Much of northwestern Alaska remained unglaciated during the Pleistocene and thus offers a favorable setting for examining long-term records of high-latitude geological and biological change. Epiguruk, a large cut bank 3.5 km long and up to 36 m high on the Kobuk River south of the Brooks Range in eastern Beringia, exposes complex sedimentary successions representing cycles of upper Quaternary alluviation and eolian sedimentation, downcutting, and soil formation. A rich record of plants and mammals is also preserved in the section. Deposits of fluvial channels and flood plains, eolian dunes, sand sheets, loess, and ponds, as well as organic soils (Histosols) are represented. Parallel-bedded fine sand and coarse silt couplets that commonly contain root structures, ripple cross-lamination, and silt drapes are flood-plain sediments apparently deposited at the interface of fluvial and eolian environments. Multiple fluvial-to-eolian depositional sequences were caused by influx of eolian sediment to the river from intermittently active dune fields south of the Kobuk River. Alluviation in the Kobuk Valley was coeval with glaciation in the Brooks Range, whereas downcutting occurred during interstadials when dune stabilization limited sediment supply. The depositional model developed at Epiguruk may be useful in interpreting some of the widespread subhorizontally stratified late-glacial deposits of Europe and North America.
","language":"English","publisher":"GeoScienceWorld","doi":"10.1306/D4267C12-2B26-11D7-8648000102C1865D","usgsCitation":"Ashley, G., and Hamilton, T.D., 1993, Fluvial response to late Quaternary climatic fluctuations, central Kobuk Valley, northwestern Alaska: Journal of Sedimentary Research, v. 63, no. 5, p. 814-827, https://doi.org/10.1306/D4267C12-2B26-11D7-8648000102C1865D.","productDescription":"14 p.","startPage":"814","endPage":"827","costCenters":[],"links":[{"id":371595,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United 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\":{\"name\":\"Alaska\",\"nation\":\"USA \"}}]}","volume":"63","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"authors":[{"text":"Ashley, G.M.","contributorId":99313,"corporation":false,"usgs":true,"family":"Ashley","given":"G.M.","email":"","affiliations":[],"preferred":false,"id":780454,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hamilton, T. D.","contributorId":36921,"corporation":false,"usgs":true,"family":"Hamilton","given":"T.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":780455,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70207890,"text":"70207890 - 1993 - Internal structure of the Sierra Nevada batholith based on specific gravity and gravity measurements","interactions":[],"lastModifiedDate":"2020-01-16T16:55:54","indexId":"70207890","displayToPublicDate":"1993-01-16T16:47:49","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1807,"text":"Geophysical Research Letters","active":true,"publicationSubtype":{"id":10}},"title":"Internal structure of the Sierra Nevada batholith based on specific gravity and gravity measurements","docAbstract":"About 6,000 specific‐gravity (SG) measurements of samples collected from nearly 200 granitic plutons comprising the central Sierra Nevada batholith yield a SG contour map across the batholith from 36.25° to 38° north latitude. With notable exceptions, SG decreases from values generally greater than 2.7 in the west to less than 2.6 over a few small areas of high‐silica, high‐potassium granites near the east edge. A good correlation between measured SG and analyzed weight percent SiO2 enables estimation of average silica variations across the batholith. The average SG is 2.69 corresponding to an average of 68 wt. % SiO2 for the 18,000 km² central part of the batholith.
A 1‐km gridded version of the SG measurements has been used to generate a series of synthetic gravity maps, assuming that the SG of rocks at the surface extends unchanged to various depths. The synthetic map computed for a depth of 10 km shows the best correspondence with the isostatic residual gravity map indicating that variations in the observed gravity residuals are largely caused by SG variations of the plutonic rocks exposed at the surface that apparently extend downward to an average depth of about 10 km.
Although the 10‐km synthetic gravity map gives the best overall fit to the observed gravity data, comparison of individual anomalies indicates that the bottoms of the plutons as defined by SG variations at the surface are generally shallower along the west edge of the Sierra Nevada (7±2 km) and deeper in the younger and more felsic eastern part (12±3 km). These depths do not necessarily represent a distinct base of the Sierra Nevada batholith. They may indicate the depth below which density homogenization occurs, either by igneous, or possibly, structural processes.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/93GL01379","usgsCitation":"Oliver, H., Moore, B., and Sikora, R.F., 1993, Internal structure of the Sierra Nevada batholith based on specific gravity and gravity measurements: Geophysical Research Letters, v. 20, no. 20, p. 2179-2182, https://doi.org/10.1029/93GL01379.","productDescription":"4 p.","startPage":"2179","endPage":"2182","costCenters":[{"id":617,"text":"Volcano Science Center","active":true,"usgs":true}],"links":[{"id":371333,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Sierra Nevada batholith","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -120.08056640625,\n 36.13787471840729\n ],\n [\n -117.94921874999999,\n 36.13787471840729\n ],\n [\n -117.94921874999999,\n 38.272688535980976\n ],\n [\n -120.08056640625,\n 38.272688535980976\n ],\n [\n -120.08056640625,\n 36.13787471840729\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"20","issue":"20","noUsgsAuthors":false,"publicationDate":"2012-12-07","publicationStatus":"PW","contributors":{"authors":[{"text":"Oliver, H.W.","contributorId":16703,"corporation":false,"usgs":true,"family":"Oliver","given":"H.W.","email":"","affiliations":[],"preferred":false,"id":779657,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Moore, Bryan bmoore@usgs.gov","contributorId":2417,"corporation":false,"usgs":true,"family":"Moore","given":"Bryan","email":"bmoore@usgs.gov","affiliations":[],"preferred":true,"id":779658,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sikora, R. F.","contributorId":21923,"corporation":false,"usgs":true,"family":"Sikora","given":"R.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":779659,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":66929,"text":"i1420(NJ15) - 1993 - Quaternary geologic map of the Ozark Plateau 4° x 6° quadrangle, United States","interactions":[],"lastModifiedDate":"2022-04-12T20:25:32.244195","indexId":"i1420(NJ15)","displayToPublicDate":"1993-01-13T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":320,"text":"IMAP","code":"I","active":false,"publicationSubtype":{"id":5}},"seriesNumber":"1420(NJ-15)","subseriesTitle":"GAUS","title":"Quaternary geologic map of the Ozark Plateau 4° x 6° quadrangle, United States","docAbstract":"The Quaternary Geologic Map of the Ozark Plateau 4° x 6° Quadrangle was mapped as part of the Quaternary Geologic Atlas of the United States. The atlas was begun as an effort to depict the areal distribution of surficial geologic deposits and other materials that accumulated or formed during the past 2+ million years, the period that includes all activities of the human species. These materials are at the surface of the earth. They make up the \"ground\" on which we walk, the \"dirt\" in which we dig foundations, and the \"soil\" in which we grow crops. Most of our human activity is related in one way or another to these surface materials that are referred to collectively by many geologists as regolith, the mantle of fragmental and generally unconsolidated material that overlies the bedrock foundation of the continent. The maps were compiled at 1:1,000,000 scale.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/i1420(NJ15)","collaboration":"Prepared in cooperation with the Missouri Department of Natural Resources, Division of Geology and Land Survey, Kansas Geological Survey, Arkansas Geological Commission, Illinois State Geological Survey, and Oklahoma Geological Survey","usgsCitation":"Ward, R.A., Denne, J., Holbrook, D.F., Bush, W.V., Lineback, J.A., Luza, K.V., Jensen, K.M., Fishman, W.D., Weide, D.L., and Bush, C.A., 1993, Quaternary geologic map of the Ozark Plateau 4° x 6° quadrangle, United States: U.S. Geological Survey IMAP 1420(NJ-15), Report: 15 p.; 1 Plate: 49. 54 inches x 33.89 inches; Downloads Directory, https://doi.org/10.3133/i1420(NJ15).","productDescription":"Report: 15 p.; 1 Plate: 49. 54 inches x 33.89 inches; Downloads Directory","costCenters":[{"id":308,"text":"Geology and Environmental Change Science Center","active":false,"usgs":true}],"links":[{"id":259660,"rank":400,"type":{"id":17,"text":"Plate"},"url":"https://pubs.usgs.gov/imap/i-1420/nj-15/pdf/i1420_nj-15_map.pdf","linkFileType":{"id":1,"text":"pdf"}},{"id":259661,"rank":300,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/imap/i-1420/nj-15/downloads/textonly.pdf","linkFileType":{"id":1,"text":"pdf"}},{"id":259659,"rank":100,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.usgs.gov/imap/i-1420/nj-15/","linkFileType":{"id":5,"text":"html"}},{"id":392348,"rank":6,"type":{"id":2,"text":"Additional Report Piece"},"url":"https://pubs.usgs.gov/imap/i-1420/nj-15/downloads/"},{"id":392347,"rank":5,"type":{"id":36,"text":"NGMDB Index Page"},"url":"https://ngmdb.usgs.gov/Prodesc/proddesc_9212.htm"},{"id":187468,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"}],"scale":"1000000","projection":"Lambert Conformal Conic","country":"United States","state":"Arkansas, Illinois, Kansas, Missouri, Oklahoma","otherGeospatial":"Ozark Plateau 4° x 6° quadrangle","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -96,\n 36\n ],\n [\n -90,\n 36\n ],\n [\n -90,\n 40\n ],\n [\n -96,\n 40\n ],\n [\n -96,\n 36\n ]\n ]\n ]\n }\n }\n ]\n}","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a81e4b07f02db64a25a","contributors":{"compilers":[{"text":"Whitfield, John W.","contributorId":39058,"corporation":false,"usgs":true,"family":"Whitfield","given":"John","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":749869,"contributorType":{"id":3,"text":"Compilers"},"rank":1}],"editors":[{"text":"Richmond, Gerald M.","contributorId":87165,"corporation":false,"usgs":true,"family":"Richmond","given":"Gerald M.","affiliations":[],"preferred":false,"id":749868,"contributorType":{"id":2,"text":"Editors"},"rank":1}],"authors":[{"text":"Ward, R. A.","contributorId":21022,"corporation":false,"usgs":true,"family":"Ward","given":"R.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":275307,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Denne, J. E.","contributorId":77784,"corporation":false,"usgs":true,"family":"Denne","given":"J. E.","affiliations":[],"preferred":false,"id":275312,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Holbrook, D. F.","contributorId":88198,"corporation":false,"usgs":true,"family":"Holbrook","given":"D.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":275314,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Bush, W. V.","contributorId":40233,"corporation":false,"usgs":true,"family":"Bush","given":"W.","email":"","middleInitial":"V.","affiliations":[],"preferred":false,"id":275309,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Lineback, J. A.","contributorId":56903,"corporation":false,"usgs":true,"family":"Lineback","given":"J.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":275311,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Luza, K. V.","contributorId":14856,"corporation":false,"usgs":true,"family":"Luza","given":"K.","email":"","middleInitial":"V.","affiliations":[],"preferred":false,"id":275306,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Jensen, Kathleen M.","contributorId":84492,"corporation":false,"usgs":true,"family":"Jensen","given":"Kathleen","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":275313,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Fishman, W. D.","contributorId":106250,"corporation":false,"usgs":true,"family":"Fishman","given":"W.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":275317,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Weide, David L.","contributorId":48537,"corporation":false,"usgs":true,"family":"Weide","given":"David","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":275310,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Bush, Charles A.","contributorId":97876,"corporation":false,"usgs":true,"family":"Bush","given":"Charles","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":275315,"contributorType":{"id":1,"text":"Authors"},"rank":10}]}} ,{"id":70207775,"text":"70207775 - 1993 - Paleo-oceanographic cycles and events during the Late Cretaceous in the Western Interior Seaway of North America","interactions":[],"lastModifiedDate":"2020-06-18T15:22:55.494454","indexId":"70207775","displayToPublicDate":"1993-01-10T10:18:48","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3458,"text":"Special Paper - Geological Association of Canada","active":true,"publicationSubtype":{"id":10}},"title":"Paleo-oceanographic cycles and events during the Late Cretaceous in the Western Interior Seaway of North America","docAbstract":"No abstract available.
","language":"English","publisher":"Geological Association of Canada","issn":"0072-1042","usgsCitation":"Pratt, L., Arthur, M., Dean, W.E., and Scholle, P., 1993, Paleo-oceanographic cycles and events during the Late Cretaceous in the Western Interior Seaway of North America: Special Paper - Geological Association of Canada, v. 39, p. 333-353.","productDescription":"21 p.","startPage":"333","endPage":"353","costCenters":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"links":[{"id":371148,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"39","noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"authors":[{"text":"Pratt, L.M.","contributorId":217906,"corporation":false,"usgs":false,"family":"Pratt","given":"L.M.","email":"","affiliations":[{"id":37145,"text":"Indiana University","active":true,"usgs":false}],"preferred":false,"id":779284,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Arthur, M.A.","contributorId":24791,"corporation":false,"usgs":true,"family":"Arthur","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":779285,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dean, Walter E. dean@usgs.gov","contributorId":1801,"corporation":false,"usgs":true,"family":"Dean","given":"Walter","email":"dean@usgs.gov","middleInitial":"E.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":779286,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Scholle, Peter A.","contributorId":60194,"corporation":false,"usgs":true,"family":"Scholle","given":"Peter A.","affiliations":[],"preferred":false,"id":779287,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70207773,"text":"70207773 - 1993 - Stable carbon and oxygen isotope studies of the sediments of Elk Lake, Minnesota","interactions":[],"lastModifiedDate":"2020-06-19T14:24:57.105855","indexId":"70207773","displayToPublicDate":"1993-01-09T16:21:57","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1727,"text":"GSA Special Papers","active":true,"publicationSubtype":{"id":10}},"title":"Stable carbon and oxygen isotope studies of the sediments of Elk Lake, Minnesota","docAbstract":"Variations in the ratios of 18O:16O and 13C:12C in calcite throughout the Holocene in Elk Lake, Minnesota, are recorded in three varve-calibrated carbonate cores. Marl in a varved deep-basin (29.6 m) core consists mainly of calcite precipitated from surface waters during the summer and probably provides the least complicated isotope record. Marl in a sublittoral (10 m) core consists of calcite contributed from several inorganic and organic sources and probably is the most complicated of the three isotope records. Calcite from shells of the ostracod Candona ohioensis in the sublittoral core provides a record of shallow-water conditions in Elk Lake for the period between 10,500 and 5500 varve yr. Variations in the 13C:12C ratio of organic carbon deposited in Elk Lake during the Holocene are recorded in organic matter in the deep-basin core.
All three oxygen isotope records show that, in general, the 18O:16O ratio in carbonate was enriched in 18O by several parts per mil during the mid-Holocene relative to the past few thousand years. This pattern of oxygen isotope variation is similar to that observed for carbonate materials from other lakes in the northeastern and north-central United States. Oxygen isotope records from these other lakes also show that the 18O:16O ratio during the early Holocene was lower than during the mid-Holocene, and this pattern has been interpreted as representing a response to a generally warmer and drier climate during the mid-Holocene beginning about 8000 varve yr (the so-called hypsithermal). Ostracod and diatom assemblages from Elk Lake cores show, however, that the lake was colder and more saline than at present until at least 6700 varve yr, with conditions similar to those that exist today in cold prairie lakes of Canada. It may be more appropriate, therefore, to refer to the mid-Holocene in northwestern Minnesota as the “prairie period” rather than the hypsithermal, indicating that the climate was drier, but with no connotation regarding temperature. The oxygen isotope data from the three Elk Lake records for this period are somewhat equivocal. Values of δ 18O in the marl from the sublittoral core and shells of Candona increase from 10,000 to about 6800 varve yr. However, values of δ 18O in the marl that accumulated in the deepest part of the lake over the same interval (10,000–6800 varve yr) are more or less constant and enriched in 18O; this probably reflects the cold, saline prairie-lake conditions predicted from the ostracod and diatom assemblage data. All three oxygen isotope records show decreases in 18O:16O ratios after about 6800 varve yr in response to an increase in temperature and decrease in salinity of the lake.
The 13C:12C ratios in carbonates from all three Elk Lake records show a distinct pattern; the ratio increased gradually from 10,000 to 8000 varve yr going into the mid-Holocene prairie period and then decreased gradually coming out of the prairie period between about 5500 and 2500 varve yr. These changes in the 13C:12C ratio could have been related to temperature through its effect on solubility of carbon dioxide; however, this interpretation is not supported by the oxygen isotope data. Another possibility is that changes in the 13C:12C ratio are related to organic productivity that removes 13C-depleted organic carbon and results in 13C-enriched surface waters. This interpretation implies that organic productivity was higher in Elk Lake during the mid-Holocene prairie period.
Support for the high-productivity, 13C-enriched surface-water model for the mid-Holocene prairie period in Elk Lake is provided by changes in the 13C:12C ratio of organic carbon in the deep-basin core. These changes parallel almost exactly those in the 13C:12C ratio of carbonate carbon, but are about 2% larger (about 6% as opposed to about 4% for carbonate carbon). The difference of about 2% may represent 13C depletion due to CO2 limitation. The percentage of organic carbon in the sediment did not increase during the prairie period because it was diluted by an increased flux of detrital clastic material. The ultimate burial rate of organic carbon increased considerably, however, indicating that organic productivity was higher and/or the degree of preservation increased. Diatom assemblages and plant-pigment concentrations indicate that productivity was higher during the prairie period. Pyrolysis hydrogen and oxygen indices show that the 13C-enriched organic matter that accumulated during the prairie period was hydrogen rich and oxygen poor relative to organic matter that accumulated before and after. These two indices demonstrate that the organic matter that accumulated during the prairie period was much better preserved.
","language":"English","publisher":"GSA","doi":"10.1130/SPE276-p163","usgsCitation":"Dean, W.E., and Stuiver, M., 1993, Stable carbon and oxygen isotope studies of the sediments of Elk Lake, Minnesota: GSA Special Papers, v. 276, p. 163-180, https://doi.org/10.1130/SPE276-p163.","productDescription":"18 p.","startPage":"163","endPage":"180","costCenters":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"links":[{"id":371132,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnestoa","otherGeospatial":"Elk Park, Itasca State Park","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -95.23180961608887,\n 47.17781217347543\n ],\n [\n -95.20254135131836,\n 47.17781217347543\n ],\n [\n -95.20254135131836,\n 47.20056040488173\n ],\n [\n -95.23180961608887,\n 47.20056040488173\n ],\n [\n -95.23180961608887,\n 47.17781217347543\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"276","noUsgsAuthors":false,"publicationDate":"1993-01-01","publicationStatus":"PW","contributors":{"authors":[{"text":"Dean, Walter E. dean@usgs.gov","contributorId":1801,"corporation":false,"usgs":true,"family":"Dean","given":"Walter","email":"dean@usgs.gov","middleInitial":"E.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":779277,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Stuiver, Minze","contributorId":34915,"corporation":false,"usgs":true,"family":"Stuiver","given":"Minze","email":"","affiliations":[],"preferred":false,"id":779278,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70207743,"text":"70207743 - 1993 - Modern sedimentation in Elk Lake, Clearwater County, Minnesota","interactions":[],"lastModifiedDate":"2020-01-08T16:21:09","indexId":"70207743","displayToPublicDate":"1993-01-08T16:12:19","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1727,"text":"GSA Special Papers","active":true,"publicationSubtype":{"id":10}},"title":"Modern sedimentation in Elk Lake, Clearwater County, Minnesota","docAbstract":"The varved sediments of Elk Lake, Clearwater County, Minnesota, contain a 10,000 year record of climatic and limnologic events. Sediment traps deployed in the lake’s water column from 1979 to 1981 and from 1983 to 1984 collected samples that permitted us to identify materials, to see the timing of sedimentation events, and to deduce processes that form the microlaminae within varves. Fall and spring microlaminae consist mainly of sequential accumulations of biogenic silica and resuspended calcific and siliceous materials. Precipitates of iron, manganese, and organic detritus dominate the thin winter microlaminae. Calcific microlaminae are deposited in summer. Concentrated iron and manganese precipitates form when the onset of seasonal circulation (especially in autumn) oxygenates the lower water column, but precipitation of these metals also continues throughout periods of seasonal stratification, when these dissolved elements migrate upward and are converted to particles that rain back to the bottom. Mineraloids dominate the sediment; minerals compose only a minor part and include quartz, calcite, rhodochrosite, and rockbridgeite (iron phosphate).
The bulk of the bottom accumulation occurs during the longer, calmer summer and winter periods, but important contributions are also made during spring and autumn overturn events. Sediment resuspended from the shallows accumulates together with newly formed endogenic sediment, and can even briefly dominate the seston in autumn and spring. Vigor and duration of seasonal circulations in the upper water column dictate the amount of resuspended sediment contributed annually to a varve. When abrupt warming within days after ice-out stratifies the lake, sedimentation in that year is diminished by resultant suppression of plankton blooms and lack of vernal resuspension that would normally move sediment from the littoral areas into the deep parts of Elk Lake. Thin sections of varves confirm that resuspension during autumn and spring is a varve-forming process that has probably varied in importance as a function of climate and changing morphometry due to infilling. Through an entire year, sediment traps catch a greater proportion of material from spring and autumn overturns than accumulates on the bottom. Lake morphometry is the most important factor governing sediment resuspension and associated annual accumulation rates in traps.
","language":"English","publisher":"GSA","doi":"10.1130/SPE276-p75","usgsCitation":"Nuhfer, E., Anderson, R., Bradbury, J.P., and Dean, W.E., 1993, Modern sedimentation in Elk Lake, Clearwater County, Minnesota: GSA Special Papers, v. 276, https://doi.org/10.1130/SPE276-p75.","productDescription":"22 p.","startPage":"96","costCenters":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"links":[{"id":371089,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnesota","otherGeospatial":"Elk Lake ","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -95.23017883300781,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.17967906219905\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"276","edition":"75","noUsgsAuthors":false,"publicationDate":"1993-01-01","publicationStatus":"PW","contributors":{"authors":[{"text":"Nuhfer, E.B.","contributorId":89281,"corporation":false,"usgs":true,"family":"Nuhfer","given":"E.B.","email":"","affiliations":[],"preferred":false,"id":779154,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Anderson, R.Y.","contributorId":22789,"corporation":false,"usgs":true,"family":"Anderson","given":"R.Y.","email":"","affiliations":[],"preferred":false,"id":779155,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bradbury, J. Platt","contributorId":91106,"corporation":false,"usgs":true,"family":"Bradbury","given":"J.","email":"","middleInitial":"Platt","affiliations":[],"preferred":false,"id":779156,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Dean, Walter E. dean@usgs.gov","contributorId":1801,"corporation":false,"usgs":true,"family":"Dean","given":"Walter","email":"dean@usgs.gov","middleInitial":"E.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":779157,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70207742,"text":"70207742 - 1993 - Chronology of Elk Lake sediments: Coring, sampling, and time-series construction","interactions":[],"lastModifiedDate":"2020-06-18T15:19:08.108229","indexId":"70207742","displayToPublicDate":"1993-01-08T15:58:25","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1727,"text":"GSA Special Papers","active":true,"publicationSubtype":{"id":10}},"title":"Chronology of Elk Lake sediments: Coring, sampling, and time-series construction","docAbstract":"A 22 m series of cores from a continuously laminated sequence of postglacial sediment was recovered from 29.6 m of water from the deepest part of Elk Lake, Clearwater County, Minnesota, by piston and freeze-coring methods during the winters of 1978 and 1982. A varve time series constructed and used as a basis for subsampling the cores and samples, based on the varve chronology, allows precise determination of fluxes of geochemical and biological sediment components. Chronological and petrographic studies have shown that the laminations are varves and their measurement and enumeration has produced a 10,400 year time series that estimates the rates and timing of paleolimnologic and paleoenvironmental changes in Elk Lake and its drainage. A radiocarbon date from surface sediment is 850 years. The difference between radiocarbon and varve dates continues down core; varve dates are older than radiocarbon dates, probably because of systematic incorporation of dead carbon (as bicarbonate) in organic matter in the sediment. Varve-dated boundaries of pollen zones in the Elk Lake cores compare closely with the ages of the same zones in cores from nearby lakes that have been radiocarbon dated.
","language":"English","publisher":"GSA","doi":"10.1130/SPE276-p37","usgsCitation":"Anderson, R., Bradbury, J.P., Dean, W.E., and Stuiver, M., 1993, Chronology of Elk Lake sediments: Coring, sampling, and time-series construction: GSA Special Papers, v. 276, p. 37-43, https://doi.org/10.1130/SPE276-p37.","productDescription":"7 p.","startPage":"37","endPage":"43","costCenters":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"links":[{"id":371088,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnestoa","otherGeospatial":"Elk Lake","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -95.23017883300781,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.17967906219905\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"276","noUsgsAuthors":false,"publicationDate":"1993-01-01","publicationStatus":"PW","contributors":{"authors":[{"text":"Anderson, R.Y.","contributorId":22789,"corporation":false,"usgs":true,"family":"Anderson","given":"R.Y.","email":"","affiliations":[],"preferred":false,"id":779150,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bradbury, J. Platt","contributorId":91106,"corporation":false,"usgs":true,"family":"Bradbury","given":"J.","email":"","middleInitial":"Platt","affiliations":[],"preferred":false,"id":779151,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dean, Walter E. dean@usgs.gov","contributorId":1801,"corporation":false,"usgs":true,"family":"Dean","given":"Walter","email":"dean@usgs.gov","middleInitial":"E.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":779152,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Stuiver, Minze","contributorId":34915,"corporation":false,"usgs":true,"family":"Stuiver","given":"Minze","email":"","affiliations":[],"preferred":false,"id":779153,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70207741,"text":"70207741 - 1993 - Geochemistry of surface sediments of Minnesota lakes","interactions":[],"lastModifiedDate":"2021-04-07T12:54:19.45039","indexId":"70207741","displayToPublicDate":"1993-01-08T15:50:55","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1727,"text":"GSA Special Papers","active":true,"publicationSubtype":{"id":10}},"title":"Geochemistry of surface sediments of Minnesota lakes","docAbstract":"Analyses of 36 trace, minor, and major elements were used to classify the sediments of 46 Minnesota lakes. Q-mode factor analyses grouped Minnesota lake sediments according to clastic-, carbonate-, organic-, and redox-related elements. Carbonate lakes occur in west-central Minnesota; their sediments have relatively high concentrations of CaCO3, Ba, and Sr. Lakes with sediments containing more than 30% organic matter occur in east-central and northeastern Minnesota; these sediments have high concentrations of organic C, N, and H, and slightly elevated concentrations of Pb. Only three lakes have sediments included in the “redox” group, with relatively high concentrations of Fe, Mn, Mo, La, and Zn. High concentrations of redox-sensitive elements appear to be associated with oxidized iron and manganese minerals, but in Elk Lake, one of the three lakes in this group, a significant amount of iron and manganese is contained in iron phosphate, iron sulfide, and manganese carbonate. Clastic lake sediments are not diluted by large amounts of organic matter, carbonate minerals, or iron-manganese minerals, and are of two types: a western group derived largely from Cretaceous shales in the prairie regions, and a northeastern group derived from Precambrian crystalline rocks in the forested arrowhead region. Western clastic lake sediments have higher concentrations of Al, Na, K, B, Ba, V, Mg, and Sr. Most northeastern clastic lake sediments contain higher concentrations of Cu, Y, Be, and Ni, but several are chemically more similar to those of western prairie lakes.
","language":"English","publisher":"Geological Society of America","doi":"10.1130/SPE276-p115","usgsCitation":"Dean, W.E., Gorham, E., and Swaine, D.J., 1993, Geochemistry of surface sediments of Minnesota lakes: GSA Special Papers, v. 276, p. 115-133, https://doi.org/10.1130/SPE276-p115.","productDescription":"19 p.","startPage":"115","endPage":"133","costCenters":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"links":[{"id":371086,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnesota","otherGeospatial":"Lakes of 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\"}}]}","volume":"276","noUsgsAuthors":false,"publicationDate":"1993-01-01","publicationStatus":"PW","contributors":{"authors":[{"text":"Dean, Walter E. dean@usgs.gov","contributorId":1801,"corporation":false,"usgs":true,"family":"Dean","given":"Walter","email":"dean@usgs.gov","middleInitial":"E.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":779147,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gorham, Eville","contributorId":29689,"corporation":false,"usgs":true,"family":"Gorham","given":"Eville","email":"","affiliations":[],"preferred":false,"id":779148,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Swaine, Dalway J.","contributorId":221614,"corporation":false,"usgs":false,"family":"Swaine","given":"Dalway","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":779149,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70207740,"text":"70207740 - 1993 - Holocene climatic and limnologic history of the north-central United States as recorded in the varved sediments of Elk Lake, Minnesota: A synthesis","interactions":[],"lastModifiedDate":"2020-06-18T15:18:26.480542","indexId":"70207740","displayToPublicDate":"1993-01-08T15:36:57","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1727,"text":"GSA Special Papers","active":true,"publicationSubtype":{"id":10}},"title":"Holocene climatic and limnologic history of the north-central United States as recorded in the varved sediments of Elk Lake, Minnesota: A synthesis","docAbstract":"Integration of the results and interpretations of geochemical, paleoecological, and sedimentological analyses of a varved sediment record provides a detailed chronicle of limnological and climatic changes for the past 10 ka at Elk Lake, west-central Minnesota. The early Holocene record at Elk Lake was controlled by circumstances of glacial history (e.g., basin morphometry and surrounding till lithology) in combination with global warming at the end of the Pleistocene. Later, the interplay of climate change and a disintegrating ice sheet determined the character of local environments that were affected by reduction of precipitation and increased windiness during the middle Holocene. Elk Lake became more productive and clastic sediment increased to dominate the record as the forests thinned and prairie vegetation characterized the region. During this prairie period, winters may have been cold because disintegrating northern ice sheets ceased to block winter outbreaks of Arctic air. Correlations of wind-deposited materials throughout much of the eastern two-thirds of the United States suggest that drought conditions and strong winds were widespread between 8 and 4 ka. The mid-Holocene was climatically variable, however, with strong fluctuations in varve thickness at decadal, centennial, and millennial scales testifying to rapid climatic changes. Although the cause of such climatic cycles is not yet clear, correlations between 14C anomalies and varve thickness suggest that variations in solar flux and resulting magnetic storms and zonal winds may have induced strong climatic changes. A particularly strong 600 yr fluctuation to cool and wet climates that may document neoglacial conditions around 5 ka interrupted the prairie period. After 4 ka, the climate at Elk Lake was dominated by a tropical airstream during the summer, and dry arctic and Pacific airstreams during the winter. Large-scale variations ceased, although decadal and multi-decadal variations in varve thickness chronicle changes similar, but not clearly correlative, to historically documented climatic episodes such as the Medieval Warm Period and the Little Ice Age.
","language":"English","publisher":"GSA","doi":"10.1130/SPE276-p309","usgsCitation":"Bradbury, J.P., Dean, W.E., and Anderson, R., 1993, Holocene climatic and limnologic history of the north-central United States as recorded in the varved sediments of Elk Lake, Minnesota: A synthesis: GSA Special Papers, v. 276, p. 309-328, https://doi.org/10.1130/SPE276-p309.","productDescription":"20 p.","startPage":"309","endPage":"328","costCenters":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"links":[{"id":371084,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnesota","otherGeospatial":"Elk Lake","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -95.23017883300781,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.17967906219905\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"276","noUsgsAuthors":false,"publicationDate":"1993-01-01","publicationStatus":"PW","contributors":{"authors":[{"text":"Bradbury, J. Platt","contributorId":91106,"corporation":false,"usgs":true,"family":"Bradbury","given":"J.","email":"","middleInitial":"Platt","affiliations":[],"preferred":false,"id":779141,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Dean, Walter E. dean@usgs.gov","contributorId":1801,"corporation":false,"usgs":true,"family":"Dean","given":"Walter","email":"dean@usgs.gov","middleInitial":"E.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":779142,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Anderson, R.Y.","contributorId":22789,"corporation":false,"usgs":true,"family":"Anderson","given":"R.Y.","email":"","affiliations":[],"preferred":false,"id":779143,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70207739,"text":"70207739 - 1993 - Elk Lake in perspective","interactions":[],"lastModifiedDate":"2020-01-08T15:33:01","indexId":"70207739","displayToPublicDate":"1993-01-08T15:26:41","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1727,"text":"GSA Special Papers","active":true,"publicationSubtype":{"id":10}},"title":"Elk Lake in perspective","docAbstract":"Elk Lake is located in the forested region of north-central Minnesota at the headwaters of the Mississippi River and occupies one of countless basins left behind as the last great Pleistocene ice sheet retreated northward into Canada. In this respect it resembles many other moderately deep, dimictic, hard-water lakes in the north-central United States, the sediments of which contain a history of postglacial and Holocene climatic and environmental change. Elk Lake is different, however, because the Holocene sediments in the deeper part of the lake form an uninterrupted sequence of annual laminations or varves. The varves are a chronometer for timing precisely the biologic, geochemical, and sedimentological responses in the lake to cyclic and progressive changes in climate. The varves also, through profound changes in their composition, divide the history of Elk Lake into three, sharply defined episodes; a postglacial lake, a prairie lake, and a modern, mesic-forest lake. We use these episodes and the character of the varves as a framework to guide the reader to the chapters and discussions found in this volume.
","language":"English","publisher":"GSA","doi":"10.1130/SPE276-p1","usgsCitation":"Anderson, R., Dean, W.E., and Bradbury, J.P., 1993, Elk Lake in perspective: GSA Special Papers, v. 276, p. 1-6, https://doi.org/10.1130/SPE276-p1.","productDescription":"6 p.","startPage":"1","endPage":"6","costCenters":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"links":[{"id":371083,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnesota","otherGeospatial":"Elk Lake, Itasca State Park","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -95.23017883300781,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.17967906219905\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"276","noUsgsAuthors":false,"publicationDate":"1993-01-01","publicationStatus":"PW","contributors":{"authors":[{"text":"Anderson, R.Y.","contributorId":22789,"corporation":false,"usgs":true,"family":"Anderson","given":"R.Y.","email":"","affiliations":[],"preferred":false,"id":779138,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Dean, Walter E. dean@usgs.gov","contributorId":1801,"corporation":false,"usgs":true,"family":"Dean","given":"Walter","email":"dean@usgs.gov","middleInitial":"E.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":779139,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bradbury, J. Platt","contributorId":91106,"corporation":false,"usgs":true,"family":"Bradbury","given":"J.","email":"","middleInitial":"Platt","affiliations":[],"preferred":false,"id":779140,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70207738,"text":"70207738 - 1993 - Climatic and limnologic setting of Elk Lake","interactions":[],"lastModifiedDate":"2020-01-08T15:23:19","indexId":"70207738","displayToPublicDate":"1993-01-08T15:18:26","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1727,"text":"GSA Special Papers","active":true,"publicationSubtype":{"id":10}},"title":"Climatic and limnologic setting of Elk Lake","docAbstract":"Elk Lake is located on the Itasca moraine near the source of the Mississippi River in northwestern Minnesota. The basin is in calcareous glacial drift, and the lake water is a dilute solution of calcium and magnesium bicarbonate. Low-magnesian calcite formed by precipitation from the lake water has been a major component of the sediment throughout the lake’s history. The sediment also is laminated with alternating light and dark, millimeter-thick layers containing diatoms, organic matter, Fe(OH)3, and CaCO3.
The sediment microstratigraphy has been preserved because the lake is unusually deep (maximum depth is 30 m) for its size (surface area is 1.01 km2). Oxygen is present in low concentrations or absent in the deepest water during summer and winter. Water movements in the deepest part of the lake are insufficient some years for the complete aeration of the deepst water during spring and autumn circulation periods.
Phytoplankton photosynthesis, which occurs mostly in the surficial 6 m of water, typically removes 0.5 g C m−2 day−1 from the epilimnion, which becomes strongly oversaturated with calcite during late spring and summer as the pH increases above the equilibrium pH (7.73) for calcite saturation. Most of the CaCO3 that makes up the light-colored layers of sediments probably is formed during the late summer, when concentrations of calcium in the epilimnion decrease most rapidly. The silica and organic matter that form the darker sediment laminae are deposited earlier in the year, during a period extending from April to late June, when silica decreases fastest in the epilimnion.
","language":"English","publisher":"GSA","doi":"10.1130/SPE276-p19","usgsCitation":"Megard, R., Bradbury, J.P., and Dean, W.E., 1993, Climatic and limnologic setting of Elk Lake: GSA Special Papers, v. 276, p. 19-36, https://doi.org/10.1130/SPE276-p19.","productDescription":"18 p.","startPage":"19","endPage":"36","costCenters":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"links":[{"id":371082,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnesota","otherGeospatial":"Elk Lake, Itsaca Park","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -95.23017883300781,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.17967906219905\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"276","noUsgsAuthors":false,"publicationDate":"1993-01-01","publicationStatus":"PW","contributors":{"authors":[{"text":"Megard, R.O.","contributorId":221612,"corporation":false,"usgs":false,"family":"Megard","given":"R.O.","email":"","affiliations":[],"preferred":false,"id":779135,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bradbury, J. Platt","contributorId":91106,"corporation":false,"usgs":true,"family":"Bradbury","given":"J.","email":"","middleInitial":"Platt","affiliations":[],"preferred":false,"id":779136,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dean, Walter E. dean@usgs.gov","contributorId":1801,"corporation":false,"usgs":true,"family":"Dean","given":"Walter","email":"dean@usgs.gov","middleInitial":"E.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":779137,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70207737,"text":"70207737 - 1993 - Environment of deposition of CaCO3 in Elk Lake, Minnesota","interactions":[],"lastModifiedDate":"2020-06-18T15:13:04.885935","indexId":"70207737","displayToPublicDate":"1993-01-08T15:06:35","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1727,"text":"GSA Special Papers","active":true,"publicationSubtype":{"id":10}},"displayTitle":"Environment of deposition of CaCO3 in Elk Lake, Minnesota","title":"Environment of deposition of CaCO3 in Elk Lake, Minnesota","docAbstract":"Elk Lake is near the present forest-prairie border in northwestern Minnesota, and is also located on the boundary between hard-water lakes that are typical of once-glaciated parts of the north-central United States and more saline prairie lakes of western Minnesota and the Dakotas. The sediments of the prairie lakes just west of Elk Lake are unusual in that they commonly contain high-Mg calcite and dolomite in addition to low-Mg calcite, which is the dominant carbonate mineral in most marl lakes. During the mid-Holocene dry period, prairie conditions expanded eastward into the forested regions of Minnesota. Variations in types and abundances of carbonate minerals in the Holocene sediments of Elk Lake recorded this climatic change.
Studies of primary productivity, carbonate saturation, water chemistry, and sediment-trap samples show that low-Mg calcite precipitates during the summer, triggered by algal photosynthesis. The epilimnion of Elk Lake is always oversaturated with calcite, and the degree of oversaturation increases progressively during the summer. The pH of the epilimnion increases from <8.0 after spring overturn to almost 9.0 in late summer in response to photosynthetic removal of CO2 during the summer months. The rate of calcium depletion from the epilimnion is proportional to the increase in pH and the rate of photosynthetic carbon fixation.
Today the only carbonate minerals that are accumulating in the sediments of Elk Lake are low-Mg calcite and manganese carbonate (rhodochrosite). Rhodochrosite, and probably manganese oxyhydroxide, precipitates when manganese-rich anoxic bottom waters come in contact with carbonate-rich oxic surface waters. During the arid mid-Holocene prairie period, however, low-Mg calcite, dolomite, aragonite, and rhodochrosite all accumulated in the sediments of Elk Lake. Dolomite formed in Elk Lake during this period in response to a higher Mg:Ca ratio in the water, just as it is forming today in lakes of the prairie regions of western Minnesota. The coincident occurrence of aragonite and biological indicators of high salinity suggests that the salinity of Elk Lake and the Mg:Ca ratio were higher than in any of the present prairie lakes of western Minnesota.
","language":"English","publisher":"GSA","doi":"10.1130/SPE276-p97","usgsCitation":"Dean, W.E., and Megard, R., 1993, Environment of deposition of CaCO3 in Elk Lake, Minnesota: GSA Special Papers, v. 276, p. 97-113, https://doi.org/10.1130/SPE276-p97.","productDescription":"17 p.","startPage":"97","endPage":"113","costCenters":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"links":[{"id":371081,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnesota","otherGeospatial":"Elk Lake, Itasca Park","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -95.23017883300781,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.17967906219905\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"276","noUsgsAuthors":false,"publicationDate":"1993-01-01","publicationStatus":"PW","contributors":{"authors":[{"text":"Dean, Walter E. dean@usgs.gov","contributorId":1801,"corporation":false,"usgs":true,"family":"Dean","given":"Walter","email":"dean@usgs.gov","middleInitial":"E.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":779133,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Megard, R.O.","contributorId":221612,"corporation":false,"usgs":false,"family":"Megard","given":"R.O.","email":"","affiliations":[],"preferred":false,"id":779134,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70207736,"text":"70207736 - 1993 - Physical properties, mineralogy, and geochemistry of Holocene varved sediments from Elk Lake, Minnesota","interactions":[],"lastModifiedDate":"2020-06-18T15:11:25.592156","indexId":"70207736","displayToPublicDate":"1993-01-08T14:12:32","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1727,"text":"GSA Special Papers","active":true,"publicationSubtype":{"id":10}},"title":"Physical properties, mineralogy, and geochemistry of Holocene varved sediments from Elk Lake, Minnesota","docAbstract":"Elk Lake in northwestern Minnesota is situated close to a climatically sensitive ecotone, the forest-prairie border, that migrated back and forth over the drainage basin of the lake during the Holocene. The entire postglacial (Holocene) sediment record in the deepest part of Elk Lake is composed of annual layers (varves) that record the seasonal pulses of many sediment components, and, most important, provide high-resolution (seasonal) time calibration of rates and timing of environmental change. These varved sediments contain many allochthonous and autochthonous components that are sensitive to changing environmental conditions in the drainage basin and the lake.
The mineral components of Elk Lake sediments consist mainly of authigenic calcium, magnesium, and manganese carbonate minerals (low-Mg calcite, high-Mg calcite, dolomite, and rhodochrosite), opaline silica (from diatoms), X-ray amorphous iron and manganese oxyhydroxides, and an iron phosphate mineral tentatively identified as rock-bridgeite [(Fe, Mn)Fe4(PO4)3(OH)5], plus minor contributions from fine-grained detrital quartz, feldspar, illite, and kaolinite. The most notable characteristic of the sediments in Elk Lake is that most of the components were formed in the lake.
Q-mode factor analysis of sediment geochemistry reduced 23 observed compositional variables, expressed as percent or parts per million of elements, to three composite variables (factor loadings) whose “concentrations” are expressed on a scale of −1.0 to 1.0. Factor 1 expresses the composition of the inorganic clastic fraction based on concentrations of Mg, Na, Al, Cr, V, Y, Sc, Ni, Sr, Co, and Cu. Factor 2 expresses the similarities in variations of Fe, Mn, P, organic carbon, and Mo. Factor 3 loadings are a synthesis of concentrations of Mn, S, Ca, La, and Ba.
Geochemical characteristics define three distinct chemical stages in the development of Elk lake: (1) a carbonate-, manganese-, iron-, sulfur-rich early-lake stage that lasted from 10,400 to 8200 varve yr; (2) a clastic- and diatom-rich mid-Holocene prairie-lake stage that lasted from 8200 to 4000 varve yr; and (3) a final iron-, manganese-, phosphate-, and organic-rich modern-lake stage that developed over the past 4000 yr. The chemical characteristics of the sediments deposited during these three lake phases can be represented by the average compositions of three groups of samples: (1) the average composition of sediments deposited over the past 2000 yr, representing the modern-lake stage; (2) the composition of a 50 varve sample centered on 5700 varve yr that represents the maximum clastic influx into the lake during the prairie period; and (3) the average composition of sediments deposited over the initial 2000 yr of the lake’s existence (10,400 to 8400 varve yr).
The amplitudes of climatic oscillations, as reflected by changes in concentration of many climatically sensitive elements, were greatest during the prairie period, pronounced cycles having periodicities of several hundred years. The extremes of these oscillations occurred within several centuries or less, which suggests that significant changes in climate may occur abruptly and rapidly. Most notably, the end of the mid-Holocene prairie period, marked by a sudden decrease in the influx of detrital clastic material, occurred within a few decades.
","language":"English","publisher":"GSA","doi":"10.1130/SPE276-p135","usgsCitation":"Dean, W.E., 1993, Physical properties, mineralogy, and geochemistry of Holocene varved sediments from Elk Lake, Minnesota: GSA Special Papers, v. 276, p. 135-157, https://doi.org/10.1130/SPE276-p135.","productDescription":"23 p.","startPage":"135","endPage":"157","costCenters":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"links":[{"id":371080,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Minnesota","otherGeospatial":"Elk Lake, Itasca Park","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -95.23017883300781,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.17967906219905\n ],\n [\n -95.20442962646483,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.1981110637904\n ],\n [\n -95.23017883300781,\n 47.17967906219905\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"276","noUsgsAuthors":false,"publicationDate":"1993-01-01","publicationStatus":"PW","contributors":{"authors":[{"text":"Dean, Walter E. dean@usgs.gov","contributorId":1801,"corporation":false,"usgs":true,"family":"Dean","given":"Walter","email":"dean@usgs.gov","middleInitial":"E.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":779132,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70018276,"text":"70018276 - 1993 - A 100-year average recurrence interval for the San Andreas fault at Wrightwood, California","interactions":[],"lastModifiedDate":"2025-09-16T15:33:33.579382","indexId":"70018276","displayToPublicDate":"1993-01-08T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3338,"text":"Science","active":true,"publicationSubtype":{"id":10}},"title":"A 100-year average recurrence interval for the San Andreas fault at Wrightwood, California","docAbstract":"Evidence for five large earthquakes during the past five centuries along the San Andreas fault zone 70 kilometers northeast of Los Angeles, California, indicates that the average recurrence interval and the temporal variability are significantly smaller than previously thought. Rapid sedimentation during the past 5000 years in a 150-meter-wide structural depression has produced a greater than 21-meter-thick sequence of debris flow and stream deposits interbedded with more than 50 datable peat layers. Fault scarps, colluvial wedges, fissure infills, upward termination of ruptures, and tilted and folded deposits above listric faults provide evidence for large earthquakes that occurred in A.D. 1857, 1812, and about 1700, 1610, and 1470.","language":"English","publisher":"American Association for the Advancement of Science","doi":"10.1126/science.259.5092.199","issn":"00368075","usgsCitation":"Fumal, T.E., Schwartz, D.P., Pezzopane, S., and Weldon, R., 1993, A 100-year average recurrence interval for the San Andreas fault at Wrightwood, California: Science, v. 259, no. 5092, p. 199-203, https://doi.org/10.1126/science.259.5092.199.","productDescription":"5 p.","startPage":"199","endPage":"203","costCenters":[],"links":[{"id":227061,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","city":"Wrightwood","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -117.67633526536574,\n 34.402130922928194\n ],\n [\n -117.67633526536574,\n 34.325968244614614\n ],\n [\n -117.589598078331,\n 34.325968244614614\n ],\n [\n -117.589598078331,\n 34.402130922928194\n ],\n [\n -117.67633526536574,\n 34.402130922928194\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"259","issue":"5092","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e277e4b0c8380cd45be8","contributors":{"authors":[{"text":"Fumal, T. E.","contributorId":25942,"corporation":false,"usgs":true,"family":"Fumal","given":"T.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":379083,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Schwartz, David P. 0000-0001-5193-9200","orcid":"https://orcid.org/0000-0001-5193-9200","contributorId":52968,"corporation":false,"usgs":true,"family":"Schwartz","given":"David","middleInitial":"P.","affiliations":[],"preferred":false,"id":379085,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Pezzopane, S.K.","contributorId":21575,"corporation":false,"usgs":true,"family":"Pezzopane","given":"S.K.","affiliations":[],"preferred":false,"id":379082,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Weldon, R.J. II","contributorId":37088,"corporation":false,"usgs":true,"family":"Weldon","given":"R.J.","suffix":"II","email":"","affiliations":[],"preferred":false,"id":379084,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70199816,"text":"70199816 - 1993 - Hydrologic budget and nitrogen distribution for an agricultural study plot in claypan soil and glacial till near Centralia, Mo.--May 1991 to May 1992","interactions":[],"lastModifiedDate":"2018-10-01T09:23:50","indexId":"70199816","displayToPublicDate":"1993-01-04T09:22:05","publicationYear":"1993","noYear":false,"publicationType":{"id":5,"text":"Book chapter"},"publicationSubtype":{"id":24,"text":"Book Chapter"},"title":"Hydrologic budget and nitrogen distribution for an agricultural study plot in claypan soil and glacial till near Centralia, Mo.--May 1991 to May 1992","docAbstract":"No abstract available.
","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Proceedings from the 3rd annual Missouri water quality conference","largerWorkSubtype":{"id":12,"text":"Conference publication"},"conferenceTitle":"3rd Annual Missouri Water Quality Conference","conferenceDate":"February 4, 1993","conferenceLocation":"Columbia, Missouri ","language":"English","publisher":"University of Missouri","publisherLocation":"Columbia, Missouri","usgsCitation":"Kelly, B.P., and Plummer, L., 1993, Hydrologic budget and nitrogen distribution for an agricultural study plot in claypan soil and glacial till near Centralia, Mo.--May 1991 to May 1992, chap. of Proceedings from the 3rd annual Missouri water quality conference, p. 100-105.","productDescription":"6 p.","startPage":"100","endPage":"105","costCenters":[{"id":396,"text":"Missouri Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":357925,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Missouri","city":"Centralia","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5c111a37e4b034bf6a81962b","contributors":{"authors":[{"text":"Kelly, Brian P. 0000-0001-6378-2837 bkelly@usgs.gov","orcid":"https://orcid.org/0000-0001-6378-2837","contributorId":897,"corporation":false,"usgs":true,"family":"Kelly","given":"Brian","email":"bkelly@usgs.gov","middleInitial":"P.","affiliations":[{"id":353,"text":"Kansas Water Science Center","active":false,"usgs":true},{"id":396,"text":"Missouri Water Science Center","active":true,"usgs":true}],"preferred":true,"id":746773,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Plummer, L.N.","contributorId":206803,"corporation":false,"usgs":false,"family":"Plummer","given":"L.N.","email":"","affiliations":[],"preferred":false,"id":746774,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70207646,"text":"70207646 - 1993 - 40Ar/39Ar thermochronology and Alleghanian development of the southernmost Appalachian Piedmont, Alabama and southwest Georgia","interactions":[],"lastModifiedDate":"2020-06-05T15:13:50.128245","indexId":"70207646","displayToPublicDate":"1993-01-02T11:21:16","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1723,"text":"GSA Bulletin","active":true,"publicationSubtype":{"id":10}},"displayTitle":"40Ar/39Ar thermochronology and Alleghanian development of the southernmost Appalachian Piedmont, Alabama and southwest Georgia","title":"40Ar/39Ar thermochronology and Alleghanian development of the southernmost Appalachian Piedmont, Alabama and southwest Georgia","docAbstract":"40Ar/39Ar age spectra of hornblende, muscovite, and microcline, and total fusion ages of biotite from metamorphic rocks of the Inner Piedmont, Pine Mountain, and Uchee belts are reported. Mineral cooling ages from the eastern part of the Inner Piedmont are as follows: hornblende, 320 Ma; muscovite, 296 Ma; biotite, 293 Ma; and microcline (diffusional release patterns) Tmax = 267 Ma, Tmin = 234 Ma. A 347 Ma hornblende spectrum from the highest Inner Piedmont structural level sampled is the oldest date determined and implies earlier passage of this level through the 500 °C isotherm. Most release spectra from Pine Mountain belt units are discordant with little or no apparent geologic meaning. Modified saddle-shaped release patterns for hornblende indicate extraneous argon with a maximum age of ∼358 Ma. Muscovite from the Pine Mountain belt cover sequence is 286 Ma (plateau age), and one from the underlying Grenville basement is 277 Ma (correlation age), indicating cooling below the 350 °C isotherm. Plateau ages on Uchee belt rocks are as follows: hornblende, from 297 to 288 Ma; muscovite, 285 Ma; biotite, 276 Ma; and microcline Tmax = 261 Ma, Tmin 230 Ma. Muscovite fish from a Bartletts Ferry fault zone phyllonite have a plateau age of 283 Ma.
The 40Ar/39Ar results combined with other geologic data indicate that (1) a large part of the southern and Inner Piedmonts of Alabama and southwest Georgia experienced a late Paleozoic amphibolite-facies thermal and deformational event contemporaneous with the Alleghanian orogeny observed in the foreland; (2) the tectonic development of this event, characterized by initial crustal thickening followed by right-slip and normal-slip movements, is grossly similar to that described for the amphibolite-facies Alleghanian belt in the eastern Piedmont of South Carolina and Georgia; and (3) extensional movements along the flanks of the Pine Mountain window occurred between ca. 277 Ma and the Late Triassic-Early Jurassic and thus may reflect latest Alleghanian extensional collapse or Mesozoic rifting.
","language":"English","publisher":"GSA","doi":"10.1130/0016-7606(1993)105<0819:AATAAD>2.3.CO;2","usgsCitation":"Steltenpohl, M.G., and Kunk, M.J., 1993, 40Ar/39Ar thermochronology and Alleghanian development of the southernmost Appalachian Piedmont, Alabama and southwest Georgia: GSA Bulletin, v. 105, no. 6, p. 819-833, https://doi.org/10.1130/0016-7606(1993)105<0819:AATAAD>2.3.CO;2.","productDescription":"15 p.","startPage":"819","endPage":"833","costCenters":[{"id":243,"text":"Eastern Geology and Paleoclimate Science Center","active":true,"usgs":true}],"links":[{"id":370931,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alabama, Georgia","otherGeospatial":"Southernmost Appalachian Piedmont","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -86.572265625,\n 35.02999636902566\n ],\n [\n -86.66015624999999,\n 32.24997445586331\n ],\n [\n -82.265625,\n 32.76880048488168\n ],\n [\n -79.62890625,\n 35.38904996691167\n ],\n [\n -80.771484375,\n 36.38591277287651\n ],\n [\n -86.572265625,\n 35.02999636902566\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"105","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"authors":[{"text":"Steltenpohl, Mark G.","contributorId":178199,"corporation":false,"usgs":false,"family":"Steltenpohl","given":"Mark","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":778738,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kunk, Michael J. 0000-0003-4424-7825 mkunk@usgs.gov","orcid":"https://orcid.org/0000-0003-4424-7825","contributorId":200968,"corporation":false,"usgs":true,"family":"Kunk","given":"Michael","email":"mkunk@usgs.gov","middleInitial":"J.","affiliations":[{"id":243,"text":"Eastern Geology and Paleoclimate Science Center","active":true,"usgs":true},{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true}],"preferred":true,"id":778739,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70207645,"text":"70207645 - 1993 - Exhumation of eclogitized continental basement during Variscan lithospheric delamination and gravitational collapse, Sudety Mountains, Poland","interactions":[],"lastModifiedDate":"2020-06-05T15:14:43.524372","indexId":"70207645","displayToPublicDate":"1993-01-02T11:00:28","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1796,"text":"Geology","active":true,"publicationSubtype":{"id":10}},"title":"Exhumation of eclogitized continental basement during Variscan lithospheric delamination and gravitational collapse, Sudety Mountains, Poland","docAbstract":"A Variscan,deep-crustal-level (eclogite-facies),continental basement massif in western Poland, the Snieznik complex, was tectonically exhumed. Crustal-penetrating mylonite zones record three main kinematic events: early top-to-the-north-directed thrusting, right-slip transpression-tension, and late top-to-the-south and -east normal faulting. Thrusting resulted in extreme crustal thickening and associated eclogite-facies metamorphism. Right-slip movements produced retrogressive crystal-plastic simple-shear zones. Normal faults flank Carboniferous to Early Permian terrigenous sedimentary basins, documenting tectonic and erosional denudation of the Snieznik complex during lithospheric extension. Sm/Nd isotopic dates previously reported for the in situ eclogite-facies metamorphic mineral assemblages are 341, 337, and 329 Ma (Brueckner et al., 1991). 40Ar/39Ar isotopic dates for metamorphic hornblende (338, 333, and 332 Ma), muscovite (329 and 329 Ma), and biotite (328 Ma) reflect times of cooling through the ∼500, 350, and 300 °C isotherms, respectively. These nearly concordant mineral dates document rapid cooling from ∼850 °C (eclogue-facies temperatures) to ∼300 °C. Rapid denudation of these deep-crustal rocks (∼19-22 kbar pressures, >70 km depth) is attributed to processes, similar to those of metamorphic-core complexes, that operated during lithospheric delamination and gravitational collapse. The sequence of late Paleozoic (Alleghanian) crustal thickening followed by right-slip transpression-tension followed by normal faulting recognized in the U.S. Appalachians implies that this tectonic pattern may exist throughout the Afleghanian-Variscan belt.
","language":"English","publisher":"GSA","doi":"10.1130/0091-7613(1993)021<1111:EOECBD>2.3.CO;2","usgsCitation":"Steltenpohl, M.G., Cymerman, Z., Krogh, E., and Kunk, M.J., 1993, Exhumation of eclogitized continental basement during Variscan lithospheric delamination and gravitational collapse, Sudety Mountains, Poland: Geology, v. 21, no. 12, p. 1111-1114, https://doi.org/10.1130/0091-7613(1993)021<1111:EOECBD>2.3.CO;2.","productDescription":"4 p.","startPage":"1111","endPage":"1114","costCenters":[{"id":243,"text":"Eastern Geology and Paleoclimate Science Center","active":true,"usgs":true},{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true}],"links":[{"id":370930,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"Poland","otherGeospatial":"Sudety Mountains","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n 15.051269531249998,\n 51.536085601784755\n ],\n [\n 14.78759765625,\n 50.764259357116465\n ],\n [\n 16.875,\n 49.937079756975294\n ],\n [\n 17.6220703125,\n 49.85215166776998\n ],\n [\n 17.86376953125,\n 50.52739681329302\n ],\n [\n 15.051269531249998,\n 51.536085601784755\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"21","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"authors":[{"text":"Steltenpohl, Mark G.","contributorId":178199,"corporation":false,"usgs":false,"family":"Steltenpohl","given":"Mark","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":778734,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Cymerman, Zbignew","contributorId":221569,"corporation":false,"usgs":false,"family":"Cymerman","given":"Zbignew","email":"","affiliations":[],"preferred":false,"id":778735,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Krogh, E.J.","contributorId":221570,"corporation":false,"usgs":false,"family":"Krogh","given":"E.J.","email":"","affiliations":[],"preferred":false,"id":778736,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kunk, Michael J. 0000-0003-4424-7825 mkunk@usgs.gov","orcid":"https://orcid.org/0000-0003-4424-7825","contributorId":200968,"corporation":false,"usgs":true,"family":"Kunk","given":"Michael","email":"mkunk@usgs.gov","middleInitial":"J.","affiliations":[{"id":243,"text":"Eastern Geology and Paleoclimate Science Center","active":true,"usgs":true},{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true}],"preferred":true,"id":778737,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70243610,"text":"70243610 - 1993 - Denitrification measurements in aquatic sediments: A comparison of three methods","interactions":[],"lastModifiedDate":"2023-05-15T00:52:34.183917","indexId":"70243610","displayToPublicDate":"1993-01-01T19:47:20","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1007,"text":"Biogeochemistry","active":true,"publicationSubtype":{"id":10}},"title":"Denitrification measurements in aquatic sediments: A comparison of three methods","docAbstract":"Measurements of denitrification using the acetylene inhibition,15N isotope tracer, and N2 flux methods were carried out concurrently using sediment cores from Vilhelmsborg sø, Denmark, in an attempt to clarify some of the limitations of each technique. Three experimental treatments of overlying water were used: control, nitrate enriched, and ammonia enriched water. The N2 flux and15N tracer experiments showed high rates of coupled nitrification/denitrification in the sediments. The acetylene inhibition method did not capture any coupled nitrification/denitrification. This could be explained by acetylene inhibition of nitrification. A combined15N tracer/acetylene inhibition experiment demonstrated that acetylene inhibition of N2O reduction was incomplete and the method, therefore, only measured approximately 50% of the denitrification due to nitrate from the overlying water. Similar rates of denitrification due to nitrate in the overlying water were measured by the N2 flux method and the acetylene inhibition method, after correcting for the 50% efficiency of acetylene inhibition. Rates of denitrification due to nitrate from the overlying water measured by the15N tracer method, however, were only approximately 35% or less of those measured by the acetylene inhibition or N2 flux methods.
","language":"English","publisher":"Springer","doi":"10.1007/BF00023750","usgsCitation":"Seitzinger, S.P., Nielsen, L.P., Caffrey, J., and Christensen, P.B., 1993, Denitrification measurements in aquatic sediments: A comparison of three methods: Biogeochemistry, v. 23, p. 147-167, https://doi.org/10.1007/BF00023750.","productDescription":"21 p.","startPage":"147","endPage":"167","costCenters":[],"links":[{"id":417019,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"23","noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"authors":[{"text":"Seitzinger, Sybil P.","contributorId":198506,"corporation":false,"usgs":false,"family":"Seitzinger","given":"Sybil","email":"","middleInitial":"P.","affiliations":[{"id":35252,"text":"Rutgers University, NJ","active":true,"usgs":false}],"preferred":false,"id":872607,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nielsen, Lars Peter","contributorId":189833,"corporation":false,"usgs":false,"family":"Nielsen","given":"Lars","email":"","middleInitial":"Peter","affiliations":[],"preferred":false,"id":872608,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Caffrey, Jane","contributorId":305391,"corporation":false,"usgs":false,"family":"Caffrey","given":"Jane","email":"","affiliations":[],"preferred":false,"id":872609,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Christensen, Peter Bondo","contributorId":305392,"corporation":false,"usgs":false,"family":"Christensen","given":"Peter","email":"","middleInitial":"Bondo","affiliations":[],"preferred":false,"id":872610,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":25172,"text":"25172 - 1993 - Conterminous U.S. land cover characteristics data set 1990 prototype","interactions":[],"lastModifiedDate":"2014-07-14T16:34:30","indexId":"25172","displayToPublicDate":"1993-01-01T16:33:53","publicationYear":"1993","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":6,"text":"USGS Unnumbered Series"},"title":"Conterminous U.S. land cover characteristics data set 1990 prototype","docAbstract":"No abstract available.","language":"English","publisher":"EROS Data Center, U.S. Geological Survey","publisherLocation":"Sioux Falls, SD","doi":"10.3133/25172","usgsCitation":"Water Resources Division, U.S. Geological Survey, 1993, Conterminous U.S. land cover characteristics data set 1990 prototype, 1 computer laser optical disk, https://doi.org/10.3133/25172.","productDescription":"1 computer laser optical disk","costCenters":[],"links":[{"id":290009,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"53c4fc07e4b0b58d96eeb575","contributors":{"authors":[{"text":"Water Resources Division, U.S. Geological Survey","contributorId":128075,"corporation":true,"usgs":false,"organization":"Water Resources Division, U.S. Geological Survey","id":529192,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70210878,"text":"70210878 - 1993 - Geologic map of Arkansas","interactions":[],"lastModifiedDate":"2020-07-06T15:25:57.372524","indexId":"70210878","displayToPublicDate":"1993-01-01T15:28:38","publicationYear":"1993","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":6,"text":"USGS Unnumbered Series"},"title":"Geologic map of Arkansas","docAbstract":"No abstract available.
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\"}}]}","noUsgsAuthors":false,"publicationStatus":"PW","contributors":{"authors":[{"text":"Haley, Boyd R.","contributorId":82274,"corporation":false,"usgs":true,"family":"Haley","given":"Boyd R.","affiliations":[],"preferred":false,"id":791918,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":33248,"text":"b2061 - 1993 - Geologic studies of the Ute Mountain Ute Indian Reservation","interactions":[{"subject":{"id":47575,"text":"b2061A - 1993 - Distribution and properties of clinoptilolite-bearing tuffs in the Upper Jurassic Morrison Formation on the Ute Mountain Ute Reservation, southwestern Colorado and northwestern New Mexico","indexId":"b2061A","publicationYear":"1993","noYear":false,"chapter":"A","title":"Distribution and properties of clinoptilolite-bearing tuffs in the Upper Jurassic Morrison Formation on the Ute Mountain Ute Reservation, southwestern Colorado and northwestern New Mexico"},"predicate":"IS_PART_OF","object":{"id":33248,"text":"b2061 - 1993 - Geologic studies of the Ute Mountain Ute Indian Reservation","indexId":"b2061","publicationYear":"1993","noYear":false,"title":"Geologic studies of the Ute Mountain Ute Indian Reservation"},"id":1},{"subject":{"id":47586,"text":"b2061B - 1994 - Heavy-mineral placer deposits of the Ute Mountain Ute Indian Reservation, southwestern Colorado and northwestern New Mexico","indexId":"b2061B","publicationYear":"1994","noYear":false,"chapter":"B","title":"Heavy-mineral placer deposits of the Ute Mountain Ute Indian Reservation, southwestern Colorado and northwestern New Mexico"},"predicate":"IS_PART_OF","object":{"id":33248,"text":"b2061 - 1993 - Geologic studies of the Ute Mountain Ute Indian Reservation","indexId":"b2061","publicationYear":"1993","noYear":false,"title":"Geologic studies of the Ute Mountain Ute Indian Reservation"},"id":2}],"lastModifiedDate":"2014-06-30T15:24:28","indexId":"b2061","displayToPublicDate":"1993-01-01T15:20:00","publicationYear":"1993","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":306,"text":"Bulletin","code":"B","active":false,"publicationSubtype":{"id":5}},"seriesNumber":"2061","title":"Geologic studies of the Ute Mountain Ute Indian Reservation","docAbstract":"No abstract available.","language":"English","publisher":"U.S. Government Printing Office","doi":"10.3133/b2061","usgsCitation":"Ute Mountain Ute Tribe, 1993, Geologic studies of the Ute Mountain Ute Indian Reservation: U.S. Geological Survey Bulletin 2061, https://doi.org/10.3133/b2061.","costCenters":[],"links":[{"id":289257,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"}],"country":"United States","state":"Colorado;New Mexico","otherGeospatial":"Ute Mountain;Ute Indian Reservation","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -108.9287,36.7901 ], [ -108.9287,37.2852 ], [ -106.9657,37.2852 ], [ -106.9657,36.7901 ], [ -108.9287,36.7901 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"53b286ede4b07b8813a554ad","contributors":{"authors":[{"text":"Ute Mountain Ute Tribe","contributorId":127908,"corporation":true,"usgs":false,"organization":"Ute Mountain Ute Tribe","id":529467,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70039262,"text":"70039262 - 1993 - Permafrost","interactions":[],"lastModifiedDate":"2012-08-04T01:01:57","indexId":"70039262","displayToPublicDate":"1993-01-01T15:04:00","publicationYear":"1993","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":6,"text":"USGS Unnumbered Series"},"seriesTitle":{"id":362,"text":"General Information Product","active":false,"publicationSubtype":{"id":6}},"title":"Permafrost","docAbstract":"In 1577, on his second voyage to the New World in search of the Northwest Passage, Sir Martin Frobisher reported finding ground in the far north that was frozen to depths of \"four or five fathoms, even in summer,\" and that the frozen condition \"so combineth the stones together that scarcely instruments with great force can unknit them.\" This permanently frozen ground, now termed permafrost, underlies perhaps a fifth of the Earth's land surface. It occurs in Antarctica but is most extensive in the Northern Hemisphere. In the lands surrounding the Arctic Ocean, its maximum thickness has been reported in thousands of feet as much as 5,000 feet in Siberia and 2,000 feet in northern Alaska.","language":"English","publisher":"U.S. Government Printing Office","publisherLocation":"Washington, D.C.","doi":"10.3133/70039262","usgsCitation":"Ray, L.L., 1993, Permafrost: General Information Product, 15 p., https://doi.org/10.3133/70039262.","productDescription":"15 p.","numberOfPages":"8","costCenters":[],"links":[{"id":261504,"rank":800,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/gip/70039262/report.pdf"},{"id":261505,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/gip/70039262/report-thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a76a0e4b0c8380cd78214","contributors":{"authors":[{"text":"Ray, Louis L.","contributorId":48527,"corporation":false,"usgs":true,"family":"Ray","given":"Louis","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":465883,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70094776,"text":"70094776 - 1993 - Preliminary results of a helicopter electromagnetic and magnetic survey of the Oak Ridge Reservation, Tennessee for environmental and geologic site characterization","interactions":[],"lastModifiedDate":"2017-11-08T13:34:28","indexId":"70094776","displayToPublicDate":"1993-01-01T14:49:00","publicationYear":"1993","noYear":false,"publicationType":{"id":4,"text":"Book"},"publicationSubtype":{"id":12,"text":"Conference publication"},"title":"Preliminary results of a helicopter electromagnetic and magnetic survey of the Oak Ridge Reservation, Tennessee for environmental and geologic site characterization","docAbstract":"The 35,252 -acre Oak Ridge Reservation (ORR), in the western portion of the\nAppalachian Valley and Ridge province in Tennessee, has been a nuclear production and\ndevelopment facility for 50 years. Contaminants in the many waste sites on the ORR\ninclude heavy radioactive isotopes as well as many organic and inorganic compounds.\nThe locations, geometry, and contents of many of these waste sites are reasonably well\nknown, while others are poorly known, and some may be unknown. To better\ncharacterize the known sites and locate and characterize additional environmentally\nhazardous sites, a two-phase aerial survey of the ORR was begun in April, 1992. Phase\nI, which began in April, 1992, consisted of aerial radiation, multispectral scanner, and\nphotographic surveys. Phase II, which began in November, 1992 and is described in this\npresentation, consisted of a helicopter electromagnetic (HEM), magnetic, and radiation\nsurvey. Targets of the survey were both man-made (drums, trench boundaries, burn pits,\nwell heads) and geologic (fractures, faults, karst features, geologic contacts).\nThe Phase II survey has three components: testing, reconnaissance, and high-resolution\ndata acquisition. To date, the testing and reconnaissance data acquisition have been\ncompleted, and part of the data have been processed. They indicate that: 1) magnetic\nand HEM data are complementary, and do not always highlight the same anomaly; 2)\nunder favorable circumstances, helicopter magnetometer systems are capable of detecting\ngroups of 4 or more 55-gallon drums at detector altitudes of 15 m or less, 3) HEM data\nprovide data which compare favorably with surface data collected over burial trenches, 4)\nwell casings seem to be related to magnetic monopole anomalies, as would be expected,\n5) Changes in EM and magnetic anomaly character are related to lithologic changes and\nmight be used to track contacts between known outcrops.","largerWorkTitle":"Proceedings of the Symposium on the Application of geophysics to engineering and environmental problems: SAGEEP '93","conferenceTitle":"Symposium on the Application of geophysics to engineering and environmental problems: SAGEEP '93","conferenceDate":"1993-04-18T00:00:00","conferenceLocation":"San Diego, CA","language":"English","publisher":"Environmental and Engineering Geophysical Society","publisherLocation":"Englewood, CO","usgsCitation":"Doll, W., Nyquist, J.E., Labson, V., and Pellerin, L., 1993, Preliminary results of a helicopter electromagnetic and magnetic survey of the Oak Ridge Reservation, Tennessee for environmental and geologic site characterization, p. 281-295.","productDescription":"p. 281-295","numberOfPages":"15","costCenters":[],"links":[{"id":282705,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Tennessee","otherGeospatial":"Oak Ridge Reservation","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -84.436334,35.876924 ], [ -84.436334,36.064688 ], [ -84.157739,36.064688 ], [ -84.157739,35.876924 ], [ -84.436334,35.876924 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"53cd6dbce4b0b29085105566","contributors":{"authors":[{"text":"Doll, W.E.","contributorId":69024,"corporation":false,"usgs":true,"family":"Doll","given":"W.E.","email":"","affiliations":[],"preferred":false,"id":490890,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nyquist, Jonathan E.","contributorId":101801,"corporation":false,"usgs":false,"family":"Nyquist","given":"Jonathan","email":"","middleInitial":"E.","affiliations":[{"id":34225,"text":"Temple University, Philadelphia, Pa.","active":true,"usgs":false}],"preferred":false,"id":490889,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Labson, V.F.","contributorId":20506,"corporation":false,"usgs":true,"family":"Labson","given":"V.F.","email":"","affiliations":[],"preferred":false,"id":490888,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Pellerin, L.","contributorId":94073,"corporation":false,"usgs":true,"family":"Pellerin","given":"L.","email":"","affiliations":[],"preferred":false,"id":490891,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70039257,"text":"70039257 - 1993 - National Geodata Policy Forum: present and emerging U.S. policies governing the development, evolution, and use of the National Spatial Data Infrastructure: summary report","interactions":[],"lastModifiedDate":"2012-08-04T01:01:57","indexId":"70039257","displayToPublicDate":"1993-01-01T14:24:00","publicationYear":"1993","noYear":false,"publicationType":{"id":4,"text":"Book"},"publicationSubtype":{"id":12,"text":"Conference publication"},"seriesTitle":{"id":430,"text":"General Information Product","active":false,"publicationSubtype":{"id":12}},"title":"National Geodata Policy Forum: present and emerging U.S. policies governing the development, evolution, and use of the National Spatial Data Infrastructure: summary report","docAbstract":"The first National Geo-Data Policy Forum was held on May 10-12, 1993, in Tyson's Corner, Virginia. The objective of the National Geo-Data Policy Forum was to examine policies related to the evolution and use of the National Spatial Data Infrastructure (NSDI). A second goal was to identify issues concerning spatial data technology and its use by all citizens. Policy makers from the public and private sectors offered ideas on the myriad issues and questions related to the NSDI and learned of concerns that their organizations must address. The links that connect the NSDI to the Clinton Administration's National Information Infrastructure were identified and discussed. The forum offered participants an opportunity to define the NSDI's role in carrying out technology policy.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","usgsCitation":"Federal Geographic Data Committee, U.G., 1993, National Geodata Policy Forum: present and emerging U.S. policies governing the development, evolution, and use of the National Spatial Data Infrastructure: summary report: General Information Product, vi, 26 p.; Appendices.","productDescription":"vi, 26 p.; Appendices","numberOfPages":"35","costCenters":[],"links":[{"id":261491,"rank":800,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/confpub/70039257/report.pdf"},{"id":261492,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/confpub/70039257/report-thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a61e1e4b0c8380cd71bf2","contributors":{"authors":[{"text":"Federal Geographic Data Committee, U.S. Geological Survey","contributorId":25810,"corporation":false,"usgs":true,"family":"Federal Geographic Data Committee","given":"U.S.","email":"","middleInitial":"Geological Survey","affiliations":[],"preferred":false,"id":465877,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":25171,"text":"25171 - 1993 - Conterminous U.S. AVHRR companion disc: USA-USGS-EDC-AVHRR-9502","interactions":[],"lastModifiedDate":"2014-07-14T14:24:23","indexId":"25171","displayToPublicDate":"1993-01-01T14:23:52","publicationYear":"1993","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":6,"text":"USGS Unnumbered Series"},"title":"Conterminous U.S. AVHRR companion disc: USA-USGS-EDC-AVHRR-9502","docAbstract":"No abstract available.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/25171","usgsCitation":"Water Resources Division, U.S. Geological Survey, 1993, Conterminous U.S. AVHRR companion disc: USA-USGS-EDC-AVHRR-9502, 1 computer laser optical disc, https://doi.org/10.3133/25171.","productDescription":"1 computer laser optical disc","costCenters":[],"links":[{"id":289975,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"53c4fc06e4b0b58d96eeb573","contributors":{"authors":[{"text":"Water Resources Division, U.S. Geological Survey","contributorId":128075,"corporation":true,"usgs":false,"organization":"Water Resources Division, U.S. Geological Survey","id":529191,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ]}