Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
- Keyword
Articles 1 - 5 of 5
Full-Text Articles in Glaciology
Mountain Evolution And Environmental Changes Of Huangshan, China, P.-H. Huang, Robert F. Diffendal Jr., M. Yang, Patricia E. Helland
Mountain Evolution And Environmental Changes Of Huangshan, China, P.-H. Huang, Robert F. Diffendal Jr., M. Yang, Patricia E. Helland
Department of Earth and Atmospheric Sciences: Faculty Publications
Huangshan (Yellow Mountain) is located in southern part of the lower reaches of the Yangtze River. The highest Lotus Flower peak is 1,864 m above sea level. Formative ages of the Huangshan and its granite, process of mountain geomorphic evolution from the Eocene to Quaternary, environmental changes of Quaternary, formative origin of beautiful peaks and fascinating rocks were studied and questionable "Pleistocene glaciation" was also discussed in this paper.
Mapping Subglacial Surfaces Of Temperate Valley Glaciers By Two-Pass Migration Of A Radio-Echo Sounding Survey, Brian C. Welch, W. Tad Pfeffer, Joel T. Harper, Neil F. Humphrey
Mapping Subglacial Surfaces Of Temperate Valley Glaciers By Two-Pass Migration Of A Radio-Echo Sounding Survey, Brian C. Welch, W. Tad Pfeffer, Joel T. Harper, Neil F. Humphrey
Geosciences Faculty Publications
High-resolution maps of the glacier bed are developed through a pseudo-three-dimensional migration of a dense array of radio-echo sounding profiles. Resolution of three-dimensional maps of sub-glacial surfaces is determined by the radio-echo sounding wavelength, data spacing in the field, and migration. Based on synthetic radio-echo sounding profile experiments, the maximum resolution of the final map cannot exceed one half-wavelength. A methodology of field and processing techniques is outlined to develop a maximum-resolution map of the glacier bed. The field and processing techniques valley glacier in south-central Alaska. The field techniques and the processing steps used on the glacier result in …
Quartzite Fabric Transition In A Cordilleran Metamorphic Core Complex, Allen J. Mcgrew, Martin Casey
Quartzite Fabric Transition In A Cordilleran Metamorphic Core Complex, Allen J. Mcgrew, Martin Casey
Department of Earth, Environment and Sustainability Faculty Publications
Photomicrographs 143A-143F record fabric variations in quartzite with increasing structural depth in a > 1 km thick, amphibolite-facies, normal-sense shear zone in the East Humboldt metamorphic core complex, Nevada (Figure 143.1). This shear zone and the overlying detachment system unroofed an infrastructure of high-grade, migmatitic gneiss during Oligocene to early Miocene extension (Dallmeyer and others, 1986; Wright and Snoke, 1993; McGrew and Snee, 1994). Thermobarometric constraints from near the base of the mylonitic zone record deformation conditions of 550°- 620°C and 300-400 MPa (Hurlow and others, 1991). Sample WBC6 (l43A and 143B) characterizes the mylonitic zone, whereas sample 8706-1 (143C and …
Crevasse Patterns And The Strain-Rate Tensor: A High-Resolution Comparison, Joel T. Harper, Neil Humphrey, W. Tad Pfeffer
Crevasse Patterns And The Strain-Rate Tensor: A High-Resolution Comparison, Joel T. Harper, Neil Humphrey, W. Tad Pfeffer
Geosciences Faculty Publications
Values of the strain-rate tensor represented at a 20 m length scale are found to explain the pattern and orientation of crevasses in a 0.13 km2 reach of Worthington Glacier, Alaska, U.S.A. The flow field of the reach is constructed from surveyed displacements of 110 markers spaced 20-30 m apart. A velocity gradient method is then used to calculate values of the principal strain-rate axes at the nodes of a 20 m x 20 m orthogonal grid. Crevasses in the study reach are of two types, splaying and transverse, and are everywhere normal to the trajectories of greatest (most …
Lead Isotopes And Selected Metals In Ice From Law Dome, Antarctica, K. J. R. Rosman, W. Chisholm, C. F. Boutron, S. Hong, R. Edwards, Vin Morgan, Peter N. Sedwick
Lead Isotopes And Selected Metals In Ice From Law Dome, Antarctica, K. J. R. Rosman, W. Chisholm, C. F. Boutron, S. Hong, R. Edwards, Vin Morgan, Peter N. Sedwick
OES Faculty Publications
The isotopic composition. of Pb and the concentrations of Pb, Ba and Bi were measured in selected ice-core samples from Law Dome, East Antarctica, to a depth of 1196 m. The range of concentrations found in decontaminated ice was 0.03-1.5 pg g-1 for Pb, 0.9-6.1 pg g-1 for Ba and 0.4-17 fg g-1 for Bi, excluding the deepest sample which contained ∼1 ppm of rock dust. The abundances of all four stable lead isotopes were measured and gave 206Pb/207Pb ratios ≤ ∼1.23. A value of 208Pb/207Pb = 2.78 was measured in …