Other Earth Sciences Commons^™

Understanding New Trends On Gold Mineralization At The Yellowknife City Gold Project, Northwest Territories, Using Synchrotron X-Ray Spectroscopy, Ramjay Jude L. Botor

Electronic Thesis and Dissertation Repository

The Yellowknife City Gold Project (YCGP) currently encompasses 780 sq. km of contiguous land north, south and east of the city of Yellowknife. The project lies in the prolific Archean north-south trending Yellowknife Greenstone Belt, a suite of mafic and felsic volcanics and greywacke turbidites overlying a gneissic basement. Exploration and drilling efforts have been focused along 70 km of strike length on the southern and northern extensions of the mineralized shear zones and quartz veins associated with the past-producing high-grade Con (6.1 Moz @ 16.1 g/t Au) and Giant (8.1 Moz @ 16.0 g/t Au) gold mines.

Synchrotron X-ray …

Elevated Black Carbon Concentrations And Atmospheric Pollution Around Singrauli Coal-Fired Thermal Power Plants (India) Using Ground And Satellite Data, Ramesh Singh, Sarvan Kumar, Abhay K. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

The tropospheric NO₂ concentration from OMI AURA always shows high concentrations of NO₂ at a few locations in India, one of the high concentrations of NO2 hotspots is associated with the locations of seven coal-fired Thermal Power plants (TPPs) in Singrauli. Emissions from TPPs are among the major sources of black carbon (BC) soot in the atmosphere. Knowledge of BC emissions from TPPs is important in characterizing regional carbonaceous particulate emissions, understanding the fog/haze/smog formation, evaluating regional climate forcing, modeling aerosol optical parameters and concentrations of black carbon, and evaluating human health. Furthermore, elevated BC concentrations, over the …

Groundwater Contamination At Coal Ash Deposit Sites In Kentucky, Brandon Rose

Scholars Week

No abstract provided.

Characterization Of Kelyphite Rims: Relevance To Diamond Exploration, Mallory N.G. Metcalf

Electronic Thesis and Dissertation Repository

A detailed investigation into the mineralogy and chemistry of kelyphitic rims/veins on garnets was conducted using µXRD, EPMA and Raman spectroscopy for a suite of samples from economic and non-economic kimberlites in Canada and South Africa. Mineralogy demonstrates the influence of metasomatic fluids during the reactions which produced kelyphite in all localities and was used to propose P-T regions where kelyphite could have formed. Using chemical analyses of host garnets and the mineralogy obtained for kelyphite, modified chemical reactions representing Types 1 and 2 kelyphite are provided to describe kelyphite reactions in open systems. Elastically-strained secondary garnet is common in …

Review Of Curbing Catastrophe: Natural Hazards And Risk Reduction In The Modern World, Kira H. Hamman

Numeracy

Timothy H. Dixon. 2017. Curbing Catastrophe: Natural Hazards and Risk Reduction in the Modern World. (New York, NY: Cambridge University Press) 300 pp. ISBN 978-1108113663.

In Curbing Catastrophe, Timothy H. Dixon explores commonalities among natural disasters like Hurricane Katrina, the 2010 earthquake in Haiti, and the meltdown at Fukushima. He identifies communication failure between scientists and policy makers as a major culprit in the devastation that results from such events and offers strategies for improving that communication. He includes optional in-depth scientific and quantitative examinations of the events and the resulting devastation, making the book appropriate for use …

Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding how precipitation isotopes vary spatially and temporally is important for tracer applications. We tested how well month‐to‐month variations in precipitation δ18O and δ2H were captured by sinusoidal cycles, and how well spatial variations in these seasonal cycles could be predicted, across Switzerland. Sine functions representing seasonal cycles in precipitation isotopes explained between 47% and 94% of the variance in monthly δ18O and δ2H values at each monitoring site. A significant sinusoidal cycle was also observed in line‐conditioned excess. We interpolated the amplitudes, phases, and offsets of these sine functions across the landscape, using multiple linear …

An Assessment Of Atmospheric And Meteorological Factors Regulating Red Sea Phytoplankton Growth, Wenzhao Li, Hesham El-Askary, Mohamed A. Qurban, Emmanouil Proestakis, Michael J. Garay, Olga V. Kalishnikova, Vassilis Amiridis, Antonis Gkikas, Eleni Marinou, Thomas Piechota, K. P. Manikandan

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study considers the various factors that regulate nutrients supply in the Red Sea. Multi-sensor observation and reanalysis datasets are used to examine the relationships among dust deposition, sea surface temperature (SST), and wind speed, as they may contribute to anomalous phytoplankton blooms, through time-series and correlation analyses. A positive correlation was found at 0–3 months lag between chlorophyll-a (Chl-a) anomalies and dust anomalies over the Red Sea regions. Dust deposition process was further examined with dust aerosols’ vertical distribution using satellite lidar data. Conversely, a negative correlation was found at 0–3 months lag between SST anomalies …

Landscapes From The Waves—Marine Terraces Of California, Marjorie Schulz, Corey Lawrence, Daniel R. Muhs, Carol Prentice, Sam Flanagan

Publications of the US Geological Survey

M any coastlines around the world have stair-step landforms, known as marine terraces. Marine terraces make up a large part of coastal California’s landscape—from San Diego to Crescent City. Find out how these landscapes form, why marine terraces are of interest to scientists, and where you can explore these landscapes.

Marine terraces result from the interaction of two geologic processes: uplift of the land surface and the natural rise and fall of sea level over hundreds of thousands of years. As sea level rises, waves move underwater sediment—sand and gravel—back and forth against bedrock, acting like sandpaper to hone bedrock …

Stable Bromine Isotope Signature Of Bromoform From Enzymatic And Abiotic Formation Pathways And Its Application In Identifying Sources Of Environmental Bromoform In The Damariscotta River, Chengyang Wang

Honors Theses

Bromoform is a major source of atmospheric bromine. Most bromoform is produced by marine organisms including macroalgae and phytoplankton, using the enzyme bromoperoxidase (BPO). Bromoform can also be a byproduct of industrial processes such as water disinfection. Identifying sources of environmental bromoform is still a challenge. A novel technique of using quadrupole mass spectrometry coupled to a gas chromatography (GCqMS) was developed and optimized for Br isotope analyses. The study shows that GCqMS in single ion monitoring (SIM) mode can measure 81Br with precision of around ±0.7‰ (60pmol bromoform injected). This study aims to investigate stable Br isotopes of bromoform …

Assessing The Impact Of The Conservation Reserve Program On Honey Bee Health, Otto, C.R.V., O'Dell, S., Bryant, R.B., Euliss, N.H., Bush

Publications of the US Geological Survey

Insect pollinators are critically important for maintaining U.S. food production and ecosystem health. The upper Midwest is home to more than 40 percent of all U.S. honey bee colonies and is considered by many beekeepers to be America’s last beekeeping refuge. Beekeepers come to this region because their honey bees require high-quality grassland and bee-friendly agricultural crops to make honey and to improve bee health. Agricultural grassland, such as those enrolled in the Conservation Reserve Program (CRP), support flowers that provide bees with the pollen and nectar they need. In 2014, the U.S. Department of Agriculture (USDA) and the U.S. …

Adaptive Management In Native Grasslands Managed By The U.S. Fish And Wildlife Service—Implications For Grassland Birds, Lawrence D. Igl, Welsey E. Newton, Todd A. Grant, Cami S. Dixon

Publications of the US Geological Survey

Burning and grazing are natural processes in native prairies that also serve as important tools in grassland management to conserve plant diversity, to limit encroachment of woody and invasive plants, and to maintain or improve prairies. Native prairies managed by the U.S. Fish and Wildlife Service (FWS) in the Prairie Pothole Region of the northern Great Plains have been extensively invaded by nonnative, cool-season species of grasses. These invasions were believed to reflect a common management history of long-term rest and little or no defoliation by natural processes (burning and grazing). To address the challenges associated with these invasive species, …

Appendix 1. Testing The Influence Of Management Regime And Year On Vegetation Structure Variables On Two Grass Types On Federal Lands Managed Under An Adaptive-Management Framework By The U.S. Fish And Wildlife Service In North Dakota, South Dakota, Minnesota, And Montana, 2011–13, J.J Gannon, T.L. Shaffer, C.T. Moore

Publications of the US Geological Survey

Generalized linear mixed model (assuming a beta distribution with a logit link) testing the influence of management regime and year on mean bare-ground cover (percent) on two grass types on Federal lands managed under an adaptive-management framework by the U.S. Fish and Wildlife Service (Gannon and others, 2013) in North Dakota, South Dakota, Minnesota, and Montana, 2011–13.

The Pothole Hydrology-Linked Systems Simulator (Phyliss)—Development And Application Of A Systems Model For Prairie-Pothole Wetlands, Owen P. Mckenna, David M. Mushet, Eric J. Scherff, Kyle I. Mclean, Christopher T. Mills

Publications of the US Geological Survey

The North American Prairie Pothole Region covers about 770,000 square kilometers of the United States and Canada (including parts of 5 States and 3 provinces: North Dakota, South Dakota, Montana, Minnesota, Iowa, Saskatchewan, Manitoba, and Alberta). The Laurentide Ice Sheet shaped the landscape of the region about 12,000 to 14,000 years ago. The retreat of the ice sheet left behind low-permeability glacial till and a landscape dotted with millions of depressions known today as prairie potholes. The wetlands that subsequently formed in these depressions, prairie-pothole wetlands, provide critical migratory-bird habitat and support dynamic aquatic communities. Extensive grasslands and productive agricultural …