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

Physical Sciences and Mathematics Commons

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

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

Resolving A One-Year Ecesis Interval For Alaska Paper Birch: Dating A Rockfall Event, Wishbone Hill, Southcentral Alaska, Riley E. Whitney, Alexander K. Stewart, Trent D. Hubbard, Anabella S. Kowalski, Oscar A. Wilkerson May 2021

Resolving A One-Year Ecesis Interval For Alaska Paper Birch: Dating A Rockfall Event, Wishbone Hill, Southcentral Alaska, Riley E. Whitney, Alexander K. Stewart, Trent D. Hubbard, Anabella S. Kowalski, Oscar A. Wilkerson

The Compass: Earth Science Journal of Sigma Gamma Epsilon

Numerous large boulders at the base of Wishbone Hill, northeast of Anchorage, Alaska, suggest a historic rockfall event and potential for future surface instability, putting lives and property at risk. The source of the rockfall-boulders is an exposed syncline with a cliff face composed of conglomerate. The age of trees growing atop boulders provides a minimum exposure-age of those boulders and, thus, the rockfall event. To determine when the rockfall occurred, we dated trees growing atop the boulders using tree-ring samples collected from 30 Alaska paper birch trees. After mounting and polishing, each tree-ring sample was dot-counted, and tree-ring widths …


Using Gis To Create Hazard Maps And Assess Evacuation Routes Around “The Gate To Hell”; Masaya Volcano, Nicaragua, Rebecca Hedges, Stevie Mcdermaid, Jason Kaiser, David Maxwell, Kathy Matthews May 2021

Using Gis To Create Hazard Maps And Assess Evacuation Routes Around “The Gate To Hell”; Masaya Volcano, Nicaragua, Rebecca Hedges, Stevie Mcdermaid, Jason Kaiser, David Maxwell, Kathy Matthews

The Compass: Earth Science Journal of Sigma Gamma Epsilon

Volcán Masaya in Nicaragua is made of a series of calderas and craters that lies 7 km from the city of Masaya with a population of over 100,000. Masaya is part of the Central American Volcanic Arc (CAVA) which contains hundreds of volcanoes. While many of the volcanoes of the arc produce small, quiescent eruptions, some are capable of large explosive events. The recent cycle of volcanism at Masaya began 7000 years ago. Initial eruptions were primarily lava, small ash flows, ashfalls, and degassing events which eventually gave way to climactic Vulcanian eruptions. The hazards presented from this system affect …


Late Cretaceous Dinosaur Tracks From The Iron Springs Formation, Iron County, Utah, Jennifer K. Crowell, Grant T. Shimer May 2021

Late Cretaceous Dinosaur Tracks From The Iron Springs Formation, Iron County, Utah, Jennifer K. Crowell, Grant T. Shimer

The Compass: Earth Science Journal of Sigma Gamma Epsilon

Located in Iron County, Utah, the Parowan Gap dinosaur track site contains over one hundred natural casts of non-avian dinosaur tracks preserved in sandstones and siltstones of the Late Cretaceous (≈83 Ma) Iron Springs Formation. For this study, the authors returned to the area to survey for and describe previously unidentified tracks. Many tracks from this new study occur as in situ casts found on the basal surfaces of sandstones deposited by braided and meandering rivers on the coastal plain of the Western Interior Seaway, with some specimens from fallen talus blocks. Over the course of two years, the research …


Strain Accomodation In The Footwall Of The Rubys Inn Thrust Fault, Hillsdale Canyon, Southern Utah, Claire Cleveland, Rhiannon M. Garrard, Devin M. Mclemore, Jeff C.E. Yon, Genevieve Kidman, John S. Maclean Feb 2015

Strain Accomodation In The Footwall Of The Rubys Inn Thrust Fault, Hillsdale Canyon, Southern Utah, Claire Cleveland, Rhiannon M. Garrard, Devin M. Mclemore, Jeff C.E. Yon, Genevieve Kidman, John S. Maclean

The Compass: Earth Science Journal of Sigma Gamma Epsilon

The Rubys Inn thrust fault in southern Utah has produced several styles of deformation in its footwall. This project describes four exceptionally well exposed examples of strain accommodation, including a mountain-scale, ductile footwall drag fold, cataclastic flexural slip between bedding surfaces of differing competencies, plastically deformed petrified wood within the zone of flexural slip, and cataclastic shear expressed as deformation bands. Such examples show how various lithologies can be deformed into a wide array of structures during a single deformation event. Furthermore, some of these structures result in changes in permeability, which are important for those interested in subsurface fluid …


Stone Walls: Stories From Minnesota's Geologic Past, Larry E. Davis May 2012

Stone Walls: Stories From Minnesota's Geologic Past, Larry E. Davis

Headwaters

No abstract provided.


Mary Anning Of Lyme Regis: 19th Century Pioneer In British Palaeontology, Larry E. Davis May 2012

Mary Anning Of Lyme Regis: 19th Century Pioneer In British Palaeontology, Larry E. Davis

Headwaters

No abstract provided.