Physical Sciences and Mathematics Commons^™

Geochemical Characteristics And Storm Dynamics Of Surface Waters And Groundwater At Eastern Kentucky University’S Meadowbrook Farm, Madison County, Kentucky, Reid E. Buskirk, Walter S. Borowski, Jonathan M. Malzone

EKU Faculty and Staff Scholarship

Agricultural activities often contaminate watersheds with excess nutrients leading to poor water quality and eutrophication. Eastern Kentucky University’s Meadowbrook Farm raises crops and livestock, contributing dissolved nutrients to the neighboring Muddy Creek watershed. Consequently, the Farm is developing methods to sequester and limit nutrient contamination.

Before phosphorous sequestration methods can be tested, the geochemistry of surface water and groundwater on the Farm need to be better understood to determine hydrological pathways. We use naturally-occurring, dissolved cations as tracers to identify the contribution of different water sources and interpret storm events.

Water samples taken from springs (groundwater), surface water, and storm …

The Geochemistry Of Loess: Asian And North American Deposits Compared, Daniel R. Muhs

United States Geological Survey: Staff Publications

Loess is widely distributed over Asia and North America and constitutes one of the most important surficial deposits that serve as terrestrial records of the Quaternary. The oldest Pleistocene loess in China is likely ∼2.6 Ma, thus spanning much or all of the Pleistocene. In North America, most loess is no older than the penultimate glacial period, with the exception of Alaska, where the record may go back to ∼3.0 Ma. On both continents, loess deposits date primarily to glacial periods, and interglacial or interstadial periods are represented by paleosols. Both glacial and non-glacial sources of silts that comprise the …

Changes In Mineralogy And Geochemistry Of Quartz And Feldspars In Response To Impact Cratering, Steven Jaret

Geosciences Research Data

Impact cratering is an important geologic process that has affected all objects in the Solar System. The goal of this work is to understand how this process affects the mineralogy and geochemistry of planetary surfaces. Studies of extraterrestrial materials (e.g., laboratory studies of meteorites) and studies of planetary surfaces via orbiter or lander missions encounter impacted and shocked materials. Therefore, knowing how this secondary process of cratering has altered the rocks and minerals is critical to our ability to deconvolve the secondary effects of shock from the original primary geology. Specifically, I seek to understand impact metamorphism in three ways: …

Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Marcelo I. Guzman, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali

Chemistry Faculty Publications

How primordial metabolic networks such as the reverse tricarboxylic acid (rTCA) cycle and clay mineral catalysts coevolved remains a mystery in the puzzle to understand the origin of life. While prebiotic reactions from the rTCA cycle were accomplished via photochemistry on semiconductor minerals, the synthesis of clays was demonstrated at low temperature and ambient pressure catalyzed by oxalate. Herein, the crystallization of clay minerals is catalyzed by succinate, an example of a photoproduced intermediate from central metabolism. The experiments connect the synthesis of sauconite, a model for clay minerals, to prebiotic photochemistry. We report the temperature, pH, and concentration dependence …

An Antarctic Stratigraphic Record Of Stepwise Ice Growth Through The Eocene-Oligocene Transition, Sandra Passchier, Daniel J. Ciarletta, Triantafilo E. Miriagos, Peter K. Bijl, Steven M. Bohaty

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Earth’s current icehouse phase began ∼34 m.y. ago with the onset of major Antarctic glaciation at the Eocene-Oligocene transition. Changes in ocean circulation and a decline in atmospheric greenhouse gas levels were associated with stepwise cooling and ice growth at southern high latitudes. The Antarctic cryosphere plays a critical role in the ocean-atmosphere system, but its early evolution is still poorly known. With a near-field record from Prydz Bay, Antarctica, we demonstrate that Antarctic ice growth was stepwise and had an earlier onset than previously suggested. Prydz Bay lies downstream of a major East Antarctic Ice Sheet drainage system, and …