Multiple paleoceanographic proxies in a zonal transect across the California Current near 42°N record modern and last glacial maximum (LGM) thermal and nutrient gradients. The offshore thermal gradient, derived from foraminiferal species assemblages and oxygen isotope data, was similar at the LGM to that at present (warmer offshore), but average temperatures were 3.3° ±1.5°C colder. Observed gradients require that the sites remained under the southward flow of the California Current, and thus that the polar front remained north of 42°N during the LGM. Carbon isotopic and foraminiferal flux data suggests enhanced nutrients and productivity of foraminfera in the northern California Current up to 650 km offshore. In contrast, marine organic carbon and coastal diatom burial rates decreased during the LGM. These seemingly contradictory results are reconciled by model simulations of the LGM wind- field, which suggest that wind stress curl at 42°N (and thus open-ocean upwelling) increased, while offshore Ekman transport (and thus coastal upwelling) decreased during the last ice age. The ecosystem of the northern California Current during the LGM approximated that of the modern Gulf of Alaska. Cooling and production in this region was thus driven by stronger open-ocean upwelling and/or southward flow of high-latitude water masses, rather than by coastal upwelling.
","language":"English","publisher":"AGU Publications","doi":"10.1029/96PA03165","issn":"08838305","usgsCitation":"Ortiz, J., Mix, A.C., Hostetler, S.W., and Kashgarian, M., 1997, The California current of the last glacial maximum: reconstruction at 42°N based on multiple proxies: Paleoceanography, v. 12, no. 2, p. 191-205, https://doi.org/10.1029/96PA03165.","productDescription":"15 p.","startPage":"191","endPage":"205","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":479014,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/96pa03165","text":"Publisher Index Page"},{"id":227854,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"12","issue":"2","noUsgsAuthors":false,"publicationDate":"2010-05-04","publicationStatus":"PW","scienceBaseUri":"505ba6b8e4b08c986b321258","contributors":{"authors":[{"text":"Ortiz, Joseph D.","contributorId":103175,"corporation":false,"usgs":true,"family":"Ortiz","given":"Joseph D.","affiliations":[],"preferred":false,"id":384301,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mix, Alan C.","contributorId":83346,"corporation":false,"usgs":true,"family":"Mix","given":"Alan","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":384299,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hostetler, Steven W. 0000-0003-2272-8302 swhostet@usgs.gov","orcid":"https://orcid.org/0000-0003-2272-8302","contributorId":3249,"corporation":false,"usgs":true,"family":"Hostetler","given":"Steven","email":"swhostet@usgs.gov","middleInitial":"W.","affiliations":[{"id":200,"text":"Coop Res Unit Seattle","active":true,"usgs":true},{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":384298,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kashgarian, Michaele","contributorId":68473,"corporation":false,"usgs":true,"family":"Kashgarian","given":"Michaele","email":"","affiliations":[],"preferred":false,"id":384300,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019803,"text":"70019803 - 1997 - Environmental geochemistry of shale-hosted Ag-Pb-Zn massive sulfide deposits in northwest Alaska: Natural background concentrations of metals in water from mineralized areas","interactions":[],"lastModifiedDate":"2012-03-12T17:19:17","indexId":"70019803","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":835,"text":"Applied Geochemistry","active":true,"publicationSubtype":{"id":10}},"title":"Environmental geochemistry of shale-hosted Ag-Pb-Zn massive sulfide deposits in northwest Alaska: Natural background concentrations of metals in water from mineralized areas","docAbstract":"Red Dog, Lik and Drenchwater are shale-hosted stratiform Ag-Pb-Zn massive sulfide deposits in the northwestern Brooks Range. Natural background concentrations of metals in waters from the undisturbed (unmined) Drenchwater prospect and Lik deposit were compared to pre-mining baseline studies conducted at Red Dog. The primary factors affecting water chemistry are the extent of exposure of the deposits, the grade of mineralization, the presence of carbonate reeks in the section, and the proportion of Fe-sulfide in the ore. Surface water samples from the Drenchwater prospect, which has pyrite-dominant mineralization exposed in outcrop, have pH values as low as 2.8 and high dissolved concentrations of metals including as much as 95 mg 1-1 Al, 270 mg 1-1 Fe, 8 ??1-1 Cd, 10 ??1-1 Pb, and 2600 ??1-1 Zn, with As up to 26 ??g1-1. Surface waters from the Red Dog deposit prior to mining were also acidic and metal-rich, however, dissolved metal concentrations in Red Dog waters were many times greater. The higher metal concentrations in Red Dog waters reflect the high Zn grades and the abundant sphalerite, pyrite, and galena that were present in outcrop prior to mining. In contrast, despite significant mineralization at the Lik deposit, carbonate rocks in the section buffer the system, resulting in less acidic, mostly near-neutral pH values with low concentrations of most metals except Zn.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Applied Geochemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0883-2927(97)00009-7","issn":"08832927","usgsCitation":"Kelley, K., and Taylor, C., 1997, Environmental geochemistry of shale-hosted Ag-Pb-Zn massive sulfide deposits in northwest Alaska: Natural background concentrations of metals in water from mineralized areas: Applied Geochemistry, v. 12, no. 4, p. 397-409, https://doi.org/10.1016/S0883-2927(97)00009-7.","startPage":"397","endPage":"409","numberOfPages":"13","costCenters":[],"links":[{"id":206000,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0883-2927(97)00009-7"},{"id":227809,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"12","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a09c7e4b0c8380cd5206e","contributors":{"authors":[{"text":"Kelley, K.D. 0000-0002-3232-5809","orcid":"https://orcid.org/0000-0002-3232-5809","contributorId":75157,"corporation":false,"usgs":true,"family":"Kelley","given":"K.D.","affiliations":[],"preferred":false,"id":383959,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Taylor, C. D. 0000-0001-6376-6298","orcid":"https://orcid.org/0000-0001-6376-6298","contributorId":100401,"corporation":false,"usgs":true,"family":"Taylor","given":"C. D.","affiliations":[],"preferred":false,"id":383960,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019776,"text":"70019776 - 1997 - Effects of spring environment on nesting phenology and clutch size of Black Brant","interactions":[],"lastModifiedDate":"2024-12-27T22:14:03.496847","indexId":"70019776","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1318,"text":"Condor","active":true,"publicationSubtype":{"id":10}},"title":"Effects of spring environment on nesting phenology and clutch size of Black Brant","docAbstract":"We studied the effects of timing of spring snowmelt on nesting phenology, nest site selection, and clutch size of Black Brant (Branta bernicla nigricans) breeding at the Tutakoke river colony, Yukon-Kuskokwim Delta, Alaska. In late springs, brant nested later: however, time between peak arrival at Tutakoke and nest initiation (6 to 12 days) was similar in early and late springs. Nest initiation was more synchronized in late springs than early springs. Height of nests relative to spring meltwater levels was lower in late springs than early springs, indicating that the interval between snowmelt and nest initiation was shorten reduced availability of nest sites and increased nesting synchrony in late years may result in greater competition for available nest sites and reduced site fidelity. Clutch size was greater in late springs than in early springs. This increase in clutch size may result from greater accumulation of endogenous reserves on spring staging areas in late springs, or from demographic changes in the breeding population.","language":"English","publisher":"Oxford Academic","doi":"10.2307/1369944","issn":"00105422","usgsCitation":"Lindberg, M.S., Sedinger, J., and Flint, P.L., 1997, Effects of spring environment on nesting phenology and clutch size of Black Brant: Condor, v. 99, no. 2, p. 381-388, https://doi.org/10.2307/1369944.","productDescription":"8 p.","startPage":"381","endPage":"388","numberOfPages":"8","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":480017,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.2307/1369944","text":"Publisher Index Page"},{"id":227975,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"99","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a07d9e4b0c8380cd51882","contributors":{"authors":[{"text":"Lindberg, M. S.","contributorId":94413,"corporation":false,"usgs":false,"family":"Lindberg","given":"M.","email":"","middleInitial":"S.","affiliations":[],"preferred":false,"id":383878,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sedinger, J.S.","contributorId":75471,"corporation":false,"usgs":true,"family":"Sedinger","given":"J.S.","email":"","affiliations":[],"preferred":false,"id":383877,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Flint, Paul L. 0000-0002-8758-6993 pflint@usgs.gov","orcid":"https://orcid.org/0000-0002-8758-6993","contributorId":3284,"corporation":false,"usgs":true,"family":"Flint","given":"Paul","email":"pflint@usgs.gov","middleInitial":"L.","affiliations":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"preferred":true,"id":383876,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019747,"text":"70019747 - 1997 - Nesting ecology of Townsend's warblers in relation to habitat characteristics in a mature boreal forest","interactions":[],"lastModifiedDate":"2023-11-22T21:55:16.428433","indexId":"70019747","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1318,"text":"Condor","active":true,"publicationSubtype":{"id":10}},"title":"Nesting ecology of Townsend's warblers in relation to habitat characteristics in a mature boreal forest","docAbstract":"We investigated the nesting ecology of Townsend's Warblers (Dendroica townsendi) from 1993-1995 in an unfragmented boreal forest along the lower slopes of the Chugach Mountains in southcentral Alaska. We examined habitat characteristics of nest sites in relation to factors influencing reproductive success. Almost all territory-holding males (98%, n = 40) were successful in acquiring mates. Nest success was 54% (n = 24 nests), with nest survivorship greater during incubation (87%) than during the nestling period (62%). Most nesting failure (80%) was attributable to predation, which occurred primarily during the nestling period. Fifty-five percent of nests containing nestling were infested with the larvae of bird blow-flies (Protocalliphora braueri and P. spenceri), obligatory blood-feeding parasites. The combined effects of Protocalliphora infestation and inclement weather apparently resulted in nestling mortality in 4 of the 24 nests. Nests that escaped predation were placed in white spruce with larger diameter than those lost to predation: nests that escaped blow-fly parasitism were located higher in nest trees and in areas with lower densities of woody shrubs than those that were infested. The availability of potential nest sites with these key features may be important in determining reproductive success in Townsend's Warblers.","language":"English","publisher":"Oxford Academic","doi":"10.2307/1369933","issn":"00105422","usgsCitation":"Matsuoka, S.M., Handel, C.M., and Roby, D.D., 1997, Nesting ecology of Townsend's warblers in relation to habitat characteristics in a mature boreal forest: Condor, v. 99, no. 2, p. 271-281, https://doi.org/10.2307/1369933.","productDescription":"11 p.","startPage":"271","endPage":"281","numberOfPages":"11","costCenters":[],"links":[{"id":489817,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.2307/1369933","text":"Publisher Index Page"},{"id":228134,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"99","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a64bee4b0c8380cd72a4e","contributors":{"authors":[{"text":"Matsuoka, Steven M. 0000-0001-6415-1885 smatsuoka@usgs.gov","orcid":"https://orcid.org/0000-0001-6415-1885","contributorId":184173,"corporation":false,"usgs":true,"family":"Matsuoka","given":"Steven","email":"smatsuoka@usgs.gov","middleInitial":"M.","affiliations":[{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"preferred":true,"id":383775,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Handel, Colleen M. 0000-0002-0267-7408 cmhandel@usgs.gov","orcid":"https://orcid.org/0000-0002-0267-7408","contributorId":3067,"corporation":false,"usgs":true,"family":"Handel","given":"Colleen","email":"cmhandel@usgs.gov","middleInitial":"M.","affiliations":[{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"preferred":true,"id":383773,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Roby, Daniel D. 0000-0001-9844-0992 droby@usgs.gov","orcid":"https://orcid.org/0000-0001-9844-0992","contributorId":3702,"corporation":false,"usgs":true,"family":"Roby","given":"Daniel","email":"droby@usgs.gov","middleInitial":"D.","affiliations":[{"id":200,"text":"Coop Res Unit Seattle","active":true,"usgs":true}],"preferred":true,"id":383774,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019659,"text":"70019659 - 1997 - Spatial and temporal variability of microgeographic genetic structure in white-tailed deer","interactions":[],"lastModifiedDate":"2017-03-06T11:55:02","indexId":"70019659","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2373,"text":"Journal of Mammalogy","onlineIssn":"1545-1542","printIssn":"0022-2372","active":true,"publicationSubtype":{"id":10}},"title":"Spatial and temporal variability of microgeographic genetic structure in white-tailed deer","docAbstract":"Techniques are described that define contiguous genetic subpopulations of white-tailed deer (Odocoileus virginianus) based on the spatial dispersion of 4,749 individuals that possessed discrete character values (alleles or genotypes) during each of 6 years (1974-1979). White-tailed deer were not uniformly distributed in space, but exhibited considerable spatial genetic structuring. Significant non-random clusters of individuals were documented during each year based on specific alleles and genotypes at the Sdh locus. Considerable temporal variation was observed in the position and genetic composition of specific clusters, which reflected changes in allele frequency in small geographic areas. The position of clusters did not consistently correspond with traditional management boundaries based on major discontinuities in habitat (swamp versus upland) and hunt compartments that were defined by roads and streams. Spatio-temporal stability of observed genetic contiguous clusters was interpreted relative to method and intensity of harvest, movements, and breeding ecology.
","language":"English","publisher":"Oxford Academic","doi":"10.2307/1382933","issn":"00222372","usgsCitation":"Scribner, K.T., Smith, M.H., and Chesser, R.K., 1997, Spatial and temporal variability of microgeographic genetic structure in white-tailed deer: Journal of Mammalogy, v. 78, no. 3, p. 744-755, https://doi.org/10.2307/1382933.","productDescription":"12 p.","startPage":"744","endPage":"755","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":479022,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.2307/1382933","text":"Publisher Index Page"},{"id":228013,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"78","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9452e4b08c986b31a9e0","contributors":{"authors":[{"text":"Scribner, Kim T.","contributorId":146113,"corporation":false,"usgs":false,"family":"Scribner","given":"Kim","email":"","middleInitial":"T.","affiliations":[{"id":135,"text":"Biological Resources Division","active":false,"usgs":true},{"id":16582,"text":"Department of Fisheries and Wildlife and Department of Zoology, 480 Wilson Rd. 13 Natural Resources Building, Michigan State University, East Lansing, MI 48824","active":true,"usgs":false}],"preferred":false,"id":383476,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Smith, Michael H.","contributorId":111664,"corporation":false,"usgs":true,"family":"Smith","given":"Michael","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":383475,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Chesser, Ronald K.","contributorId":113098,"corporation":false,"usgs":true,"family":"Chesser","given":"Ronald","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":383474,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019589,"text":"70019589 - 1997 - Soluble trace elements and total mercury in Arctic Alaskan snow","interactions":[],"lastModifiedDate":"2023-08-14T14:56:28.6","indexId":"70019589","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":894,"text":"Arctic","active":true,"publicationSubtype":{"id":10}},"title":"Soluble trace elements and total mercury in Arctic Alaskan snow","docAbstract":"Ultraclean field and laboratory procedures were used to examine trace element concentrations in northern Alaskan snow. Sixteen soluble trace elements and total mercury were determined in snow core samples representing the annual snowfall deposited during the 1993-94 season at two sites in the Prudhoe Bay oil field and nine sites in the Arctic National Wildlife Refuge (Arctic NWR). Results indicate there were two distinct point sources for trace elements in the Prudhoe Bay oil field- a source associated with oil and gas production and a source associated with municipal solid-waste incineration. Soluble trace element concentrations measured in snow from the Arctic NWR resembled concentrations of trace elements measured elsewhere in the Arctic using clean sample-collection and processing techniques and were consistent with deposition resulting from widespread arctic atmospheric contamination. With the exception of elements associated with sea salts, there were no orographic or east-west trends observed in the Arctic NWR data, nor were there any detectable influences from the Prudhoe Bay oil field, probably because of the predominant easterly and northeasterly winds on the North Slope of Alaska. However, regression analysis on latitude suggested significant south-to-north increases in selected trace element concentrations, many of which appear unrelated to the sea salt contribution.
","language":"English","publisher":"Arctic Institute of North America","doi":"10.14430/arctic1102","usgsCitation":"Snyder-Conn, E., Garbarino, J.R., Hoffman, G.L., and Oelkers, A., 1997, Soluble trace elements and total mercury in Arctic Alaskan snow: Arctic, v. 50, no. 3, p. 201-215, https://doi.org/10.14430/arctic1102.","productDescription":"15 p.","startPage":"201","endPage":"215","numberOfPages":"15","costCenters":[{"id":452,"text":"National Water Quality Laboratory","active":true,"usgs":true}],"links":[{"id":479955,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.14430/arctic1102","text":"Publisher Index Page"},{"id":228239,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -152.00780315828374,\n 71.06255434580251\n ],\n [\n -152.00780315828374,\n 68.45974566234574\n ],\n [\n -140.87836627646902,\n 68.45974566234574\n ],\n [\n -140.87836627646902,\n 71.06255434580251\n ],\n [\n -152.00780315828374,\n 71.06255434580251\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"50","issue":"3","noUsgsAuthors":false,"publicationDate":"1997-01-01","publicationStatus":"PW","scienceBaseUri":"505b924de4b08c986b319e19","contributors":{"authors":[{"text":"Snyder-Conn, E.","contributorId":7026,"corporation":false,"usgs":true,"family":"Snyder-Conn","given":"E.","email":"","affiliations":[],"preferred":false,"id":383250,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Garbarino, John R. jrgarb@usgs.gov","contributorId":2189,"corporation":false,"usgs":true,"family":"Garbarino","given":"John","email":"jrgarb@usgs.gov","middleInitial":"R.","affiliations":[{"id":5046,"text":"Branch of Analytical Serv (NWQL)","active":true,"usgs":true}],"preferred":true,"id":383253,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hoffman, Gerald L.","contributorId":89172,"corporation":false,"usgs":true,"family":"Hoffman","given":"Gerald","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":383252,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Oelkers, A.","contributorId":17000,"corporation":false,"usgs":true,"family":"Oelkers","given":"A.","email":"","affiliations":[],"preferred":false,"id":383251,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019505,"text":"70019505 - 1997 - Recovery strategies for the California clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem","interactions":[],"lastModifiedDate":"2018-05-20T11:50:44","indexId":"70019505","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2603,"text":"Landscape and Urban Planning","active":true,"publicationSubtype":{"id":10}},"displayTitle":"Recovery strategies for the California clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem","title":"Recovery strategies for the California clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem","docAbstract":"The California clapper rail (Rallus longirostris obsoletus), a Federal- and State-listed endangered marsh bird, has a geographic range restricted to one of the most heavily-urbanized estuaries in the world. The rail population has long been in a state of decline, although the exact contribution of each of the many contributing causes remains unclear. The rail is one of the key targets of emerging plans to conserve and restore tidal marshlands. Reduction of tidal marsh habitat, estimated at 85–95%, has been the major historical cause of rail decline. Increased predation intensity may be the more important present problem, because habitat fragmentation and alteration coupled with the invasion of the red fox have made the remaining populations more vulnerable to predators. Population viability analysis shows that adult survivorship is the key demographic variable; reversals in population fate occur over a narrow range of ecologically realistic values. Analysis of habitat requirements and population dynamics of the clapper rail in the San Francisco Estuary shows that decreased within-marsh habitat quality, particularly reduction of tidal flows and alteration of drainage, is an important barrier to population recovery. Management and restoration activities should emphasize the development of well-channelized high tidal marsh, because this is the key requirement of rail habitat. Developing effective restoration programs depends upon having information that field research will not provide. The effect of spatial pattern of reserves requires accurate estimation of the effects of prédation and inter-marsh movement, both of which are practically impossible to measure adequately. It will be necessary to develop and use simulation models that can be applied to geographic data to accomplish this task.
","language":"English","publisher":"Elsevier","doi":"10.1016/S0169-2046(97)00036-4","usgsCitation":"Foin, T.C., Garcia, E.J., Gill, R., Culberson, S.D., and Collins, J.N., 1997, Recovery strategies for the California clapper rail (Rallus longirostris obsoletus) in the heavily-urbanized San Francisco estuarine ecosystem: Landscape and Urban Planning, v. 38, no. 3-4, p. 229-243, https://doi.org/10.1016/S0169-2046(97)00036-4.","productDescription":"15 p.","startPage":"229","endPage":"243","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":226433,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"38","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"50e4a349e4b0e8fec6cdb7ff","contributors":{"authors":[{"text":"Foin, Theodore C.","contributorId":174646,"corporation":false,"usgs":false,"family":"Foin","given":"Theodore","email":"","middleInitial":"C.","affiliations":[{"id":13461,"text":"U.C. Davis","active":true,"usgs":false}],"preferred":false,"id":382997,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Garcia, E. Jacqueline","contributorId":174039,"corporation":false,"usgs":false,"family":"Garcia","given":"E.","email":"","middleInitial":"Jacqueline","affiliations":[{"id":12711,"text":"UC Davis","active":true,"usgs":false}],"preferred":false,"id":382993,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gill, Robert E. Jr. 0000-0002-6385-4500 rgill@usgs.gov","orcid":"https://orcid.org/0000-0002-6385-4500","contributorId":171747,"corporation":false,"usgs":true,"family":"Gill","given":"Robert E.","suffix":"Jr.","email":"rgill@usgs.gov","affiliations":[{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"preferred":true,"id":382994,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Culberson, Steven D.","contributorId":82166,"corporation":false,"usgs":true,"family":"Culberson","given":"Steven","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":382996,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Collins, Joshua N.","contributorId":150531,"corporation":false,"usgs":false,"family":"Collins","given":"Joshua","email":"","middleInitial":"N.","affiliations":[{"id":12703,"text":"San Francisco Estuary Institute","active":true,"usgs":false}],"preferred":false,"id":382995,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70019445,"text":"70019445 - 1997 - Lithofacies and seismic-reflection interpretation of temperate glacimarine sedimentation in Tarr Inlet, Glacier Bay, Alaska","interactions":[],"lastModifiedDate":"2012-03-12T17:19:12","indexId":"70019445","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2667,"text":"Marine Geology","active":true,"publicationSubtype":{"id":10}},"title":"Lithofacies and seismic-reflection interpretation of temperate glacimarine sedimentation in Tarr Inlet, Glacier Bay, Alaska","docAbstract":"High-resolution seismic-reflection profiles of sediment fill within Tart Inlet of Glacier Bay, Alaska, show seismic facies changes with increasing distance from the glacial termini. Five types of seismic facies are recognized from analysis of Huntec and minisparker records, and seven lithofacies are determined from detailed sedimentologic study of gravity-, vibro- and box-cores, and bottom grab samples. Lithofacies and seismic facies associations, and fjord-floor morphology allow us to divide the fjord into three sedimentary environments: ice-proximal, iceberg-zone and ice-distal. The ice-proximal environment, characterized by a morainal-bank depositional system, can be subdivided into bank-back, bank-core and bank-front subenvironments, each of which is characterized by a different depositional subsystem. A bank-back subsystem shows chaotic seismic facies with a mounded surface, which we infer consists mainly of unsorted diamicton and poorly sorted coarse-grained sediments. A bank-core depositional subsystem is a mixture of diamicton, rubble, gravel, sand and mud. Seismic-reflection records of this subsystem are characterized by chaotic seismic facies with abundant hyperbolic diffractions and a hummocky surface. A bank-front depositional subsystem consists of mainly stratified and massive sand, and is characterized by internal hummocky facies on seismic-reflection records with significant surface relief and sediment gravity flow channels. The depositional system formed in the iceberg-zone environment consists of rhythmically laminated mud interbedded with thin beds of weakly stratified diamicton and stratified or massive sand and silt. On seismic-reflection profiles, this depositional system is characterized by discontinuously stratified facies with multiple channels on the surface in the proximal zone and a single channel on the largely flat sediment surface in the distal zone. The depositional system formed in the ice-distal environment consists of interbedded homogeneous or laminated mud and massive or stratified sand and coarse silt. This depositional system shows continuously stratified seismic facies with smooth and flat surfaces on minisparker records, and continuously stratified seismic facies which are interlayered with thin weakly stratified facies on Huntec records.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Marine Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/S0025-3227(97)00088-1","issn":"00253227","usgsCitation":"Cai, J., Powell, R., Cowan, E.A., and Carlson, P., 1997, Lithofacies and seismic-reflection interpretation of temperate glacimarine sedimentation in Tarr Inlet, Glacier Bay, Alaska: Marine Geology, v. 143, no. 1-4, p. 5-37, https://doi.org/10.1016/S0025-3227(97)00088-1.","startPage":"5","endPage":"37","numberOfPages":"33","costCenters":[],"links":[{"id":205781,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0025-3227(97)00088-1"},{"id":226747,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"143","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4835e4b0c8380cd67cc6","contributors":{"authors":[{"text":"Cai, J.","contributorId":10172,"corporation":false,"usgs":true,"family":"Cai","given":"J.","email":"","affiliations":[],"preferred":false,"id":382757,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Powell, R.D.","contributorId":74015,"corporation":false,"usgs":true,"family":"Powell","given":"R.D.","email":"","affiliations":[],"preferred":false,"id":382759,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Cowan, E. A.","contributorId":16423,"corporation":false,"usgs":true,"family":"Cowan","given":"E.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":382758,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Carlson, P.R.","contributorId":97055,"corporation":false,"usgs":true,"family":"Carlson","given":"P.R.","email":"","affiliations":[],"preferred":false,"id":382760,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019442,"text":"70019442 - 1997 - Distribution of autumn-staging Lesser Snow Geese on the northeast coastal plain of Alaska","interactions":[],"lastModifiedDate":"2018-06-12T21:23:17","indexId":"70019442","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2284,"text":"Journal of Field Ornithology","active":true,"publicationSubtype":{"id":10}},"title":"Distribution of autumn-staging Lesser Snow Geese on the northeast coastal plain of Alaska","docAbstract":"We conducted aerial surveys of Lesser Snow Geese (Chen caerulescens caerulescens) during autumn staging on the coastal plain of the Arctic National Wildlife Refuge (ANWR) in northeast Alaska from late August through September, 1982 - 1993. We evaluated numbers and distribution of Snow Geese that staged on the ANWR, compared abundance of birds among 5 x 5-km cells used frequently (5 - 8 yr), periodically (3 - 4 yr), or infrequently (1 - 2 yr), and examined distribution changes within years. Maximum numbers of Snow Geese observed annually were highly variable (range 12,828 - 309,225). Snow Goose flocks occurred across 605,000 ha of the coastal plain, but used some areas more frequently than others. Frequently used cells (38 of 363 cells in the study area) were non-randomly distributed and primarily occurred on the central coastal plain between the wet coastal and steep foothills regions. Abundance of geese was greatest in frequently used, intermediate in periodically used, and lowest in infrequently used cells. Within years, Snow Goose numbers and flock locations varied between surveys, possibly because geese moved to different foraging areas during staging. The widespread distribution and annual variability in numbers of Snow Geese on the coastal plain was likely because birds used foraging habitats that were spatially and temporally heterogeneous. The ANWR coastal plain is an important component of the fall-staging area used by Snow Geese that nest in the western Canadian Arctic. Management decisions that affect the region should reflect its value to migrating Snow Geese.
","language":"English","publisher":"Wiley","issn":"02738570","usgsCitation":"Robertson, D.G., Brackney, A.W., Spindler, M.A., and Hupp, J.W., 1997, Distribution of autumn-staging Lesser Snow Geese on the northeast coastal plain of Alaska: Journal of Field Ornithology, v. 68, no. 1, p. 124-134.","productDescription":"11 p.","startPage":"124","endPage":"134","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":226704,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":300608,"rank":1,"type":{"id":15,"text":"Index Page"},"url":"https://www.jstor.org/stable/4514202"}],"country":"United States","state":"Alaska","otherGeospatial":"Arctic National Wildlife Refuge","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -145.2117919921875,\n 69.22304834651695\n ],\n [\n -141.0040283203125,\n 69.22304834651695\n ],\n [\n -141.0040283203125,\n 70.32613725493573\n ],\n [\n -145.2117919921875,\n 70.32613725493573\n ],\n [\n -145.2117919921875,\n 69.22304834651695\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"68","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a02bfe4b0c8380cd501b3","contributors":{"authors":[{"text":"Robertson, Donna G.","contributorId":29965,"corporation":false,"usgs":true,"family":"Robertson","given":"Donna","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":382746,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Brackney, Alan W.","contributorId":60982,"corporation":false,"usgs":true,"family":"Brackney","given":"Alan","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":382748,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Spindler, Michael A.","contributorId":56811,"corporation":false,"usgs":true,"family":"Spindler","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":382747,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hupp, Jerry W. 0000-0002-6439-3910 jhupp@usgs.gov","orcid":"https://orcid.org/0000-0002-6439-3910","contributorId":127803,"corporation":false,"usgs":true,"family":"Hupp","given":"Jerry","email":"jhupp@usgs.gov","middleInitial":"W.","affiliations":[{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true},{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"preferred":true,"id":382745,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019405,"text":"70019405 - 1997 - Hematological and plasma biochemical reference ranges of Alaskan seabirds: Their ecological significance and clinical importance","interactions":[],"lastModifiedDate":"2017-11-18T09:38:12","indexId":"70019405","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1272,"text":"Colonial Waterbirds","printIssn":"07386028","active":false,"publicationSubtype":{"id":10}},"title":"Hematological and plasma biochemical reference ranges of Alaskan seabirds: Their ecological significance and clinical importance","docAbstract":"Blood was analyzed from 151 pelagic marine birds to establish reference ranges for hematological and plasma biochemical parameters from healthy, wild populations of Pacific seabirds. Of the 13 species examined, 9 were from the Family Alcidae (N = 122 individuals) and the remainder (N = 29) from the Families Phalacrocoracidae, Laridae, and Procellariidae. Three of 8 hematological parameters (total white blood cell count, lymphocyte count and eosinophil count) differed significantly among species, as did 9 of 13 plasma biochemical parameters (alkaline phosphatase, aspartate aminotransferase, creatine kinase, cholesterol, glucose, lactate dehydrogenase, total bilirubin, total protein and field total protein). There were no differences among species for packed cell volume, buffy coat, cell counts of heterophils, monocytes and basophils, or for concentrations of alanine aminotransferase, triglycerides, uric acid and calcium. Plasma calcium concentration, triglyceride levels and field total protein varied significantly between sexes, with females having higher mean concentrations of all 3 parameters. However, no significant relationships between measures of breeding condition (brood patch size, subcutaneous and mesenteric fat deposits, or ovarian follicle size and ovary weight) and calcium or alkaline phosphatase concentrations in female birds could be identified. Alanine aminotransferase and uric acid were the only analytes which did not differ significantly between species or sexes.
","language":"English","publisher":"The Waterbird Society","doi":"10.2307/1521600","issn":"07386028","usgsCitation":"Newman, S.H., Piatt, J.F., and White, J., 1997, Hematological and plasma biochemical reference ranges of Alaskan seabirds: Their ecological significance and clinical importance: Colonial Waterbirds, v. 20, no. 3, p. 492-504, https://doi.org/10.2307/1521600.","productDescription":"13 p.","startPage":"492","endPage":"504","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":226557,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"20","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3051e4b0c8380cd5d543","contributors":{"authors":[{"text":"Newman, S. H.","contributorId":21888,"corporation":false,"usgs":false,"family":"Newman","given":"S.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":382626,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Piatt, John F. 0000-0002-4417-5748 jpiatt@usgs.gov","orcid":"https://orcid.org/0000-0002-4417-5748","contributorId":3025,"corporation":false,"usgs":true,"family":"Piatt","given":"John","email":"jpiatt@usgs.gov","middleInitial":"F.","affiliations":[{"id":116,"text":"Alaska Science Center Biology MFEB","active":true,"usgs":true},{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true}],"preferred":true,"id":382628,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"White, J.","contributorId":56355,"corporation":false,"usgs":true,"family":"White","given":"J.","affiliations":[],"preferred":false,"id":382627,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019336,"text":"70019336 - 1997 - Deep seismic structure and tectonics of northern Alaska: Crustal-scale duplexing with deformation extending into the upper mantle","interactions":[],"lastModifiedDate":"2024-07-19T15:45:22.378216","indexId":"70019336","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Deep seismic structure and tectonics of northern Alaska: Crustal-scale duplexing with deformation extending into the upper mantle","docAbstract":"Seismic reflection and refraction and laboratory velocity data collected along a transect of northern Alaska (including the east edge of the Koyukuk basin, the Brooks Range, and the North Slope) yield a composite picture of the crustal and upper mantle structure of this Mesozoic and Cenozoic compressional orogen. The following observations are made: (1) Northern Alaska is underlain by nested tectonic wedges, most with northward vergence (i.e., with their tips pointed north). (2) High reflectivity throughout the crust above a basal decollement, which deepens southward from about 10 km depth beneath the northern front of the Brooks Range to about 30 km depth beneath the southern Brooks Range, is interpreted as structural complexity due to the presence of these tectonic wedges, or duplexes. (3) Low reflectivity throughout the crust below the decollement is interpreted as minimal deformation, which appears to involve chiefly bending of a relatively rigid plate consisting of the parautochthonous North Slope crust and a 10- to 15-km-thick section of mantle material. (4) This plate is interpreted as a southward verging tectonic wedge, with its tip in the lower crust or at the Moho beneath the southern Brooks Range. In this interpretation the middle and upper crust, or all of the crust, is detached in the southern Brooks Range by the tectonic wedge, or indentor: as a result, crust is uplifted and deformed above the wedge, and mantle is depressed and underthrust beneath this wedge. (5) Underthrusting has juxtaposed mantle of two different origins (and seismic velocities), giving rise to a prominent sub-Moho reflector.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/96JB03959","issn":"01480227","usgsCitation":"Fuis, G., Murphy, J., Lutter, W.J., Moore, T., Bird, K.J., and Christensen, N., 1997, Deep seismic structure and tectonics of northern Alaska: Crustal-scale duplexing with deformation extending into the upper mantle: Journal of Geophysical Research B: Solid Earth, v. 102, no. B9, p. 20873-20896, https://doi.org/10.1029/96JB03959.","productDescription":"24 p.","startPage":"20873","endPage":"20896","numberOfPages":"24","costCenters":[],"links":[{"id":479959,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/96jb03959","text":"Publisher Index Page"},{"id":226642,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B9","noUsgsAuthors":false,"publicationDate":"1997-09-10","publicationStatus":"PW","scienceBaseUri":"5059fe2ae4b0c8380cd4eb67","contributors":{"authors":[{"text":"Fuis, G. S.","contributorId":83131,"corporation":false,"usgs":true,"family":"Fuis","given":"G. S.","affiliations":[],"preferred":false,"id":382387,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Murphy, J.M.","contributorId":84760,"corporation":false,"usgs":true,"family":"Murphy","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":382388,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lutter, W. J.","contributorId":90361,"corporation":false,"usgs":true,"family":"Lutter","given":"W.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":382390,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Moore, Thomas E. 0000-0002-0878-0457","orcid":"https://orcid.org/0000-0002-0878-0457","contributorId":85592,"corporation":false,"usgs":true,"family":"Moore","given":"Thomas E.","affiliations":[],"preferred":false,"id":382389,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Bird, K. J.","contributorId":57824,"corporation":false,"usgs":false,"family":"Bird","given":"K.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":382386,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Christensen, N.I.","contributorId":28016,"corporation":false,"usgs":true,"family":"Christensen","given":"N.I.","email":"","affiliations":[],"preferred":false,"id":382385,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70019283,"text":"70019283 - 1997 - Late Mesozoic and Cenozoic thermotectonic evolution of the central Brooks Range and adjacent North Slope foreland basin, Alaska: Including fission track results from the Trans-Alaska Crustal Transect (TACT)","interactions":[],"lastModifiedDate":"2024-07-19T15:43:32.357663","indexId":"70019283","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Late Mesozoic and Cenozoic thermotectonic evolution of the central Brooks Range and adjacent North Slope foreland basin, Alaska: Including fission track results from the Trans-Alaska Crustal Transect (TACT)","docAbstract":"Apatite fission track data are used to evaluate the thermal and tectonic history of the central Brooks Range and the North Slope foreland basin in northern Alaska along the northern leg of the Trans-Alaska Crustal Transect (TACT). Fission track analyses of the detrital apatite grains in most sedimentary units resolve the timing of structures and denudation within the Brooks Range, ranging in scale from the entire mountain range to relatively small-scale folds and faults. Interpretation of the results indicates that rocks exposed within the central Brooks Range cooled rapidly from paleotemperatures 110° to 50°C during discrete episodes at ∼ 100±5 Ma, ∼60±4 Ma, and ∼24±3 Ma, probably in response to kilometer-scale denudation. North of the mountain front, rocks in the southern half of the foreland basin were exposed to maximum paleotemperatures 110°C in the Late Cretaceous to early Paleocene as a result of burial by Upper Jurassic and Cretaceous sedimentary rocks. Rapid cooling from these elevated paleotemperatures also occurred due to distinct episodes of kilometer-scale denudation at ∼60±4 Ma, 46±3 Ma, 35±2 Ma, and ∼24±3 Ma. Combined, the apatite analyses indicate that rocks exposed along the TACT line through the central Brooks Range and foreland basin experienced episodic rapid cooling throughout the Late Cretaceous and Cenozoic in response to at least three distinct kilometer-scale denudation events. Future models explaining orogenic events in northern Alaska must consider these new constraints from fission track thermochronology.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/96JB03411","issn":"01480227","usgsCitation":"O’Sullivan, P.B., Murphy, J., and Blythe, A., 1997, Late Mesozoic and Cenozoic thermotectonic evolution of the central Brooks Range and adjacent North Slope foreland basin, Alaska: Including fission track results from the Trans-Alaska Crustal Transect (TACT): Journal of Geophysical Research B: Solid Earth, v. 102, no. B9, p. 20821-20845, https://doi.org/10.1029/96JB03411.","productDescription":"25 p.","startPage":"20821","endPage":"20845","numberOfPages":"25","costCenters":[],"links":[{"id":480086,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/96jb03411","text":"Publisher Index Page"},{"id":226420,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B9","noUsgsAuthors":false,"publicationDate":"1997-09-10","publicationStatus":"PW","scienceBaseUri":"505a44f1e4b0c8380cd66ee6","contributors":{"authors":[{"text":"O’Sullivan, P. B.","contributorId":39950,"corporation":false,"usgs":true,"family":"O’Sullivan","given":"P.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":382229,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Murphy, J.M.","contributorId":84760,"corporation":false,"usgs":true,"family":"Murphy","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":382231,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Blythe, A.E.","contributorId":66002,"corporation":false,"usgs":true,"family":"Blythe","given":"A.E.","email":"","affiliations":[],"preferred":false,"id":382230,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019188,"text":"70019188 - 1997 - Permian Tethyan Fusulinina from the Kenai Peninsula, Alaska","interactions":[],"lastModifiedDate":"2024-06-07T00:22:51.603003","indexId":"70019188","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2412,"text":"Journal of Paleontology","active":true,"publicationSubtype":{"id":10}},"title":"Permian Tethyan Fusulinina from the Kenai Peninsula, Alaska","docAbstract":"Two samples from a large, allochthonous limestone block in the McHugh Complex of the Chugach terrane on the Kenai Peninsula, Alaska, contain species of 12 genera of Permian Fusulinina including Abadehella, Kahlerina, Pseudokahlerina?, Nankinella, Codonofusiella, Dunbarula, Parafusulina?, Chusenella, Verbeekina, Pseudodoliolina, Metadoliolina?, Sumatrina?, and Yabeina, as well as several other foraminiferans and one alga. The assemblage of fusulinids is characteristically Tethyan, belonging to the Yabeina archaica zone of early Midian (late Wordian) age. Similar faunas are known from the Pamirs, Transcaucasia, and Japan, as well as from allochthonous terranes in British Columbia, northwestern Washington, and Koryakia in eastern Siberia.
Epithermal mineral deposits and occurrences of southwestern Alaska consist of Hg-Sb and gold- and sulfide-bearing vein lodes. Numerous Hg-Sb lodes are located throughout a region measuring several tens of thousands of square kilometers in and surrounding the Kuskokwim River basin in southwestern Alaska. The Hg-Sb lodes are hosted in sedimentary rocks of the Cretaceous Kuskokwim Group, the Triassic to Cretaceous Gemuk Group, and the Paleozoic Holitna Group, as well as in Late Cretaceous and early Tertiary mafic to felsic intrusive rocks. Mineralized Hg-Sb vein and vein breccia lodes are found in the sedimentary or igneous rocks or at their contacts. The minerology of the Hg-Sb lodes is dominated by cinnabar and stibnite, with subordinate realgar, orpiment, and native mercury, pyrite, gold, and hematite, as well as solid and liquid hydrocarbons; quartz, carbonate, limonite, dickite, and sercite are alteration gangue minerals. The largest mercury mine in Alaska, Red Devil, produced about 36,000 flasks of mercury, but the Hg-Sb lodes of southwestern Alaska generally consist of small, discontinuous veins that rarely exceed a few meters in width and a few tens of meters in strike length. The Hg-Sb lodes generally contain about 1 to 5 percent Hg and less than 1 percent Sb and As but are generally poor in base emtals and precious metals. Anomalous concentrations of gold in some lodes, however, suggest that gold deposits may be present in higher temperature environments below some of the Hg-Sb lodes.
The formation of the Hg-Sb lodes is closely correlated with igneous activity of a Late Cretaceous and early tertiary magmatic arc in southwestern Alaska. Geologic and geochemical characteristics of the Hg-Sb lodes suggest that ore fluids were generated in local sedimentary rocks as they were intruded by magmas. These intrusions provided the heat to initiate dehydration reactions and expel fluids from hydrous minerals and formational waters in the sedimentary rocks, causing thermal convection and hydrothermal fluid flow along fractures and faults. Isotopic data from sulfide and alteration minerals of the Hg-Sb lodes indicate multiple sources for the ore fluids; most fluids appear to have originated from local sedimentary rocks. Hydrothermal fluids with isotopically heavy oxygen but isotopically light hydrogen and sulfur compositions indicate derivation of these species from sedimentary rocks. Isotopically shifted, evolved meteoric water was a primary component in ore fluids from a few Hg-Sb lodes. Geochemical, isotopic, and fluid inclusion data also indicate that Hg, Co2, CH4, N2, and local hydrocarbons were derived from breakdown of organic matter in sedimentary rocks when they were heated by intrusions. Radiometric 40Ar/39Ar ages of 70 ± 3 Ma from hydrothermal sercites in the Hg-Sb lodes indicate a temporal association of igneous activity and mineralization, which is consistent with the geologic characteristics.
Most epithermal gold-bearing vein lodes on the Alaska Peninsula and Aleutian Islands are located in Eocene to Pleistocene volcanic-arc rocks, commonly andesite and dacite. These vein and vein breccia lodes, such as the Alaska-Apollo and Shumagin deposits on Unga Island, tend to be aligned along regional, northeast-striking, steeply dipping faults and fractures. The Alaska-Apollo mine produced about 500,000 metric tons (t) of ore that yielded an estimated 3,500 kg (130,000 oz) of gold from veins that were as much as 12 m wide and extended for 1,500 m laterally and 420 m vertically. Ore minerals include gold, galena, sphalerite, chalcopyrite, pyrite, marcasite, arsenopyrite, and native copper; gangue minerals are quartz, sericite, calcite, and chlorite and locally, barsite, clay, rhodonite, and adularia. Ores generally have Au-Ag-Te-Pb-Zn-Mn-Cu geochemical signatures, with wide As-Hg aureoles around some veins. Geologic and mineralogical characteristics of these lodes are similar to adularia-sericite volcanic-hosted epithermal deposits. The gold-bearing vein lodes may be related to arc porphyry systems, but more data are required to verify this association.
","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Mineral Deposits of Alaska (Economic Geology Monographs, volume 9)","largerWorkSubtype":{"id":15,"text":"Monograph"},"language":"English","publisher":"Economic Geology Publishing Company","isbn":"978-1-629495-56-9","usgsCitation":"Gray, J.E., Gent, C.A., Snee, L., and Wilson, F.H., 1997, Epithermal mercury-antimony and gold-bearing vein lodes of southwestern Alaska, chap. of Mineral Deposits of Alaska (Economic Geology Monographs, volume 9): Economic Geology Monographs, v. 9, p. 287-305.","productDescription":"19 p.","startPage":"287","endPage":"305","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":342729,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":342728,"rank":1,"type":{"id":15,"text":"Index Page"},"url":"https://www.segweb.org/store/detail.aspx?id=EDOCMONO09"}],"country":"United States","state":"Alaska","volume":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"594b85b6e4b062508e382ba2","contributors":{"editors":[{"text":"Goldfarb, Richard J. goldfarb@usgs.gov","contributorId":1205,"corporation":false,"usgs":true,"family":"Goldfarb","given":"Richard","email":"goldfarb@usgs.gov","middleInitial":"J.","affiliations":[{"id":171,"text":"Central Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"preferred":false,"id":698977,"contributorType":{"id":2,"text":"Editors"},"rank":1},{"text":"Miller, Lance D.","contributorId":30287,"corporation":false,"usgs":true,"family":"Miller","given":"Lance","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":698978,"contributorType":{"id":2,"text":"Editors"},"rank":2}],"authors":[{"text":"Gray, John E. jgray@usgs.gov","contributorId":1275,"corporation":false,"usgs":true,"family":"Gray","given":"John","email":"jgray@usgs.gov","middleInitial":"E.","affiliations":[{"id":171,"text":"Central Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"preferred":true,"id":698973,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gent, Carol A.","contributorId":40646,"corporation":false,"usgs":true,"family":"Gent","given":"Carol","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":698974,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Snee, Lawrence W.","contributorId":81534,"corporation":false,"usgs":true,"family":"Snee","given":"Lawrence W.","affiliations":[],"preferred":false,"id":698975,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wilson, Frederic H. 0000-0003-1761-6437 fwilson@usgs.gov","orcid":"https://orcid.org/0000-0003-1761-6437","contributorId":67174,"corporation":false,"usgs":true,"family":"Wilson","given":"Frederic","email":"fwilson@usgs.gov","middleInitial":"H.","affiliations":[{"id":119,"text":"Alaska Science Center Geology Minerals","active":true,"usgs":true},{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"preferred":true,"id":698976,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70188707,"text":"70188707 - 1997 - Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska","interactions":[],"lastModifiedDate":"2017-07-04T00:23:20","indexId":"70188707","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":5,"text":"Book chapter"},"publicationSubtype":{"id":24,"text":"Book Chapter"},"seriesTitle":{"id":5435,"text":"Economic Geology Monographs","active":true,"publicationSubtype":{"id":24}},"title":"Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska","docAbstract":"Placer gold and precious metal-bearing lode deposits of southwestern Alaska lie within a region 550 by 350 km, herein referred to as the Kuskokwim mineral belt. This mineral belt has yielded 100,240 kg (3.22 Moz) of gold, 12, 813 kg (412,000 oz) of silver, 1,377,412 kg (39,960 flasks) of mercury, and modest amounts of antimony and tungsten derived primarily from the late Cretaceous-early Tertiary igneous complexes of four major types: (1) alkali-calcic, comagmatic volcanic-plutonic complexes and isolated plutons, (2) calc-alkaline, meta-aluminous reduced plutons, (3) peraluminous alaskite or granite-porphyry sills and dike swarms, and (4) andesite-rhyolite subaerial volcanic rocks.
About 80 percent of the 77 to 52 Ma intrusive and volcanic rocks intrude or overlie the middle to Upper Cretaceous Kuskokwim Group sedimentary and volcanic rocks, as well as the Paleozoic-Mesozoic rocks of the Nixon Fork, Innoko, Goodnews, and Ruby preaccretionary terranes.
The major precious metal-bearing deposit types related to Late Cretaceous-early Tertiary igneous complexes of the Kuskokwim mineral belt are subdivided as follows: (1) plutonic-hosted copper-gold polymetallic stockwork, skarn, and vein deposits, (2) peraluminous granite-porphory-hosted gold polymetallic deposits, (3) plutonic-related, boron-enriched silver-tin polymetallic breccia pipes and replacement deposits, (4) gold and silver mineralization in epithermal systems, and (5) gold polymetallic heavy mineral placer deposits. Ten deposits genetically related to Late Cretaceous-early Tertiary intrusions contain minimum, inferred reserves amounting to 162,572 kg (5.23 Moz) of gold, 201,015 kg (6.46 Moz) silver, 12,160 metric tons (t) of tin, and 28,088 t of copper.
The lodes occur in veins, stockworks, breccia pipes, and replacement deposits that formed in epithermal to mesothermal temperature-pressure conditions. Fluid inclusion, isotopic age, mineral assemblage, alteration assemblage, and structural data indicate that many of the mineral deposits associated with Late Cretaceous-early tertiary volcanic and plutonic rocks represent geologically and spatially related, vertically zoned hydrothermal systems now exposed at several erosional levels.
Polymetallic gold deposits of the Kuskokwim mineral belt are probably related to 77 to 52 Ma plutonism and volcanism associated with a period of rapid, north-directed subduction of the Kula plate. The geologic interpretation suggests that igneous complexes of the Kuskokwim mineral belt formed in an intracontinental back-arc setting during a period of extensional, wrench fault tectonics.
The Kuskokwim mineral belt has many geologic and metallogenic features similar to other precious metal-bearing systems associated with arc-related igneous rocks such as the Late Cretaceous-early Tertiary Rocky Mountain alkalic province, the Jurassic Mount Milligan district of central British Columbia, the Andean orogen of South America, and the Okhotsk-Chukotka belt of northeast Asia.
","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Mineral Deposits of Alaska (Economic Geology Monographs, volume 9)","largerWorkSubtype":{"id":15,"text":"Monograph"},"language":"English","publisher":"Economic Geology Publishing Company","isbn":"978-1-629495-56-9","usgsCitation":"Bundtzen, T., and Miller, M.L., 1997, Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska, chap. of Mineral Deposits of Alaska (Economic Geology Monographs, volume 9): Economic Geology Monographs, v. 9, p. 242-286.","productDescription":"47 p.","startPage":"242","endPage":"286","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":342732,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":342731,"rank":1,"type":{"id":15,"text":"Index Page"},"url":"https://www.segweb.org/store/detail.aspx?id=EDOCMONO09"}],"country":"United States","state":"Alaska","otherGeospatial":"Kuskokwim mineral belt","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -162,\n 64\n ],\n [\n -162,\n 58.5\n ],\n [\n -158,\n 58.5\n ],\n [\n -158,\n 60.5\n ],\n [\n -155,\n 60.5\n ],\n [\n -155,\n 64\n ],\n [\n -162,\n 64\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"594b85b6e4b062508e382b9e","contributors":{"editors":[{"text":"Goldfarb, Richard J. goldfarb@usgs.gov","contributorId":1205,"corporation":false,"usgs":true,"family":"Goldfarb","given":"Richard","email":"goldfarb@usgs.gov","middleInitial":"J.","affiliations":[{"id":171,"text":"Central Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"preferred":false,"id":698981,"contributorType":{"id":2,"text":"Editors"},"rank":1},{"text":"Miller, Lance D.","contributorId":30287,"corporation":false,"usgs":true,"family":"Miller","given":"Lance","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":698982,"contributorType":{"id":2,"text":"Editors"},"rank":2}],"authors":[{"text":"Bundtzen, Thomas K.","contributorId":83560,"corporation":false,"usgs":true,"family":"Bundtzen","given":"Thomas K.","affiliations":[],"preferred":false,"id":698979,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Miller, Marti L. 0000-0003-0285-4942 mlmiller@usgs.gov","orcid":"https://orcid.org/0000-0003-0285-4942","contributorId":561,"corporation":false,"usgs":true,"family":"Miller","given":"Marti","email":"mlmiller@usgs.gov","middleInitial":"L.","affiliations":[{"id":119,"text":"Alaska Science Center Geology Minerals","active":true,"usgs":true}],"preferred":true,"id":698980,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70184433,"text":"70184433 - 1997 - Population genetics studies of the walrus (Odobenus rosmarus): A summary and interpretation of results and research needs","interactions":[],"lastModifiedDate":"2017-03-08T15:21:50","indexId":"70184433","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":5,"text":"Book chapter"},"publicationSubtype":{"id":24,"text":"Book Chapter"},"title":"Population genetics studies of the walrus (Odobenus rosmarus): A summary and interpretation of results and research needs","docAbstract":"A summary of population genetics data is presented for the walrus (Odobenus rosmarus). Current information on the ecology and behavior of the species is highlighted to aid in the interpretation of genetics results and to suggest future areas of research. Walruses are discontinuously distributed across the Arctic and are currently subdivided into six regional populations on the basis of historical distribution and morphology. Few population genetics studies have been conducted on the walrus. Only three of the six trigonal populations have been surveyed with biochemical or molecular techniques. Analysis of mitochondrial DNA (mtDNA) variation among walruses from the northern Pacific (Chukchi Sea) and western Atlantic (Greenland) regions revealed 13 haplotypes; 6 were found only in Pacific walruses while 7 were unique to the Atlantic subspecies. Estimates of sequence divergence between Atlantic and Pacific haplotypes were 1.0%-1.6%. No evidence of microgeographic structuring within the northern Pacific or western Atlantic regional populations was found on the basis of mtDNA haplotype frequency distributions or multilocus minisatellite band sharing. Minisatellite analysis of adult-juvenile and adult-adult pairs suggests that assemblages of walruses on individual ice floes are made up at least in part by groups of related individuals from more than one generation. Furthermore, high mtDNA haplotype diversities and low minisatellite band-sharing values suggest that both the northern Pacific and western Atlantic walruses have retained a high degree of genetic variability.
","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"Molecular Genetics of Marine Mammals: Special Publication 3","largerWorkSubtype":{"id":15,"text":"Monograph"},"language":"English","publisher":"Society for Marine Mammalogy","usgsCitation":"Scribner, K.T., Hills, S., Fain, S.R., and Cronin, M.A., 1997, Population genetics studies of the walrus (Odobenus rosmarus): A summary and interpretation of results and research needs, chap. of Molecular Genetics of Marine Mammals: Special Publication 3, p. 173-184.","productDescription":"12 p.","startPage":"173","endPage":"184","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":337133,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"58c12663e4b014cc3a3d351b","contributors":{"editors":[{"text":"Dizon, Andrew E.","contributorId":187660,"corporation":false,"usgs":false,"family":"Dizon","given":"Andrew","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":681471,"contributorType":{"id":2,"text":"Editors"},"rank":1},{"text":"Chivers, Susan J.","contributorId":187661,"corporation":false,"usgs":false,"family":"Chivers","given":"Susan","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":681472,"contributorType":{"id":2,"text":"Editors"},"rank":2},{"text":"Perrin, William F.","contributorId":47298,"corporation":false,"usgs":true,"family":"Perrin","given":"William","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":681473,"contributorType":{"id":2,"text":"Editors"},"rank":3}],"authors":[{"text":"Scribner, Kim T.","contributorId":146113,"corporation":false,"usgs":false,"family":"Scribner","given":"Kim","email":"","middleInitial":"T.","affiliations":[{"id":16582,"text":"Department of Fisheries and Wildlife and Department of Zoology, 480 Wilson Rd. 13 Natural Resources Building, Michigan State University, East Lansing, MI 48824","active":true,"usgs":false},{"id":135,"text":"Biological Resources Division","active":false,"usgs":true}],"preferred":false,"id":681467,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hills, Susan","contributorId":103995,"corporation":false,"usgs":false,"family":"Hills","given":"Susan","email":"","affiliations":[],"preferred":false,"id":681468,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Fain, Steven R.","contributorId":187719,"corporation":false,"usgs":false,"family":"Fain","given":"Steven","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":681469,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Cronin, Matthew A.","contributorId":57307,"corporation":false,"usgs":false,"family":"Cronin","given":"Matthew","email":"","middleInitial":"A.","affiliations":[{"id":28157,"text":"LGL Alaska Research Associates, Anchorage, AK","active":true,"usgs":false},{"id":7211,"text":"University of Alaska, Fairbanks","active":true,"usgs":false}],"preferred":false,"id":681470,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019345,"text":"70019345 - 1997 - Stratigraphic and structural implications of conodont and detrital zircon U-Pb ages from metamorphic rocks of the Coldfoot terrane, Brooks Range, Alaska","interactions":[],"lastModifiedDate":"2024-07-19T15:41:44.766392","indexId":"70019345","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Stratigraphic and structural implications of conodont and detrital zircon U-Pb ages from metamorphic rocks of the Coldfoot terrane, Brooks Range, Alaska","docAbstract":"New paleontologic and isotopic data from the Emma Creek and Marion Creek schists of the Coldfoot terrane, Arctic Alaska superterrane, central Brooks Range, suggest Devonian and possibly younger ages of deposition for their sedimentary protoliths. Conodonts from marble of the Emma Creek schist, intruded by a roughly 392 Ma orthogneiss, are late Lochkovian (early Early Devonian, between about 408 and 396 Ma) and Silurian to Devonian at two other locations. Spherical to oblong detrital zircons from quartz-mica schist of the overlying Marion Creek schist yield mostly discordant U—Pb data suggestive of provenance ages of 3.0, 2.0–1.8, and 1.5–1.4 Ga; however, several euhedral grains of zircon from Marion Creek quartz-mica schist have concordant U—Pb ages from 370 to 360 Ma. The Marion Creek schist in our study area therefore is at least 26 m.y. younger than the Emma Creek schist. The age data imply that the protolith of the Emma Creek schist is age correlative with Devonian carbonate rocks in the Hammond and North Slope terranes, whereas the Marion Creek schist is age correlative with Upper Devonian and Lower Mississippian clastic sedimentary rocks of the Endicott Group in the Endicott Mountains terrane and shale and carbonate units in the De Long Mountains and Sheenjek River terranes. Consequently, tectonic models restoring the entire Coldfoot terrane beneath partly or wholly coeval rocks of the Hammond, Endicott Mountains, De Long Mountains, and Sheenjek River terranes of the Arctic Alaska superterrane require revision. Alternative reconstructions, including restoration of the Coldfoot terrane inboard of the Endicott Mountains terrane or outboard of the De Long Mountains and Sheenjek River terranes are plausible but require either larger amounts of shortening than previously suggested or indicate problematic facies relations.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/96JB02351","issn":"01480227","usgsCitation":"Moore, T., Aleinikoff, J.N., and Harris, A., 1997, Stratigraphic and structural implications of conodont and detrital zircon U-Pb ages from metamorphic rocks of the Coldfoot terrane, Brooks Range, Alaska: Journal of Geophysical Research B: Solid Earth, v. 102, no. B9, p. 20797-20820, https://doi.org/10.1029/96JB02351.","productDescription":"24 p.","startPage":"20797","endPage":"20820","numberOfPages":"24","costCenters":[],"links":[{"id":480066,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/96jb02351","text":"Publisher Index Page"},{"id":226786,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B9","noUsgsAuthors":false,"publicationDate":"1997-09-10","publicationStatus":"PW","scienceBaseUri":"505b98d3e4b08c986b31c151","contributors":{"authors":[{"text":"Moore, Thomas E. 0000-0002-0878-0457","orcid":"https://orcid.org/0000-0002-0878-0457","contributorId":85592,"corporation":false,"usgs":true,"family":"Moore","given":"Thomas E.","affiliations":[],"preferred":false,"id":382416,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Aleinikoff, J. N. 0000-0003-3494-6841","orcid":"https://orcid.org/0000-0003-3494-6841","contributorId":75132,"corporation":false,"usgs":true,"family":"Aleinikoff","given":"J.","email":"","middleInitial":"N.","affiliations":[],"preferred":false,"id":382415,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Harris, A. G.","contributorId":39791,"corporation":false,"usgs":true,"family":"Harris","given":"A. G.","affiliations":[],"preferred":false,"id":382414,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70020299,"text":"70020299 - 1997 - Effect of day length on germination of seeds collected in Alaska","interactions":[],"lastModifiedDate":"2023-01-05T14:55:55.090212","indexId":"70020299","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":724,"text":"American Journal of Botany","active":true,"publicationSubtype":{"id":10}},"title":"Effect of day length on germination of seeds collected in Alaska","docAbstract":"Day length control can effectively limit seed germination to favorable seasons, but this phenomenon has been studied in relatively few wild plants. I tested species from interior Alaska for day length control of germination under controlled conditions, and I also monitored germination phenology in natural habitats. Unstratified and cold-stratified seeds were germinated on short (13 h) and long (22 h) day length and in the dark at constant and alternating temperatures. On long day length, unstratified Ledum decumbens and Saxifraga tricuspidata seeds germinated from 5°C to 20°C, but on short day length few or no seeds germinated at 5°C and 10°C and germination was reduced at higher temperatures. Unstratified seeds of Diapensia lapponica and Chamaedaphne calyculata germinated only at 15°C and 20°C on long day length, and short day length completely inhibited germination. Cold stratification widened the temperature range for germination on both long and short day lengths, but germination was still lower on short than long day length. Germination phenology in natural habitats was consistent with germination in controlled conditions. In these species, short day length and low temperatures interact to inhibit germination in the fall. After overwintering, seeds germinate in the spring at low temperatures and on long day lengths. The inhibitory effect of short day length is not important in the spring because day length is already long at snowmelt.
","language":"English","publisher":"Botanical Society of america","doi":"10.2307/2446088","issn":"00029122","usgsCitation":"Densmore, R., 1997, Effect of day length on germination of seeds collected in Alaska: American Journal of Botany, v. 84, no. 2, p. 274-278, https://doi.org/10.2307/2446088.","productDescription":"5 p.","startPage":"274","endPage":"278","costCenters":[],"links":[{"id":231051,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","city":"Fairbanks","otherGeospatial":"Brooks Range, Denali National Park, Dietrich River Valley, Eagle Summit, White Mountains","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -148.28305372426826,\n 64.93848840504893\n ],\n [\n -148.28305372426826,\n 64.70479021882716\n ],\n [\n -147.29977735708087,\n 64.70479021882716\n ],\n [\n -147.29977735708087,\n 64.93848840504893\n ],\n [\n -148.28305372426826,\n 64.93848840504893\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n },\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -149.55360340375898,\n 68.4550376318235\n ],\n [\n -149.42124575059574,\n 68.39612237488353\n ],\n [\n -149.4351781351392,\n 68.3280515689024\n ],\n [\n -149.44562742354674,\n 68.29329553994637\n ],\n [\n -149.6162991342049,\n 68.26235676445629\n ],\n [\n -149.7347244028247,\n 68.2119917443342\n ],\n [\n -149.7486567873684,\n 68.14077545384367\n ],\n [\n -149.70685963373776,\n 68.0680369079929\n ],\n [\n -149.82528503483593,\n 67.96895223927837\n ],\n [\n -149.71034286235187,\n 67.94673040732081\n ],\n [\n -149.37944872944328,\n 67.99376322480265\n ],\n [\n -149.47349232511206,\n 68.0628325366651\n ],\n [\n -149.3968642101227,\n 68.09404137470054\n ],\n [\n -149.47349232511206,\n 68.13429031425423\n ],\n [\n -149.34810086422044,\n 68.16410697608677\n ],\n [\n -149.34810086422044,\n 68.25074394409117\n ],\n [\n -149.26648507824703,\n 68.36327802141153\n ],\n [\n -149.2978329434699,\n 68.44532401127194\n ],\n [\n -149.40232582754624,\n 68.49900558082891\n ],\n [\n -149.55360340375898,\n 68.4550376318235\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n },\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -145.29195294246986,\n 65.54535833990516\n ],\n [\n -145.29195294246986,\n 65.51241166624851\n ],\n [\n -145.17155894124767,\n 65.51241166624851\n ],\n [\n -145.17155894124767,\n 65.54535833990516\n ],\n [\n -145.29195294246986,\n 65.54535833990516\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n },\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -152.16428563163504,\n 64.08371762955241\n ],\n [\n -152.26585366627998,\n 64.08371762955241\n ],\n [\n -152.2489256605059,\n 63.66255173449474\n ],\n [\n -152.90911788569795,\n 63.658796371485096\n ],\n [\n -152.89218987992385,\n 62.571962874117844\n ],\n [\n -152.90911788569795,\n 62.28992053388927\n ],\n [\n -152.31663768360252,\n 62.19531435584207\n ],\n [\n -151.87650953347438,\n 62.03697671509164\n ],\n [\n -151.74108548728123,\n 62.285984533822926\n ],\n [\n -151.80879751037787,\n 62.364606792789544\n ],\n [\n -151.76647749594235,\n 62.45868225197037\n ],\n [\n -150.60690910041268,\n 62.48215495395536\n ],\n [\n -150.25142097915537,\n 62.715869298017424\n ],\n [\n -149.92978886944638,\n 62.85907836232505\n ],\n [\n -149.2949886529156,\n 63.299762603520605\n ],\n [\n -148.93950053165833,\n 63.36054749202086\n ],\n [\n -148.80407648546503,\n 63.43634822702947\n ],\n [\n -148.76175647102966,\n 63.621215387698896\n ],\n [\n -148.87178850856168,\n 63.76375877923945\n ],\n [\n -149.11724459228697,\n 64.01334300602812\n ],\n [\n -151.36020535736264,\n 64.00592481514519\n ],\n [\n -151.3686693602497,\n 64.08371762955241\n ],\n [\n -152.16428563163504,\n 64.08371762955241\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"84","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a05cde4b0c8380cd50f88","contributors":{"authors":[{"text":"Densmore, R.V.","contributorId":72953,"corporation":false,"usgs":true,"family":"Densmore","given":"R.V.","email":"","affiliations":[],"preferred":false,"id":385728,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70020132,"text":"70020132 - 1997 - Long-period seismicity at Redoubt Volcano, Alaska, 1989-1990 related to magma degassing","interactions":[],"lastModifiedDate":"2012-03-12T17:19:20","indexId":"70020132","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2499,"text":"Journal of Volcanology and Geothermal Research","active":true,"publicationSubtype":{"id":10}},"title":"Long-period seismicity at Redoubt Volcano, Alaska, 1989-1990 related to magma degassing","docAbstract":"The mass of exsolved magmatic H2O is estimated and compared to the mass of superheated steam (25-50 Mtons) released through the resonating crack producing the December 13-14, 1989 swarm of long-period seismic events at Redoubt Volcano. Results indicate degassing of a H2O-CO2-SO2-saturated magma upon ascending from at least 12 km to 3-4 km beneath the crater as the source of the superheated steam. The mass of exsolved H2O (3.2-250 Mtons) is estimated from solubility diagrams of H2O-CO2-saturated silicate melts for the ascent history of the Redoubt magmas. Crystal size distribution, seismological, petrological, and geochemical data are used to constrain the ascent history of the two andesitic magmas prior to the eruption. Two stages of crystallization are inferred from crystal size distributions of plagioclase crystals in andesites erupted in December 1989. The first stage occurred 30-150 years before the eruption in both magmas and the second stage occurred at least 8 years and 15 years before the eruption in the dacitic andesite and rhyolitic andesite, respectively. The depths of crystallization are constrained from the spatial and temporal variations of volcano-tectonic earthquakes locations (Lahr et al., 1994) and from the P-wave and S-wave velocity structures (Benz et al., 1996). These data suggest that the rhyolitic andesite magma ascended to a depth of 7-8 km within at least 15 years of the eruption. Within at least 8 years of the eruption, the dacitic andesite magma migrated to a depth just below the other magma body where it resided until hours to days of the eruption. At this time, the dacitic andesite magma mixed with the rhyolitic andesite magma and established the reservoir for the eruption. Near the top of the reservoir, some of the mixed magma was displaced into fractures which extended 4-5 km toward the surface. This displaced magma created the eruption conduit and released the fluids related to the resonating crack. This scenario is consistent with the trends in major-and trace-element chemistry, and the stability of hornblende in the pre-eruption Redoubt magmas. It also provides a source for the SO2 and CO2 emissions measured during the eruption.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Volcanology and Geothermal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"03770273","usgsCitation":"Morrissey, M., 1997, Long-period seismicity at Redoubt Volcano, Alaska, 1989-1990 related to magma degassing: Journal of Volcanology and Geothermal Research, v. 75, no. 3-4, p. 321-335.","startPage":"321","endPage":"335","numberOfPages":"15","costCenters":[],"links":[{"id":227912,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"75","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a496fe4b0c8380cd685db","contributors":{"authors":[{"text":"Morrissey, M.M.","contributorId":41477,"corporation":false,"usgs":true,"family":"Morrissey","given":"M.M.","email":"","affiliations":[],"preferred":false,"id":385146,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019512,"text":"70019512 - 1997 - Crustal implications of bedrock geology along the Trans-Alaska Crustal Transect (TACT) in the Brooks Range, northern Alaska","interactions":[],"lastModifiedDate":"2024-07-19T14:45:49.183847","indexId":"70019512","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Crustal implications of bedrock geology along the Trans-Alaska Crustal Transect (TACT) in the Brooks Range, northern Alaska","docAbstract":"Geologic mapping of the Trans-Alaska Crustal Transect (TACT) project along the Dalton Highway in northern Alaska indicates that the Endicott Mountains allochthon and the Hammond terrane compose a combined allochthon that was thrust northward at least 90 km in the Early Cretaceous. The basal thrust of the combined allochthon climbs up section in the hanging wall from a ductile shear zone in the south through lower Paleozoic rocks of the Hammond terrane and into Upper Devonian rocks of the Endicott Mountains allochthon at the Mount Doonerak antiform, culminating in Early Cretaceous shale in the northern foothills of the Brooks Range. Footwall rocks north of the Mount Doonerak antiform are everywhere parautochthonous Permian and Triassic shale of the North Slope terrane rather than Jurassic and Lower Cretaceous strata of the Colville Basin as shown in most other tectonic models of the central Brooks Range. Stratigraphic and structural relations suggest that this thrust was the basal detachment for Early Cretaceous deformation. Younger structures, such as the Tertiary Mount Doonerak antiform, deform the Early Cretaceous structures and are cored by thrusts that root at a depth of about 10 to 30 km along a deeper detachment than the Early Cretaceous detachment. The Brooks Range, therefore, exposes (1) an Early Cretaceous thin-skinned deformational belt developed during arc-continent collision and (2) a mainly Tertiary thick-skinned orogen that is probabty the northward continuation of the Rocky Mountains orogenic belt. A down-to-the-south zone of both ductile and brittle normal faulting along the southern margin of the Brooks Range probably formed in the mid-Cretaceous by extensional exhumation of the Early Cretaceous contractional deformation.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/96JB03733","issn":"01480227","usgsCitation":"Moore, T., Wallace, W.K., Mull, C.G., Adams, K., Plafker, G., and Nokleberg, W., 1997, Crustal implications of bedrock geology along the Trans-Alaska Crustal Transect (TACT) in the Brooks Range, northern Alaska: Journal of Geophysical Research B: Solid Earth, v. 102, no. B9, p. 20645-20684, https://doi.org/10.1029/96JB03733.","productDescription":"40 p.","startPage":"20645","endPage":"20684","numberOfPages":"40","costCenters":[],"links":[{"id":489043,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/96jb03733","text":"Publisher Index Page"},{"id":226382,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B9","noUsgsAuthors":false,"publicationDate":"1997-09-10","publicationStatus":"PW","scienceBaseUri":"5059fcdfe4b0c8380cd4e49d","contributors":{"authors":[{"text":"Moore, Thomas E. 0000-0002-0878-0457","orcid":"https://orcid.org/0000-0002-0878-0457","contributorId":85592,"corporation":false,"usgs":true,"family":"Moore","given":"Thomas E.","affiliations":[],"preferred":false,"id":383016,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wallace, W. K.","contributorId":31781,"corporation":false,"usgs":true,"family":"Wallace","given":"W.","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":383012,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mull, C. G.","contributorId":40220,"corporation":false,"usgs":true,"family":"Mull","given":"C.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":383014,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Adams, K.E.","contributorId":9410,"corporation":false,"usgs":true,"family":"Adams","given":"K.E.","email":"","affiliations":[],"preferred":false,"id":383011,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Plafker, George 0000-0003-3972-0390","orcid":"https://orcid.org/0000-0003-3972-0390","contributorId":36603,"corporation":false,"usgs":true,"family":"Plafker","given":"George","affiliations":[],"preferred":false,"id":383013,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Nokleberg, W. J. 0000-0002-1574-8869","orcid":"https://orcid.org/0000-0002-1574-8869","contributorId":68312,"corporation":false,"usgs":true,"family":"Nokleberg","given":"W. J.","affiliations":[],"preferred":false,"id":383015,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":1012831,"text":"1012831 - 1997 - Home ranges and movements of arctic fox (Alopex lagopus) in western Alaska","interactions":[],"lastModifiedDate":"2023-08-14T15:02:41.409639","indexId":"1012831","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":894,"text":"Arctic","active":true,"publicationSubtype":{"id":10}},"displayTitle":"Home ranges and movements of arctic fox (Alopex lagopus) in western Alaska","title":"Home ranges and movements of arctic fox (Alopex lagopus) in western Alaska","docAbstract":"During the period from 1985 to 1990, radio collars were attached to 61 arctic foxes (Alopex lagopus) in the coastal region of the Yukon-Kuskokwim Delta in western Alaska. Radio tracking using hand-held receivers from aircraft and from fixed towers was conducted to determine daily and seasonal movements of foxes. Intensive radio tracking of 18 foxes from May through July indicated that males used larger areas (x = 10.22±6.18 sq. km) than females (x = 4.57±1.94 sq. km) regardless of breeding status. Generally foxes were relocated near (x = 3.4±2.4 km) their summer home ranges during other seasons of the year. There were no complex social groups of foxes among the marked population. Foxes did not have a definitive preference for any plant community, probably because of the even distribution and abundance of prey throughout all communities. Thirty foxes were relocated repeatedly during a period of at least 10 months, which included the denning season of one year and the breeding season of the next. Of 24 confirmed deaths of collared foxes, 16 were caused by shooting or trapping by local residents and 8 had unidentified causes. Maximum distance moved between relocations was 48.4 km. Males moved farther from initial capture sites in the winter following capture than did females, largely because of greater than 20 km movements by two foxes. There were no seasonal differences in movements between males and females.
","language":"English","publisher":"Arctic Institute of North America","doi":"10.14430/arctic1097","usgsCitation":"Anthony, R.M., 1997, Home ranges and movements of arctic fox (Alopex lagopus) in western Alaska: Arctic, v. 50, no. 2, p. 147-157, https://doi.org/10.14430/arctic1097.","productDescription":"11 p.","startPage":"147","endPage":"157","numberOfPages":"11","costCenters":[{"id":106,"text":"Alaska Biological Science Center","active":false,"usgs":true}],"links":[{"id":486971,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.14430/arctic1097","text":"Publisher Index Page"},{"id":128504,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -161.68408546822315,\n 63.605520209544835\n ],\n [\n -166.22760209072726,\n 63.605520209544835\n ],\n [\n -166.22760209072726,\n 61.04125914227663\n ],\n [\n -161.68408546822315,\n 61.04125914227663\n ],\n [\n -161.68408546822315,\n 63.605520209544835\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"50","issue":"2","noUsgsAuthors":false,"publicationDate":"1997-01-01","publicationStatus":"PW","scienceBaseUri":"4f4e4ae0e4b07f02db68831d","contributors":{"authors":[{"text":"Anthony, R. Michael","contributorId":54535,"corporation":false,"usgs":false,"family":"Anthony","given":"R.","email":"","middleInitial":"Michael","affiliations":[],"preferred":false,"id":318404,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019173,"text":"70019173 - 1997 - Ecosystem development on terraces along the Kugururok River, northwest Alaska","interactions":[],"lastModifiedDate":"2017-02-21T12:39:31","indexId":"70019173","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1474,"text":"Écoscience","active":true,"publicationSubtype":{"id":10}},"title":"Ecosystem development on terraces along the Kugururok River, northwest Alaska","docAbstract":"Riverside terraces along the Kugururok River in the Noatak National Preserve provided an opportunity to study primary succession, considering general trends that apply across all terraces, and unique events that influence individual terraces. The 30-year-old willow/poplar (Salix spp., Populus balsamifera L.) terrace had no trees taller than 1.5 m; the abundant spruce trees were not tall enough to emerge from the canopy height of the willows and poplars, and moose (Alces alces [Clinton]) browsing limited the canopy height of these plants. The 75-year-old poplar/spruce (Picea glauca [Moench] Voss) terrace had a high density of poplars (> 1000/ha) and low density of spruce (125/ha); heavy browsing by moose reduced the density of poplar by about one-half. The removal of the poplar by moose in this stand resulted in sustained increases in growth of individual spruce trees. The 100-year-old younger spruce/poplar terrace had about twice as many spruce trees (1250/ha) as poplar trees (500/ha), and the spruce trees were larger on average than the poplar trees. In the 220+ year-old older spruce/poplar type, only a few poplars remained (about 25/ha), and the number of spruce trees (600/ha) was only half that of the younger stage, either from lower initial spruce density on this terrace, or increased mortality of spruce. The 240+ year-old spruce type was a second-generation forest, characterized by a high density (1950/ha) of small spruce trees, some of which were tilted, indicating discontinuous permafrost. Plant litterfall mass showed no strong trend with terrace age, although N content of litterfall appeared to decline by about 1/3 in the spruce-dominated stages. Fungal biomass increased with ecosystem age, whereas bacterial biomass and microfauna declined. We found no evidence of declining soil N supply in older stages, but fertilization experiments would be needed to determine if N limitation of productivity changed with ecosystem development. We conclude that the general successional trend of increased spruce dominance is robust for this location, but that unique events play important roles in determining tree densities and the timing of the shift in dominance from poplar to spruce. The arrival of moose in the 1970s accelerated dominance by spruce on young terraces.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecoscience","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1080/11956860.1997.11682410","issn":"11956860","usgsCitation":"Binkley, D., Suarez, F., Stottlemyer, R., and Caldwell, B., 1997, Ecosystem development on terraces along the Kugururok River, northwest Alaska: Écoscience, v. 4, no. 3, p. 311-318, https://doi.org/10.1080/11956860.1997.11682410.","startPage":"311","endPage":"318","numberOfPages":"8","costCenters":[],"links":[{"id":226910,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"4","issue":"3","noUsgsAuthors":false,"publicationDate":"2016-03-24","publicationStatus":"PW","scienceBaseUri":"505a059ce4b0c8380cd50e87","contributors":{"authors":[{"text":"Binkley, Dan","contributorId":102419,"corporation":false,"usgs":true,"family":"Binkley","given":"Dan","affiliations":[],"preferred":false,"id":381882,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Suarez, F.","contributorId":44676,"corporation":false,"usgs":true,"family":"Suarez","given":"F.","email":"","affiliations":[],"preferred":false,"id":381881,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Stottlemyer, R.","contributorId":44493,"corporation":false,"usgs":true,"family":"Stottlemyer","given":"R.","email":"","affiliations":[],"preferred":false,"id":381880,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Caldwell, B.","contributorId":40741,"corporation":false,"usgs":true,"family":"Caldwell","given":"B.","email":"","affiliations":[],"preferred":false,"id":381879,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019248,"text":"70019248 - 1997 - Stratigraphic contrasts and tectonic relationships between Carboniferous successions in the Trans-Alaska Crustal Transect corridor and adjacent areas, northern Alaska","interactions":[],"lastModifiedDate":"2024-07-19T14:59:04.410595","indexId":"70019248","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Stratigraphic contrasts and tectonic relationships between Carboniferous successions in the Trans-Alaska Crustal Transect corridor and adjacent areas, northern Alaska","docAbstract":"The Carboniferous succession along the Trans-Alaska Crustal Transect (TACT) corridor in the Atigun Gorge area of the central Brooks Range consists of the Kayak Shale (Kinderhookian) and the Lisburne Group (Kinderhookian through Chesterian). The Kayak Shale is at least 210 m thick; it is chiefly black, noncalcareous shale with several limestone beds of pelmatozoan-bryozoan packstone and formed in an open-marine setting. The Lisburne Group is a carbonate rock succession about 650 m thick and consists mainly of skeletal packstone, wackestone, and milestone which contain locally abundant calcispheres, ostracodes, algae, and sponge spicules; it accumulated largely in a shallow water platform environment with restricted circulation. This restriction was probably produced by a coeval belt of skeletal sand shoals recognized 70 km to the west in the Shainin Lake area. Significant and apparently abrupt shifts in the age and lithofacies of Carboniferous strata occur across the central and eastern Brooks Range. These shifts are most marked in a zone roughly coincident with what is interpreted by many workers to be the leading edge of the Endicott Mountains allochthon. Notable lithologie contrasts are also observed, however, between sections in the northern and southern parts of the Endicott Mountains allochthon. This suggests that considerable tectonic shortening has taken place within the allochthon, as well as between it and parautochthonous rocks to the northeast. The Carboniferous section near Mount Doonerak is more similar in age and lithofacies to coeval sections in the central Brooks Range that are considered allochthonous than to parautochthonous sections to the northeast.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/97JB02350","issn":"01480227","usgsCitation":"Dumoulin, J.A., Watts, K., and Harris, A., 1997, Stratigraphic contrasts and tectonic relationships between Carboniferous successions in the Trans-Alaska Crustal Transect corridor and adjacent areas, northern Alaska: Journal of Geophysical Research B: Solid Earth, v. 102, no. B9, p. 20709-20726, https://doi.org/10.1029/97JB02350.","productDescription":"16 p.","startPage":"20709","endPage":"20726","numberOfPages":"18","costCenters":[],"links":[{"id":479943,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/97jb02350","text":"Publisher Index Page"},{"id":226590,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B9","noUsgsAuthors":false,"publicationDate":"2012-12-19","publicationStatus":"PW","scienceBaseUri":"505b98d9e4b08c986b31c161","contributors":{"authors":[{"text":"Dumoulin, Julie A. 0000-0003-1754-1287 dumoulin@usgs.gov","orcid":"https://orcid.org/0000-0003-1754-1287","contributorId":203209,"corporation":false,"usgs":true,"family":"Dumoulin","given":"Julie","email":"dumoulin@usgs.gov","middleInitial":"A.","affiliations":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":119,"text":"Alaska Science Center Geology Minerals","active":true,"usgs":true}],"preferred":true,"id":382132,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Watts, K.F.","contributorId":45368,"corporation":false,"usgs":true,"family":"Watts","given":"K.F.","email":"","affiliations":[],"preferred":false,"id":382131,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Harris, A. G.","contributorId":39791,"corporation":false,"usgs":true,"family":"Harris","given":"A. G.","affiliations":[],"preferred":false,"id":382130,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019274,"text":"70019274 - 1997 - Opening the arctic: The drilling of Umiat #1","interactions":[],"lastModifiedDate":"2012-03-12T17:19:29","indexId":"70019274","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2897,"text":"Northeastern Geology and Environmental Sciences","active":true,"publicationSubtype":{"id":10}},"title":"Opening the arctic: The drilling of Umiat #1","docAbstract":"One of the greatest excitements for a petroleum geologist is to venture into the frontier, to explore and drill \"where no man has gone before.\" Over 50 years ago Bill Rex, a Kansas oilman, was tapped to lead the first oil drilling expedition into the Alaskan Arctic. He successfully assembled and outfitted a Naval Seabee expedition whose mission was to drill the first well north of the Arctic Circle, Umiat #1. The story of Umiat #1 is one of anecdotes and personal accounts. This paper relates the successes and tribulations of that Seabee exploration venture, as told to the writer by some of the participants.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Northeastern Geology and Environmental Sciences","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"01941453","usgsCitation":"Gerhard, L.C., 1997, Opening the arctic: The drilling of Umiat #1: Northeastern Geology and Environmental Sciences, v. 19, no. 1-2, p. 8-13.","startPage":"8","endPage":"13","numberOfPages":"6","costCenters":[],"links":[{"id":226285,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"19","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6e6ae4b0c8380cd75632","contributors":{"authors":[{"text":"Gerhard, L. C.","contributorId":30767,"corporation":false,"usgs":false,"family":"Gerhard","given":"L.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":382206,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019391,"text":"70019391 - 1997 - Permian deposition in the north central Brooks Range, Alaska: Constraints for tectonic reconstructions","interactions":[],"lastModifiedDate":"2024-07-19T15:07:21.724149","indexId":"70019391","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2314,"text":"Journal of Geophysical Research B: Solid Earth","active":true,"publicationSubtype":{"id":10}},"title":"Permian deposition in the north central Brooks Range, Alaska: Constraints for tectonic reconstructions","docAbstract":"Two opposing tectonic models have been offered to explain the regional structural relations in the north central Brooks Range fold-thrust belt of northern Alaska. The first suggests that rocks of the northern Endicott Mountains were thrust from south to north over the area of the present Mount Doonerak high and are therefore highly allochthonous. The second implies that the rocks of the northern Endicott Mountains were deposited in a basin that lay north of the Mount Doonerak high and later were thrust a short distance southward onto the northern flank of the high and are thus parautochthonous. To provide stratigraphic constraints for these models, this study examines Permian facies of the north central Brooks Range. Permian rocks in the north central Brooks Range comprise a thin (40 to 160 m thick), fining-upward succession of clastic, storm-influenced shelf deposits. When the rocks of the northern Endicott Mountains are restored south of the Mount Doonerak area, a minimum distance of 80 km, the Permian deposits grade systematically from distal facies (Siksikpuk Formation) in the southwest to proximal facies (Echooka Formation) in the northeast. Facies trends in the reconstructed Permian basin include, from southwest to northeast, (1) an increase in carbonate content and corresponding decrease in silica content, (2) a general darkening and thickening of shaley intervals, (3) an increase in proximal features of storm beds, including coarser, thicker, more abundant, and more closely spaced beds, and (4) an increase in abundance and diversity of the faunal assemblage with a corresponding decrease in age. These stratigraphic relations imply that rocks of the northern Endicott Mountains are allochthonous and structurally overlie a proximal stratigraphie succession similar to that exposed in the Mount Doonerak area and northeastern Brooks Range.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/97JB00950","issn":"01480227","usgsCitation":"Adams, K., Mull, C.G., and Crowder, R., 1997, Permian deposition in the north central Brooks Range, Alaska: Constraints for tectonic reconstructions: Journal of Geophysical Research B: Solid Earth, v. 102, no. B9, p. 20727-20748, https://doi.org/10.1029/97JB00950.","productDescription":"22 p.","startPage":"20727","endPage":"20748","numberOfPages":"22","costCenters":[],"links":[{"id":479986,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/97jb00950","text":"Publisher Index Page"},{"id":226923,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"102","issue":"B9","noUsgsAuthors":false,"publicationDate":"1997-09-10","publicationStatus":"PW","scienceBaseUri":"505a76bce4b0c8380cd782b9","contributors":{"authors":[{"text":"Adams, K.E.","contributorId":9410,"corporation":false,"usgs":true,"family":"Adams","given":"K.E.","email":"","affiliations":[],"preferred":false,"id":382571,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mull, C. G.","contributorId":40220,"corporation":false,"usgs":true,"family":"Mull","given":"C.","email":"","middleInitial":"G.","affiliations":[],"preferred":false,"id":382572,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Crowder, R.K.","contributorId":80833,"corporation":false,"usgs":true,"family":"Crowder","given":"R.K.","email":"","affiliations":[],"preferred":false,"id":382573,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ]}