Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Earth Sciences

Högbomite From The Aldan Shield, Eastern Siberia, Ussr, Edward S. Grew, Galina M. Drugova, N. V. Leskova Jun 1989

Högbomite From The Aldan Shield, Eastern Siberia, Ussr, Edward S. Grew, Galina M. Drugova, N. V. Leskova

Earth Science Faculty Scholarship

No abstract provided.


Bending Shear: The Rate-Controlling Mechanism For Calving Ice Walls, Terence J. Hughes, Masayuki Nakagawa Jan 1989

Bending Shear: The Rate-Controlling Mechanism For Calving Ice Walls, Terence J. Hughes, Masayuki Nakagawa

Earth Science Faculty Scholarship

Bending shear was observed to produce nearly vertical shear bands in a calving ice wall standing on dry land on Deception Island (Iat. 63.0 oS., long. 60.6 W.), and slabs calved straight downward when shear rupture occurred along these shear bands (Hughes, 1989). A formula for the calving rate was developed from the Deception Island data, and we have attempted to justify generalizing this formula to include ice walls standing along beaches or in water. These are environments in which a wave-washed groove develops along the base of the ice wall or along a water line above the base. The …


Timing Of Tertiary Extension In The Railroad Valley Pioche Transect, Nevada: Constraints From Ar-40/Ar-39 Ages Of Volcanic Rocks, Wanda J. Taylor, John M. Bartley, Daniel R. Lux, Gary J. Axen Jan 1989

Timing Of Tertiary Extension In The Railroad Valley Pioche Transect, Nevada: Constraints From Ar-40/Ar-39 Ages Of Volcanic Rocks, Wanda J. Taylor, John M. Bartley, Daniel R. Lux, Gary J. Axen

Earth Science Faculty Scholarship

Time-space relations of extension and volcanism place critical constraints on models of Basin and Range extensional processes. This paper addresses such relations in a 130-km-wide transect in the eastern Great Basin, bounded on the east by the Ely Springs Range and on the west by the Grant and Quinn Canyon ranges. Stratigraphic and structural data, combined with 40Ar/39Ar isotopic ages of volcanic rocks, document a protracted but distinctly episodic extensional history. Field relations indicate four periods of faulting. Only one of these periods was synchronous with nearby volcanic activity, which implies that volcanism and faulting need not …


Analysis Of A 290-Year Net Accumulation Time Series From Mt. Logan, Yukon, G. Holdsworth, H. R. Krouse, M. Nosal, M. J. Spencer, Paul Andrew Mayewski Jan 1989

Analysis Of A 290-Year Net Accumulation Time Series From Mt. Logan, Yukon, G. Holdsworth, H. R. Krouse, M. Nosal, M. J. Spencer, Paul Andrew Mayewski

Earth Science Faculty Scholarship

A 102.5-m mechanically continuous firn and ice core sequence retrieved from the Northwest Col of Mt. Logan (latitude 60°30'N; longitude 140°35'W; site location 5340 m a.s.l.) in the Yukon Territory, Canada, has been analyzed continuously for stable isotopes, pH and liquid electrolytic conductivity. Specific sections of the core have been analyzed for total β-activity (0-22 m) and trace ion concentrations (across major volcanic events) in order to date the core. In the lower half of the core, nitrate and some other ionic species are used to identify annual increments except between AD 1693 and AD 1720 and between AD 1729 …