Early to middle Pleistocene boulder deposits are common features on southern Nevada hillslopes. These darkly varnished, ancient colluvial deposits stand but in stark contrast to the underlying light-colored bedrock of volcanic tuffs, and they serve as minor divides between drainage channels on modern hillslopes. To demonstrate the antiquity of these stable hillslope features, six colluvial boulder deposits from Yucca Mountain, Nye County, Nevada, were dated by cation- ratio dating of rock varnish accreted on boulder surfaces. Estimated minimum ages of these boulder deposits range from 760 to 170 ka. Five additional older deposits on nearby Skull and Little Skull Mountains and Buckboard Mesa yielded cation-ratio minimum-age estimates of 1.38 Ma to 800 ka. An independent cosmogenic chlorine-36 surface exposure date was obtained on one deposit, which confirms an estimated early to middle Quaternary age. These deposits have provided the oldest age estimates for unconsolidated hillslope deposits in the southwestern United States.
We suggest that the colluvial boulder deposits were produced during early and middle Pleistocene glacial/pluvial episodes and were stabilized during the transition to drier interglacial climates. By comparison to modern periglacial environments, winter minimum monthly temperatures of -3 to -5 °C were necessary to initiate freeze-thaw conditions of such vigor to physically weather relatively large volumes of large boulders from the upper hillslopes of the Yucca Mountain area. These conditions imply that early and middle Pleistocene glacial winter temperatures were at least 1 to 3 °C colder than existed during the last Pleistocene glacial episode and 7 to 9 °C colder than present. We conclude that at least several early and middle Pleistocene glacial episodes were colder, and perhaps wetter, than glacial episodes of the late Pleistocene in the southern Great Basin.
Geomorphic processes necessary to form these colluvial boulder deposits are not active on modern hillslopes in the southern Great Basin. In addition, the lack of young, relatively unvarnished colluvial boulder deposits on these hillslopes suggests that boulder-forming conditions did not exist during the late Pleistocene in this region.
Modern semiarid hillslope processes primarily erode colluvium during infrequent high-intensity storms. The preservation of old, thin hillslope deposits and the less-than-2-m incision by hillslope runoff adjacent to these deposits, however, indicate that extremely low denudation rates have occurred on resistant volcanic hillslopes in the southern Great Basin during Quaternary time.
","language":"English","publisher":"Geological Society of America","doi":"10.1130/0016-7606(1993)105<1008:RCBDAP>2.3.CO;2","usgsCitation":"Whitney, J., and Harrington, C., 1993, Relict colluvial boulder deposits as paleoclimatic indicators in the Yucca Mountain region, southern Nevada: Geological Society of America Bulletin, v. 105, no. 8, p. 1008-1018, https://doi.org/10.1130/0016-7606(1993)105<1008:RCBDAP>2.3.CO;2.","productDescription":"11 p.","startPage":"1008","endPage":"1018","numberOfPages":"11","costCenters":[],"links":[{"id":228680,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Nevada","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -115.64843276598303,\n 36.3396601470037\n ],\n [\n -115.64843276598303,\n 37.359434339388415\n ],\n [\n -117.2744093284829,\n 37.359434339388415\n ],\n [\n -117.2744093284829,\n 36.3396601470037\n ],\n [\n -115.64843276598303,\n 36.3396601470037\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"105","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aa6bde4b0c8380cd85011","contributors":{"authors":[{"text":"Whitney, J.W.","contributorId":27437,"corporation":false,"usgs":true,"family":"Whitney","given":"J.W.","email":"","affiliations":[],"preferred":false,"id":377818,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Harrington, C.D.","contributorId":10570,"corporation":false,"usgs":true,"family":"Harrington","given":"C.D.","email":"","affiliations":[],"preferred":false,"id":377817,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70017848,"text":"70017848 - 1993 - 234U/238U as a ground-water tracer, SW Nevada-SE California","interactions":[],"lastModifiedDate":"2022-12-06T23:20:45.816557","indexId":"70017848","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"234U/238U as a ground-water tracer, SW Nevada-SE California","docAbstract":"The 234U/238U ratio of uranium in oxidizing ground waters is potentially an excellent ground-water tracer because of its high solubility and insensitivity to chemical reactions. Moreover, recent advances in analytical capability have made possible very precise uranium-isotopic analyses on modest (approx.100 ml) amounts of normal ground water. Preliminary results on waters from SW Nevada/Se California indicate two main mixing trends, but in detail indicate significant complexity requiring three or more main components.","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Proceedings of the 4th annual international conference on high level radioactive waste management","largerWorkSubtype":{"id":12,"text":"Conference publication"},"conferenceTitle":"High Level Radioactive Waste Management","conferenceDate":"April 26-30, 1993","conferenceLocation":"Las Vegas, NV","language":"English","publisher":"ASCE","publisherLocation":"New York, NY, United States","usgsCitation":"Ludwig, K., Peterman, Z.E., Simmons, K.R., and Gutentag, E., 1993, 234U/238U as a ground-water tracer, SW Nevada-SE California, in Proceedings of the 4th annual international conference on high level radioactive waste management, Las Vegas, NV, April 26-30, 1993, p. 1567-1572.","productDescription":"6 p.","startPage":"1567","endPage":"1572","numberOfPages":"6","costCenters":[],"links":[{"id":229002,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California, Nevada","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -117.62593241791103,\n 37.30732606841542\n ],\n [\n -117.62593241791103,\n 33.442956965141974\n ],\n [\n -114.60082639243186,\n 33.442956965141974\n ],\n [\n -114.60082639243186,\n 37.30732606841542\n ],\n [\n -117.62593241791103,\n 37.30732606841542\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e254e4b0c8380cd45ac3","contributors":{"authors":[{"text":"Ludwig, K.R.","contributorId":97112,"corporation":false,"usgs":true,"family":"Ludwig","given":"K.R.","email":"","affiliations":[{"id":218,"text":"Denver Federal Center","active":false,"usgs":true}],"preferred":false,"id":377731,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Peterman, Z. E.","contributorId":63781,"corporation":false,"usgs":true,"family":"Peterman","given":"Z.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":377728,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Simmons, K. R.","contributorId":68771,"corporation":false,"usgs":true,"family":"Simmons","given":"K.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":377729,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Gutentag, E. D.","contributorId":70015,"corporation":false,"usgs":true,"family":"Gutentag","given":"E. D.","affiliations":[],"preferred":false,"id":377730,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70017813,"text":"70017813 - 1993 - Dissimilatory Fe(III) reduction by the marine microorganism Desulfuromonas acetoxidans","interactions":[],"lastModifiedDate":"2023-01-20T15:44:40.698052","indexId":"70017813","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":850,"text":"Applied and Environmental Microbiology","active":true,"publicationSubtype":{"id":10}},"displayTitle":"Dissimilatory Fe(III) reduction by the marine microorganism Desulfuromonas acetoxidans","title":"Dissimilatory Fe(III) reduction by the marine microorganism Desulfuromonas acetoxidans","docAbstract":"The ability of the marine microorganism Desulfuromonas acetoxidans to reduce Fe(III) was investigated because of its close phylogenetic relationship with the freshwater dissimilatory Fe(III) reducer Geobacter metallireducens. Washed cell suspensions of the type strain of D. acetoxidans reduced soluble Fe(III)-citrate and Fe(III) complexed with nitriloacetic acid. The c-type cytochrome(s) of D. acetoxidans was oxidized by Fe(III)-citrate and Mn(IV)-oxalate, as well as by two electron acceptors known to support growth, colloidal sulfur and malate. D. acetoxidans grew in defined anoxic, bicarbonate-buffered medium with acetate as the sole electron donor and poorly crystalline Fe(III) or Mn(IV) as the sole electron acceptor. Magnetite (Fe3O4) and siderite (FeCO3) were the major end products of Fe(III) reduction, whereas rhodochrosite (MnCO3) was the end product of Mn(IV) reduction. Ethanol, propanol, pyruvate, and butanol also served as electron donors for Fe(III) reduction. In contrast to D. acetoxidans, G. metallireducens could only grow in freshwater medium and it did not conserve energy to support growth from colloidal S0 reduction. D. acetoxidans is the first marine microorganism shown to conserve energy to support growth by coupling the complete oxidation of organic compounds to the reduction of Fe(III) or Mn(IV). Thus, D. acetoxidans provides a model enzymatic mechanism for Fe(III) or Mn(IV) oxidation of organic compounds in marine and estuarine sediments. These findings demonstrate that 16S rRNA phylogenetic analyses can suggest previously unrecognized metabolic capabilities of microorganisms.
","language":"English","publisher":"American Society for Microbiology","doi":"10.1128/aem.59.3.734-742.1993","issn":"00992240","usgsCitation":"Roden, E.E., and Lovley, D.R., 1993, Dissimilatory Fe(III) reduction by the marine microorganism Desulfuromonas acetoxidans: Applied and Environmental Microbiology, v. 59, no. 3, p. 734-742, https://doi.org/10.1128/aem.59.3.734-742.1993.","productDescription":"9 p.","startPage":"734","endPage":"742","costCenters":[],"links":[{"id":479530,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1128/aem.59.3.734-742.1993","text":"Publisher Index Page"},{"id":228532,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"59","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0229e4b0c8380cd4fef8","contributors":{"authors":[{"text":"Roden, E. E.","contributorId":48334,"corporation":false,"usgs":true,"family":"Roden","given":"E.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":377638,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lovley, Derek R.","contributorId":107852,"corporation":false,"usgs":true,"family":"Lovley","given":"Derek","middleInitial":"R.","affiliations":[],"preferred":false,"id":377639,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70017847,"text":"70017847 - 1993 - Potential problem with mean dimensionless hydrographs at ungaged sites","interactions":[],"lastModifiedDate":"2012-03-12T17:19:54","indexId":"70017847","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Potential problem with mean dimensionless hydrographs at ungaged sites","docAbstract":"A flood hydrograph for an ungaged stream site can be estimated from a mean dimensionless hydrograph and estimates of instantaneous peak discharge (Q) and total storm runoff volume (V). However, the time base of the resulting flood hydrograph can be inversely related to the magnitude of the peak discharge if estimates of runoff volume were defined using ordinary least-squares regression relations of the form V=f(Q). Such an inverse relation is not hydrologically consistent. The problem can be solved in several ways. Redefining the relation between V and Q using an alternative model that preserves the variance in V generally will produce exponents for Q that are near 1. The resulting estimated flood-hydrograph volumes will nearly match the original volumes near the mean of the logarithms of V and Q, but will differ as volumes and peak discharges depart from the mean values. The difference will depend on how much the original exponent of Q differed from 1. Another solution is to simply hold T???, the multiplier needed to expand the time base of a mean dimensionless hydrograph into the time base of an estimated flood hydrograph, constant. That solution is a questionable approach if basins vary either in size, shape, or slope. A third solution is to define T??? as a function of time to peak, Tp. Flood volume then depends only on Q, Tp, and the dimensionless hydrograph, thereby removing the need to define a relation for estimating volume.","largerWorkTitle":"Proceedings of the Symposium on Engineering Hydrology","conferenceTitle":"Proceedings of the Symposium on Engineering Hydrology","conferenceDate":"25 July 1993 through 30 July 1993","conferenceLocation":"San Francisco, CA, USA","language":"English","publisher":"Publ by ASCE","publisherLocation":"New York, NY, United States","isbn":"087262921X","usgsCitation":"Wahl, K.L., and Rankl, J.G., 1993, Potential problem with mean dimensionless hydrographs at ungaged sites, in Proceedings of the Symposium on Engineering Hydrology, San Francisco, CA, USA, 25 July 1993 through 30 July 1993, p. 246-251.","startPage":"246","endPage":"251","numberOfPages":"6","costCenters":[],"links":[{"id":229001,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a7f57e4b0c8380cd7aa90","contributors":{"authors":[{"text":"Wahl, Kenneth L.","contributorId":61024,"corporation":false,"usgs":true,"family":"Wahl","given":"Kenneth","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":377726,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rankl, James G.","contributorId":93026,"corporation":false,"usgs":true,"family":"Rankl","given":"James","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":377727,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70017791,"text":"70017791 - 1993 - Long-term radon concentrations estimated from 210Po embedded in glass","interactions":[],"lastModifiedDate":"2012-03-12T17:19:54","indexId":"70017791","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1884,"text":"Health Physics","active":true,"publicationSubtype":{"id":10}},"title":"Long-term radon concentrations estimated from 210Po embedded in glass","docAbstract":"Measured surface-alpha activity on glass exposed in radon chambers and houses has a linear correlation to the integrated radon exposure. Experimental results in chambers and houses have been obtained on glass exposed to radon concentrations between 100 Bq m-3 and 9 MBq m-3 for periods of a few days to several years. Theoretical calculations support the experimental results through a model that predicts the fractions of airborne activity that deposit and become embedded or adsorbed. The combination of measured activity and calculated embedded fraction for a given deposition environment can be applied to most indoor areas and produces a better estimate for lifetime radon exposure than estimates based on short-term indoor radon measurements.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Health Physics","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00179078","usgsCitation":"Lively, R., and Steck, D., 1993, Long-term radon concentrations estimated from 210Po embedded in glass: Health Physics, v. 64, no. 5, p. 485-490.","startPage":"485","endPage":"490","numberOfPages":"6","costCenters":[],"links":[{"id":228951,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"64","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a49a7e4b0c8380cd687a6","contributors":{"authors":[{"text":"Lively, R.S.","contributorId":70927,"corporation":false,"usgs":true,"family":"Lively","given":"R.S.","email":"","affiliations":[],"preferred":false,"id":377574,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Steck, D.J.","contributorId":10943,"corporation":false,"usgs":true,"family":"Steck","given":"D.J.","email":"","affiliations":[],"preferred":false,"id":377573,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":1000565,"text":"1000565 - 1993 - Sustainability of hatchery-dependent salmonine fisheries in Lake Ontario: The conflict between predator demand and predator supply","interactions":[],"lastModifiedDate":"2016-04-22T12:09:36","indexId":"1000565","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3624,"text":"Transactions of the American Fisheries Society","active":true,"publicationSubtype":{"id":10}},"title":"Sustainability of hatchery-dependent salmonine fisheries in Lake Ontario: The conflict between predator demand and predator supply","docAbstract":"The offshore fish community of Lake Ontario is presently dominated by intensively managed, nonnative species: Alewife Alosa pseudoharengus and rainbow smelt Osmerus mordax at the planktivore level and stocked salmonines at the piscivore level. Salmonine stocking rates per unit area of Lake Ontario are the highest in the Great Lakes, and fishery managers are concerned about the sustainability of the fishery under present stocking policies, particularly with the recent collapse of the Lake Michigan fishery for chinook salmon Oncorhynchus tshawytscha. In this paper, we describe and present the results of a simulation model that integrates predator demand estimates derived from bioenergetics, prey and predator population dynamics, and a predation model based on the multiple-species functional response, Model reconstructions of historical alewife biomass trends and salmonine diets corresponded reasonably well with existing data for the period 1978–1992. The simulations suggest that current predator demand does not exceed the threshold beyond which alewife biomass cannot be sustained, but they indicate that the sustainability of the prey fish community is extremely sensitive to fluctuations in overwinter survival of alewife; an additional mortality of 25% in a single winter would be sufficient to cause the collapse of the alewife population. The model includes a number of assumptions and simplifications with a limited empirical basis; better estimates of salmonine survival rates, an evaluation of the importance of spatial and temporal interactions among predators and prey, and incorporation of the effects of recently observed declines in system productivity at lower trophic levels would significantly increase confidence in the model's projections.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Transactions of the American Fisheries Society","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1577/1548-8659(1993)122<1002:SOHDSF>2.3.CO;2","usgsCitation":"Jones, M., Koonce, J.F., and O’Gorman, R., 1993, Sustainability of hatchery-dependent salmonine fisheries in Lake Ontario: The conflict between predator demand and predator supply: Transactions of the American Fisheries Society, v. 122, no. 5, p. 1002-1018, https://doi.org/10.1577/1548-8659(1993)122<1002:SOHDSF>2.3.CO;2.","productDescription":"17 p.","startPage":"1002","endPage":"1018","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"links":[{"id":133098,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"122","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4ae0e4b07f02db687fec","contributors":{"authors":[{"text":"Jones, Michael L.","contributorId":7219,"corporation":false,"usgs":false,"family":"Jones","given":"Michael L.","affiliations":[{"id":6590,"text":"Department of Fisheries and Wildlife, Michigan State University","active":true,"usgs":false}],"preferred":false,"id":308783,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Koonce, Joseph F.","contributorId":106069,"corporation":false,"usgs":true,"family":"Koonce","given":"Joseph","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":308784,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"O’Gorman, Robert rogorman@usgs.gov","contributorId":3451,"corporation":false,"usgs":true,"family":"O’Gorman","given":"Robert","email":"rogorman@usgs.gov","affiliations":[],"preferred":true,"id":308782,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":7000011,"text":"7000011 - 1993 - Fossils, rocks, and time","interactions":[],"lastModifiedDate":"2014-07-10T11:36:15","indexId":"7000011","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":6,"text":"USGS Unnumbered Series"},"seriesTitle":{"id":363,"text":"General Interest Publication","active":false,"publicationSubtype":{"id":6}},"title":"Fossils, rocks, and time","docAbstract":"We study out Earth for many reasons: to find water to drink or oil to run our cars or coal to heat our homes, to know where to expect earthquakes or landslides or floods, and to try to understand our natural surroundings. Earth is constantly changing--nothing on its surface is truly permanent. Rocks that are not on top of a mountain may once have been on the bottom of the sea. Thus, to understand the world we live on, we must add the dimension of time. We must study Earth's history.
\nWhen we talk about recorded history, time is measured in years, centuries, and tens of centuries. When we talk about Earth history, time is measured in millions and billions of years.
\nTime is an everyday part of our lives. We keep track of time with a marvelous invention, the calendar, which is based on the movements of the Earth in space. One spin of Earth on its axis is a day, and one trip around the sun is a year. The modern calendar is a great achievement, developed over many thousands of years as theory and technology improved.
\nPeople who study Earth's history also use a type of calendar, called the geologic time scale. It looks very different from the familiar calendar. In some ways, it is more like a book, and the rocks are its pages. Some of the pages are torn or missing, and the pages are not numbered, but geology gives us the tools to help us read this book.
","language":"English","publisher":"U.s. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/7000011","usgsCitation":"Edwards, L.E., and Pojeta, J., 1993, Fossils, rocks, and time: General Interest Publication, 24 p., https://doi.org/10.3133/7000011.","productDescription":"24 p.","numberOfPages":"24","costCenters":[],"links":[{"id":18584,"rank":100,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.usgs.gov/gip/fossils/","linkFileType":{"id":5,"text":"html"}},{"id":134197,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/gip/7000011/report-thumb.jpg"},{"id":115651,"rank":300,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/gip/7000011/report.pdf","size":"8461","linkFileType":{"id":1,"text":"pdf"}}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1be4b07f02db6a91a4","contributors":{"authors":[{"text":"Edwards, Lucy E. 0000-0003-4075-3317 leedward@usgs.gov","orcid":"https://orcid.org/0000-0003-4075-3317","contributorId":2647,"corporation":false,"usgs":true,"family":"Edwards","given":"Lucy","email":"leedward@usgs.gov","middleInitial":"E.","affiliations":[{"id":40020,"text":"Florence Bascom Geoscience Center","active":true,"usgs":true},{"id":243,"text":"Eastern Geology and Paleoclimate Science Center","active":true,"usgs":true}],"preferred":true,"id":343963,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Pojeta, John Jr.","contributorId":44514,"corporation":false,"usgs":true,"family":"Pojeta","given":"John","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":343964,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":1000807,"text":"1000807 - 1993 - Accumulation of PCBs by lake trout (Salvelinus namaycush): an individual-based model approach","interactions":[],"lastModifiedDate":"2013-02-05T15:18:22","indexId":"1000807","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1169,"text":"Canadian Journal of Fisheries and Aquatic Sciences","active":true,"publicationSubtype":{"id":10}},"title":"Accumulation of PCBs by lake trout (Salvelinus namaycush): an individual-based model approach","docAbstract":"To explain the variation in growth and in concentration of polychlorinated biphenyls (PCBs) among individual fish, an individual-based model (IBM) was applied to the lake trout (Salvelinus namaycush) population in Lake Michigan. The IBM accurately represented the variation in growth exhibited by the different age classes of lake trout. Uncertainty analysis of the IBM revealed that mean PCB concentration for the lake trout population was most sensitive to PCB concentration in their prey. The variability in PCB concentration among lake trout individuals was not adequately explained by the IBM, unless variation in prey fish PCBs was included in the model. To accomplish this, the simulated lake trout population was divided into subsets subjected to different levels of PCB concentration in the prey fish. Thus, model results indicated that variability in prey fish PCB concentration was an important component of the variation in PCB concnetration observed among individual lake trout comprising the Lake Michigan population.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Canadian Journal of Fisheries and Aquatic Sciences","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1139/f93-012","usgsCitation":"Madenjian, C.P., Carpenter, S.R., Eck, G.W., and Miller, M.A., 1993, Accumulation of PCBs by lake trout (Salvelinus namaycush): an individual-based model approach: Canadian Journal of Fisheries and Aquatic Sciences, v. 50, no. 1, p. 97-109, https://doi.org/10.1139/f93-012.","productDescription":"13 p.","startPage":"97","endPage":"109","numberOfPages":"13","costCenters":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"links":[{"id":130329,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":267052,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1139/f93-012"}],"volume":"50","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b13e4b07f02db6a35e4","contributors":{"authors":[{"text":"Madenjian, Charles P. 0000-0002-0326-164X cmadenjian@usgs.gov","orcid":"https://orcid.org/0000-0002-0326-164X","contributorId":2200,"corporation":false,"usgs":true,"family":"Madenjian","given":"Charles","email":"cmadenjian@usgs.gov","middleInitial":"P.","affiliations":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"preferred":true,"id":309497,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Carpenter, Stephen R.","contributorId":89477,"corporation":false,"usgs":true,"family":"Carpenter","given":"Stephen","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":309499,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Eck, Gary W.","contributorId":106053,"corporation":false,"usgs":true,"family":"Eck","given":"Gary","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":309500,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Miller, Michael A.","contributorId":85920,"corporation":false,"usgs":false,"family":"Miller","given":"Michael","email":"","middleInitial":"A.","affiliations":[{"id":6913,"text":"Wisconsin Department of Natural Resources","active":true,"usgs":false}],"preferred":false,"id":309498,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70186318,"text":"70186318 - 1993 - Exact Scheffé-type confidence intervals for output from groundwater flow models: 2. Combined use of hydrogeologic information and calibration data","interactions":[],"lastModifiedDate":"2018-03-06T14:27:43","indexId":"70186318","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3722,"text":"Water Resources Research","onlineIssn":"1944-7973","printIssn":"0043-1397","active":true,"publicationSubtype":{"id":10}},"title":"Exact Scheffé-type confidence intervals for output from groundwater flow models: 2. Combined use of hydrogeologic information and calibration data","docAbstract":"Calibration data (observed values corresponding to model-computed values of dependent variables) are incorporated into a general method of computing exact Scheffé-type confidence intervals analogous to the confidence intervals developed in part 1 (Cooley, this issue) for a function of parameters derived from a groundwater flow model. Parameter uncertainty is specified by a distribution of parameters conditioned on the calibration data. This distribution was obtained as a posterior distribution by applying Bayes' theorem to the hydrogeologically derived prior distribution of parameters from part 1 and a distribution of differences between the calibration data and corresponding model-computed dependent variables. Tests show that the new confidence intervals can be much smaller than the intervals of part 1 because the prior parameter variance-covariance structure is altered so that combinations of parameters that give poor model fit to the data are unlikely. The confidence intervals of part 1 and the new confidence intervals can be effectively employed in a sequential method of model construction whereby new information is used to reduce confidence interval widths at each stage.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/92WR01864","usgsCitation":"Cooley, R.L., 1993, Exact Scheffé-type confidence intervals for output from groundwater flow models: 2. Combined use of hydrogeologic information and calibration data: Water Resources Research, v. 29, no. 1, p. 35-50, https://doi.org/10.1029/92WR01864.","productDescription":"16 p. ","startPage":"35","endPage":"50","costCenters":[],"links":[{"id":339109,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"29","issue":"1","noUsgsAuthors":false,"publicationDate":"2010-07-09","publicationStatus":"PW","scienceBaseUri":"58e35f91e4b09da67997ed14","contributors":{"authors":[{"text":"Cooley, Richard L.","contributorId":8831,"corporation":false,"usgs":true,"family":"Cooley","given":"Richard","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":688311,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":1000792,"text":"1000792 - 1993 - Individual-based model for dieldrin contamination in lake trout","interactions":[],"lastModifiedDate":"2016-04-25T08:53:18","indexId":"1000792","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":887,"text":"Archives of Environmental Contamination and Toxicology","active":true,"publicationSubtype":{"id":10}},"title":"Individual-based model for dieldrin contamination in lake trout","docAbstract":"An individual-based model (IBM) was applied to dieldrin contamination in the lake trout (Salvelinus namaycush) population of Lake Michigan in order to determine if a model structure originally developed for contamination by polychlorinated biphenyls (PCBs) in Lake Michigan lake trout would also apply to dieldrin contamination. Many different congeners constitute PCBs, whereas dieldrin is a single chemical compound. The model accurately accounted for the variation in dieldrin concentrations exhibited within the Lake Michigan lake trout population. The degree of variability included in dieldrin concentrations of the prey fish was similar to that used for modeling total PCBs. These results supported the argument that any heterogeneity in PCB congener distribution in Lake Michigan contributed relatively little to the observed variability in lake trout total PCB concentrations. Furthermore, these results indicate that the IBM has potential to be applicable to a variety of organochlorine contaminants. The IBM should prove useful for risk assessment of contaminants in fish.
","language":"English","publisher":"Taylor & Francis","doi":"10.1007/BF01061092","usgsCitation":"Madenjian, C.P., Carpenter, S.R., and Noguchi, G.E., 1993, Individual-based model for dieldrin contamination in lake trout: Archives of Environmental Contamination and Toxicology, v. 24, no. 1, p. 78-82, https://doi.org/10.1007/BF01061092.","productDescription":"5 p.","startPage":"78","endPage":"82","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"links":[{"id":133826,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"24","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e49f7e4b07f02db5f23f0","contributors":{"authors":[{"text":"Madenjian, Charles P. 0000-0002-0326-164X cmadenjian@usgs.gov","orcid":"https://orcid.org/0000-0002-0326-164X","contributorId":2200,"corporation":false,"usgs":true,"family":"Madenjian","given":"Charles","email":"cmadenjian@usgs.gov","middleInitial":"P.","affiliations":[{"id":324,"text":"Great Lakes Science Center","active":true,"usgs":true}],"preferred":true,"id":309443,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Carpenter, Stephen R.","contributorId":89477,"corporation":false,"usgs":true,"family":"Carpenter","given":"Stephen","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":309445,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Noguchi, George E.","contributorId":42552,"corporation":false,"usgs":true,"family":"Noguchi","given":"George","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":309444,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70185279,"text":"70185279 - 1993 - Histopathologic lesions in sea otters exposed to crude oil","interactions":[],"lastModifiedDate":"2017-06-28T16:46:25","indexId":"70185279","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3687,"text":"Veterinary Pathology","active":true,"publicationSubtype":{"id":10}},"title":"Histopathologic lesions in sea otters exposed to crude oil","docAbstract":"Following the Exxon Valdez oil spill in Prince William Sound, Alaska, sea otters (Enhydra lutris) that appeared to be contaminated with oil, that were in danger of becoming contaminated, or that were behaving abnormally were captured and taken to rehabilitation centers. Exposure to oil was assessed by visual examination when otters arrived at the centers. Degree of oil exposure was graded according to the following criteria: oil covering greater than 60% of the body - heavily contaminated; oil covering 30–60% of the body - moderately contaminated; oil covering less than 30% of the body or light sheen on fur - lightly contaminated. If there was no oil visible, otters were considered uncontaminated. Tissues from 51 oil-contaminated sea otters (14 males, 37 females) and from six uncontaminated sea otters (three males, three females) that died in rehabilitation centers were examined histologically. Among oil-contaminated sea otters, 19/46 had interstitial pulmonary emphysema, 13/40 had gastric erosion and hemorrhage, 11/47 had centrilobular hepatic necrosis, 14/47 had periportal to diffuse hepatic lipidosis, and 10/42 had renal tubular lipidosis. Of the uncontaminated sea otters, 1/6 had gastric erosion and hemorrhage and 1/6 had diffuse hepatic lipidosis. Histologic examinations were performed on tissues from five sea otters (three males, two females) found dead with external oil present 15 to 16 days after the spill. Periportal hepatic lipidosis and renal tubular lipidosis were found in 3/5, and interstitial pulmonary emphysema was found in 1/5. Tissues from six apparently normal sea otters (four males, two females) collected from an area not affected by an oil spill were examined histologically, and none of these lesions were found. We conclude that interstitial pulmonary emphysema, centrilobular hepatic necrosis, and hepatic and renal lipidosis of sea otters were associated with exposure to crude oil. Gastric erosion and hemorrhage may have been associated with stress of captivity and/or oil exposure.
","language":"English","publisher":"SAGE Journals","doi":"10.1177/030098589303000101","usgsCitation":"Lipscomb, T., Harris, R., Moeller, R., Pletcher, J., Haebler, R., and Ballachey, B.E., 1993, Histopathologic lesions in sea otters exposed to crude oil: Veterinary Pathology, v. 30, no. 1, p. 1-11, https://doi.org/10.1177/030098589303000101.","productDescription":"12 p.","startPage":"1","endPage":"11","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":480303,"rank":0,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1177/030098589303000101","text":"Publisher Index Page"},{"id":337819,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","volume":"30","issue":"1","noUsgsAuthors":false,"publicationDate":"1993-01-01","publicationStatus":"PW","scienceBaseUri":"58ccf5a1e4b0849ce97f0d0e","contributors":{"authors":[{"text":"Lipscomb, T.P.","contributorId":174540,"corporation":false,"usgs":false,"family":"Lipscomb","given":"T.P.","email":"","affiliations":[],"preferred":false,"id":685000,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Harris, R.K.","contributorId":189492,"corporation":false,"usgs":false,"family":"Harris","given":"R.K.","email":"","affiliations":[],"preferred":false,"id":685001,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Moeller, R.B.","contributorId":189498,"corporation":false,"usgs":false,"family":"Moeller","given":"R.B.","affiliations":[],"preferred":false,"id":685002,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Pletcher, J.M.","contributorId":189499,"corporation":false,"usgs":false,"family":"Pletcher","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":685003,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Haebler, R.J.","contributorId":189500,"corporation":false,"usgs":false,"family":"Haebler","given":"R.J.","affiliations":[],"preferred":false,"id":685004,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Ballachey, Brenda E. 0000-0003-1855-9171 bballachey@usgs.gov","orcid":"https://orcid.org/0000-0003-1855-9171","contributorId":2966,"corporation":false,"usgs":true,"family":"Ballachey","given":"Brenda","email":"bballachey@usgs.gov","middleInitial":"E.","affiliations":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":116,"text":"Alaska Science Center Biology MFEB","active":true,"usgs":true}],"preferred":true,"id":685005,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70018349,"text":"70018349 - 1993 - An exsolution silica-pump model for the origin of myrmekite","interactions":[],"lastModifiedDate":"2012-03-12T17:19:23","indexId":"70018349","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1336,"text":"Contributions to Mineralogy and Petrology","active":true,"publicationSubtype":{"id":10}},"title":"An exsolution silica-pump model for the origin of myrmekite","docAbstract":"Myrmekite, as defined here, is the microscopic intergrowth between vermicular quartz and modestly anorthitic plagioclase (calcic albite-oligoclase), intimately associated with potassium feldspar in plutonic rocks of granitic composition. Hypotheses previously invoked in explanation of myrmekite include: (1) direct crystallization; (2) replacement; (3) exsolution. The occurrence of myrmekite in paragneisses and its absence in rocks devold of discrete grains of potassium feldspar challenge those hypotheses based on direct crystallization or replacement. However, several lines of evidence indicate that myrmekite may in fact originate in response to kinetic effects associated with the exsolution of calcic alkali feldspar into discrete potassium feldspar and plagioclase phases. Exsolution of potassium feldspar system projected from [AlSi2O8] involves the exchange CaAlK-1Si-1, in which the AlSi-1 tetrahedral couple is resistant to intracrystalline diffusion. By contrast, diffusion of octahedral K proceeds relatively easily where it remains uncoupled to the tetrahedral exchange. We suggest here that where the ternary feldspar system is open to excess silica, the exchange reaction that produces potassium feldspar in the ternary plane is aided by the net-transfer reaction K+Si=Orthoclase, leaving behind indigenous Si that reports as modal quartz in the evolving plagioclase as the CaAl component is concomitantly incorporated in this same phase. Thus silica is \"pumped\" into the reaction volume from a \"silica reservoir\", a process that enhances redistribution of both Si and Al through the exsolving ternary feldspar. ?? 1993 Springer-Verlag.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Contributions to Mineralogy and Petrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Springer-Verlag","doi":"10.1007/BF00712978","issn":"00107999","usgsCitation":"Castle, R.O., and Lindsley, D., 1993, An exsolution silica-pump model for the origin of myrmekite: Contributions to Mineralogy and Petrology, v. 115, no. 1, p. 58-65, https://doi.org/10.1007/BF00712978.","startPage":"58","endPage":"65","numberOfPages":"8","costCenters":[],"links":[{"id":227419,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":205914,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00712978"}],"volume":"115","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ea6be4b0c8380cd48854","contributors":{"authors":[{"text":"Castle, R. O.","contributorId":79880,"corporation":false,"usgs":true,"family":"Castle","given":"R.","email":"","middleInitial":"O.","affiliations":[],"preferred":false,"id":379298,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lindsley, D.H.","contributorId":89265,"corporation":false,"usgs":true,"family":"Lindsley","given":"D.H.","email":"","affiliations":[],"preferred":false,"id":379299,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70017830,"text":"70017830 - 1993 - Structure of Crater Flat and Yucca Mountain, Southeastern Nevada, as inferred from gravity data","interactions":[],"lastModifiedDate":"2012-03-12T17:19:55","indexId":"70017830","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Structure of Crater Flat and Yucca Mountain, Southeastern Nevada, as inferred from gravity data","docAbstract":"Existing gravity data in the vicinity of Yucca Mountain and Crater Flat have been examined to determine if these data support only the caldera model or if they support other geologic models such as for a high-angle graben or detachment fault. The west to east isostatic gravity profile reduced for a density of 2.0 g/cm3 shows a gravity low of about 20 mGal centered only 2 km from the eastern edge of Crater Flat relative to a gravity high over the eastern boundary of Yucca Mountain. In the western part of Crater Flat, isostatic anomalies rise about 50 mGal across the flat, reaching a maximum gradient of 9 mGal/km about 3 km east of the Bare Mountain range-front fault. Computer modeling of these data indicate that a model that consists of a detachment fault that dips to the west at 12?? under Yucca Mountain and intersects a 27?? east-dipping Bare Mountain fault fits the observed gravity data generally as well as the caldera model.","largerWorkTitle":"High Level Radioactive Waste Management","conferenceTitle":"Proceedings of the 4th Annual International Conference on High Level Radioactive Waste Management","conferenceDate":"26 April 1993 through 30 April 1993","conferenceLocation":"Las Vegas, NV, USA","language":"English","publisher":"Publ by ASCE","publisherLocation":"New York, NY, United States","isbn":"0872629503","usgsCitation":"Oliver, H.W., and Fox, K., 1993, Structure of Crater Flat and Yucca Mountain, Southeastern Nevada, as inferred from gravity data, in High Level Radioactive Waste Management, Las Vegas, NV, USA, 26 April 1993 through 30 April 1993, p. 1812-1817.","startPage":"1812","endPage":"1817","numberOfPages":"6","costCenters":[],"links":[{"id":228775,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9c58e4b08c986b31d3b9","contributors":{"authors":[{"text":"Oliver, H. W.","contributorId":85570,"corporation":false,"usgs":true,"family":"Oliver","given":"H.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":377682,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fox, K.F.","contributorId":15641,"corporation":false,"usgs":true,"family":"Fox","given":"K.F.","email":"","affiliations":[],"preferred":false,"id":377681,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70186795,"text":"70186795 - 1993 - Advection and diffusion in a variable-salinity confining layer","interactions":[],"lastModifiedDate":"2018-03-06T14:32:20","indexId":"70186795","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3722,"text":"Water Resources Research","onlineIssn":"1944-7973","printIssn":"0043-1397","active":true,"publicationSubtype":{"id":10}},"title":"Advection and diffusion in a variable-salinity confining layer","docAbstract":"A numerical model that simulates groundwater flow and solute transport for cases in which fluid properties are variable was applied in one dimension (vertical) to the shallow, low-permeability, clayey, confining layer in Doñana National Park in southwestern Spain. The salinity in the 80-m-thick confining layer decreases from a brine near the land surface to fresh water near its base. Results of model simulations indicate that the system could be in or close to a steady state condition. The model calibration was very sensitive to small variations in individual model parameters and was nonunique in the sense that equally good calibrations could be achieved by compensatory joint perturbations in the permeability, diffusion coefficient, and overall governing hydraulic gradient. At present, there is probably an upward flow of the order of 1 mm yr−1 to 1 cm yr−1 and a balance in the solute flux between upward advection and downward diffusion. The time scale of calculated responses to changes in boundary conditions in this low-permeability system ranges from thousands to hundreds of thousands of years when considering extremes within the range of uncertainty of values of the evaluated parameters.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/93WR00965","usgsCitation":"Konikow, L.F., and Arevalo, J.R., 1993, Advection and diffusion in a variable-salinity confining layer: Water Resources Research, v. 29, no. 8, p. 2747-2761, https://doi.org/10.1029/93WR00965.","productDescription":"15 p. ","startPage":"2747","endPage":"2761","costCenters":[],"links":[{"id":339548,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"29","issue":"8","noUsgsAuthors":false,"publicationDate":"2010-07-09","publicationStatus":"PW","scienceBaseUri":"58ec9a31e4b0b4d95d335274","contributors":{"authors":[{"text":"Konikow, Leonard F. 0000-0002-0940-3856 lkonikow@usgs.gov","orcid":"https://orcid.org/0000-0002-0940-3856","contributorId":158,"corporation":false,"usgs":true,"family":"Konikow","given":"Leonard","email":"lkonikow@usgs.gov","middleInitial":"F.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":690586,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Arevalo, Javier Rodriguez","contributorId":190739,"corporation":false,"usgs":false,"family":"Arevalo","given":"Javier","email":"","middleInitial":"Rodriguez","affiliations":[],"preferred":false,"id":690587,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70186729,"text":"70186729 - 1993 - The system controlling the composition of clastic sediments","interactions":[],"lastModifiedDate":"2017-04-07T14:57:52","indexId":"70186729","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3459,"text":"Special Paper of the Geological Society of America","active":true,"publicationSubtype":{"id":10}},"title":"The system controlling the composition of clastic sediments","docAbstract":"The composition of clastic sediments and rocks is controlled by a complex suite of parameters operating during pedogenesis, erosion, transport, deposition, and burial. The principal first-order parameters include source rock composition, modification by chemical weathering, mechanical disaggregation and abrasion, authigenic inputs, hydrodynamic sorting, and diagenesis. Each of these first-order parameters is influenced to varying degrees by such factors as the tectonic settings of the source region, transportational system and depositional environment, climate, vegetation, relief, slope, and the nature and energy of transportational and depositional systems. These factors are not independent; rather a complicated web of interrelationships and feedback mechanisms causes many factors to be modulated by others. Accordingly, processes controlling the composition of clastic sediments are best viewed as constituting a system, and in evaluating compositional information the dynamics of the system must be considered as whole.
","language":"English","publisher":"Geological Society of America","doi":"10.1130/SPE284-p1","usgsCitation":"Johnsson, M.J., 1993, The system controlling the composition of clastic sediments: Special Paper of the Geological Society of America, v. 284, p. 1-20, https://doi.org/10.1130/SPE284-p1.","productDescription":"20 p. ","startPage":"1","endPage":"20","costCenters":[],"links":[{"id":339461,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"284","noUsgsAuthors":false,"publicationDate":"1993-01-01","publicationStatus":"PW","scienceBaseUri":"58e8a553e4b09da6799d6402","contributors":{"authors":[{"text":"Johnsson, Mark J.","contributorId":58631,"corporation":false,"usgs":true,"family":"Johnsson","given":"Mark","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":690386,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70018368,"text":"70018368 - 1993 - Experimental investigation and application of the equilibrium rutile + orthopyroxene = quartz + ilmenite","interactions":[],"lastModifiedDate":"2012-03-12T17:19:24","indexId":"70018368","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1336,"text":"Contributions to Mineralogy and Petrology","active":true,"publicationSubtype":{"id":10}},"title":"Experimental investigation and application of the equilibrium rutile + orthopyroxene = quartz + ilmenite","docAbstract":"Equilibria in the Sirf (Silica-Ilmenite-Rutile-Ferrosilite) system: {Mathematical expression} have been calibrated in the range 800-1100?? C and 12-26 kbar using a piston-cylinder apparatus to assess the potential of the equilibria for geobarometry in granulite facies assemblages that lack garnet. Thermodynamic calculations indicate that the two end-member equilibria involving quartz + geikielite = rutile + enstatite, and quartz + ilmenite = rutile + ferrosilite, are metastable. We therefore reversed equilibria over the compositional range Fs40-70, using Ag80Pd20 capsules with {Mathematical expression} buffered at or near iron-wu??stite. Ilmenite compositions coexisting with orthopyroxene are {Mathematical expression} of 0.06 to 0.15 and {Mathematical expression} of 0.00 to 0.01, corresponding to KD values of 13.3, 10.2, 9.0 and 8.0 (??0.5) at 800, 900, 1000 and 1100?? C, respectively, where KD=(XMg/XFe)Opx/(XMg/XFe)Ilm. Pressures have been calculated using equilibria in the Sirf system for granulites from the Grenville Province of Ontario and for granulite facies xenoliths from central Mexico. Pressures are consistent with other well-calibrated geobarometers for orthopyroxeneilmenite pairs from two Mexican samples in which oxide textures appear to represent equilibrium. Geologically unreasonable pressures are obtained, however, where oxide textures are complex. Application of data from this study on the equilibrium distribution of iron and magnesium between ilmenite and orthopyroxene suggests that some ilmenite in deep crustal xenoliths is not equilibrated with coexisting pyroxene, while assemblages from exposed granulite terranes have reequilibrated during retrogression. The Sirf equilibria are sensitive to small changes in composition and may be used for determination of activity/composition (a/X) relations of orthopyroxene if an ilmenite model is specified. A symmetric regular solution model has been used for orthopyroxene in conjunction with activity models for ilmenite available from the literature to calculate a/X relations in orthopyroxene of intermediate composition. Data from this study indicate that FeSiO3-MgSiO3 orthopyroxene exhibits small, positive deviations from ideality over the range 800-1100??C. ?? 1993 Springer-Verlag.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Contributions to Mineralogy and Petrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Springer-Verlag","doi":"10.1007/BF00712975","issn":"00107999","usgsCitation":"Hayob, J., Bohlen, S., and Essene, E., 1993, Experimental investigation and application of the equilibrium rutile + orthopyroxene = quartz + ilmenite: Contributions to Mineralogy and Petrology, v. 115, no. 1, p. 18-35, https://doi.org/10.1007/BF00712975.","startPage":"18","endPage":"35","numberOfPages":"18","costCenters":[],"links":[{"id":479513,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"http://hdl.handle.net/2027.42/47307>","text":"External Repository"},{"id":205835,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00712975"},{"id":227024,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"115","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0dd4e4b0c8380cd531f1","contributors":{"authors":[{"text":"Hayob, J.L.","contributorId":107866,"corporation":false,"usgs":true,"family":"Hayob","given":"J.L.","email":"","affiliations":[],"preferred":false,"id":379352,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bohlen, S.R.","contributorId":105436,"corporation":false,"usgs":true,"family":"Bohlen","given":"S.R.","email":"","affiliations":[],"preferred":false,"id":379351,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Essene, E.J.","contributorId":91625,"corporation":false,"usgs":true,"family":"Essene","given":"E.J.","email":"","affiliations":[],"preferred":false,"id":379350,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70017347,"text":"70017347 - 1993 - Method of estimating the amount of in situ gas hydrates in deep marine sediments","interactions":[],"lastModifiedDate":"2019-11-10T11:10:13","indexId":"70017347","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2682,"text":"Marine and Petroleum Geology","active":true,"publicationSubtype":{"id":10}},"title":"Method of estimating the amount of in situ gas hydrates in deep marine sediments","docAbstract":"The bulk volume of gas hydrates in marine sediments can be estimated by measuring interval velocities and amplitude blanking of hydrated zones from true amplitude processed multichannel seismic reflection data. In general, neither velocity nor amplitude information is adequate to independently estimate hydrate concentration. A method is proposed that uses amplitude blanking calibrated by interval velocity information to quantify hydrate concentrations in the Blake Ridge area of the US Atlantic continental margin. On the Blake Ridge, blanking occurs in conjunction with relatively low interval velocities. The model that best explains this relation linearly mixes two end-member sediments: hydrated and unhydrated sediment. Hydrate concentration in the hydrate end-member can be calculated from a weighted equation that uses velocity estimated from the seismic data, known properties of the pure hydrate, and porosity inferred from a velocity-porosity relationship. Amplitude blanking can be predicted as the proportions of hydrated and unhydrated sediment change across a reflection boundary. Our analysis of a small area near DSDP 533 indicates that the amount of gas hydrates is about 6% in total volume when the interval velocity is used as a criterion and about 9.5% when amplitude information is used. This compares with a calculated value of about 8% derived from the only available measurement in DSDP 533.
","language":"English","publisher":"Elsevier","doi":"10.1016/0264-8172(93)90050-3","issn":"02648172","usgsCitation":"Lee, M.W., Hutchinson, D.R., Dillon, W.P., Miller, J.J., Agena, W., and Swift, B., 1993, Method of estimating the amount of in situ gas hydrates in deep marine sediments: Marine and Petroleum Geology, v. 10, no. 5, p. 493-506, https://doi.org/10.1016/0264-8172(93)90050-3.","productDescription":"14 p.","startPage":"493","endPage":"506","costCenters":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":225020,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"North Carolina, South Carolina","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -81.40869140625,\n 32.287132632616384\n ],\n [\n -74.50927734375,\n 32.287132632616384\n ],\n [\n -74.50927734375,\n 35.8356283888737\n ],\n [\n -81.40869140625,\n 35.8356283888737\n ],\n [\n -81.40869140625,\n 32.287132632616384\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"10","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a555fe4b0c8380cd6d1c7","contributors":{"authors":[{"text":"Lee, Myung W.","contributorId":84358,"corporation":false,"usgs":true,"family":"Lee","given":"Myung","middleInitial":"W.","affiliations":[],"preferred":false,"id":376204,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hutchinson, D. R.","contributorId":31770,"corporation":false,"usgs":true,"family":"Hutchinson","given":"D.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":376200,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dillon, William P. bdillon@usgs.gov","contributorId":79820,"corporation":false,"usgs":true,"family":"Dillon","given":"William","email":"bdillon@usgs.gov","middleInitial":"P.","affiliations":[{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":false,"id":376205,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Miller, J. J.","contributorId":54588,"corporation":false,"usgs":true,"family":"Miller","given":"J.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":376202,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Agena, Warren F.","contributorId":67079,"corporation":false,"usgs":true,"family":"Agena","given":"Warren F.","affiliations":[],"preferred":false,"id":376203,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Swift, B.A.","contributorId":32937,"corporation":false,"usgs":true,"family":"Swift","given":"B.A.","affiliations":[],"preferred":false,"id":376201,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70017348,"text":"70017348 - 1993 - Spectral Distinctions between the Leading and Trailing Hemispheres of Callisto: New Observations","interactions":[],"lastModifiedDate":"2012-03-12T17:18:47","indexId":"70017348","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1963,"text":"Icarus","active":true,"publicationSubtype":{"id":10}},"title":"Spectral Distinctions between the Leading and Trailing Hemispheres of Callisto: New Observations","docAbstract":"An analysis of recent telescopic observations of Callisto results in new insights regarding spectral variations from the leading to the trailing hemisphere of Callisto. Examination of data in the wavelength range from 2.0 to 2.5 ??m indicates that previous suggestions of spectral differences are most likely the result of experimental uncertainty or error. Slight variations in the slope of this wavelength range are consistent with larger ice grain sizes on the trailing hemisphere. The new observations confirm the presence of an absorption feature centered on 3.4 ??m in the spectrum of the leading hemisphere. Theoretical spectral modeling indicates this feature is caused by small amounts of fine-grained water ice. Finally, an absorption feature near 3.1 ??m is indicated but cannot be confirmed due to the strong variation in the spectrum of water ice in this region. If this feature is real, rather than an artifact of the reflectance modeling, it is similar in location and bandwidth to a feature seen in the spectrum of Ceres, attributed to NH4-bearing clays. ?? 1993 Academic Press. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Icarus","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1006/icar.1993.1083","issn":"00191035","usgsCitation":"Calvin, W.M., and Clark, R.N., 1993, Spectral Distinctions between the Leading and Trailing Hemispheres of Callisto: New Observations: Icarus, v. 104, no. 1, p. 69-78, https://doi.org/10.1006/icar.1993.1083.","startPage":"69","endPage":"78","numberOfPages":"10","costCenters":[],"links":[{"id":205596,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1006/icar.1993.1083"},{"id":225064,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"104","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9534e4b08c986b31adc5","contributors":{"authors":[{"text":"Calvin, W. M.","contributorId":17379,"corporation":false,"usgs":false,"family":"Calvin","given":"W.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":376207,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Clark, R. N.","contributorId":6568,"corporation":false,"usgs":true,"family":"Clark","given":"R.","email":"","middleInitial":"N.","affiliations":[],"preferred":false,"id":376206,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018316,"text":"70018316 - 1993 - Pilot studies of seismic hazard and risk in North Sulawesi Province, Indonesia","interactions":[],"lastModifiedDate":"2012-03-12T17:19:28","indexId":"70018316","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1436,"text":"Earthquake Spectra","active":true,"publicationSubtype":{"id":10}},"title":"Pilot studies of seismic hazard and risk in North Sulawesi Province, Indonesia","docAbstract":"Earthquake ground motions in North Sulawesi on soft soil that have a 90% probability of not been exceeded in 560 years are estimated to be 0.63 g (63% of the acceleration of gravity) at Palu, 0.31 g at Gorontalo, and 0.27 g at Manado. Estimated ground motions for rock conditions for the same probability level and exposure time are 56% of those for soft soil. The hazard estimates are obtained from seismic sources that model the earthquake potential to a depth of 100 km beneath northern and central Sulawesi and include the Palu fault zone of western Sulawesi, the North Sulawesi subduction zone, and the southern most segment of the Sangihe subduction zone beneath the Molucca Sea. An attenuation relation based on Japanese strong-motion data and considered appropriate for subduction environments of the western Pacific was used in determination of ground motions. Following the 18 April 1990 North Sulawesi earthquake (Ms 7.3) a seismic hazard and risk assessment was carried out. -from Authors","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Earthquake Spectra","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1193/1.1585707","issn":"87552930","usgsCitation":"Thenhaus, P., Hanson, S., Effendi, I., Kertapati, E., and Algermissen, S.T., 1993, Pilot studies of seismic hazard and risk in North Sulawesi Province, Indonesia: Earthquake Spectra, v. 9, no. 1, p. 97-120, https://doi.org/10.1193/1.1585707.","startPage":"97","endPage":"120","numberOfPages":"24","costCenters":[],"links":[{"id":205951,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1193/1.1585707"},{"id":227597,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"9","issue":"1","noUsgsAuthors":false,"publicationDate":"1993-02-01","publicationStatus":"PW","scienceBaseUri":"505a7b63e4b0c8380cd79400","contributors":{"authors":[{"text":"Thenhaus, P.C.","contributorId":46089,"corporation":false,"usgs":true,"family":"Thenhaus","given":"P.C.","affiliations":[],"preferred":false,"id":379203,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hanson, S.L.","contributorId":47361,"corporation":false,"usgs":true,"family":"Hanson","given":"S.L.","email":"","affiliations":[],"preferred":false,"id":379204,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Effendi, I.","contributorId":36810,"corporation":false,"usgs":true,"family":"Effendi","given":"I.","email":"","affiliations":[],"preferred":false,"id":379201,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kertapati, E.K.","contributorId":82986,"corporation":false,"usgs":true,"family":"Kertapati","given":"E.K.","email":"","affiliations":[],"preferred":false,"id":379205,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Algermissen, S. T.","contributorId":39790,"corporation":false,"usgs":true,"family":"Algermissen","given":"S.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":379202,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70017350,"text":"70017350 - 1993 - Composition of steam in the system NaCl-KCl-H2O-quartz at 600°C","interactions":[],"lastModifiedDate":"2015-05-21T15:47:31","indexId":"70017350","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1759,"text":"Geochimica et Cosmochimica Acta","active":true,"publicationSubtype":{"id":10}},"title":"Composition of steam in the system NaCl-KCl-H2O-quartz at 600°C","docAbstract":"In the system NaCl-KCl-H2O, with and without ??-quartz present, steam was equilibrated in a large-volume reaction vessel with brine and/or precipitated salt at 600??C and pressures ranging from about 100 to 0.4 MPa. Episodically, steam was extracted for chemical analysis, accompanied by a decrease in pressure within the reaction vessel. In the absence of precipitated salt, within the analytical uncertainty stoichiometric quantities of Cl and total alkali, metals (Na + K) dissolve in steam coexisting with chloriderich brine. In contrast, in the presence of precipitated salt (in our experiments halite with some KCl in solid solution), significant excess chloride as associated hydrogen chloride (HCl0??) dissolves in steam. The HCl0 is generated by the reaction of steam with solid NaCl(s), producing solid NaOH(s) that diffuses into halite, forming a solid solution. In our quasistatic experiments, compared to dynamic flow-through experiments of others, higher initial ratios of H2O/NaCl have apparently resulted in higher model fractions of NaOH(s) in solid solution in halite. This, in turn, resulted in incrementally higher concentrations of associated NaOHo dissolved in steam. Addition of quartz to the system NaCl + KC1 + H2O resulted in an order of magnitude increase in the concentration of HCl0 dissolved in steam, apparently as a consequence of the formation of sodium disilicate by reaction of silica with NaOH(s). The measured dissolved silica in steam saturated with alkali halides at 600??C in the pressure range 7-70 MPa agrees nicely with calculated values of the solubility of ??-quartz obtained using the equation of Fournier and Potter (1982), corrected for dissolved salt by the method of fournier (1983). Na K ratios in steam at 600??C tend to be slightly greater than in coexisting brine. When precipitated halite is present, larger mole fractions of NaOH(s) in solid solution in that halite apparently result in even larger Na K ratios in coexisting steam. Precipitation of more halite as a consequence of repeated depressurization episodes results in decreased Na K ratios in both the brine and coexisting steam phases, indicating that the lower pressures begin to favor K over Na in the vapor. When steam is in contact with precipitated salts in the absence of brine, the Na K ratio in the steam is less than that of the bulk composition of the salt-H2O system. ?? 1993.","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7037(93)90488-I","issn":"00167037","usgsCitation":"Fournier, R.O., and Thompson, J.M., 1993, Composition of steam in the system NaCl-KCl-H2O-quartz at 600°C: Geochimica et Cosmochimica Acta, v. 57, no. 18, p. 4365-4375, https://doi.org/10.1016/0016-7037(93)90488-I.","productDescription":"11 p.","startPage":"4365","endPage":"4375","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":225115,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"57","issue":"18","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f92ce4b0c8380cd4d49a","contributors":{"authors":[{"text":"Fournier, Robert O.","contributorId":73202,"corporation":false,"usgs":true,"family":"Fournier","given":"Robert","email":"","middleInitial":"O.","affiliations":[],"preferred":false,"id":376209,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Thompson, J. Michael","contributorId":40239,"corporation":false,"usgs":true,"family":"Thompson","given":"J.","email":"","middleInitial":"Michael","affiliations":[],"preferred":false,"id":376210,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70018346,"text":"70018346 - 1993 - Kinematic stratification in the hinterland of the central Scandinavian Caledonides","interactions":[],"lastModifiedDate":"2024-05-10T00:00:29.898034","indexId":"70018346","displayToPublicDate":"1993-01-01T00:00:00","publicationYear":"1993","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2468,"text":"Journal of Structural Geology","active":true,"publicationSubtype":{"id":10}},"title":"Kinematic stratification in the hinterland of the central Scandinavian Caledonides","docAbstract":"A transect through west-central Norway illustrates the changing geometry and kinematics of collision in the hinterland of the central Scandinavian Caledonides. A depth section through the crust is exposed on Fosen Peninsula, comprising three tectonic units separated by two shear zones. The lowest unit, exposed in the Roan window, is a modestly deformed, Caledonian granulite complex framed by a subhorizontal décollement, with NW-SE oriented lineations and kinematic indicators showing top-to-the-northwest transport. The middle unit, the Vestranden gneiss complex, contains relict granulites, but was penetratively deformed at amphibolite facies to produce an orogen-parallel family of structures during translation on the décollement. Shallow plunging lineations on steep schistosities are subparallel to fold axes of the dominant, upright, non-cylindrical folds. A small component of sinistral strike slip is also recorded. In contrast, southernmost Fosen Peninsula contains an abundance of cover rocks infolded with Proterozoic basement in a fold nappe, with shallow, E-dipping schistosities, down-dip lineations, and orogen-oblique, top-to-the-west shear sense indicators. A NE-striking, sinistral shear zone separates the gneisses from southern Fosen. Deformation in the Scandian hinterland was partitioned both in space and time, with orogen-parallel extension and shear at middle structural levels and orogen-oblique transport at shallower levels.
Banded, epithermal quartz-adularia veins have produced about 1.5 million ounces of gold and 7 million ounces of silver from the Bodie mining district, eastern California. The veins cut dacitic lava flows, pyroclastic rocks and intrusions. Sinter boulders occur in a graben structure at the top of Bodie Bluff and fragments of sinter and mineralized quartz veins occur in hydrothermal breccias nearby. Explosive venting evidently was part of the evolution of the ore-forming geothermal systems which, at one time, must had reached the paleosurface. Previous reconnaissance studies at Bodie Bluff suggested that the geometry of alteration mineral assemblages and distribution of some of the major and trace elements throughout the system correspond to those predicted by models of hot-spring, volcanic rock hosted precious metal deposits (Silberman, 1982; Silberman and Berger, 1985). The current study was undertaken to evaluate these sugestions further.
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