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Depositional Environments And Paleoecology Of The Lower Ordovician Pogonip Group, Opd Unit, Arrow Canyon Range, Clark County, Nevada, Jeffrey K. Donovan
Depositional Environments And Paleoecology Of The Lower Ordovician Pogonip Group, Opd Unit, Arrow Canyon Range, Clark County, Nevada, Jeffrey K. Donovan
UNLV Theses, Dissertations, Professional Papers, and Capstones
The Opd Unit of the Pogonip Group is a slope-forming carbonate sequence that crops out in the Arrow Canyon Range 75 miles north of Las Vegas, Nevada. It is composed mainly of grainstones, packstones, and intraformational conglomerates and also contains Calathium-bearing bioherms composed dominantly of wackestones. These rocks were deposited in a shallow-water, high-energy, subtidal, tropical marine environment. Nuia and Nuia-crinoid shoals developed on this shallow ramp and the area was frequently disturbed by storms.
Calathium-dominated carbonate mudmounds emerged on the Nuia and Nuia-crinoid shoals. Although Calathium dominated the mounds on a macroscopic scale, the mounds …
Desorption Hysteresis In Five Ion Exchanged Montmorillonites, Jerry Paul Fairley
Desorption Hysteresis In Five Ion Exchanged Montmorillonites, Jerry Paul Fairley
UNLV Theses, Dissertations, Professional Papers, and Capstones
It is generally believed that the formation of recalcitrant (slowly desorbing) fractions of volatile organic compounds (VOCs) in soils is due to diffusion of compounds to sorption sites inaccessible to bulk fluid. The exact nature of these sites, however, is not well understood. In clay minerals, researchers favor two probable areas for the storage of persistent contamination; sites between the clay lamella, or sites with clay particle aggregates.
To test the hypothesis that recalcitrant fractions are formed in interlamellar spaces, a Na/Ca Montmorillonite (Smectite) was ion exchanged with five different cations (K+, Na+, Ca+, …