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- Trace fossils -- North Atlantic Ocean (2)
- Aquatic ecology -- Antarctica (1)
- Forest ecology (1)
- Geobiology (1)
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- Geology -- California -- Gabilan Range (1)
- Geomorphology -- California -- Gabilan Range (1)
- Glaciers -- Sierra Nevada (Calif. and Nev.)-- Climatic factors (1)
- Glaciers -- Sierra Nevada (Calif. and Nev.)-- Environmental aspects (1)
- Historic agricultural landscapes -- Oregon (1)
- Ice sheets -- Antarctica (1)
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- Micropaleontology -- North Atlantic Ocean (1)
- Niche (Ecology) (1)
- Plant-soil relationships (1)
- Plants -- Oregon -- History (1)
- Sediment transport -- Mathematical models (1)
- Soils -- Composition (1)
- Structural geology (1)
- Subglacial lakes -- Antarctica (1)
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- United States. General Land Office -- Surveys (1)
Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
Historical Vegetation Of Central Southwest Oregon, Based On Glo Survey Notes : Final Report To Usdi Bureau Of Land Management, Medford District, O. Eugene Hickman, John A. Christy
Historical Vegetation Of Central Southwest Oregon, Based On Glo Survey Notes : Final Report To Usdi Bureau Of Land Management, Medford District, O. Eugene Hickman, John A. Christy
Institute for Natural Resources Publications
Historical vegetation at the time of European settlement is of great interest to both the public and land managers, but is poorly documented. One source of data are the earliest land survey records of the General Land Office (GLO). Rectangular township surveys in Southwest Oregon were initiated in the mid 1850’s as settlers began to claim homesteads in the Bear Creek Valley surrounding what is now Medford. We examined GLO land survey field notes and plats (maps) accompanying the surveys, transcribed GLO landscape data into an Access database, and classified the data set into very general vegetation types for mapping. …
Quantifying 20th Century Glacier Change In The Sierra Nevada, California, Andrew G. Fountain, Hassan J. Basagic
Quantifying 20th Century Glacier Change In The Sierra Nevada, California, Andrew G. Fountain, Hassan J. Basagic
Geology Faculty Publications and Presentations
Numerous small alpine glaciers occupy the high elevation regions of the central and southern Sierra Nevada, California. An inventory based on 1:24,000 topographic maps revealed 1719 glaciers and perennial snowfields for a total area of 39.15 +/- 0.13 km(2). The number of 'true' glaciers, versus non-moving ice, is estimated to be 122 covering 14.89 +/- 0.08 km(2) or 38% of the ice-covered area. Historic photographs, geologic evidence, and field mapping were used to determine the magnitude of area change over the past century at 14 glaciers. The area change between 1903 and 2004 ranged from -31% to -78%, averaging -55%. …
Mapping Of Unstable And Potentially Unstable Slopes In Sogne Og Fjordane, Reginald L. Hermanns, Luzia Fischer, Thierry Oppikofer, M. Bøhme, John F. Dehls, H. Henriksen, Adam M. Booth, R. Eilertsen, O. Longva, Trond Eiken
Mapping Of Unstable And Potentially Unstable Slopes In Sogne Og Fjordane, Reginald L. Hermanns, Luzia Fischer, Thierry Oppikofer, M. Bøhme, John F. Dehls, H. Henriksen, Adam M. Booth, R. Eilertsen, O. Longva, Trond Eiken
Geology Faculty Publications and Presentations
For the past three years NGU has worked on 25 unstable and potentially unstable rock slopes in Sogn og Fjordane. In addition Fjærlandsfjord, Hyenfjord and Årdalsvatnet were systematically mapped for deposits of prehistoric and historic rock slope failures onshore and with help of a bathymetry. Mapping on land included structural mapping of ten sites by on-site field mapping and nine sites by remote structural mapping using terrestrial laser scanning technology (TLS). Field work also included periodic monitoring of 14 sites using differential Global Positioning Systems (dGPS) and TLS at 4 sites. Synthetic Aperture Radar was app lied for the entire …
Potential Fossil Endoliths In Vesicular Pillow Basalt, Coral Patch Seamount, Eastern North Atlantic Ocean, Barbara Cavalazzi, Frances Westall, Sherry L. Cady, Roberto Barbieri, Frédéric Foucher
Potential Fossil Endoliths In Vesicular Pillow Basalt, Coral Patch Seamount, Eastern North Atlantic Ocean, Barbara Cavalazzi, Frances Westall, Sherry L. Cady, Roberto Barbieri, Frédéric Foucher
Geology Faculty Publications and Presentations
The chilled rinds of pillow basalt from the Ampere-Coral Patch Seamounts in the eastern North Atlantic were studied as a potential habitat of microbial life. A variety of putative biogenic structures, which include filamentous and spherical microfossil-like structures, were detected in K-phillipsite-filled amygdules within the chilled rinds. The filamentous structures (similar to 2.5 mu m in diameter) occur as K-phillipsite tubules surrounded by an Fe-oxyhydroxide (lepidocrocite) rich membranous structure, whereas the spherical structures (from 4 to 2 mu m in diameter) are associated with Ti oxide (anatase) and carbonaceous matter. Several lines of evidence indicate that the microfossil-like structures in …
A 1-D Mechanistic Model For The Evolution Of Earthflow-Prone Hillslopes, Adam M. Booth, Joshua J. Roering
A 1-D Mechanistic Model For The Evolution Of Earthflow-Prone Hillslopes, Adam M. Booth, Joshua J. Roering
Geology Faculty Publications and Presentations
In mountainous terrain, deep‐seated landslides transport large volumes of material on hillslopes, exerting a dominant control on erosion rates and landscape form. Here, we develop a mathematical landscape evolution model to explore interactions between deep‐seated earthflows, soil creep, and gully processes at the drainage basin scale over geomorphically relevant (>103 year) timescales. In the model, sediment flux or incision laws for these three geomorphic processes combine to determine the morphology of actively uplifting and eroding steady state topographic profiles. We apply the model to three sites, one in the Gabilan Mesa, California, with no earthflow activity, and two …
'Sticky Spots' And Subglacial Lakes Under Ice Streams Of The Siple Coast, Antarctica, Olga V. Sergienko, Christina L. Hulbe
'Sticky Spots' And Subglacial Lakes Under Ice Streams Of The Siple Coast, Antarctica, Olga V. Sergienko, Christina L. Hulbe
Geology Faculty Publications and Presentations
Locations of subglacial lakes discovered under fast-moving West Antarctic ice streams tend to be associated with topographic features of the subglacial bed or with areas that have strong variations in basal conditions. Inversion of ice-stream surface velocity indicates that basal conditions under ice streams can be highly variable and that there can be widespread regions where basal traction is high. To seek an explanation for why lakes appear to be sited near areas with high basal traction, we use numerical models to simulate ice-stream dynamics, thermodynamics and subglacial water flow. We demonstrate that the ice flow over high basal traction …
Foliar Nutrient Concentrations Related To Soil Sources Across A Range Of Sites In The Northeastern United States, Melissa S. Lucash, Ruth D. Yanai, Joel D. Blum, B. B. Park
Foliar Nutrient Concentrations Related To Soil Sources Across A Range Of Sites In The Northeastern United States, Melissa S. Lucash, Ruth D. Yanai, Joel D. Blum, B. B. Park
Environmental Science and Management Faculty Publications and Presentations
Understanding the supply of nutrients from various soil sources and the sensitivity of tree species to soil nutrient availability is critical for predicting the effects of declines in base cations due to acid rain and forest harvesting on forest health and productivity. We collected soil samples from 19 sites in the northeastern United States, chemically analyzed them using a sequential extraction procedure, and compared them to the chemical composition of foliage of the dominant tree species. Concentrations of Ca and Mg in foliage were correlated with exchangeable Ca and Mg concentrations in the upper mineral soil; for most tree species …
Volcanism And Astrobiology: Life On Earth And Beyond, Charles S. Cockell, Sherry L. Cady, Nicola Mcloughlin
Volcanism And Astrobiology: Life On Earth And Beyond, Charles S. Cockell, Sherry L. Cady, Nicola Mcloughlin
Geology Faculty Publications and Presentations
Editorial Introduction to the 2011 Special Issue of Astrobiology.