means range from 0.0 to 0.04 Cl atoms, calculated on the basis of 26(O, F, Cl, OH)], suggesting that the apatite is not unusually resistant to annealing. Fission tracks are preserved in these apatites at exceptionally high present-day temperatures. Track loss is not complete until temperatures reach the extreme of 167-178??C (at 3795-4090 m depth). The temperature-time annealing relationships indicated by the new data from Santa Fe Springs conflict with predictions based on previously published, commonly used, kinetic annealing models for apatite. Work is proceeding on samples from another area of the basin that may resolve this discrepancy.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements","largerWorkSubtype":{"id":10,"text":"Journal Article"},"conferenceTitle":"Proceedings of the 6th International Fission Track Dating Workshop","conferenceLocation":"Besancon, Fr","language":"English","publisher":"Elsevier","doi":"10.1016/1359-0189(90)90097-H","issn":"0191278X","usgsCitation":"Naeser, N.D., Crowley, K.D., McCulloh, T.H., and Reaves, C.M., 1990, High temperature annealing of fission tracks in fluorapatite, Santa Fe Springs oil field, Los Angeles Basin, California: International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements, v. 17, no. 3, https://doi.org/10.1016/1359-0189(90)90097-H.","startPage":"424","costCenters":[],"links":[{"id":268865,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/1359-0189(90)90097-H"},{"id":222869,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"17","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a30d5e4b0c8380cd5d9ae","contributors":{"editors":[{"text":"Couchot PierreFromm M.Chambaudet A.Rebetez M.Van den haute Peteret al","contributorId":128349,"corporation":true,"usgs":false,"organization":"Couchot PierreFromm M.Chambaudet A.Rebetez M.Van den haute Peteret al","id":536309,"contributorType":{"id":2,"text":"Editors"},"rank":1}],"authors":[{"text":"Naeser, Nancy D.","contributorId":82753,"corporation":false,"usgs":true,"family":"Naeser","given":"Nancy","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":371871,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Crowley, Kevin D.","contributorId":63536,"corporation":false,"usgs":true,"family":"Crowley","given":"Kevin","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":371870,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"McCulloh, Thane H.","contributorId":100450,"corporation":false,"usgs":true,"family":"McCulloh","given":"Thane","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":371872,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Reaves, Chris M.","contributorId":10554,"corporation":false,"usgs":true,"family":"Reaves","given":"Chris","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":371869,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70015903,"text":"70015903 - 1990 - Trace element and isotopic constraints on magmatic evolution at Lassen volcanic center","interactions":[],"lastModifiedDate":"2024-05-24T16:58:12.300978","indexId":"70015903","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","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":"Trace element and isotopic constraints on magmatic evolution at Lassen volcanic center","docAbstract":"Magmatic evolution at the Lassen volcanic center (LVC) is characterized by a transition from predominantly andesitic to predominantly silicic volcanism with time. Magmas of the andesitic, or “Brokeoff phase” of volcanism range in composition from basaltic andesite io dacite, whereas those of silicic, or “Lassen phase” range in composition from basaltic andesite to rhyolite. The compositions of magmas from each phase define well organized but distinct variation trends. Compared with Brokeoff-phase magmas of similar SiO2 content, most Lassen-phase magmas contain lower concentrations of most incompatible minor and trace elements. Based on the behavior of both incompatible and compatible trace elements, the geochemical trends defined by the Brokeoff-phase magmas cannot be ascribed merely to fractional crystallization from a single or multiple mafic parental magmas, Moreover, the Lassen-phase magmas cannot be derived from the Brokeoff-phase magmas by fractional crystallization. Rather, the geochemical trends that characterize each volcanic phase define arrays that primarily indicate mixing between well-homogenized silicic and heterogeneous mafic magmas. The distinctive mixing-dominated arrays for each volcanic phase manifest the generation and evolution of two physically distinct, but genetically related magma systems. The LVC magmas have Sr, Nd, and Pb isotopic characteristics that approximate two-component mixing arrays. One isotopic component is similar in composition to that of NE Pacific Ocean ridge and seamount basalts (“MORB” component), the other to mafic Mesozoic granitoids sampled from the neighboring KSamath and Sierra Nevada provinces (“KSN” component). The isotopic compositions of the most silicic LVC magmas lie within the ranges defined by the more mafic LVC magmas, which in turn lie within broad ranges defined by primitive mafic lavas sampled from the Lassen region. The lack of a correlation between the major element and isotopic compositions of LVC magmas seriously limits any model for magmatic evolution that relies on assimilation of old middle to upper crust by isotopically homogeneous mafic magmas during their ascent through the crust. Alternatively, the isotopic and geochemical uniformity of the most silicic magmas of the Brokeoff and Lassen phases suggests that they are well-homogenized partial melts. The likely source region for these silicic melts is the lower crust, which we envision to consist primarily of mafic igneous rocks that are similar in geochemical and isotopic diversity to the regional mafic lavas. Magmatic evolution at LVC can be viewed in terms of a series of mantle melting events that subsequently stimulated meiting in a progressively increasing volume of the lower crust. In general, the LVC magmas represent slightly fractionated mixtures of the mantle-derived mafic magmas and silicic partial melts of the lower crust, the latter melts increasing in relative proportion over the history of the volcanic center. The voluminous rhyolitic lavas and pyroclastic materials erupted during the early Lassen phase represent lower crustal melts thai pooled into sufficient volumes to avoid significant blending and dilution with intruding mafic magmas. The geochemical and isotopic heterogeneity of both Brokeoff-phase andésites and mafic magmatic inclusions in the silicic Lassen-phase magmas must in part record the corresponding diversity of the mantle-derived contributions to arc magmagenesis in this region.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB095iB12p19671","issn":"01480227","usgsCitation":"Bullen, T., and Clynne, M., 1990, Trace element and isotopic constraints on magmatic evolution at Lassen volcanic center: Journal of Geophysical Research Solid Earth, v. 95, no. B12, p. 19671-19691, https://doi.org/10.1029/JB095iB12p19671.","productDescription":"21 p.","startPage":"19671","endPage":"19691","costCenters":[],"links":[{"id":223132,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"95","issue":"B12","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505bb634e4b08c986b326b11","contributors":{"authors":[{"text":"Bullen, T.D.","contributorId":79911,"corporation":false,"usgs":true,"family":"Bullen","given":"T.D.","email":"","affiliations":[],"preferred":false,"id":372042,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Clynne, M.A.","contributorId":90722,"corporation":false,"usgs":true,"family":"Clynne","given":"M.A.","affiliations":[],"preferred":false,"id":372043,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70016066,"text":"70016066 - 1990 - Modeling electrostatic and heterogeneity effects on proton dissociation from humic substances","interactions":[],"lastModifiedDate":"2023-10-19T01:44:16.722603","indexId":"70016066","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Modeling electrostatic and heterogeneity effects on proton dissociation from humic substances","docAbstract":"No abstract available.
","language":"English","publisher":"American Chemical Society","doi":"10.1021/es00081a012","issn":"0013936X","usgsCitation":"Tipping, E., Reddy, M., and Hurley, M., 1990, Modeling electrostatic and heterogeneity effects on proton dissociation from humic substances: Environmental Science & Technology, v. 24, no. 11, p. 1700-1705, https://doi.org/10.1021/es00081a012.","productDescription":"6 p.","startPage":"1700","endPage":"1705","costCenters":[],"links":[{"id":223400,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"24","issue":"11","noUsgsAuthors":false,"publicationDate":"2002-05-01","publicationStatus":"PW","scienceBaseUri":"505a5bf5e4b0c8380cd6f922","contributors":{"authors":[{"text":"Tipping, E.","contributorId":90880,"corporation":false,"usgs":true,"family":"Tipping","given":"E.","email":"","affiliations":[],"preferred":false,"id":372465,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Reddy, M.M.","contributorId":24363,"corporation":false,"usgs":true,"family":"Reddy","given":"M.M.","email":"","affiliations":[],"preferred":false,"id":372464,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hurley, M.A.","contributorId":7845,"corporation":false,"usgs":true,"family":"Hurley","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":372463,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70016332,"text":"70016332 - 1990 - Rupture process of a multiple main shock sequence: analysis of teleseismic, local and field observations of the Tennant Creek, Australia, earthquakes of January 22, 1988","interactions":[],"lastModifiedDate":"2024-05-24T15:43:52.901579","indexId":"70016332","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","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":"Rupture process of a multiple main shock sequence: analysis of teleseismic, local and field observations of the Tennant Creek, Australia, earthquakes of January 22, 1988","docAbstract":"On January 22, 1988, three large intraplate earthquakes (with MS 6.3, 6.4, and 6.7) occurred within a 12-hour period near Tennant Creek, Australia. These earthquakes, which occurred over a small interval of time and within a small volume of space, present a unique opportunity to study the rupture process of the class of intraplate earthquakes that occur as multiple main shocks. Broadband displacement and velocity records of body waves from teleseismically recorded data are analyzed to determine source mechanisms, depths, and complexity of rupture of each of the three main shocks. Hypocenters of an additional 150 foreshocks and aftershocks constrained by local arrival time data and field observations of surface rupture are used to complement the source characteristics of the main shocks in order to derive as complete a description of the rupture process as possible. The interpretation of the combined data sets suggests that the overall rupture process involved unusually complicated stress release. As locations of the main shock hypocenters progressively moved from west to east, we infer that the first and third main shocks, denoted as MS1 and MS3, produced the southeast-northwest trending scarps observed at the western end (the Kunayungku fault) and at the eastern end (the east end of the Lake Surprise fault), respectively, of the rupture zone. The epicenter of the only immediate foreshock was located in the gap between these two fault scarps. MS1 nucleated near this epicenter and ruptured upward and to the northwest from a depth of 6.5 km. MS3 ruptured predominantly to the SE at a depth of 4.5 km. The second main shock, MS2, is inferred to have produced the deformation of the southwest trending central scarp segment (the western end of the Lake Surprise fault). From the sense of thrusting seen at the surface and from the distribution of aftershock hypocenters, the south dipping nodal planes derived from waveform modeling are identified as the fault planes for earthquakes MS1 and MS3. In contrast, the dip of the central fault scarp is reversed relative to the dips of the western and eastern fault scarps. The rupture process Of MS2 turns out to be commensurately complex and sufficiently explains the geological complexity. MS2 consisted of three subevents. The southeast dipping nodal plane of the first two subevents is coplanar with a southeast dipping plane implied by locations of aftershocks which did not break the surface. Choice of the north dipping plane as the rupture plane of the third subevent, consistent with the surface deformation and coplanar with a second plane delineated by aftershocks, would imply conjugate faulting. The majority of the aftershocks are concentrated near the edges of the fault planes, and there is an absence of activity in the center of the planes. The areas of absent activity may represent the failed asperities of the main shocks in which substantial stress relief occurred. The rupture process of each main shock is characterized by the rapid release of energy followed by a much slower release of moment and by aftershock zones whose dimensions exceed the inferred dimensions of the rupture. These characteristics suggest that substantial slow slip occurred on each of the three fault interfaces that was not accompanied by major energy release. The first main shock nucleated at the deepest part of its aftershock zone and ruptured upward. In contrast, MS2 and MS3 nucleated at depths that were one third to one half of the maximum depth of their aftershock zones. This variation of focal depth and the strong increase of moment and radiated energy with each main shock imply that lateral variations of strength were more important than vertical gradients of shear stress in controlling the progression of rupture.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB095iB05p06867","issn":"01480227","usgsCitation":"Choy, G.L., and Bowman, J.R., 1990, Rupture process of a multiple main shock sequence: analysis of teleseismic, local and field observations of the Tennant Creek, Australia, earthquakes of January 22, 1988: Journal of Geophysical Research Solid Earth, v. 95, no. B5, p. 6867-6882, https://doi.org/10.1029/JB095iB05p06867.","productDescription":"16 p.","startPage":"6867","endPage":"6882","numberOfPages":"16","costCenters":[],"links":[{"id":222904,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"95","issue":"B5","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505aaed7e4b0c8380cd87253","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":373203,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bowman, J. R.","contributorId":29496,"corporation":false,"usgs":false,"family":"Bowman","given":"J.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":373202,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70016080,"text":"70016080 - 1990 - Natural sources of greenhouse gases: carbon dioxide emissions from volcanoes","interactions":[],"lastModifiedDate":"2012-03-12T17:18:59","indexId":"70016080","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Natural sources of greenhouse gases: carbon dioxide emissions from volcanoes","docAbstract":"Volcanic degassing of carbon dioxide plays an important role in keeping the atmosphere-ocean portion of the carbon geochemical cycle in balance. The atmosphere-ocean carbon deficit requires replenishment of 6??1012 mol CO2/yr, and places an upper limit on the output of carbon dioxide from volcanoes. The CO2 output of the global mid-oceanic ridge system is ca. 0.7??1012 mol/yr, thus supplying only a fraction of the amount needed to balance the carbon deficit. The carbon dioxide flux from subaerial volcanoes is poorly known, but it appears to be at least as large as the mid-oceanic ridge flux. Much (perhaps most) of the CO2 emitted from volcanoes is degassed noneruptively. This mode of degassing may lead to impacts on the environment and biosphere that are fundamentally different in character from those envisioned in published scenarios, which are based on the assumption that CO2 degassing occurs predominantly by eruptive processes. Although the flux of carbon dioxide from volcanoes is poorly constrained at present, it is clearly two orders of magnitude lower than the anthropogenic output of CO2.","largerWorkTitle":"Transactions - Geothermal Resources Council","conferenceTitle":"1990 International Symposium on Geothermal Energy","conferenceDate":"20 August 1990 through 24 August 1990","conferenceLocation":"Kailua-Kona, HI, USA","language":"English","publisher":"Publ by Geothermal Resources Council","publisherLocation":"Davis, CA, United States","issn":"01935933","isbn":"0934412677","usgsCitation":"Gerlach, T., 1990, Natural sources of greenhouse gases: carbon dioxide emissions from volcanoes, in Transactions - Geothermal Resources Council, v. 14, no. pt 1, Kailua-Kona, HI, USA, 20 August 1990 through 24 August 1990, p. 639-641.","startPage":"639","endPage":"641","numberOfPages":"3","costCenters":[],"links":[{"id":223551,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"14","issue":"pt 1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a635de4b0c8380cd72467","contributors":{"authors":[{"text":"Gerlach, Terrence","contributorId":97252,"corporation":false,"usgs":true,"family":"Gerlach","given":"Terrence","affiliations":[],"preferred":false,"id":372496,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70016204,"text":"70016204 - 1990 - Climatic change and permafrost. Record from surficial deposits","interactions":[],"lastModifiedDate":"2024-04-19T19:17:29.790706","indexId":"70016204","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2221,"text":"Journal of Cold Regions Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Climatic change and permafrost. Record from surficial deposits","docAbstract":"The physical and chemical characteristics of surficial deposits and the floral and faunal remains they contain provide information that is useful for interpreting both paleoclimate and past permafrost conditions. Surficial deposits thus provide a record of climatic change and permafrost history. This record suggests that initiation of permafrost in lowland areas of the Southern Arctic Archipelago and continents of the northern hemisphere may have occurred about 2,400,000 years ago during the pronounced cooling that led to the first major glaciation of late Cenozoic time. Since then, climate has been relatively cold but cyclically variable, characterized by the growth and shrinkage of large, continental ice sheets. Permafrost has expanded and contracted in response to these climatic changes, and we can expect the present permafrost conditions to change in response to future climatic changes. To predict the response of permafrost and the landscape to future climatic change we should: (1) Define relations between climate and the modern landscape; (2) establish long‐term records of past climatic change and landscape response; and (3) determine the paleoenvironments of past warm periods as possible analogs for future global warming.
","language":"English","publisher":"ASCE","doi":"10.1061/(ASCE)0887-381X(1990)4:1(43)","issn":"0887381X","usgsCitation":"Carter, L.D., 1990, Climatic change and permafrost. Record from surficial deposits: Journal of Cold Regions Engineering, v. 4, no. 1, p. 43-53, https://doi.org/10.1061/(ASCE)0887-381X(1990)4:1(43).","productDescription":"11 p.","startPage":"43","endPage":"53","numberOfPages":"11","costCenters":[],"links":[{"id":223100,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"4","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f65de4b0c8380cd4c70c","contributors":{"authors":[{"text":"Carter, L. David","contributorId":16827,"corporation":false,"usgs":true,"family":"Carter","given":"L.","email":"","middleInitial":"David","affiliations":[],"preferred":false,"id":372833,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70015877,"text":"70015877 - 1990 - Controls on porphyrin concentrations of Pennsylvanian organic-rich shales, Western U.S.A.","interactions":[],"lastModifiedDate":"2023-12-16T00:48:39.549206","indexId":"70015877","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1506,"text":"Energy & Fuels","active":true,"publicationSubtype":{"id":10}},"title":"Controls on porphyrin concentrations of Pennsylvanian organic-rich shales, Western U.S.A.","docAbstract":"Organic-rich black shales of Middle Pennsylvanian (Desmoinesian) age occur over much of the central U.S. and as far west as the northern Denver and southeastern Powder River basins. Total organic carbon contents (Corg) are commonly greater than 10 wt %. Porphyrin concentrations (vanadyl + nickel) are as high as 40000 ppm relative to extractable bitumen. In bulk, the organic matter contained in the shales is mostly type II and III (Rock-Eval hydrogen indexes 200-400 mg of hydrocarbons/g of Corg). The finding of high porphyrin concentrations in type III organic matter is unusual but can be explained by a depositional model wherein high preservation of primary organic production (water column photosynthesis) is combined with substantial input of allochthonous organic matter. The allochthonous organic matter (low porphyrin concentration) may come from erosion during advance of the sea across the area or from fluvial transport from shore.","language":"English","publisher":"American Chemical Society","doi":"10.1021/ef00024a004","issn":"08870624","usgsCitation":"Clayton, J., and Michael, G., 1990, Controls on porphyrin concentrations of Pennsylvanian organic-rich shales, Western U.S.A.: Energy & Fuels, v. 4, no. 6, p. 644-646, https://doi.org/10.1021/ef00024a004.","productDescription":"3 p.","startPage":"644","endPage":"646","numberOfPages":"3","costCenters":[],"links":[{"id":223487,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"4","issue":"6","noUsgsAuthors":false,"publicationDate":"2002-05-01","publicationStatus":"PW","scienceBaseUri":"5059fbd2e4b0c8380cd4dfac","contributors":{"authors":[{"text":"Clayton, J.L.","contributorId":76767,"corporation":false,"usgs":true,"family":"Clayton","given":"J.L.","email":"","affiliations":[],"preferred":false,"id":371980,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Michael, G.E.","contributorId":63456,"corporation":false,"usgs":true,"family":"Michael","given":"G.E.","email":"","affiliations":[],"preferred":false,"id":371979,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70016379,"text":"70016379 - 1990 - Rheological properties of simulated debris flows in the laboratory environment","interactions":[],"lastModifiedDate":"2012-03-12T17:18:42","indexId":"70016379","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Rheological properties of simulated debris flows in the laboratory environment","docAbstract":"Steady debris flows with or without a snout are simulated in a 'conveyor-belt' flume using dry glass spheres of a uniform size, 5 or 14 mm in diameter, and their rheological properties described quantitatively in constants in a generalized viscoplastic fluid (GVF) model. Close agreement of the measured velocity profiles with the theoretical ones obtained from the GVF model strongly supports the validity of a GVF model based on the continuum-mechanics approach. Further comparisons of the measured and theoretical velocity profiles along with empirical relations among the shear stress, the normal stress, and the shear rate developed from the 'ring-shear' apparatus determine the values of the rheological parameters in the GVF model, namely the flow-behavior index, the consistency index, and the cross-consistency index. Critical issues in the evaluation of such rheological parameters using the conveyor-belt flume and the ring-shear apparatus are thus addressed in this study.","largerWorkTitle":"Hydraulics/Hydrology of Arid Lands","conferenceTitle":"Proceedings of the International Symposium on Hydraulics/Hydrology of Arid Lands and 1990 National Conference on Hydraulic Engineering","conferenceDate":"30 July 1990 through 2 August 1990","conferenceLocation":"San Diego, CA, USA","language":"English","publisher":"Publ by ASCE","publisherLocation":"Boston, MA, United States","isbn":"0872627713","usgsCitation":"Ling, C., Chen, C., and Jan, C., 1990, Rheological properties of simulated debris flows in the laboratory environment, in Hydraulics/Hydrology of Arid Lands, San Diego, CA, USA, 30 July 1990 through 2 August 1990, p. 218-224.","startPage":"218","endPage":"224","numberOfPages":"7","costCenters":[],"links":[{"id":222848,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aad3ce4b0c8380cd86e74","contributors":{"editors":[{"text":"French Richard H.","contributorId":128450,"corporation":true,"usgs":false,"organization":"French Richard H.","id":536329,"contributorType":{"id":2,"text":"Editors"},"rank":1}],"authors":[{"text":"Ling, Chi-Hai","contributorId":55154,"corporation":false,"usgs":true,"family":"Ling","given":"Chi-Hai","email":"","affiliations":[],"preferred":false,"id":373326,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Chen, Cheng-lung","contributorId":30752,"corporation":false,"usgs":true,"family":"Chen","given":"Cheng-lung","email":"","affiliations":[],"preferred":false,"id":373325,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Jan, Chyan-Deng","contributorId":60384,"corporation":false,"usgs":true,"family":"Jan","given":"Chyan-Deng","email":"","affiliations":[],"preferred":false,"id":373327,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70016228,"text":"70016228 - 1990 - Thermal infrared exploration in the Carlin trend, northern Nevada","interactions":[],"lastModifiedDate":"2024-04-18T15:43:08.247728","indexId":"70016228","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1808,"text":"Geophysics","active":true,"publicationSubtype":{"id":10}},"title":"Thermal infrared exploration in the Carlin trend, northern Nevada","docAbstract":"Experimental Thermal Infrared Multispectral Scanner (TIMS) aircraft data have been acquired for the Rodeo Creek NE 7 1/2 minute quadrangle, Eureka County, northern Nevada, covering the Carlin gold mine. A simple model has been developed to extract spectral emissivities for mapping surface lithology and alteration based on the physical properties of geologic materials. Emissivity-ratio images were prepared that allow generalized lithologic discrimination, identification of areas with high silica content, and the first reported detection of the carbonate secondary reststrahlen feature. Together with thermal-inertia images, they permit identification of areas of subtle lithologic variation not shown on conventional geologic maps. Emissivity-ratio spectra extracted from the data compare favorably with modeled laboratory spectra and establish for the first time the link among theory, measured physical properties, and color-composited TIMS images. Identification of previously unknown silicification in the Tertiary volcanic rocks and mapping of a silicified structure and possible extensions in alluvium indicate that TIMS data can be a valuable tool for detecting subtle alteration associated with mineralization, particularly in less accessible or less well-known areas.
","language":"English","publisher":"Society of Exploration Geophysicists","doi":"10.1190/1.1442773","issn":"00168033","usgsCitation":"Watson, K., Kruse, F., and Hummer-Miller, S., 1990, Thermal infrared exploration in the Carlin trend, northern Nevada: Geophysics, v. 55, no. 1, p. 70-79, https://doi.org/10.1190/1.1442773.","productDescription":"10 p.","startPage":"70","endPage":"79","numberOfPages":"10","costCenters":[],"links":[{"id":223559,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"55","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb22ae4b08c986b32563d","contributors":{"authors":[{"text":"Watson, K.","contributorId":39123,"corporation":false,"usgs":true,"family":"Watson","given":"K.","email":"","affiliations":[],"preferred":false,"id":372908,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kruse, F.A.","contributorId":30676,"corporation":false,"usgs":true,"family":"Kruse","given":"F.A.","email":"","affiliations":[],"preferred":false,"id":372907,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hummer-Miller, S.","contributorId":53088,"corporation":false,"usgs":true,"family":"Hummer-Miller","given":"S.","affiliations":[],"preferred":false,"id":372909,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70015966,"text":"70015966 - 1990 - Coupled variations in helium isotopes and fluid chemistry: Shoshone Geyser Basin, Yellowstone National Park","interactions":[],"lastModifiedDate":"2024-04-12T14:28:28.577866","indexId":"70015966","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","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":"Coupled variations in helium isotopes and fluid chemistry: Shoshone Geyser Basin, Yellowstone National Park","docAbstract":"Early studies of 3He/4He variations in geothermal systems have generally attributed these fluctuations to either differences in the source of the magmatic 3He-rich helium or to local differences in the deep flux of magmatic 3He-rich helium. Kennedy et al. (1987), however, show that near-surface processes such as boiling and dilution may also drastically affect
The flattened musk turtle Sternotherus depressus has disappeared from more than half of its former range because of habitat modifications to stream and river channels in the Warrior River Basin, Alabama. Only 6·9% of its probable historic range contains relatively healthy populations, and most populations are fragmented by extensive areas of unsuitable habitat. Turtles in the best remaining habitats continue to be vulnerable to disease and human-related disturbance, collecting and habitat modification. These factors lead to population declines and abnormal population structure. Habitat fragmentation, especially in small populations, increases vulnerability to human-caused catastrophes and demographic accidents, and could lead to eventual extinction. The threats facing fragmented populations of this turtle probably parallel those affecting many other stream-dwelling species throughout the southeastern United States.
","language":"English","publisher":"Elsevier","doi":"10.1016/0006-3207(90)90040-V","usgsCitation":"Dodd, C., 1990, Effects of habitat fragmentation on a stream-dwelling species, the flattened musk turtle Sternotherus depressus: Biological Conservation, v. 54, p. 33-45, https://doi.org/10.1016/0006-3207(90)90040-V.","productDescription":"13 p.","startPage":"33","endPage":"45","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":130911,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"54","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a2ee4b07f02db615160","contributors":{"authors":[{"text":"Dodd, C.K. Jr.","contributorId":86286,"corporation":false,"usgs":true,"family":"Dodd","given":"C.K.","suffix":"Jr.","affiliations":[],"preferred":false,"id":318074,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":1003528,"text":"1003528 - 1990 - Effect of pH on the accumulation kinetics of pentachlorophenol in goldfish","interactions":[],"lastModifiedDate":"2023-12-11T17:38:05.210823","indexId":"1003528","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":887,"text":"Archives of Environmental Contamination and Toxicology","active":true,"publicationSubtype":{"id":10}},"title":"Effect of pH on the accumulation kinetics of pentachlorophenol in goldfish","docAbstract":"The kinetics of accumulation of pentachlorophenol (PCP) at various pH values were investigated to explore how pH-dependent accumulation might influence PCP toxicity. Goldfish (Carassius auratus) were exposed to 5 μg PCP/L in a static system buffered with 7.5 mM bicine orN,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid (BES) at pH 7.0, 8.0, or 9.0. The amount of PCP in the fish, concentration of PCP in water, and the total amount of metabolites in the system were measured after exposure of fish from 1 to 96 hr. Equations for these variables based on a two compartment pharmacokinetic model were fitted simultaneously to the data using NONLIN, which uses an iterative nonlinear least squares technique. Uptake clearance, metabolic clearance, and apparent volume of distribution of PCP decreased as pH increased. The decrease in PCP accumulation with increased pH was not due solely to a pH-induced decrease in uptake. In addition, the distribution of PCP within the fish was altered by changes in the external pH. The pH-associated changes in distribution may have altered access of PCP to sites of metabolism, thereby altering the metabolic clearance. The pH-related changes in the pharmacokinetics of PCP resulted in a decrease in its bioconcentration factor with an increase in pH and account both for the decreased capacity of the fish to accumulate PCP and for its reduced LC50.
","language":"English","publisher":"Springer","doi":"10.1007/BF01054993","usgsCitation":"Stehly, G., and Hayton, W.L., 1990, Effect of pH on the accumulation kinetics of pentachlorophenol in goldfish: Archives of Environmental Contamination and Toxicology, v. 19, no. 3, p. 464-470, https://doi.org/10.1007/BF01054993.","productDescription":"7 p.","startPage":"464","endPage":"470","numberOfPages":"7","costCenters":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"links":[{"id":201921,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"19","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a4be4b07f02db6255f8","contributors":{"authors":[{"text":"Stehly, G. R.","contributorId":34081,"corporation":false,"usgs":true,"family":"Stehly","given":"G. R.","affiliations":[],"preferred":false,"id":313455,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hayton, W. L.","contributorId":100325,"corporation":false,"usgs":true,"family":"Hayton","given":"W.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":313456,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ]}