Samarium-neodymium isotopic data on whole rocks and minerals of the Sudbury Complex in Canada gave an igneous crystallization age of 1840 ± 21 × 106 years. The initial epsilon neodymium values for 15 whole rocks are similar to those for average upper continental crust, falling on the crustal trend of neodymium isotopic evolution as defined by shales. The rare earth element concentration patterns of Sudbury rocks are also similar to upper crustal averages. These data suggest that the Sudbury Complex formed from melts generated in the upper crust and are consistent with a meteoritic impact.
","language":"English","publisher":"American Association for the Advancement of Science","doi":"10.1126/science.230.4724.436","issn":"00368075","usgsCitation":"Faggart, B., Basu, A.R., and Tatsumoto, M., 1985, Origin of the Sudbury Complex by meteoritic impact: Neodymium isotopic evidence: Science, v. 230, no. 4724, p. 436-439, https://doi.org/10.1126/science.230.4724.436.","productDescription":"4 p.","startPage":"436","endPage":"439","costCenters":[],"links":[{"id":221859,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"Canada","state":"Ontario","otherGeospatial":"Sudbury Complex","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -82.6927933840347,\n 47.26473966930919\n ],\n [\n -82.6927933840347,\n 45.97696306148865\n ],\n [\n -79.77241195204732,\n 45.97696306148865\n ],\n [\n -79.77241195204732,\n 47.26473966930919\n ],\n [\n -82.6927933840347,\n 47.26473966930919\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"230","issue":"4724","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a70fee4b0c8380cd763ba","contributors":{"authors":[{"text":"Faggart, B.E. Jr.","contributorId":39939,"corporation":false,"usgs":true,"family":"Faggart","given":"B.E.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":364918,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Basu, A. R.","contributorId":99697,"corporation":false,"usgs":true,"family":"Basu","given":"A.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":364920,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Tatsumoto, Mitsunobu","contributorId":10444,"corporation":false,"usgs":true,"family":"Tatsumoto","given":"Mitsunobu","email":"","affiliations":[],"preferred":false,"id":364919,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":5223357,"text":"5223357 - 1985 - Contaminant residues in fish and sediments from lakes in the Atchafalaya River Basin (Louisiana)","interactions":[],"lastModifiedDate":"2023-12-12T16:12:05.521341","indexId":"5223357","displayToPublicDate":"1985-09-01T12:18:59","publicationYear":"1985","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":"Contaminant residues in fish and sediments from lakes in the Atchafalaya River Basin (Louisiana)","docAbstract":"Conversion of bottomland hardwood forests ℴ agricultural land has reduced habitat and water quality in many lakes in the floodplain of the lower Mississippi River. The objectives of this study were to ascertain current contaminant residue concentrations in fish and sediment from lakes in the Atchafalaya River Basin and to determine the influence of overflow and agricultural land use on contaminant levels. Fish and sediment samples were collected from eight lakes that differed in overflow (no overflow, headwater overflow, backwater overflow) and land-use characteristics (presence or absence of agricultural land). Residue analysis of 24 sediment and 82 fish samples collected from the study lakes showed that contaminant residues were uniformly low. Total DDT concentrations, consisting mainly of DDE, were found in 98% of the fish samples and generally were the highest residues though they rarely exceeded 0.50 μg/g. Dieldrin, α-BHC and γ-BHC, in concentrations rarely exceeding 0.05 μg/g, were detected in about 50% of the fish samples. Total organochlorine pesticide and PCB residues were less than 2.00 μg/g in all fish from all lakes, except for a 3.46 μg/g total in spotted gar (Lepisosteus oculatus) from one lake. Sediments were free from pesticide residues except for occasional traces (0.01 μg/g) of α-BHC. Metal residue concentrations in fish and sediment samples were typical of uncontaminated areas. Lake systems in the Atchafalaya River Basin appeared to be relatively uncontaminated by agricultural pesticides, but metal and organic residues in fish were similar from lakes with the same land-use and overflow characteristics.
","language":"English","publisher":"Springer","doi":"10.1007/BF01055388","usgsCitation":"Winger, P.V., and Andreasen, J.K., 1985, Contaminant residues in fish and sediments from lakes in the Atchafalaya River Basin (Louisiana): Archives of Environmental Contamination and Toxicology, v. 14, no. 5, p. 579-586, https://doi.org/10.1007/BF01055388.","productDescription":"8 p.","startPage":"579","endPage":"586","numberOfPages":"8","costCenters":[{"id":531,"text":"Patuxent Wildlife Research Center","active":true,"usgs":true}],"links":[{"id":199348,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Louisiana","otherGeospatial":"Atchafalaya River Basin","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -89.35068322053141,\n 29.278637011487447\n ],\n [\n -89.98641481029229,\n 29.706700645240673\n ],\n [\n -90.07037935988335,\n 29.977215216142227\n ],\n [\n -90.71810588529938,\n 30.029153141543134\n ],\n [\n -91.197903311534,\n 30.309147206940025\n ],\n [\n -91.63571846297276,\n 30.918204495029755\n ],\n [\n -91.05396408366363,\n 32.17549525199841\n ],\n [\n -91.20989810279053,\n 32.94885275839151\n ],\n [\n -92.82321694850341,\n 32.94885275839151\n ],\n [\n -92.52934102493508,\n 31.41086526110982\n ],\n [\n -92.60730810669784,\n 30.85129000681927\n ],\n [\n -92.57732076755853,\n 30.101817488823315\n ],\n [\n -92.09152171464704,\n 29.550300375725115\n ],\n [\n -91.0239724412757,\n 29.200135832922854\n ],\n [\n -89.35068322053141,\n 29.278637011487447\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"14","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4af6e4b07f02db6929bb","contributors":{"authors":[{"text":"Winger, Parley V.","contributorId":27983,"corporation":false,"usgs":true,"family":"Winger","given":"Parley","email":"","middleInitial":"V.","affiliations":[],"preferred":false,"id":338522,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Andreasen, J. K.","contributorId":38513,"corporation":false,"usgs":true,"family":"Andreasen","given":"J.","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":338521,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70210235,"text":"70210235 - 1985 - The relocation of microearthquakes in the northern Mississippi Embayment","interactions":[],"lastModifiedDate":"2024-06-25T14:42:00.171972","indexId":"70210235","displayToPublicDate":"1985-05-22T07:59:38","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":6453,"text":"Journal of Geophysical Research Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"The relocation of microearthquakes in the northern Mississippi Embayment","docAbstract":"Three-component seismograms, recorded by a small array of digital instruments in the northern Mississippi embayment, consistently show a high-amplitude phase on the vertical component that arrives approximately 0.8 s before the shear wave. On the basis of its timing and apparent velocity, this phase is identified as an S-P conversion from the boundary between the unconsolidated Cenozoic sediments and the underlying Paleozoic rocks. Synthetic models of ground motion in the Mississippi embayment indicate that vertical displacement amplitudes are higher for S-P conversions than for transmitted shear waves at all angles of incidence. The models and their agreement with observations of the three-component seismograms suggest that true shear waves cannot be reliably identified from vertical component seismograms recorded in this area. The travel times of converted phases are used, together with crustal velocity models derived from a recent seismic refraction survey, to relocate approximately 500 microearthquakes recorded by the Central Mississippi Valley regional seismic network. Since the network data are recorded by vertical component seismographs, we assume that the S phases, observed at the stations sited on unconsolidated sediments, are S-P conversions. This assumption significantly reduces the average rms residual and provides well-constrained hypocentral locations for 350 earthquakes. The relocated microearthquakes cluster tightly along previously identified epicentral trends. Focal depths range from 0.5 to 22 km, but events deeper than 14 km are rare, and events shallower than 3 km are confined, almost exclusively, to the area between Ridgely, Tennessee, and New Madrid, Missouri. Focal mechanisms are generally consistent with the results of previous studies. The axial seismicity trend, which extends from Caruthersville, Missouri, to Marked Tree, Arkansas, is characterized by right-lateral strike-slip motion on a northeast trending, nearly vertical fault plane. The events between Ridgely, Tennessee, and New Madrid, Missouri, commonly show strike-slip focal mechanisms, with minor components of both normal and reverse dip slip.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB090iB12p10223","usgsCitation":"Andrews, M., Mooney, W.D., and Meyer, R., 1985, The relocation of microearthquakes in the northern Mississippi Embayment: Journal of Geophysical Research Solid Earth, v. 90, no. B12, p. 10223-10236, https://doi.org/10.1029/JB090iB12p10223.","productDescription":"14 p.","startPage":"10223","endPage":"10236","costCenters":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"links":[{"id":375012,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","otherGeospatial":"Northern Mississippi Embayment","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -92.92236328125,\n 37.055177106660814\n ],\n [\n -88.43994140625,\n 37.055177106660814\n ],\n [\n -88.43994140625,\n 44.402391829093915\n ],\n [\n -92.92236328125,\n 44.402391829093915\n ],\n [\n -92.92236328125,\n 37.055177106660814\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"90","issue":"B12","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","contributors":{"authors":[{"text":"Andrews, M.C.","contributorId":62602,"corporation":false,"usgs":true,"family":"Andrews","given":"M.C.","email":"","affiliations":[],"preferred":false,"id":789699,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mooney, Walter D. 0000-0002-5310-3631 mooney@usgs.gov","orcid":"https://orcid.org/0000-0002-5310-3631","contributorId":3194,"corporation":false,"usgs":true,"family":"Mooney","given":"Walter","email":"mooney@usgs.gov","middleInitial":"D.","affiliations":[{"id":237,"text":"Earthquake Science Center","active":true,"usgs":true}],"preferred":true,"id":789700,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Meyer, R.P.","contributorId":39146,"corporation":false,"usgs":true,"family":"Meyer","given":"R.P.","email":"","affiliations":[],"preferred":false,"id":789701,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70013001,"text":"70013001 - 1985 - The plumbotectonics of the West Shasta mining district, eastern Klamath Mountains, California","interactions":[],"lastModifiedDate":"2024-01-08T23:19:13.416275","indexId":"70013001","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1472,"text":"Economic Geology","active":true,"publicationSubtype":{"id":10}},"title":"The plumbotectonics of the West Shasta mining district, eastern Klamath Mountains, California","docAbstract":"The tectonic setting comprising the West Shasta mining district has often been compared with that of primitive island arcs. Concentrations of uranium, thorium, and lead and lead isotope compositions were determined for Devonian ores and rocks of the West Shasta district, eastern Klamath Mountains, California, to help evaluate the tectonic classification. The lead isotope pattern is found to be complex. From comparison of the data with those on younger ores and rocks in the region and with those isotopic patterns found in modern tectonic terranes, however, a number of conclusions are possible. A lead isotope point for the Devonian oceanic mantle is now well established from this study on the West Shasta district. This isotopic composition is in agreement with that suggested by Slawson in 1983--i.e., from a sample of massive sulfide ore from the Golinsky deposit--with a 206 Pb/ 204 Pb of 17.830, a 207 Pb/ 204 Pb of 15.450, and a 208 Pb/ 204 Pb of 37.313. If the Devonian mantle is analogous to the modern mantle, the determined value is probably at the more radiogenic end of the Devonian oceanic mantle array.Some samples of volcanic rocks and ores that have elevated values of 207 Pb/ 204 Pb and 208 Pb/ 204 Pb indicate that subducted pelagic sediments or interaction of the magmas with other sediments downsection have been involved to varying degrees in the generation of magmas. The high ratios were not attained by addition of lead to the volcanic rocks or ores during subsequent magmatic events, such as intrusion of the Permian Pit River stock to the east or of the Cretaceous Shasta Bally batholith that crops out to the south and west and may underlie part of the district. Some values of 207 Pb/ 204 Pb are sufficiently high as to suggest that West Shasta may have developed nearer a continent than was previously supposed. Lead isotope data for Quaternary volcanic rocks are somewhat more radiogenic than for Cretaceous ores and plutonic rocks. Permo-Triassic ores are again a bit less radiogenic. The isotopic differences between the Permo-Triassic and Quaternary data could be accounted for by a value for 238 U/ 204 Pb of 10.42 in common source material. Using this value of 238 U/ 204 Pb to calculate even further back to 400 m.y., the resulting ratios are found to fall very close to the \"best value\" for the lead isotope mixing line between the Devonian mantle and pelagic sediments. We interpret this intersection to be the \"mean value\" for the assimilated Devonian sediment lead--18.250 for 206 Pb/ 204 Pb and 15.582 for 207 Pb/ 204 Pb. As deduced for the lead isotope composition for the Devonian mantle at this location, the pelagic sediment, lead isotope composition also is toward the more radiogenic end of the values expected for pelagic sediments in the Devonian. Lack of sediments in the observed volcanic section of the West Shasta district suggests a submerged volcanic-arc setting (as interpreted by others for the Troodos and Samail ophiolites) rather than an island-arc situation (such as the Green Tuff area of Japan) or an incipient spreading ridge setting (that might have grown to be a subaerial Iceland). The elevated values of 207 Pb/ 204 Pb for some samples suggest a submerged volcanic are whereas the exceedingly low values of thorium--which is not easily mobilized during alteration events--for both basaltic andesites and plagiorhyolites is suggestive of depleted source material such as is found for most oceanic spreading centers. Elevated values of 207 Pb/ 204 Pb are exceedingly rare in midocean ridge basalts and low contents of thorium are known in island arcs, so a submerged volcanic arc is the preferred interpretation. Some similarity exists between the 206 Pb/ 204 Pb values of Devonian ores having elevated values of 207 Pb/ 204 Pb and those of the Permo-Triassic ores of the East Shasta district, as mentioned by Slawson in 1983. This similarity is now confirmed to be a coincidence. We find it due first of all to some incorporation of sediment lead in the magmas, followed later by some migration of radiogenic lead--probably locally derived--into the ores during subsequent events. Because there was some postdepositional lead migration into the ores, some migration of copper also into the ores cannot be excluded. Lead, especially radiogenic lead, however, is more mobile than copper. As the migrating lead is deduced to have been locally derived from the observed section rather than exotically derived, any copper added was probably locally derived also.
","language":"English","publisher":"Society of Economic Geologists","doi":"10.2113/gsecongeo.80.8.2136","issn":"03610128","usgsCitation":"Doe, B.R., Delevaux, M., and Albers, J.P., 1985, The plumbotectonics of the West Shasta mining district, eastern Klamath Mountains, California: Economic Geology, v. 80, no. 8, p. 2136-2148, https://doi.org/10.2113/gsecongeo.80.8.2136.","productDescription":"13 p.","startPage":"2136","endPage":"2148","numberOfPages":"13","costCenters":[],"links":[{"id":220457,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"80","issue":"8","noUsgsAuthors":false,"publicationDate":"1985-12-01","publicationStatus":"PW","scienceBaseUri":"505baea1e4b08c986b324221","contributors":{"authors":[{"text":"Doe, B. R.","contributorId":52173,"corporation":false,"usgs":true,"family":"Doe","given":"B.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":365040,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Delevaux, M.H.","contributorId":27853,"corporation":false,"usgs":true,"family":"Delevaux","given":"M.H.","email":"","affiliations":[],"preferred":false,"id":365039,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Albers, J. P.","contributorId":81505,"corporation":false,"usgs":true,"family":"Albers","given":"J.","email":"","middleInitial":"P.","affiliations":[],"preferred":false,"id":365041,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70012731,"text":"70012731 - 1985 - Precambrian tholeiitic-dacitic rock-suites and Cambrian ultramafic rocks in the Pennine nappe system of the Alps: Evidence from Sm-Nd isotopes and rare earth elements","interactions":[],"lastModifiedDate":"2012-03-12T17:19:02","indexId":"70012731","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","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":"Precambrian tholeiitic-dacitic rock-suites and Cambrian ultramafic rocks in the Pennine nappe system of the Alps: Evidence from Sm-Nd isotopes and rare earth elements","docAbstract":"Major element, trace element and Sm-Nd isotope analyses were made of polymetamorphic hornblendefelses, plagioclase amphibolites and banded amphibolites from the Berisal complex in the Simplon area (Italy, Switzerland) to determine their age, origin and genetic relationships. In light of major and rare earth element data, the hornblendefelses are inferred to have originally been pyroxene-rich cumulates, the plagioclase amphibolites and the dark layers of the banded amphibolites to have been tholeiitic basalts and the light layers dacites. The Sm-Nd isotope data yield isochron ages of 475??81 Ma for the hornblendefelses, 1,018??59 Ma for the plagioclase amphibolites and 1,071??43 Ma for the banded amphibolites. The 1 Ga magmatic event is the oldest one ever found in the crystalline basement of the Pennine nappes. The Sm -Nd isotope data support the consanguinity of the tholeiitic dark layers and the dacitic light layers of the banded amphibolites with the tholeiitic plagioclase amphibolites and the ultramafic hornblendefelses. The initial e{open}Nd values indicate that all three rock types originated from sources depleted in light rare earth elements. We suggest that plagioclase and banded amphibolites were a Proterozoic tholeiite-dacite sequence that was strongly deformed and flattened during subsequent folding. The hornblendefelses are thought to be Cambrian intrusions of pyroxene-rich material. ?? 1985 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/BF00379452","issn":"00107999","usgsCitation":"Stille, P., and Tatsumoto, M., 1985, Precambrian tholeiitic-dacitic rock-suites and Cambrian ultramafic rocks in the Pennine nappe system of the Alps: Evidence from Sm-Nd isotopes and rare earth elements: Contributions to Mineralogy and Petrology, v. 89, no. 2-3, p. 184-192, https://doi.org/10.1007/BF00379452.","startPage":"184","endPage":"192","numberOfPages":"9","costCenters":[],"links":[{"id":205225,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF00379452"},{"id":222321,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"89","issue":"2-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a8108e4b0c8380cd7b324","contributors":{"authors":[{"text":"Stille, P.","contributorId":70113,"corporation":false,"usgs":true,"family":"Stille","given":"P.","email":"","affiliations":[],"preferred":false,"id":364378,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tatsumoto, M.","contributorId":76798,"corporation":false,"usgs":true,"family":"Tatsumoto","given":"M.","email":"","affiliations":[],"preferred":false,"id":364379,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70012951,"text":"70012951 - 1985 - Geology of the Silsilah ring complex, and associated tin mineralization, Kingdom of Saudi Arabia - a synopsis.","interactions":[],"lastModifiedDate":"2012-03-12T17:19:04","indexId":"70012951","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":738,"text":"American Mineralogist","active":true,"publicationSubtype":{"id":10}},"title":"Geology of the Silsilah ring complex, and associated tin mineralization, Kingdom of Saudi Arabia - a synopsis.","docAbstract":"A tin greisen deposit is associated with an alkali-feldspar granite that forms part of a ring complex at Jabal as Silsilah. The petrological and geochemical characteristics of the Fawwarah alkali-feldspar granite resemble those of granites located elsewhere that are also associated with deposits of Sn, W and rare metals. The alkali-feldspar granite is peraluminous, incompatible trace-element-enriched, and is characterized by a flat chondrite-normalized REE pattern that includes a very large, negative Eu anomaly. The distinctive mineralogy of the alkali-feldspar granite includes zinnwaldite and topaz. Differentiation and mineral fractionation controlled magma evolution while components of the ring complex were sequentially emplaced. Evolution of the ring complex and its associated tin deposit concluded with local, intense alteration of the Fawwarah alkali-feldspar granite to a cassiterite-bearing greisen. Samples of greisens suggest that the locus of economic tin deposits is not restricted to the two known, strongly mineralized greisens.-J.A.Z.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"American Mineralogist","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"0003004X","usgsCitation":"Bray, D., 1985, Geology of the Silsilah ring complex, and associated tin mineralization, Kingdom of Saudi Arabia - a synopsis.: American Mineralogist, v. 70, no. 11-12, p. 1075-1086.","startPage":"1075","endPage":"1086","numberOfPages":"12","costCenters":[],"links":[{"id":221860,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"70","issue":"11-12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2688e4b0c8380cd5913f","contributors":{"authors":[{"text":"Bray, du","contributorId":28749,"corporation":false,"usgs":true,"family":"Bray","given":"du","email":"","affiliations":[],"preferred":false,"id":364921,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":96349,"text":"96349 - 1985 - 1985 Rare Plant Study Findings. A Report to the California State Dept. of Fish and Game, Endangered Plant Species Program and the Superintendent, Channel Islands National Park","interactions":[],"lastModifiedDate":"2012-02-02T00:03:56","indexId":"96349","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":9,"text":"Other Report"},"title":"1985 Rare Plant Study Findings. A Report to the California State Dept. of Fish and Game, Endangered Plant Species Program and the Superintendent, Channel Islands National Park","docAbstract":"No abstract available at this time","language":"English","usgsCitation":"Fowler, R., and Halvorson, W.L., 1985, 1985 Rare Plant Study Findings. A Report to the California State Dept. of Fish and Game, Endangered Plant Species Program and the Superintendent, Channel Islands National Park.","costCenters":[{"id":651,"text":"Western Ecological Research Center","active":true,"usgs":true}],"links":[{"id":127662,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b32e4b07f02db6b45ae","contributors":{"authors":[{"text":"Fowler, R.","contributorId":30572,"corporation":false,"usgs":true,"family":"Fowler","given":"R.","email":"","affiliations":[],"preferred":false,"id":299485,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Halvorson, W. L.","contributorId":26246,"corporation":false,"usgs":true,"family":"Halvorson","given":"W.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":299484,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70012741,"text":"70012741 - 1985 - HIGH-ANGLE AEOLIAN CROSSBEDDING AT TRAIL RIDGE, FLORIDA.","interactions":[],"lastModifiedDate":"2012-03-12T17:19:08","indexId":"70012741","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1985,"text":"Industrial Minerals","active":true,"publicationSubtype":{"id":10}},"title":"HIGH-ANGLE AEOLIAN CROSSBEDDING AT TRAIL RIDGE, FLORIDA.","docAbstract":"This paper described new evidence concerning the origin of the Trail Ridge mineral sands deposit in Florida. Rarely exposed sections of the orebody exhibit structures indicative of sand dune formation rather than coastal beach sand accumulation. The implications for mineral sands exploration, and therefore resources, in the southeastern USA are highlighted.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Industrial Minerals","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"00198544","usgsCitation":"Force, E., and Garnar, T., 1985, HIGH-ANGLE AEOLIAN CROSSBEDDING AT TRAIL RIDGE, FLORIDA.: Industrial Minerals, no. 215.","costCenters":[],"links":[{"id":222493,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"215","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2e7de4b0c8380cd5c5b4","contributors":{"authors":[{"text":"Force, Eric","contributorId":41918,"corporation":false,"usgs":true,"family":"Force","given":"Eric","affiliations":[],"preferred":false,"id":364404,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Garnar, Tom","contributorId":17373,"corporation":false,"usgs":true,"family":"Garnar","given":"Tom","email":"","affiliations":[],"preferred":false,"id":364403,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70012750,"text":"70012750 - 1985 - Analysis of low levels of rare earths by radiochemical neutron activation analysis","interactions":[],"lastModifiedDate":"2012-03-12T17:19:05","indexId":"70012750","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2440,"text":"Journal of Radioanalytical and Nuclear Chemistry Articles","active":true,"publicationSubtype":{"id":10}},"title":"Analysis of low levels of rare earths by radiochemical neutron activation analysis","docAbstract":"A procedure for the radiochemical neutron-activation analysis for the rare earth elements (REE) involves the separation of the REE as a group by rapid ion-exchange methods and determination of yields by reactivation or by energy dispersive X-ray fluorescence (EDXRF) spectrometry. The U. S. Geological Survey (USGS) standard rocks, BCR-1 and AGV-1, were analyzed to determine the precision and accuracy of the method. We found that the precision was ??5-10% on the basis of replicate analysis and that, in general the accuracy was within ??5% of accepted values for most REE. Data for USGS standard rocks BIR-1 (Icelandic basalt) and DNC-1 (North Carolina diabase) are also presented. ?? 1985 Akade??miai Kiado??.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Radioanalytical and Nuclear Chemistry Articles","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisherLocation":"Kluwer Academic Publishers","doi":"10.1007/BF02219757","issn":"02365731","usgsCitation":"Wandless, G., and Morgan, J.W., 1985, Analysis of low levels of rare earths by radiochemical neutron activation analysis: Journal of Radioanalytical and Nuclear Chemistry Articles, v. 92, no. 2, p. 273-282, https://doi.org/10.1007/BF02219757.","startPage":"273","endPage":"282","numberOfPages":"10","costCenters":[],"links":[{"id":205272,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/BF02219757"},{"id":222610,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"92","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059eb1fe4b0c8380cd48c2f","contributors":{"authors":[{"text":"Wandless, G.A.","contributorId":107716,"corporation":false,"usgs":true,"family":"Wandless","given":"G.A.","affiliations":[],"preferred":false,"id":364434,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Morgan, J. W.","contributorId":92384,"corporation":false,"usgs":true,"family":"Morgan","given":"J.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":364433,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70012908,"text":"70012908 - 1985 - Pollen analysis of a late pliocene and early pleistocene section from the Gubik Formation of Arctic Alaska","interactions":[],"lastModifiedDate":"2013-01-26T15:38:50","indexId":"70012908","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3218,"text":"Quaternary Research","active":true,"publicationSubtype":{"id":10}},"title":"Pollen analysis of a late pliocene and early pleistocene section from the Gubik Formation of Arctic Alaska","docAbstract":"A 14-m-thick section of marine and nonmarine sediments of the Gubik Formation of northern Alaska, exposed in bluffs near Ocean Point on the Colville River, has been studied by means of pollen analysis. Pollen from the marine sediments, of probable late Pliocene age, records a boreal forest of spruce and birch with minor amounts of alder in the adjacent terrestrial vegetation. Pine and perhaps true fir were probably at or near their northern limit here, but hemlocks and hardwoods were absent. The suggested environment for the Arctic Slope during the time represented by the marine sediments is similar to that of present-day Anchorage. Pollen floras from the overlying fluvial strata, of early or middle Pleistocene age, record predominantly herbaceous taxa indicating tundra conditions probably more severe than those of the present day. These deposits were most likely contemporaneous with glacial conditions in the Brooks Range to the south. Pollen of woody taxa (spruce, alder, birch, heaths) is rare through most of the section, although birch and alder percentages similar to those found in modern river sediments indicate an interstadial or interglacial warming in midsection. Inland climates during glacial episodes may have been similar to those of the present Arctic coast. ?? 1985.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Quaternary Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","publisherLocation":"Amsterdam, Netherlands","doi":"10.1016/0033-5894(85)90052-3","issn":"00335894","usgsCitation":"Nelson, R., and Carter, L.D., 1985, Pollen analysis of a late pliocene and early pleistocene section from the Gubik Formation of Arctic Alaska: Quaternary Research, v. 24, no. 3, p. 295-306, https://doi.org/10.1016/0033-5894(85)90052-3.","startPage":"295","endPage":"306","numberOfPages":"12","costCenters":[],"links":[{"id":266548,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/0033-5894(85)90052-3"},{"id":222231,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"24","issue":"3","noUsgsAuthors":false,"publicationDate":"2017-01-20","publicationStatus":"PW","scienceBaseUri":"505a7ccde4b0c8380cd79bb3","contributors":{"authors":[{"text":"Nelson, R.E.","contributorId":53881,"corporation":false,"usgs":true,"family":"Nelson","given":"R.E.","email":"","affiliations":[],"preferred":false,"id":364808,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Carter, L. D.","contributorId":87959,"corporation":false,"usgs":true,"family":"Carter","given":"L.","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":364809,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70013060,"text":"70013060 - 1985 - Root zone of the late Proterozoic Salma caldera, northeastern Arabian Shield, Kingdom of Saudi Arabia","interactions":[],"lastModifiedDate":"2024-06-27T15:36:35.888731","indexId":"70013060","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":6453,"text":"Journal of Geophysical Research Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Root zone of the late Proterozoic Salma caldera, northeastern Arabian Shield, Kingdom of Saudi Arabia","docAbstract":"The eroded root of the late Proterozoic Salma caldera crops out in a striking, roughly elliptical feature, about 27 km long and 22 km wide, near the northeastern edge of the Arabian Shield. The caldera is genetically part of an elongate alkalic granitic massif (Jabal Salma) that extends 35 km from the caldera to the southwest. Comenditic ash flow tuff and lava(?) of the caldera fill, probably more than 1 km thick, are the oldest recognized rocks of the caldera complex. These rocks were erupted during caldera collapse associated with the rapid evacuation of the upper, mildly peralkalic part of a zoned magma reservoir. Within the caldera fill, a massive, lithic-rich intracaldera rhyolite, probably a lava in excess of 1 km thick, is overlain by a layered ash flow sequence. Numerous megabreccia blocks, probably derived from the caldera wall, occur in the massive rhyolite. Open folds in the layered volcanic rocks may be due to high-temperature slumping of the rocks toward the center of the caldera following collapse. Later peralkalic granite that intruded the caldera ring fracture zone occurs in an arcuate pattern outside the area of exposed caldera fill. After caldera collapse, metaluminous to peraluminous magma rose beneath the caldera at approximately 580 Ma and solidified as biotite alkali granite, rim syenogranite, and late, high-level granophyre. Rare earth element abundances indicate that the layered rhyolite tuff, peralkalic granite, and granophyre are chemically more evolved than the biotite alkali granite and rim syenogranite. The granophyre intruded the caldera fill as a dome-shaped body composed of numerous sheetlike masses. Granophyric texture resulted from rapid pressure release and quenching accompanying the intrusion of each sheet. Maximum penetration of the granophyre into overlying rocks occurred in the central region and along the west side of the caldera, where the caldera fill volcanic rocks have been removed by erosion. No apparent structural doming of the exposed volcanic rocks along the east side of the caldera took place; the layered ash flows commonly dip steeply toward the center of the caldera. Postemplacement deformation and metamorphism of the caldera are minimal. Small-displacement strike-slip faults cut the complex, which is tilted to the northeast by no more than about 2°.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB090iB13p11253","issn":"01480227","usgsCitation":"Kellogg, K., 1985, Root zone of the late Proterozoic Salma caldera, northeastern Arabian Shield, Kingdom of Saudi Arabia: Journal of Geophysical Research Solid Earth, v. 90, no. B13, p. 11253-11262, https://doi.org/10.1029/JB090iB13p11253.","productDescription":"10 p.","startPage":"11253","endPage":"11262","costCenters":[],"links":[{"id":220289,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"90","issue":"B13","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505aae8ae4b0c8380cd8710c","contributors":{"authors":[{"text":"Kellogg, K.S.","contributorId":99145,"corporation":false,"usgs":true,"family":"Kellogg","given":"K.S.","email":"","affiliations":[],"preferred":false,"id":365196,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70012746,"text":"70012746 - 1985 - Ages of tuff beds at East African early hominid sites and sediments in the Gulf of Aden","interactions":[],"lastModifiedDate":"2012-03-12T17:19:06","indexId":"70012746","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2840,"text":"Nature","active":true,"publicationSubtype":{"id":10}},"title":"Ages of tuff beds at East African early hominid sites and sediments in the Gulf of Aden","docAbstract":"The early hominids of East Africa were dated by determining the ages of tuff beds at the sites. Despite much research using palaeomagnetic and K/Ar-dating techniques, some of those ages are still controversial 1,2. To obtain independent age estimates for these tephra layers, we have examined cores from DSDP Sites 231 and 232 in the Gulf of Aden (Fig. 1a) which consist mainly of calcareous nannofossil ooze, but also contain rare tephra horizons3 dated by interpolation from the established nannofossil stratigraphy (Fig. 1b). Chemical analysis confirms that the identity and sequence of these horizons is the same as that at the East African sites. We conclude that the age of the Tulu Bor Tuff is <3.4 Myr and hence that the Hadar hominid specimens are also Colonial rugose corals are rare and generally poorly diversified in the Upper Pennsylvanian of the western interior region, conterminous USA. Paraheritschioides n.gen., which includes P. grandis n.sp., and P. complexa n.sp. from the Oquirrh Formation in Idaho, provides a new tool for distinguishing Upper Pennsylvanian rocks in the western interior. The new genus is also represented by P. stevensi (Wilson) in the Permian McCloud Limestone of northern California. The new family Heritschioididae is created to include Paraheritschioides, Heritschioides, Amandophyllum and Heintzella.","language":"English","publisher":"Paleontology Society","issn":"00223360","usgsCitation":"Sando, W., 1985, Paraheritschioides, a new rugose coral genus from the Upper Pennsylvanian of Idaho: Journal of Paleontology, v. 59, no. 4, p. 979-985.","productDescription":"7 p.","startPage":"979","endPage":"985","numberOfPages":"7","costCenters":[],"links":[{"id":430688,"rank":2,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.geoscienceworld.org/jpaleontol/article/59/4/979/108175/paraheritschioides-a-new-rugose-coral-genus-from"},{"id":222044,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"59","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a74c8e4b0c8380cd77817","contributors":{"authors":[{"text":"Sando, W.J.","contributorId":59470,"corporation":false,"usgs":true,"family":"Sando","given":"W.J.","email":"","affiliations":[],"preferred":false,"id":364781,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70012907,"text":"70012907 - 1985 - Geochemistry and petrogenesis of lamproites, late cretaceous age, Woodson County, Kansas, U.S.A.","interactions":[],"lastModifiedDate":"2024-03-19T16:57:59.645656","indexId":"70012907","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","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":"Geochemistry and petrogenesis of lamproites, late cretaceous age, Woodson County, Kansas, U.S.A.","docAbstract":"Lamproite sills and their associated sedimentary and contact metamorphic rocks from Woodson County, Kansas have been analyzed for major elements, selected trace elements, and strontium isotopic composition. These lamproites, like lamproites elsewhere, are alkalic (molecular
Ba and, to a lesser extent, K and Rb and have been transported from the intrusions at shallow depth into the surrounding contact metamorphic zone. The Silver City lamproite has vertical fractionation of some elements due either to volatile transport or to variations in the abundance of phenocrysts relative to groundmass most probably due to flow differentiation although multiple injection or fractional crystallization cannot be conclusively rejected.
","language":"English","publisher":"Elsevier","doi":"10.1016/0016-7037(85)90289-3","issn":"00167037","usgsCitation":"Cullers, R., Ramakrishnan, S., Berendsen, P., and Griffin, T., 1985, Geochemistry and petrogenesis of lamproites, late cretaceous age, Woodson County, Kansas, U.S.A.: Geochimica et Cosmochimica Acta, v. 49, no. 6, p. 1383-1402, https://doi.org/10.1016/0016-7037(85)90289-3.","productDescription":"20 p.","startPage":"1383","endPage":"1402","numberOfPages":"20","costCenters":[],"links":[{"id":222230,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"49","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a16dbe4b0c8380cd552b2","contributors":{"authors":[{"text":"Cullers, R.L.","contributorId":103007,"corporation":false,"usgs":true,"family":"Cullers","given":"R.L.","email":"","affiliations":[],"preferred":false,"id":364806,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ramakrishnan, S.","contributorId":71698,"corporation":false,"usgs":true,"family":"Ramakrishnan","given":"S.","email":"","affiliations":[],"preferred":false,"id":364805,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Berendsen, P.","contributorId":68037,"corporation":false,"usgs":true,"family":"Berendsen","given":"P.","affiliations":[],"preferred":false,"id":364804,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Griffin, T.","contributorId":108252,"corporation":false,"usgs":true,"family":"Griffin","given":"T.","email":"","affiliations":[],"preferred":false,"id":364807,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70012764,"text":"70012764 - 1985 - Mineralization of breccia pipes in northern Arizona","interactions":[],"lastModifiedDate":"2024-01-08T23:38:46.572288","indexId":"70012764","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1472,"text":"Economic Geology","active":true,"publicationSubtype":{"id":10}},"title":"Mineralization of breccia pipes in northern Arizona","docAbstract":"The Paleozoic sedimentary rocks on the Colorado Plateau of northern Arizona are host to hundreds ofbreccia pipes. The uranium and copper deposits in these breccia pipes transgress formation boundaries from the Mississippian Redwall Limestone to the Triassic Chinle Formation. They are not classic breccia pipes in that there is no volcanic rock associated with them in time or space. They are the result of solution-collapse within the Redwall Limestone and stoping of the overlying strata. The karst development in the Redwall Limestone began in the Mississippian and apparently either continued to the Triassic or was at least once again active during that time. The mineralization apparently occurred shortly thereafter, sometime during the Mesozoic. Mining activity in breccia pipes of the Grand Canyon region began during the nineteenth century and continues today with the operation of the Hack I, II, and III mines, although the exploited commodity has changed from Cu to U. Although small in size, these pipes contain samples with up to 55 percent U 3 O 8 and can yield ore averaging between 0.30 and 0.60 percent U 3 O 8 .Mineralization at the surface commonly occurs within nodules and concretions associated with pyrite and goethite and along fractures, while the primary ore of the unoxidized zones is commonly within a comminuted sandstone matrix surrounding breccia fragments of overlying formations. The ore mineral is uraninite, although associated with it are sphalerite, galena, chalcopyrite, tennantite, millerite, siegenite, and/molybdenite. Some of the surface nodules are encrusted with malachite and are exceptionally enriched in Ag. Pyrite is abundant, and the organic carbon content of some rocks is high enough to suggest that it, along with the pyrite, may be a reductant for uranium. In contrast, it is possible, if uranium were transported as a bicarbonate or carbonate complex, that only a conduit of brecciated rock was necessary to release CO 2 , thus disrupting the equilibrium and allowing uraninite to precipitate. An extensive suite of elements is significantly enriched in the mineralized rock: Ag, As, Ba, Cd, Co, Cr, Cs, Cu, Hg, Mo, Ni, Pb, Sb, Se, Sr, U, V, Zn, and the rare earth elements. Of these, Cu, Pb, Zn, Ag, and particularly As appear to be the best geochemical indicators of mineralized pipes. At present the origin of the mineralizing fluids is not known. The lack of extensive silification within the breccia, along with the 80 degrees to 173 degrees C fluid inclusion-filling temperatures on sphalerite, dolomite, quartz, and calcite, suggests relatively low-temperature mineralizing fluids, although heated in excess of what would be expected from the normal geothermal gradient on the Colorado Plateau. With the exception of the U-mineralized rock, the mineral assemblage and geochemistry is similar to Mississippi Valley-type deposits.
","language":"English","publisher":"Society of Economic Geologists","doi":"10.2113/gsecongeo.80.6.1722","issn":"03610128","usgsCitation":"Wenrich, K.J., 1985, Mineralization of breccia pipes in northern Arizona: Economic Geology, v. 80, no. 6, p. 1722-1735, https://doi.org/10.2113/gsecongeo.80.6.1722.","productDescription":"14 p.","startPage":"1722","endPage":"1735","numberOfPages":"14","costCenters":[],"links":[{"id":221844,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"80","issue":"6","noUsgsAuthors":false,"publicationDate":"1985-10-01","publicationStatus":"PW","scienceBaseUri":"505a5a83e4b0c8380cd6ef15","contributors":{"authors":[{"text":"Wenrich, Karen J.","contributorId":19177,"corporation":false,"usgs":true,"family":"Wenrich","given":"Karen","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":364462,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70012392,"text":"70012392 - 1985 - The McKinley Sequence of granitic rocks: A key element in the accretionary history of southern Alaska","interactions":[],"lastModifiedDate":"2024-06-27T15:44:19.906636","indexId":"70012392","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":6453,"text":"Journal of Geophysical Research Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"The McKinley Sequence of granitic rocks: A key element in the accretionary history of southern Alaska","docAbstract":"The McKinley sequence of granitic rocks consists of several discrete plutons in the central Alaska Range. Most of these plutons crop out south of the Denali fault system (DFS) in the Talkeetna quadrangle. Plutons of the McKinley sequence largely intrude deformed upper Meszoic flysch between the DFS and the northern edges of Wrangellia and the Peninsular terrane, which jointly make up the Talkeetna superterrane. The average K-Ar age of biotite from nine granites of the McKinley sequence is 57.3 Ma; Rb-Sr data for whole rock samples indicate that the McKinley sequence cannot be older than 60 Ma. A selected suite of 20 samples of granite and granodiorite range in SiO2 from 65.9 to 77.6%. All 20 samples are corundum normative, and 18 are moderately peraluminous. Initial 87Sr/86Sr ratios range from 0.7054 to 0.7085. The σ18O values range from +11.2 to +14.6‰. These high and variable Sr isotopic ratios, peraluminous nature, rare earth element patterns, and high σ18O values suggest that granitic rocks of the McKinley sequence crystallized from hybrid magmas produced by assimilation of sedimentary rocks by a mantle-derived melt. Mesozoic flysch is the likely source of the crustal component of the hybrid magmas. Geologic evidence suggests that the Talkeetna superterrane collided with stable Alaska after Early Cretaceous time. The flysch basin, lying south of stable Alaska, was closed by northward movement of the Talkeetna superterrane; maximum age for basin closure and terrane accretion is middle Cretaceous (Cenomanian). Paleomagnetic evidence indicates that all terranes north of the DFS have been part of stable Alaska since the Paleocene and that northward movement of Wrangellia was completed by 50 Ma. Granitic rocks of the McKinley sequence may be products of terrane accretion; the granitic rocks crystallized from hybrid magmas produced during terrane collision and deformation of the flysch basin. Isotopic ages of the McKinley sequence establish the time of final accretion of the Talkeetna superterrane as Paleocene.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/JB090iB13p11413","issn":"01480227","usgsCitation":"Lanphere, M.A., and Reed, B., 1985, The McKinley Sequence of granitic rocks: A key element in the accretionary history of southern Alaska: Journal of Geophysical Research Solid Earth, v. 90, no. B13, p. 11413-11430, https://doi.org/10.1029/JB090iB13p11413.","productDescription":"18 p.","startPage":"11413","endPage":"11430","costCenters":[],"links":[{"id":222475,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"90","issue":"B13","noUsgsAuthors":false,"publicationDate":"2012-09-20","publicationStatus":"PW","scienceBaseUri":"505ba7dde4b08c986b321855","contributors":{"authors":[{"text":"Lanphere, M. A.","contributorId":35298,"corporation":false,"usgs":true,"family":"Lanphere","given":"M.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":363435,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Reed, B.L.","contributorId":29434,"corporation":false,"usgs":true,"family":"Reed","given":"B.L.","email":"","affiliations":[],"preferred":false,"id":363434,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70135813,"text":"70135813 - 1985 - Why deposits of longitudinal dunes are rarely recognized in the geologic record","interactions":[],"lastModifiedDate":"2014-12-17T13:41:56","indexId":"70135813","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3369,"text":"Sedimentology","active":true,"publicationSubtype":{"id":10}},"title":"Why deposits of longitudinal dunes are rarely recognized in the geologic record","docAbstract":"Dunes that are morphologically of linear type, many of which are probably of longitudinal type in a morphodynamic sense, are common in modern deserts, but their deposits are rarely identified in aeolian sandstones. One reason for non-recognition of such dunes is that they can migrate laterally when they are not exactly parallel to the long-term sand-transport direction, thereby depositing cross-strata that have unimodal cross-bed dip directions and consequently resemble deposits of transverse dunes. Dune-parallel components of sand transport can be recognized in ancient aeolian sands by examining compound cross-bedding formed by small dunes that migrated across the lee slopes of large dunes and documenting that the small dunes migrated with a component in a preferred along-crest direction over the large dunes.
","language":"English","publisher":"Wiley","doi":"10.1111/j.1365-3091.1985.tb00498.x","usgsCitation":"Rubin, D.M., and Hunter, R., 1985, Why deposits of longitudinal dunes are rarely recognized in the geologic record: Sedimentology, v. 32, no. 1, p. 147-157, https://doi.org/10.1111/j.1365-3091.1985.tb00498.x.","productDescription":"11 p.","startPage":"147","endPage":"157","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true}],"links":[{"id":296761,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"32","issue":"1","noUsgsAuthors":false,"publicationDate":"2006-06-14","publicationStatus":"PW","scienceBaseUri":"5492b748e4b00eda8915ad33","contributors":{"authors":[{"text":"Rubin, David M. 0000-0003-1169-1452 drubin@usgs.gov","orcid":"https://orcid.org/0000-0003-1169-1452","contributorId":3159,"corporation":false,"usgs":true,"family":"Rubin","given":"David","email":"drubin@usgs.gov","middleInitial":"M.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":536896,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hunter, Ralph E.","contributorId":53759,"corporation":false,"usgs":true,"family":"Hunter","given":"Ralph E.","affiliations":[],"preferred":false,"id":536897,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70175195,"text":"70175195 - 1985 - Abundance fluctuations among benthic invertebrates in two pacific estuaries","interactions":[],"lastModifiedDate":"2016-08-02T13:26:53","indexId":"70175195","displayToPublicDate":"1985-01-01T00:00:00","publicationYear":"1985","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1583,"text":"Estuaries","active":true,"publicationSubtype":{"id":10}},"title":"Abundance fluctuations among benthic invertebrates in two pacific estuaries","docAbstract":"Long-term studies were used to examine (1) contrasting time scales and mechanisms of structural variations within two benthic communities and (2) the usefulness of long data sets for evaluating human impact. A 10-year study of a San Francisco Bay mudflat, the details of which are reported elsewhere, has revealed large short-term (on the order of months) variations in species abundances within a community composed predominantly of opportunistic species. The study site, located in a highly urbanized estuary, is subject to the influence of a nearby sewage-treatment facility. However, rapid changes in population size of the common species, in part due to periodic natural habitat disturbance, impedes the detection of anthropogenic influences on community composition. Only a very long-term data set may provide evidence of progressive change. Data collected for a 20-year period on the benthic community at 200 m depth in the main basin of Puget Sound, an environment subject to little apparent habitat disturbance show that numerical abundance of the common species can also change markedly. Here, however, numerical dominance shifts from one species to another at irregular, multiyear intervals. Recent increases in two heretofore rare species, and a significant increase in total numbers of individuals suggest that long-term changes may be occurring in this community. These two long-term data sets demonstrate the importance of measuring both the amplitude and the periodicity of fluctuations in population size of aquatic species as well as long-term fluctuations and patterns in environmental factors before attempting to demonstrate the effect of anthropogenic influences on aquatic communities. The results of these studies also demonstrate the usefulness of long-term data sets for revealing the potential importance of interactions among species in determining abundance patterns in the soft-bottom benthos.
","language":"English","publisher":"Springer","doi":"10.2307/1351863","usgsCitation":"Nichols, F.H., 1985, Abundance fluctuations among benthic invertebrates in two pacific estuaries: Estuaries, v. 8, no. 2, p. 136-144, https://doi.org/10.2307/1351863.","productDescription":"9 p.","startPage":"136","endPage":"144","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":552,"text":"San Francisco Bay-Delta","active":false,"usgs":true},{"id":5079,"text":"Pacific Regional Director's Office","active":true,"usgs":true}],"links":[{"id":325930,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"8","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"57a1c42ce4b006cb45552bea","contributors":{"authors":[{"text":"Nichols, Frederic H.","contributorId":25548,"corporation":false,"usgs":true,"family":"Nichols","given":"Frederic","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":644294,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70162158,"text":"70162158 - 1984 - Appearance and quantification of infectious hematopoietic necrosis virus in female sockeye salmon (Oncorhynchus nerka) during their spawning migration","interactions":[],"lastModifiedDate":"2016-01-14T11:16:39","indexId":"70162158","displayToPublicDate":"2015-09-15T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":892,"text":"Archives of Virology","active":true,"publicationSubtype":{"id":10}},"title":"Appearance and quantification of infectious hematopoietic necrosis virus in female sockeye salmon (Oncorhynchus nerka) during their spawning migration","docAbstract":"The incidence and amount of infectious hematopoietic necrosis (IHN) virus was determined in 10 organs and body fluids from each of 100 female sockeye salmon(Oncorhynchus nerka) before, during, and after their spawning migration into freshwater. Virus was found in high concentrations only in fish sampled during and after spawning. Infection rates increased from nil to 100 percent within 2 weeks. In spawning fish, incidences of IHN virus were high in all organs and fluids except brain and serum, and the highest concentrations were in the pyloric caeca and lower gut. Immediately before spawning, IHN virus was found most frequently in the gills, less frequently in the pyloric caeca and spleen, and rarely in other organs.
","language":"English","publisher":"Springer-Verlag","doi":"10.1007/BF01310657","usgsCitation":"Mulcahy, D., Jenes, C., and Pascho, R., 1984, Appearance and quantification of infectious hematopoietic necrosis virus in female sockeye salmon (Oncorhynchus nerka) during their spawning migration: Archives of Virology, v. 80, no. 2-3, p. 171-181, https://doi.org/10.1007/BF01310657.","productDescription":"11 p.","startPage":"171","endPage":"181","numberOfPages":"11","costCenters":[{"id":654,"text":"Western Fisheries Research Center","active":true,"usgs":true}],"links":[{"id":314335,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"80","issue":"2-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5698d4bde4b0fbd3f7fa4c0c","contributors":{"authors":[{"text":"Mulcahy, D.","contributorId":82642,"corporation":false,"usgs":true,"family":"Mulcahy","given":"D.","email":"","affiliations":[],"preferred":false,"id":588710,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Jenes, C.K.","contributorId":152262,"corporation":false,"usgs":false,"family":"Jenes","given":"C.K.","email":"","affiliations":[],"preferred":false,"id":588711,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Pascho, R.J.","contributorId":65796,"corporation":false,"usgs":true,"family":"Pascho","given":"R.J.","email":"","affiliations":[],"preferred":false,"id":588712,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":5221934,"text":"5221934 - 1984 - Recuperation of a severely debilitated wolf","interactions":[],"lastModifiedDate":"2024-07-19T11:04:23.663523","indexId":"5221934","displayToPublicDate":"2010-06-16T12:19:24","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2507,"text":"Journal of Wildlife Diseases","active":true,"publicationSubtype":{"id":10}},"title":"Recuperation of a severely debilitated wolf","docAbstract":"Opportunities are rare for determining the degree to which an animal can starve and still survive. Therefore we describe here an incident in which a wild wolf (Canis lupus) starved almost to death and was then restored to her former free-ranging state. The incident took place in northern Lake County, Minnesota
","language":"English","publisher":"Wildlife Disease Association","doi":"10.7589/0090-3558-20.2.166","usgsCitation":"Mech, L., Seal, U., and Arthur, S., 1984, Recuperation of a severely debilitated wolf: Journal of Wildlife Diseases, v. 20, no. 2, p. 166-168, https://doi.org/10.7589/0090-3558-20.2.166.","productDescription":"3 p.","startPage":"166","endPage":"168","numberOfPages":"3","costCenters":[{"id":531,"text":"Patuxent Wildlife Research Center","active":true,"usgs":true}],"links":[{"id":197441,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"20","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a60e4b07f02db6353c8","contributors":{"authors":[{"text":"Mech, L.D. 0000-0003-3944-7769","orcid":"https://orcid.org/0000-0003-3944-7769","contributorId":75466,"corporation":false,"usgs":false,"family":"Mech","given":"L.D.","email":"","affiliations":[],"preferred":false,"id":335067,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Seal, U.S.","contributorId":40564,"corporation":false,"usgs":false,"family":"Seal","given":"U.S.","email":"","affiliations":[],"preferred":false,"id":335065,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Arthur, S.M.","contributorId":65195,"corporation":false,"usgs":true,"family":"Arthur","given":"S.M.","email":"","affiliations":[],"preferred":false,"id":335066,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70013151,"text":"70013151 - 1984 - Geochemical investigation of Archaean Bimodal and Dwalile metamorphic suites, Ancient Gneiss Complex, Swaziland","interactions":[],"lastModifiedDate":"2025-06-25T16:51:09.565498","indexId":"70013151","displayToPublicDate":"2003-04-10T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3112,"text":"Precambrian Research","active":true,"publicationSubtype":{"id":10}},"title":"Geochemical investigation of Archaean Bimodal and Dwalile metamorphic suites, Ancient Gneiss Complex, Swaziland","docAbstract":"The bimodal suite (BMS) comprises leucotonalitic and trondhjemitic gneisses interlayered with amphibolites. Based on geochemical parameters three main groups of siliceous gneiss are recognized: (i) SiO2 < 73%, Al2O3 > 14%, and fractionated light rare-earth element (REE) and flat heavy REE patterns; (ii) SiO2 and Al2O3 contents similar to (i) but with strongly fractionated REE patterns with steep heavy REE slopes; (iii) SiO2 > 73%, Al2O3 < 14%, Zr ∼ 500 ppm and high contents of total REE having fractionated light REE and flat heavy REE patterns with large negative Eu anomalies. The interlayered amphibolites have major element abundances similar to those of basaltic komatiites, Mg-tholeiites and Fe-rich tholeiites. The former have gently sloping REE patterns, whereas the Mg-tholeiites have non-uniform REE patterns ranging from flat (∼ 10 times chondrite) to strongly light REE-enriched. The Fe-rich amphibolites have flat REE patterns at 20–30 times chondrite.
The Dwalile metamorphic suite, which is preserved in the keels of synforms within the BMS, includes peridotitic komatiites that have depleted light REE patterns similar to those of compositionally similar volcanics in the Onverwacht Group, Barberton, basaltic komatiites and tholeiites. The basaltic komatiites have REE patterns parallel to those of the BMS basaltic komatiites but with lower total REE contents. The Dwalile tholeiites have flat REE patterns.
The basic and ultrabasic liquids were derived by partial melting of a mantle source which may have been heterogeneous or the heterogeneity may have resulted from sequential melting of the mantle source. The Fe-rich amphibolites were derived either from liquids generated at shallow levels or from liquids generated at depth which subsequently underwent extensive fractionation.
The Qufar quadrangle, south of the city of Ha' il in the northern Arabian Shield is underlain by late Proterozoic granitic and dioritic rocks and two volcano-sedimentary sequences. Phanerozoic rocks include a few outcrops of the Cambrian and Ordovician Saq Sandstone and small remnants of Miocene basalt flows and plugs.
\nThe oldest rocks in the quadrangle comprise the Nuf formation, a layered sequence of submarine, tholeiitic metabasalt and meta-andesite, and interbedded metagraywacke and marble. The Nuf formation may correlate with rocks mapped as Halaban or Hulayfah group (approximately 780-720 Ma old) to the south of the quadrangle. Cogenetic subvolcanic rocks include gabbro and diorite. Voluminous plutonic rocks of approximately monzogranite composition intruded and dismembered the Nuf formation, gabbro, and diorite, which were simultaneously metamorphosed and internally deformed. Metamorphism of the Nuf formation was variable, but generally' upper greenstone-facies assemblages were produced.
\nFollowing a period of extensive erosion, the Hadn formation, dacitic to rhyolitic ignimbrite and flow breccia, and interbedded subgraywacke, arkose, and minor conglomerate was deposited. The Hadn formation may be a continental equivalent of the Murdama group, which is mapped to the south of the quadrangle and is approximately 650 to 610 Ma old.
\nNumerous plutons, predominantly monzogranite, but ranging from gabbro to alkali-feldspar granite, post-date the Hadn formation. Of these, the Malayhah granite is particularly noteworthy because it has a broad zone of cataclasis along the western and southern border. Country rock within several kilometers of the western contact is also highly sheared, predominantly along northerly trends. Locally, a melange of several rock types was produced. Contact metamorphism to garnet-amphibolite hornfels facies occurred at this time, and may be responsible for the formation of small sub-economic magnetite lenses interlayered with some of the marbles of the Nuf formation. In the northern part of the quadrangle, southeast dipping imbricate thrust faults probably closely post-date the emplacement of the Mulayhah granite. These thrusts were followed in time by predominantly northeast-trending high-angle faults.
\nThe last major plutonic event in the area is the intrusion of the alkalic granite complexes at Jabal Aja and Jabal Sal ma about 580 Ma ago. Of particular note is a per alkalic border facies of the Jabal Aja complex that is associated with pegmatites enriched in thorium, niobium, and rare-earth elements.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/ofr84159","usgsCitation":"Kellogg, K., 1984, Reconnaissance geology of the Qufar Quadrangle, sheet 27/41 D, Kingdom of Saudi Arabia: U.S. Geological Survey Open-File Report 84-159, iii, 39 p. :maps ;28 cm., https://doi.org/10.3133/ofr84159.","productDescription":"iii, 39 p. :maps ;28 cm.","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":49085,"rank":400,"type":{"id":17,"text":"Plate"},"url":"https://pubs.usgs.gov/of/1984/0159/plate-1.pdf","linkFileType":{"id":1,"text":"pdf"}},{"id":49086,"rank":401,"type":{"id":17,"text":"Plate"},"url":"https://pubs.usgs.gov/of/1984/0159/plate-2.pdf","linkFileType":{"id":1,"text":"pdf"}},{"id":49087,"rank":300,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1984/0159/report.pdf","linkFileType":{"id":1,"text":"pdf"}},{"id":152590,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/of/1984/0159/report-thumb.jpg"}],"country":"Saudi Arabia","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n 40,\n 26\n ],\n [\n 40,\n 28\n ],\n [\n 42,\n 28\n ],\n [\n 42,\n 26\n ],\n [\n 40,\n 26\n ]\n ]\n ]\n }\n }\n ]\n}","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a6de4b07f02db63f234","contributors":{"authors":[{"text":"Kellogg, K.S.","contributorId":99145,"corporation":false,"usgs":true,"family":"Kellogg","given":"K.S.","email":"","affiliations":[],"preferred":false,"id":181220,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":21054,"text":"ofr84123 - 1984 - A program in Hewlett-Packard BASIC for plotting rare-earth element diagrams, using HP-series 80 computers","interactions":[],"lastModifiedDate":"2012-02-02T00:07:55","indexId":"ofr84123","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"84-123","title":"A program in Hewlett-Packard BASIC for plotting rare-earth element diagrams, using HP-series 80 computers","language":"ENGLISH","publisher":"U.S. Geological Survey,","doi":"10.3133/ofr84123","usgsCitation":"Stuckless, J., and Christiansen, E.H., 1984, A program in Hewlett-Packard BASIC for plotting rare-earth element diagrams, using HP-series 80 computers: U.S. Geological Survey Open-File Report 84-123, 18 p. :ill. ;28 cm., https://doi.org/10.3133/ofr84123.","productDescription":"18 p. :ill. ;28 cm.","costCenters":[],"links":[{"id":154427,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/of/1984/0123/report-thumb.jpg"},{"id":50644,"rank":300,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1984/0123/report.pdf","linkFileType":{"id":1,"text":"pdf"}}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1be4b07f02db6a8f20","contributors":{"authors":[{"text":"Stuckless, J. S.","contributorId":6060,"corporation":false,"usgs":true,"family":"Stuckless","given":"J. S.","affiliations":[],"preferred":false,"id":183755,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Christiansen, E. H.","contributorId":65077,"corporation":false,"usgs":true,"family":"Christiansen","given":"E.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":183756,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":5864,"text":"pp1272 - 1984 - High-temperature, large-volume, lavalike ash-flow tuffs without calderas in southwestern Idaho","interactions":[],"lastModifiedDate":"2012-02-02T00:05:51","indexId":"pp1272","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1984","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":331,"text":"Professional Paper","code":"PP","onlineIssn":"2330-7102","printIssn":"1044-9612","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"1272","title":"High-temperature, large-volume, lavalike ash-flow tuffs without calderas in southwestern Idaho","docAbstract":"Rhyolitic rocks were erupted from vents in and adjacent to the Owyhee Mountains and Owyhee Plateau of southwestern Idaho from 16 m.y. ago to about 10 m.y. ago. They were deposited on a highly irregular surface developed on a variety of basement rocks that include granitic rocks of Cretaceous age, quartz latite and rhyodacite tuffs and lava flows of Eocene age, andesitic and basaltic lava flows of Oligocene age, and latitic and basaltic lava flows of early Miocene age. \r\n\r\nThe rhyolitic rocks are principally welded tuffs that, regardless of their source, have one feature in common-namely internal characteristics indicating en-masse, viscous lavalike flowage. The flowage features commonly include considerable thicknesses of flow breccia at the bases of various cooling units. On the basis of the tabular nature of the rhyolitic deposits, their broad areal extents, and the local preservation of pyroclastic textures at the bases, tops, and distal ends of some of the deposits, we have concluded that the rocks were emplaced as ash flows at extremely high temperatures and that they coalesced to liquids before final emplacement and cooling. Temperatures of l090?C and higher are indicated by iron-titanium oxide compositions. \r\n\r\nRhyolites that are about 16 m.y. old are preserved mostly in the downdropped eastern and western flanks of the Silver City Range and they are inferred to have been erupted from the Silver City Range. They rarely contain more than about 2 percent phenocrysts that consist of quartz and subequal amounts of plagioclase and alkali feldspar; commonly, they contain biotite, and they are the only rhyolitic rocks in the area to do so. The several rhyolitic units that are 14 m.y. to about 10 m.y. old contain only pyroxene-principally ferriferous and intermediate pigeonites-as mafic constituents. The rhyolites of the Silver City Range comprise many cooling units, none of which can be traced for great distances. \r\n\r\nRocks erupted from the Owyhee Plateau include two sequences that were traced over areas having diameters of about 100 km. These two sheets are the herein-named Swisher Mountain Tuff, which is about 13.8 m.y. old, and the Little Jacks Tuff, which is about 10 m.y. old. The Swisher Mountain Tuff was erupted from the Juniper Mountain volcanic center, a gentle dome that is not bounded by arcuate faults indicative of cauldron subsidence. The tuff is 200 m thick over a considerable area in and adjacent to its source. It apparently thins gradually toward its distal edges, and it is inferred to be uniformly distributed around its source at Juniper Mountain. The unit contains vitrophyres at various intervals from base to top, and, although the vitrophyres are, in general, flow layered and commonly flow brecciated, they occasionally contain well-defined pumice clasts. The vitrophyres indicate compound cooling, and, near the distal edges of the sheet, some of them probably represent complete cooling breaks. \r\n\r\nThe Little Jacks Tuff onlaps the Swisher Mountain Tuff in expo sures east of Juniper Mountain, and it is inferred to have been erupted from a source on the part of the Owyhee Plateau that lies just east of the area studied. This inferred source area, like that at Juniper Mountain, is also expressed today as a gentle dome without structural features indicative of cauldron subsidence. The Little Jacks Tuff, in most exposures in the deep canyons of the Plateau, consists of at least four cooling units, and, in places in the eastern part of the studied area near the source area, it possibly comprises as many as six. Although there is no obvious evidence of erosion between the various cooling units, magnetic polarity measurements indicate that there were at least two magnetic reversals during the eruption interval of the Little Jacks Tuff. Like the Swisher Mountain Tuff, the Little Jacks has flattened pumice clasts in a few outcrops-principally at the bases of the various cooling units. \r\n\r\nThe two tuff sequences are calc-a","language":"ENGLISH","publisher":"U.S. G.P.O.,","doi":"10.3133/pp1272","usgsCitation":"Ekren, E.B., McIntyre, D.H., and Bennett, E.H., 1984, High-temperature, large-volume, lavalike ash-flow tuffs without calderas in southwestern Idaho: U.S. Geological Survey Professional Paper 1272, 76 p.; 2 plates in pocket, https://doi.org/10.3133/pp1272.","productDescription":"76 p.; 2 plates in pocket","costCenters":[],"links":[{"id":126352,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/pp/1272/report-thumb.jpg"},{"id":247321,"rank":400,"type":{"id":17,"text":"Plate"},"url":"https://pubs.usgs.gov/pp/1272/plate-1.pdf","size":"4589","linkFileType":{"id":1,"text":"pdf"}},{"id":247322,"rank":401,"type":{"id":17,"text":"Plate"},"url":"https://pubs.usgs.gov/pp/1272/plate-2.pdf","size":"4882","linkFileType":{"id":1,"text":"pdf"}},{"id":32655,"rank":300,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/pp/1272/report.pdf","linkFileType":{"id":1,"text":"pdf"}}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a58e4b07f02db62efd5","contributors":{"authors":[{"text":"Ekren, E. B.","contributorId":14371,"corporation":false,"usgs":true,"family":"Ekren","given":"E.","middleInitial":"B.","affiliations":[],"preferred":false,"id":151701,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McIntyre, David H.","contributorId":46490,"corporation":false,"usgs":true,"family":"McIntyre","given":"David","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":151702,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bennett, Earl H.","contributorId":97093,"corporation":false,"usgs":true,"family":"Bennett","given":"Earl","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":151703,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ]}