Regional sets of steeply dipping joints and faults are common throughout the Sierra Nevada batholith, yet relatively little is known about how or when they formed. Within some east-northeast-striking, left-lateral fault zones in the Mount Abbot quadrangle of the central Sierra Nevada, the host granodiorite is hydrothermally altered to a lower greenschist assemblage that contains muscovite. The muscovite yields a mean K-Ar and 40Ar/39Ar age of 79 Ma, which provides a minimum age for the faulting. Field relations show that these faults developed from earlier formed, mineralized joints, so these ages also provide a minimum age for the jointing. Published ages of biotite, hornblende, and zircon from the host granodiorite of Lake Edison are 80 Ma (K-Ar), 85 Ma (K-Ar), and 90 Ma (U-Pb), respectively. The geochronology, field relations, and hydrothermal mineral assemblages together suggest that the mineralized joints and faults all formed between 85 and 79 Ma, soon after the host pluton was emplaced.
In Mars' north polar cap the probable composition of material residual from the annual condensation cycle is a mixture of fine dust and H2O grains of comparable size and abundance. However, metamorphism of such material will gradually lower its albedo by increasing the size of the H2O grains only. If the cap is undergoing net annual sublimation (as inferred from water vapor observations), late summer observations should be of old ice with H2O grain sizes of 100 μm or more. Ice of this granularity containing 30% fine dust has a reflectivity similar to that of dust alone; the observed albedo and computed ice grain size imply dust concentrations of 1 part per 1000 or less. The brightness of the icy areas conflicts with what would be expected for a residual cap deposited by an annual cycle similar to that observed by Viking and aged for thousands of years. The residual cap surface cannot be “old dirty” ice. It could be old, coarse, and clean; or it could be young, fine, and dirty. This brings into question both the source of the late summer water vapor and the formation rate of laminated terrain.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB095iB02p01481","issn":"01480227","usgsCitation":"Kieffer, H.H., 1990, H2O grain size and the amount of dust in Mars' residual North polar cap: Journal of Geophysical Research, v. 95, no. B2, p. 1481-1493, https://doi.org/10.1029/JB095iB02p01481.","productDescription":"13 p.","startPage":"1481","endPage":"1493","numberOfPages":"13","costCenters":[],"links":[{"id":223514,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"95","issue":"B2","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505a2e76e4b0c8380cd5c56a","contributors":{"authors":[{"text":"Kieffer, H. H.","contributorId":40725,"corporation":false,"usgs":false,"family":"Kieffer","given":"H.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":373174,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70016319,"text":"70016319 - 1990 - Age of the Peach Springs Tuff, southeastern California and western Arizona","interactions":[],"lastModifiedDate":"2024-05-24T16:10:17.573836","indexId":"70016319","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":"Age of the Peach Springs Tuff, southeastern California and western Arizona","docAbstract":"Sanidine separates from pumice of the early Miocene Peach Springs Tuff are concordantly dated at 18.5±0.2 Ma by two isotopic techniques. The Peach Springs Tuff is the only known unit that can be correlated between isolated outcrops of Miocene strata from the central Mojave Desert of southeastern California to the western Colorado Plateau in Arizona, across five structural provinces, a distance of 350 km. Thus the age of the Peach Springs Tuff is important to structural and paleogeographic reconstructions of a large region. Biotite and sanidine separates from bulk samples of the Peach Springs Tuff from zones of welding and vapor-phase alteration have not produced consistent ages by the K-Ar method. Published ages of mineral separates from 17 localities ranged from 16.2 to 20.5 Ma. Discordant 40Ar/39Ar incremental release spectra were obtained for one biotite and two of the sanidine separates. Ages that correspond to the last gas increments are as old as 27 Ma. The 40Ar/39Ar incremental release determinations on sanidine separated from blocks of Peach Springs Tuff pumice yield ages of 18.3±0.3 and 18.6±0.4 Ma. Laser fusion measurements yield a mean age of 18.51±0.10. The results suggest that sanidine and biotite K-Ar ages older than about 18.5 Ma are due to inherited Ar from pre-Tertiary contaminants, which likely were incorporated into the tuff during deposition. Sanidine K-Ar ages younger than 18 Ma probably indicate incomplete extraction of radiogenic 40Ar, whereas laser fusion dates of biotite and hornblende younger than 18 Ma likely are due to postdepositional alteration. Laser fusion ages as high as 19.01 Ma on biotite grains from pumice suggest that minerals from pre-Tertiary country rocks also were incorporated in the magma chamber.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB095iB01p00571","issn":"01480227","usgsCitation":"Nielson, J.E., Lux, D.R., Dalrymple, G.B., and Glazner, A.F., 1990, Age of the Peach Springs Tuff, southeastern California and western Arizona: Journal of Geophysical Research Solid Earth, v. 95, no. B1, p. 571-580, https://doi.org/10.1029/JB095iB01p00571.","productDescription":"10 p.","startPage":"571","endPage":"580","numberOfPages":"10","costCenters":[],"links":[{"id":488619,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/jb095ib01p00571","text":"Publisher Index Page"},{"id":223513,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"95","issue":"B1","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"5059e8f1e4b0c8380cd47fc6","contributors":{"authors":[{"text":"Nielson, J. E.","contributorId":106140,"corporation":false,"usgs":true,"family":"Nielson","given":"J.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":373173,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lux, D. R.","contributorId":50581,"corporation":false,"usgs":true,"family":"Lux","given":"D.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":373171,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dalrymple, G. B.","contributorId":10407,"corporation":false,"usgs":true,"family":"Dalrymple","given":"G.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":373170,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Glazner, A. F.","contributorId":91639,"corporation":false,"usgs":false,"family":"Glazner","given":"A.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":373172,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70016317,"text":"70016317 - 1990 - Effect of anelastic and scattering structures of the lithosphere on the shape of local earthquake coda","interactions":[],"lastModifiedDate":"2012-03-12T17:18:41","indexId":"70016317","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3209,"text":"Pure and Applied Geophysics PAGEOPH","active":true,"publicationSubtype":{"id":10}},"title":"Effect of anelastic and scattering structures of the lithosphere on the shape of local earthquake coda","docAbstract":"A simple model of single acoustic scattering is used to study the dependence of the shape of local earthquake coda on the anelastic and scattering structures of the lithosphere. The model is applied to the coda of earthquakes located near Stone Canyon, central California, and provides an explanation for the features observed in the data, which include an interesting temporal variation in the coda shape. A surficial layer with a Q of 50 and thickness of 10 or 25 km underlain by a zone with a Q of 1000 extending to the bottom of the lithosphere, together with a scattering scale length, a, that varies with depth z according to the relation a=0.3 exp[-(z/45)2] are found to constitute the simplest structure of the medium compatible with the coda data and with body and surface wave attenuation data. The profile of heterogeneity sizes implies that the scattering strength increases strongly with depth, a constraint required by the necessity to boost the energy of the later coda without forcing the intrinsic Q to be excessively high in the uppermost mantle. This constraint is viewed as an artifact of the single scattering model which overstimates the scattering coefficient due to the neglect of multiple scattering. The observed temporal variation of the signal is difficult to explain by a simple change of the intrinsic Q at some depth. Rather, it is suggested that the scattering properties at depth changed with time through a variation of the fractional rms velocity fluctuation on the order of one percent. ?? 1990 Birkha??user Verlag.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Pure and Applied Geophysics PAGEOPH","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Birkha??user-Verlag","doi":"10.1007/BF00874367","issn":"00334553","usgsCitation":"Chouet, B., 1990, Effect of anelastic and scattering structures of the lithosphere on the shape of local earthquake coda: Pure and Applied Geophysics PAGEOPH, v. 132, no. 1-2, p. 289-310, https://doi.org/10.1007/BF00874367.","startPage":"289","endPage":"310","numberOfPages":"22","costCenters":[],"links":[{"id":205373,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00874367"},{"id":223464,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"132","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a05bfe4b0c8380cd50f2d","contributors":{"authors":[{"text":"Chouet, B.","contributorId":68465,"corporation":false,"usgs":true,"family":"Chouet","given":"B.","affiliations":[],"preferred":false,"id":373167,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70016316,"text":"70016316 - 1990 - Platinum-group element abundance and distribution in chromite deposits of the Acoje Block, Zambales Ophiolite Complex, Philippines","interactions":[],"lastModifiedDate":"2024-04-17T11:12:45.281981","indexId":"70016316","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","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":"Platinum-group element abundance and distribution in chromite deposits of the Acoje Block, Zambales Ophiolite Complex, Philippines","docAbstract":"Platinum-group elements (PGE) occur in ore-grade concentration in some of the chromite deposits related to the ultramafic section of the Acoje Block of the Zambales Ophiolite Complex. The deposits are of three types: Type 1 - associated with cumulate peridotites at the base of the crust; Type 2 - in dunite pods from the top 1 km of mantle harzburgite; and Type 3 - like Type 2, but in deeper levels of the harzburgite. Most of the deposites have chromite compositions that are high in Cr with Cr/(Cr + Al) (expressed as chromium index, Cr#) > 0.6; high-Al (Cr# < 0.6) chromite deposits are relatively rare, occurring as interspersed orebodies in regions of Types 2 and 3. Sulfide-bearing Type 1 high-Cr deposits are PGE-enriched; the high-Al deposits have lowest Ir and Pd. Among the PGEs, Ir ranges from <20 to 550 ppb, Rh from <100 to 1100 ppb, Rh from 0.7 to 760 ppb, Pt from <1.0 to 5960 ppb and Pd from <0.5 to 8350 ppb. Chondrite-normalized (CN) PGE patterns are diverse, and include those with both negative slope (Ir > Pd, thought to be characteristic of PGE-barren deposits) and positive slope (Ir < Pd, characteristic of PGE-rich deposits).
Iridium, Ru and Os commonly occur as micron-size laurite (sulfide) inclusions in unfractured chromite. Laurite and native Os are also found as inclusions in interstitial sulfides. Platinum and Pd occur as alloy inclusions (and possibly as solid solution) in interstitial Ni-Cu sulfides and as tellurobismuthides in serpentine and altered sulfides.
","language":"English","publisher":"Elsevier","doi":"10.1016/0375-6742(90)90086-P","issn":"03756742","usgsCitation":"Bacuta, G., Kay, R., Gibbs, A., and Lipin, B., 1990, Platinum-group element abundance and distribution in chromite deposits of the Acoje Block, Zambales Ophiolite Complex, Philippines: Journal of Geochemical Exploration, v. 37, no. 1, p. 113-145, https://doi.org/10.1016/0375-6742(90)90086-P.","productDescription":"33 p.","startPage":"113","endPage":"145","numberOfPages":"33","costCenters":[{"id":245,"text":"Eastern Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"links":[{"id":223463,"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":"505a7c2de4b0c8380cd79840","contributors":{"authors":[{"text":"Bacuta, G.C. Jr.","contributorId":89013,"corporation":false,"usgs":true,"family":"Bacuta","given":"G.C.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":373165,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kay, R.W.","contributorId":61713,"corporation":false,"usgs":true,"family":"Kay","given":"R.W.","email":"","affiliations":[],"preferred":false,"id":373164,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gibbs, A.K.","contributorId":94924,"corporation":false,"usgs":true,"family":"Gibbs","given":"A.K.","email":"","affiliations":[],"preferred":false,"id":373166,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Lipin, B. R.","contributorId":61031,"corporation":false,"usgs":true,"family":"Lipin","given":"B. R.","affiliations":[],"preferred":false,"id":373163,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70016183,"text":"70016183 - 1990 - Cosmic ray exposure dating with in situ produced cosmogenic 3He: Results from young Hawaiian lava flows","interactions":[],"lastModifiedDate":"2020-09-28T12:21:56.574857","indexId":"70016183","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1427,"text":"Earth and Planetary Science Letters","active":true,"publicationSubtype":{"id":10}},"title":"Cosmic ray exposure dating with in situ produced cosmogenic 3He: Results from young Hawaiian lava flows","docAbstract":"In an effort to determine the in situ production rate of spallation-produced cosmogenic 3He, and evaluate its use as a surface exposure chronometer, we have measured cosmogenic helium contents in a suite of Hawaiian radiocarbon-dated lava flows. The lava flows, ranging in age from 600 to 13,000 years, were collected from Hualalai and Mauna Loa volcanoes on the island of Hawaii. Because cosmic ray surface-exposure dating requires the complete absence of erosion or soil cover, these lava flows were selected specifically for this purpose. The 3He production rate, measured within olivine phenocrysts, was found to vary significantly, ranging from 47 to 150 atoms g−1 yr−1 (normalized to sea level). Although there is considerable scatter in the data, the samples younger than 10,000 years are well-preserved and exposed, and the production rate variations are therefore not related to erosion or soil cover. Data averaged over the past 2000 years indicate a sea-level 3He production rate of 125 ± 30atoms g−1yr−1, which agrees well with previous estimates. The longer record suggests a minimum in sea level normalized 3He production rate between 2000 and 7000 years (55 ± 15atoms g−1yr−1), as compared to samples younger than 2000 years (125 ± 30 atoms g−1yr−1), and those between 7000 and 10,000 years (127 ± 19atoms g−1yr−1). The minimum in production rate is similar in age to that which would be produced by variations in geomagnetic field strength, as indicated by archeomagnetic data. However, the production rate variations (a factor of 2.3 ± 0.8) are poorly determined due to the large uncertainties in the youngest samples and questions of surface preservation for the older samples. Calculations using the atmospheric production model of O'Brien (1979) [35], and the method of Lal and Peters (1967) [11], predict smaller production rate variations for similar variation in dipole moment (a factor of 1.15–1.65). Because the production rate variations, archeomagnetic data, and theoretical estimates are not well determined at present, the relationship between dipole moment and production rate will require further study. Precise determination of the production rate is an important uncertainty in the surface-exposure technique, but the data demonstrate that it is feasible to date samples as young as 600 years of age providing that there has been no erosion or soil cover. Therefore, the technique will have important applications for volcanology, glacial geology, geomorphology and archaeology.
Impulse responses including near-field terms have been obtained in closed form for the zero-offset vertical seismic profiles generated by a horizontal point force acting on the surface of an anelastic half-space. The method is based on the correspondence principle. Through transformation of variables, the Fourier transform of the elastic impulse response is put in a form such that the Fourier transform of the corresponding anelastic impulse response can be expressed as elementary functions and their definite integrals involving distance, angular frequency, phase velocities, and attenuation factors. These results are used for accurate calculation of shear-wave arrival rise times of synthetic seismograms needed for data interpretation of anelastic-attenuation measurements in near-surface sediment.
","language":"English","publisher":"Seismological Society of America","doi":"10.1785/BSSA0800040832","usgsCitation":"Liu, H., 1990, Calculation of zero-offset vertical seismic profiles generated by a horizontal point force acting on the surface of an elastic half-space: Bulletin of the Seismological Society of America, v. 80, no. 4, p. 832-856, https://doi.org/10.1785/BSSA0800040832.","productDescription":"25 p.","startPage":"832","endPage":"856","numberOfPages":"25","costCenters":[],"links":[{"id":223297,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"80","issue":"4","noUsgsAuthors":false,"publicationDate":"1990-08-01","publicationStatus":"PW","scienceBaseUri":"5059f307e4b0c8380cd4b56b","contributors":{"authors":[{"text":"Liu, Hsi-Ping","contributorId":59944,"corporation":false,"usgs":true,"family":"Liu","given":"Hsi-Ping","affiliations":[],"preferred":false,"id":372449,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70016062,"text":"70016062 - 1990 - Soil development on stable landforms and implications for landscape studies","interactions":[],"lastModifiedDate":"2024-02-05T13:11:58.885165","indexId":"70016062","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1801,"text":"Geomorphology","active":true,"publicationSubtype":{"id":10}},"title":"Soil development on stable landforms and implications for landscape studies","docAbstract":"Soil development parameters include a wide variety of morphological, chemical, and mineralogical parameters, but some of the best indicators of time and surface stability are derived from field morphology. Over long time-spans, the most common time function for soil development is exponential or logarithmic, in which rates decrease with increasing age. Over shorter time-spans in semi-arid and moister climates, Holocene and Pleistocene soil development functions appear as linear segments, with Holocene rates about 10 to 50 times those of Pleistocene rates. In contrast to significant temporal variation in rates, geographical variation in rates within (a) the southern Great Basin and (b) the east Central Valley of California is on the order of 2 or 3 times. When comparing soil development indices of the semi-arid Great Basin to those of moister central California, Holocene rates are similar, but Pleistocene rates are more than 10 times slower in the Great Basin. In a range of climatic settings, the reasons for declining rates over time are several and are complexly related to erosional history, fluxes in water and dust related to climatic changes, rates of primary mineral dissolution, and intrinsic soil processes.
Seven years of discharge and water quality records define temporal and spatial patterns of solute movement in a Colorado alpine stream system. Dissolved solids concentrations are low, generally less than 30 mg 1−1 and occasionally less than 3 mg 1−1 at the highest elevations. Calcium is the dominant cation and bicarbonate and sulfate are the main anions. Temporal changes in solute concentrations are dominated by an annual cycle with high values in late winter and spring that decrease rapidly during early summer and then return more slowly through fall. This pattern corresponds to the seasonal streamflow regime and reflects differential elution of the snowpack by meltwater and changing proportions of surface and subsurface water in the streamflow. The amplitude of the annual cycle of solute concentration is reduced with increasing catchment area and where the groundwater contribution to flow is relatively high. In general, solute concentrations increase down valley but this trend is reversed in the case of biologically important solutes, such as nitrate and potassium. Rates of geochemical denudation are dominated by the volume of water discharge and thus are highest in the parts of the basin that accumulate the greatest depths of winter snow. They vary between 5 and 26 g m−2 yr−1 for different parts of the catchment and average less than 9 g m−2 yr−1. These rates are low compared to those from high-elevation catchments elsewhere but are an order of magnitude higher than rates of sediment removal from the basin.
The transformation of benzene and a series of alkylbenzenes was studied in anoxic groundwater of a shallow glacial-outwash aquifer near Bemidji, Minnesota, U.S.A. Monoaromatic hydrocarbons, the most water-soluble components of crude oil, were transported downgradient of an oil spill, forming a plume of contaminated groundwater. Organic acids that were not original components of the oil were identified in the anoxic groundwater. The highest concentrations of these oxidized organic compounds were found in the anoxic plume where a decrease in concentrations of structurally related alkylbenzenes was observed. These results suggest that biological transformation of benzene and alkylbenzenes to organic acid intermediates may be an important attenuation process in anoxic environments. The transformation of a complex mixture of hydrocarbons to a series of corresponding oxidation products in an anoxic subsurface environment provides new insight into in situ anaerobic degradation processes.
","language":"English","publisher":"Springer","doi":"10.1007/BF01890379","issn":"01775146","usgsCitation":"Cozzarelli, I., Eganhouse, R., and Baedecker, M., 1990, Transformation of Monoaromatic hydrocarbons to organic acids in anoxic groundwater environment: Environmental Geology and Water Sciences, v. 16, no. 2, p. 135-141, https://doi.org/10.1007/BF01890379.","productDescription":"7 p.","startPage":"135","endPage":"141","numberOfPages":"7","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":205362,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF01890379"},{"id":223343,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnesota","city":"Bemidji","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -94.98916625976562,\n 47.41229100755385\n ],\n [\n -94.82711791992188,\n 47.41229100755385\n ],\n [\n -94.82711791992188,\n 47.52183788271235\n ],\n [\n -94.98916625976562,\n 47.52183788271235\n ],\n [\n -94.98916625976562,\n 47.41229100755385\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"16","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb6d2e4b08c986b326ecc","contributors":{"authors":[{"text":"Cozzarelli, I.M. 0000-0002-5123-1007","orcid":"https://orcid.org/0000-0002-5123-1007","contributorId":22343,"corporation":false,"usgs":true,"family":"Cozzarelli","given":"I.M.","affiliations":[],"preferred":false,"id":372338,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Eganhouse, R.P.","contributorId":67555,"corporation":false,"usgs":true,"family":"Eganhouse","given":"R.P.","email":"","affiliations":[],"preferred":false,"id":372340,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Baedecker, M.J.","contributorId":42702,"corporation":false,"usgs":true,"family":"Baedecker","given":"M.J.","email":"","affiliations":[],"preferred":false,"id":372339,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70016208,"text":"70016208 - 1990 - Reef growth and volcanism on the submarine southwest rift zone of Mauna Loa, Hawaii","interactions":[],"lastModifiedDate":"2012-03-12T17:18:41","indexId":"70016208","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":"Reef growth and volcanism on the submarine southwest rift zone of Mauna Loa, Hawaii","docAbstract":"A marine sampling program, utilizing the PISCES-5 submersible operated by the Hawaii Undersea Research Laboratory (NOAA), has confirmed the presence of a major submerged coral reef offshore from Ka Lae (South Point), Hawaii. The top of the reef is now 150-160 m below sea level. Radiocarbon and Useries dating indicates that it drowned about 13.9 ka by the combined effects of island subsidence (2.5 mm/year) and the rapid rise of sea level at the end of the last glaciation so that the relative submergence rate of more than 10 mm/year exceeded the upward growth rate of the reef. The submerged reef caps the offshore part of the southwest rift-zone ridge of Mauna Loa, which has apparently undergone little volcanic activity offshore since 170 ka, and possibly since 270 ka. This fact suggests that rift zone activity is becoming increasingly restricted toward the upper part of the volcano, a condition possibly heralding the end of the shield-building stage. ?? 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/BF00302049","issn":"02588900","usgsCitation":"Moore, J., Normark, W.R., and Szabo, B.J., 1990, Reef growth and volcanism on the submarine southwest rift zone of Mauna Loa, Hawaii: Bulletin of Volcanology, v. 52, no. 5, p. 375-380, https://doi.org/10.1007/BF00302049.","startPage":"375","endPage":"380","numberOfPages":"6","costCenters":[],"links":[{"id":205348,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00302049"},{"id":223203,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"52","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a419e4b0e8fec6cdba42","contributors":{"authors":[{"text":"Moore, J.G.","contributorId":67496,"corporation":false,"usgs":true,"family":"Moore","given":"J.G.","email":"","affiliations":[],"preferred":false,"id":372841,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Normark, W. R.","contributorId":87137,"corporation":false,"usgs":true,"family":"Normark","given":"W.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":372842,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Szabo, Barney J.","contributorId":6848,"corporation":false,"usgs":true,"family":"Szabo","given":"Barney","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":372840,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70016067,"text":"70016067 - 1990 - Measurement and interpretation of low levels of dissolved oxygen in ground water","interactions":[],"lastModifiedDate":"2024-03-19T22:46:36.647024","indexId":"70016067","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3825,"text":"Groundwater","active":true,"publicationSubtype":{"id":10}},"title":"Measurement and interpretation of low levels of dissolved oxygen in ground water","docAbstract":"A Rhodazine-D colorimetric technique was adapted to measure low-level dissolved oxygen concentrations in ground water. Prepared samples containing between 0 and 8.0 μmoles · 1-1 dissolved oxygen in equilibrium with known gas mixtures produced linear spectrophotometric absorbance with a lower detection limit of 0.2 μmoles · 1-1. Excellent reproducibility was found for solutions ranging in composition from deionized water to sea water with chemical interferences detected only for easily reduced metal species such as ferric ion, cupric ion, and hexavalent chromium. Such effects were correctable based on parallel reaction stoichiometries relative to oxygen. The technique, coupled with a downhole wire line tool, permitted low-level monitoring of dissolved oxygen in wells at the selenium-contaminated Kesterson Reservoir in California. Results indicated a close association between low but measurable dissolved oxygen concentrations and mobility of oxidized forms of selenium in the shallow aquifer which were in general electrochemical disequilibrium.
Paleomagnetic results from Cenozoic (62–12 Ma) volcanic rocks of the Cascade arc and adjacent areas indicate that moderate to large clockwise rotations are an important component of the tectonic history of the arc. Two mechanisms of rotation are suggested by the regional pattern of paleomagnetic rotations. The progressive increase in rotation toward the coast in arc and forearc rocks results from distributed dextral shear, which is likely driven by oblique subduction of oceanic plates to the west. Simple shear rotation is accommodated in the upper crust by strike-slip faulting. The right-lateral Mount St. Helens seismic zone may be an active manifestation of this process. Dextral shear probably obscures a subequal contribution to arc and forearc rotation that is driven by intraarc or backarc extension. This rotation is suggested by the average southward increase in continental margin rotations into the region outboard of the Basin and Range. The southward increase in rotation parallels a change in the arc tectonic regime from largely compressional in northern Washington to extensional in Oregon. Concomitant with this change is a southward increase in the volume of eruptive rocks and the number of basaltic vents in the arc. A progressive eastward shift of the arc volcanic front with time in the rotated arc terrane is the result of the westward pivoting of the arc block in front of a zone of extension since Eocene time. Westward migration of bimodal Basin and Range volcanism since at least 16 Ma is tracking westward rotation of the frontal arc block and growth of the Basin and Range in its wake.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB095iB12p19409","issn":"01480227","usgsCitation":"Wells, R., 1990, Paleomagnetic rotations and the Cenozoic tectonics of the Cascade Arc, Washington, Oregon, and California: Journal of Geophysical Research Solid Earth, v. 95, no. B12, p. 19409-19417, https://doi.org/10.1029/JB095iB12p19409.","productDescription":"9 p.","startPage":"19409","endPage":"19417","costCenters":[],"links":[{"id":223446,"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":"505a7417e4b0c8380cd77428","contributors":{"authors":[{"text":"Wells, R.E. 0000-0002-7796-0160","orcid":"https://orcid.org/0000-0002-7796-0160","contributorId":67537,"corporation":false,"usgs":true,"family":"Wells","given":"R.E.","affiliations":[],"preferred":false,"id":372471,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70016213,"text":"70016213 - 1990 - Ouachitas need more exploratory drilling","interactions":[],"lastModifiedDate":"2018-02-19T17:37:34","indexId":"70016213","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2941,"text":"Oil & Gas Journal","printIssn":"0030-1388","active":true,"publicationSubtype":{"id":10}},"title":"Ouachitas need more exploratory drilling","docAbstract":"The Ouachita Mountains in southeastern Oklahoma and western Arkansas are part of a mostly buried late Paleozoic fold and thrust belt that extends from Alabama to northern Mexico. The principal hydrocarbon reservoirs in the Ouachita tectonic province can be subdivided into those that produce natural gas from shallow-water units and those that produce oil and/or natural gas from deep-water units. They can also be divided into those that are fractured and those that produce from primary pore spaces or vugs. The first successful oil well in the Ouachita Mountains was drilled in 1913 or 1914. Since the discovery of the Redden field, over 800 oil and gas wells have been drilled in the Ouachita tectonic province in Oklahoma. Yet, most of the region remains little explored.","language":"English","publisher":"PennWell Corporation","publisherLocation":"Tulsa, OK","usgsCitation":"Suneson, N.H., and Campbell, J.A., 1990, Ouachitas need more exploratory drilling: Oil & Gas Journal, v. 88, no. 15, p. 65-69.","productDescription":"5 p.","startPage":"65","endPage":"69","costCenters":[],"links":[{"id":223306,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":351795,"rank":2,"type":{"id":15,"text":"Index Page"},"url":"https://www.ogj.com/articles/print/volume-88/issue-15/in-this-issue/exploration/ouachitas-need-more-exploratory-drilling.html"}],"country":"United States","state":"Arkansas, Oklahoma","otherGeospatial":"Ouachita Mountains","volume":"88","issue":"15","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a716de4b0c8380cd765ea","contributors":{"authors":[{"text":"Suneson, Neil H.","contributorId":10482,"corporation":false,"usgs":true,"family":"Suneson","given":"Neil","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":372858,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Campbell, Jock A.","contributorId":8343,"corporation":false,"usgs":true,"family":"Campbell","given":"Jock","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":372857,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70016070,"text":"70016070 - 1990 - Comparison of Darcian flow in corresponding flat and folded surfaces","interactions":[],"lastModifiedDate":"2018-02-27T11:38:05","indexId":"70016070","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3722,"text":"Water Resources Research","onlineIssn":"1944-7973","printIssn":"0043-1397","active":true,"publicationSubtype":{"id":10}},"title":"Comparison of Darcian flow in corresponding flat and folded surfaces","docAbstract":"Folds of aquifers are rarely accounted for in models of groundwater flow. To account for aquifer folds in groundwater flow models, the equation describing Darcian flow in a general surface is derived. The equation is used to calculate steady state hydraulic head distributions for corresponding folded and flat surfaces. Each flat surface has the same hydraulic conductivity distribution and boundary condition as the corresponding folded surface. The folded surfaces have folds similar to the folds of selected aquifers and have folds that have much larger changes in slope. The largest difference in hydraulic head caused by all folding is only about 0.5% of the largest difference in hydraulic head across each surface. Because of the smaller areal extent and the fact that the effect of a sequence of folds is not cumulative, the minor folds do not generate substantially larger hydraulic head differences than the major folds.
Degree of pyritization (DOP) is a measure of the ratio pyrite iron/(pyrite iron + reactive iron) that can be related to the depositional environment of a sediment. Several methods of DOP determination have been used but not systematically evaluated. The determination/extraction of reactive (usually acid soluble) iron is critical to the DOP determination, and the method generally used is reaction of the sample for 1 to 2 min with hot 12 N HCl. We present results for timed experiments with 1 N, 6 N, and 12 N HCl on three different samples. We also show that a 24 h room temperature treatment with 1 N HCl is equivalent to the 24 h treatment with Na-dithionite. Experiments with several suites of samples show that all three of these methods leach comparable amounts of iron; therefore, the DOP values are similar. However, the 1 N HCl, 24 h procedure is preferable because laboratory handling is less and easier.
","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7037(90)90249-K","issn":"00167037","usgsCitation":"Leventhal, J., and Taylor, C., 1990, Comparison of methods to determine degree of pyritization: Geochimica et Cosmochimica Acta, v. 54, no. 9, p. 2621-2625, https://doi.org/10.1016/0016-7037(90)90249-K.","productDescription":"5 p.","startPage":"2621","endPage":"2625","numberOfPages":"5","costCenters":[],"links":[{"id":223496,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"54","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f876e4b0c8380cd4d109","contributors":{"authors":[{"text":"Leventhal, J.","contributorId":16583,"corporation":false,"usgs":true,"family":"Leventhal","given":"J.","email":"","affiliations":[],"preferred":false,"id":372483,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Taylor, C.","contributorId":73958,"corporation":false,"usgs":true,"family":"Taylor","given":"C.","affiliations":[],"preferred":false,"id":372484,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70016252,"text":"70016252 - 1990 - Determination of trace levels of herbicides and their degradation products in surface and ground waters by gas chromatography/ion-trap mass spectrometry","interactions":[],"lastModifiedDate":"2019-10-17T16:16:47","indexId":"70016252","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":760,"text":"Analytica Chimica Acta","active":true,"publicationSubtype":{"id":10}},"title":"Determination of trace levels of herbicides and their degradation products in surface and ground waters by gas chromatography/ion-trap mass spectrometry","docAbstract":"A rapid, specific and highly sensitive method is described for the determination of several commonly used herbicides and their degradation products in surface and ground waters by using gas chromatography/ion-trap mass spectrometry. The compounds included atrazine, and its degradation products desethylatrazine and desisopropylatrazine; Simazine; Cyanazine; Metolachlor; and alachlor and its degradation products, 2-chloro-2', 6'-diethylacetanilide, 2-hydroxy-2', 6'-diethylacetanilide and 2,6-diethylaniline. The method was applied to surface-water samples collected from 16 different stations along the lower Mississippi River and its major tributaries, and ground-water samples beneath a cornfield in central Nebraska. Average recovery of a surrogate herbicide, terbuthylazine, was greater than 99%. Recoveries of the compounds of interest from river water spiked at environmental levels are also presented. Full-scan mass spectra of these compounds were obtained on 1 ng or less of analyte. Data were collected in the full-scan acquisition mode. Quantitation was based on a single characteristic ion for each compound. The detection limit was 60 pg with a signal-to-noise ratio of greater than 10:1.","language":"English","publisher":"Elsevier","doi":"10.1016/S0003-2670(00)80480-8","issn":"00032670","usgsCitation":"Pereira, W.E., Rostad, C., and Leiker, T., 1990, Determination of trace levels of herbicides and their degradation products in surface and ground waters by gas chromatography/ion-trap mass spectrometry: Analytica Chimica Acta, v. 228, no. 1, p. 69-75, https://doi.org/10.1016/S0003-2670(00)80480-8.","productDescription":"7 p.","startPage":"69","endPage":"75","numberOfPages":"7","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":223152,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":205343,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0003-2670(00)80480-8"}],"volume":"228","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ffe1e4b0c8380cd4f453","contributors":{"authors":[{"text":"Pereira, W. E.","contributorId":46981,"corporation":false,"usgs":true,"family":"Pereira","given":"W.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":372975,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rostad, C.E.","contributorId":50939,"corporation":false,"usgs":true,"family":"Rostad","given":"C.E.","email":"","affiliations":[],"preferred":false,"id":372976,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Leiker, T.J.","contributorId":96719,"corporation":false,"usgs":true,"family":"Leiker","given":"T.J.","email":"","affiliations":[],"preferred":false,"id":372977,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70016254,"text":"70016254 - 1990 - Postglacial response of a stream in central Iowa to changes in climate and Drainage basin factors","interactions":[],"lastModifiedDate":"2013-01-25T14:56:36","indexId":"70016254","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3218,"text":"Quaternary Research","active":true,"publicationSubtype":{"id":10}},"title":"Postglacial response of a stream in central Iowa to changes in climate and Drainage basin factors","docAbstract":"Postglacial geomorphic development of the Buchanan Drainage, a small tributary to the South Skunk River, is reconstructed by documenting relationships among four allostratigraphic units and 17 radiocarbon dates. Formation and headward expansion of the valley was both episodic and time-transgressive. Response to downstream conditions in the South Skunk River largely controlled the early formation of the basin. Downcutting through Pleistocene deposits produced a gravelly lag deposit that was buried by alluvium in the downstream portion of the valley during the early Holocene (10,500-7700 yr B.P.). Lag deposits formed in a similar manner continued to develop in the upper portion of the drainageway into the late Holocene (3000-2000 yr B.P.). Episodes of aggradation during the middle Holocene (7700-6300 yr B.P.) and late Holocene (3000-2000 yr B.P.) were separated by a period of soil formation. Holocene geomorphic events in the drainageway coincide with some vegetational and climatic changes as documented in upland pollen sequences from central Iowa. Analysis of plant macrofossil assemblages recovered from alluvium indicates that during the middle Holocene forest contracted and prairie expanded into the uplands within the basin. Vegetational changes within the basin apparently had only minor influence on rates of hillslope erosion, and the widely accepted relationship between prairie (versus forest) vegetative cover and increased rates of hillslope erosion did not hold. Instead, greater amounts of erosion occurred under forested conditions when local water tables were higher and seepage erosion was more effective. ?? 1990.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Quaternary Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/0033-5894(90)90085-Y","issn":"00335894","usgsCitation":"Van Nest, J., and Bettis, E., 1990, Postglacial response of a stream in central Iowa to changes in climate and Drainage basin factors: Quaternary Research, v. 33, no. 1, p. 73-85, https://doi.org/10.1016/0033-5894(90)90085-Y.","startPage":"73","endPage":"85","numberOfPages":"13","costCenters":[],"links":[{"id":223204,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":266504,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0033-5894(90)90085-Y"}],"volume":"33","issue":"1","noUsgsAuthors":false,"publicationDate":"2017-01-20","publicationStatus":"PW","scienceBaseUri":"505a7e8be4b0c8380cd7a5db","contributors":{"authors":[{"text":"Van Nest, J.","contributorId":45839,"corporation":false,"usgs":true,"family":"Van Nest","given":"J.","email":"","affiliations":[],"preferred":false,"id":372985,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bettis, E. Arthur III","contributorId":72822,"corporation":false,"usgs":true,"family":"Bettis","given":"E. Arthur","suffix":"III","affiliations":[],"preferred":false,"id":372986,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70016255,"text":"70016255 - 1990 - Early Holocene pecan, Carya illinoensis, in the Mississippi River Valley near Muscatine, Iowa","interactions":[],"lastModifiedDate":"2013-01-25T14:57:25","indexId":"70016255","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3218,"text":"Quaternary Research","active":true,"publicationSubtype":{"id":10}},"title":"Early Holocene pecan, Carya illinoensis, in the Mississippi River Valley near Muscatine, Iowa","docAbstract":"A fossil pecan, Carya illinoensis (Wang.) K. Koch, from floodplain sediments of the Mississippi River near Muscatine, Iowa, was accelerator-dated at 7280 ?? 120 yr B.P. This discovery indicates that pecan was at or near its present northern limit by that time. Carya pollen profiles from the Mississippi River Trench indicate that hickory pollen percentages were much higher in the valley than at upland locations during the early Holocene. Pecan, the hickory with the most restricted riparian habitat, is the likely candidate for producing these peaks in Carya pollen percentages. Therefore, pecan may have reached its northern limit as early as 10,300 yr B.P. Its abundance in Early Archaic archaeological sites and the co-occurrence of early Holocene Carya pollen peaks with the arrival of the Dalton artifact complex in the Upper Mississippi Valley suggest that humans may have played a role in the early dispersal of pecan. ?? 1990.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Quaternary Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/0033-5894(90)90088-3","issn":"00335894","usgsCitation":"Bettis, E., Baker, R.G., Nations, B., and Benn, D., 1990, Early Holocene pecan, Carya illinoensis, in the Mississippi River Valley near Muscatine, Iowa: Quaternary Research, v. 33, no. 1, p. 102-107, https://doi.org/10.1016/0033-5894(90)90088-3.","startPage":"102","endPage":"107","numberOfPages":"6","costCenters":[],"links":[{"id":223205,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":266505,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0033-5894(90)90088-3"}],"volume":"33","issue":"1","noUsgsAuthors":false,"publicationDate":"2017-01-20","publicationStatus":"PW","scienceBaseUri":"505a0477e4b0c8380cd509db","contributors":{"authors":[{"text":"Bettis, E. Arthur III","contributorId":72822,"corporation":false,"usgs":true,"family":"Bettis","given":"E. Arthur","suffix":"III","affiliations":[],"preferred":false,"id":372989,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Baker, R. G.","contributorId":96326,"corporation":false,"usgs":true,"family":"Baker","given":"R.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":372990,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Nations, B.K.","contributorId":67667,"corporation":false,"usgs":true,"family":"Nations","given":"B.K.","email":"","affiliations":[],"preferred":false,"id":372988,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Benn, D.W.","contributorId":61712,"corporation":false,"usgs":true,"family":"Benn","given":"D.W.","email":"","affiliations":[],"preferred":false,"id":372987,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70016256,"text":"70016256 - 1990 - Regionalization in geology by multivariate classification","interactions":[],"lastModifiedDate":"2012-03-12T17:18:41","indexId":"70016256","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2700,"text":"Mathematical Geology","active":true,"publicationSubtype":{"id":10}},"title":"Regionalization in geology by multivariate classification","docAbstract":"The concept of multivariate classification of \"geological objects\" can be combined with the concept of regionalized variables to yield a procedure for typification of geological objects, such as rock units, well records, or samples. Numerical classification is followed by subdivision of the area of investigation, and culminates in a regionalization or mapping of the classification onto the plane. Regions are subdivisions of the map area which are spatially contiguous and relatively homogeneous in their geological properties. The probability of correct classification of each point within a region as being part of that region can be assessed in terms of Bayesian probability as a space-dependent function. The procedure is applied to subsurface data from western Kansas. The geologic properties used are quantitative variables, and relationships are expressed by Mahalanobis' distances. These functions could be replaced by other metrics if qualitative or binary data derived from geological descriptions or appraisals were included in the analysis. ?? 1990 International Association for Mathematical Geology.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Mathematical Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Kluwer Academic Publishers-Plenum Publishers","doi":"10.1007/BF00890505","issn":"08828121","usgsCitation":"Harff, J., and Davis, J., 1990, Regionalization in geology by multivariate classification: Mathematical Geology, v. 22, no. 5, p. 573-588, https://doi.org/10.1007/BF00890505.","startPage":"573","endPage":"588","numberOfPages":"16","costCenters":[],"links":[{"id":205349,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00890505"},{"id":223206,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"22","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a5a6e4b0e8fec6cdbebe","contributors":{"authors":[{"text":"Harff, Jan","contributorId":63957,"corporation":false,"usgs":false,"family":"Harff","given":"Jan","email":"","affiliations":[],"preferred":false,"id":372991,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Davis, J.C.","contributorId":72121,"corporation":false,"usgs":true,"family":"Davis","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":372992,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70016260,"text":"70016260 - 1990 - Deformation monitoring at Nevado del Ruiz, Colombia - October 1985 - March 1988","interactions":[],"lastModifiedDate":"2012-03-12T17:18:41","indexId":"70016260","displayToPublicDate":"1990-01-01T00:00:00","publicationYear":"1990","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Deformation monitoring at Nevado del Ruiz, Colombia - October 1985 - March 1988","docAbstract":"Deformation studies began at Nevado del Ruiz 23 days before the devastating 13 November 1985 eruption, at least 12 months after precursory seismicity and fumarolic activity began. The late start in geodetic monitoring, limited number of stations in the pre-eruption network, and inconsistent patterns in the observed deformation limit conclusions about intrusive activity in the months and weeks prior to the eruption. However, the data require that the magma source of the devastating eruption was either deeper than 7 km or, if shallow, recovered the same volume and position within one week of the eruption. Geodetic monitoring resumed 1 week after the eruption and, by April 1986, included 11 tilt-leveling stations, 38 EDM lines, and 7 short leveling lines - a network capable of detecting emplacement or movement of magma volumes as small as 3 MCM (3 ?? 106 m3) to a depth of 2-3 km (using a point-source model), 10 MCM to 7 km, 50 MCM to 10 km, and 200 MCM to 15 km beneath Ruiz. In addition, 4 telemetered tiltmeters provided the capability of detecting, in real time, the fairly rapid ascent of much smaller magma bodies. Stations established to detect instability of the summit ice cap after the eruption were discontinued in early 1986. The data collected from the geodetic networks have higher than normal variance but demonstrate that little or no cumulative deformation of Ruiz occurred from October 1985 through March 1988. Thus, little, if any, magma intruded above 5 km beneath the summit during or after the 13 November 1985 eruption. This lack of significant intrusive activity agrees with the surprisingly low seismic energy release under Ruiz and makes direct degassing of a large batholith an improbable explanation of the large sulfur flux to date at Ruiz. Part of the variance in the geodetic data results from real but noncumulative deformation that may in part be pressure-buffered by a fairly large geothermal water-gas mixture for which abundant physical evidence exists. Part of the noncumulative deformation, some of the fairly dispersed and low-level seismicity under Ruiz, and some phreatic events appear to correlate with seasonal precipitation patterns. Hence rain/snow-loading and groundwater interaction may cause deformation events and possibly help trigger some phreatic explosions and seismic events at Ruiz and, as search of the literature reveals, at other volcanoes in metastable states. ?? 1990.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Volcanology and Geothermal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03770273","usgsCitation":"Banks, N., Carvajal, C., Mora, H., and Tryggvason, E., 1990, Deformation monitoring at Nevado del Ruiz, Colombia - October 1985 - March 1988: Journal of Volcanology and Geothermal Research, v. 41, no. 1-4, p. 269-295.","startPage":"269","endPage":"295","numberOfPages":"27","costCenters":[],"links":[{"id":223308,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"41","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fe48e4b0c8380cd4ec38","contributors":{"authors":[{"text":"Banks, N.G.","contributorId":60635,"corporation":false,"usgs":true,"family":"Banks","given":"N.G.","email":"","affiliations":[],"preferred":false,"id":372998,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Carvajal, C.","contributorId":84082,"corporation":false,"usgs":true,"family":"Carvajal","given":"C.","affiliations":[],"preferred":false,"id":373001,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mora, H.","contributorId":60777,"corporation":false,"usgs":true,"family":"Mora","given":"H.","email":"","affiliations":[],"preferred":false,"id":372999,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Tryggvason, E.","contributorId":68884,"corporation":false,"usgs":true,"family":"Tryggvason","given":"E.","email":"","affiliations":[],"preferred":false,"id":373000,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ]}