Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
A Complex Origin For The Kelso Dunes, Mojave National Preserve, California, Usa: A Case Study Using A Simple Geochemical Method With Global Applications, Daniel R. Muhs, Nicholas Lancaster, Gary L. Skipp
A Complex Origin For The Kelso Dunes, Mojave National Preserve, California, Usa: A Case Study Using A Simple Geochemical Method With Global Applications, Daniel R. Muhs, Nicholas Lancaster, Gary L. Skipp
United States Geological Survey: Staff Publications
The Kelso Dune field in southern California is intriguing because although it is of limited areal extent (~100 km2), it has a wide variety of dune forms and contains many active dunes (~40 km2), which is unusual in the Mojave Desert. Studies over the past eight decades have concluded that the dunes are derived primarily from a single source, Mojave River alluvium, under a dominant, westerly-to-northwesterly wind regime. The majority of these studies did not, however, present data to support the Mojave River as the only source.We conducted mineralogical and geochemical studies ofmost of the 14 geomorphically defined dune groups …
The Sudbury Impact Structure - New Insights Into The Origin And Emplacement Of The Basal Onaping Intrusion And The Parkin, Trill And Foy Offset Dykes Of The North Range, Denise Anders
Electronic Thesis and Dissertation Repository
The 1.85 Ga Sudbury impact structure is considered a remnant of a multi-ring basin with an estimated original diameter of 150-200 km. The so-called “Basal Onaping Intrusion” form discontinuous sheets between the Granophyre of the Sudbury Igneous Complex (SIC) and the Sandcherry Member of the Onaping Formation and had been considered part of the complex breccia series of the Onaping Formation. Based on the investigation of core and field samples from the North Range we conclude that the Basal Onaping Intrusion, in fact, are the roof rocks of the SIC and, thus, may represent the initial bulk composition of the …
Emplacement Of The Foy, Hess And Pele Offset Dykes At The Sudbury Impact Structure, Canada, Eric A. Pilles
Emplacement Of The Foy, Hess And Pele Offset Dykes At The Sudbury Impact Structure, Canada, Eric A. Pilles
Electronic Thesis and Dissertation Repository
The 1.85 Ga Sudbury impact structure is the remnant of what is generally considered to have been an ~150–200 km diameter impact basin in central Ontario, Canada. The so-called Offset Dykes are impact melt dykes that are found concentrically around – and extending radially outward from – the Sudbury Igneous Complex (SIC), a ~3 km thick differentiated impact melt sheet. The dykes are typically composed of two main phases of granodiorite: an inclusion- and sulfide-rich granodiorite in the centre of the dyke, and an inclusion- and sulfide-poor granodiorite along the margins of the dyke. This study uses a combination of …
Geochemical Evidence For Seasonal Controls On The Transportation Of Holocene Loess, Matanuska Valley, Southern Alaska, Usa, Daniel R. Muhs, James R. Budahn, Gary Skipp, John P. Mcgeehin
Geochemical Evidence For Seasonal Controls On The Transportation Of Holocene Loess, Matanuska Valley, Southern Alaska, Usa, Daniel R. Muhs, James R. Budahn, Gary Skipp, John P. Mcgeehin
United States Geological Survey: Staff Publications
Loess is a widespread Quaternary deposit in Alaska and loess accretion occurs today in some regions, such as the Matanuska Valley. The source of loess in the Matanuska Valley has been debated for more than seven decades, with the Knik River and the Matanuska River, both to the east, being the leading candidates and the Susitna River, to the west, as a less favorable source. We report here new stratigraphic, mineralogic, and geochemical data that test the competing hypotheses of these river sources. Loess thickness data are consistent with previous studies that show that a source or sources lay to …