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

Physical Sciences and Mathematics Commons

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

Articles 31 - 60 of 78

Full-Text Articles in Physical Sciences and Mathematics

Patterns And Sources Of Anthropogenic Contaminants In The Otter Creek Watershed, Madison County, Kentucky, Elijah D. Wolfe, Walter S. Borowski, Jacob L. Robin Mar 2016

Patterns And Sources Of Anthropogenic Contaminants In The Otter Creek Watershed, Madison County, Kentucky, Elijah D. Wolfe, Walter S. Borowski, Jacob L. Robin

EKU Faculty and Staff Scholarship

Stream systems are often affected by anthropogenic contaminants that affect water quality and stream ecosystems. Land use determines the type and quantity of contaminants present in natural waters. The Otter Creek watershed (170 km2; Madison County, Kentucky) consists predominantly of pasture and rural housing, with some cropland. The basin also receives runoff from the town of Richmond and a sewage treatment plant operates within the watershed. We measured concentrations of nutrients (phosphate, ammonium, nitrate) and fecal microbes to discover levels of anthropogenic contaminants affecting water quality and to identify contaminant sources.

We sampled 4 times in the summer …


Patterns Of Anthropogenic Nutrient Contaminants In The Otter Creek Watershed, Madison County, Kentucky, Elijah D. Wolfe, Walter S. Borowski, Jacob L. Robin Nov 2015

Patterns Of Anthropogenic Nutrient Contaminants In The Otter Creek Watershed, Madison County, Kentucky, Elijah D. Wolfe, Walter S. Borowski, Jacob L. Robin

EKU Faculty and Staff Scholarship

We measured nutrient concentrations within the Otter Creek watershed (Madison County, Kentucky) to: (1) discover levels of anthropogenic contaminants affecting the water quality; (2) compare these measurements to a national data set; and (3) identify nutrient sources. The watershed mainly drains rural land characterized by cattle grazing, but also drains the town of Richmond. We sampled throughout the watershed to gain a representative perspective of nutrient levels and specifically targeted localities of suspected anthropogenic nutrient sources. Water samples were passed through a 0.45 mm filter, placed in pre-acidified vials, and measured one to two days after collection. Nutrients – ammonium, …


Peralkaline Felsic Magmatism At The Nemrut Volcano, Turkey: Impact Of Volcanism On The Evolution Of Lake Van (Anatolia), Ray Macdonald, Mari Sumita, Hans-Ulrich Schmincke, Boguslaw Baginski, John C. White, Slawomir S. Ilnicki Apr 2015

Peralkaline Felsic Magmatism At The Nemrut Volcano, Turkey: Impact Of Volcanism On The Evolution Of Lake Van (Anatolia), Ray Macdonald, Mari Sumita, Hans-Ulrich Schmincke, Boguslaw Baginski, John C. White, Slawomir S. Ilnicki

EKU Faculty and Staff Scholarship

Nemrut volcano, adjacent to Lake Van (Turkey), is one of the most important peralkaline silicic centres in the world, where magmatism for ~570,000 years has been dominated by peralkaline trachytes and rhyolites. Using onshore and Lake Van drill site tephra samples, we document the phenocryst and glass matrix compositions, confirming a complete spectrum from very rare mafic to dominantly silicic magmas. Magma mixing has been common and, along with the multi-lineage nature of the magmas, indicates that Nemrut has been a very open system where, nevertheless, compositionally zoned caps developed during periods of relative eruptive quiescence. Geothermometry suggests that the …


Sources Of Nutrient And Escherichia Coli Contamination Within The Otter Creek Watershed, Madison County, Kentucky, Nathaniel C. Crockett, Walter S. Borowski Mar 2015

Sources Of Nutrient And Escherichia Coli Contamination Within The Otter Creek Watershed, Madison County, Kentucky, Nathaniel C. Crockett, Walter S. Borowski

EKU Faculty and Staff Scholarship

The Otter Creek watershed exhibits dissolved nutrient (ammonium, NH4; nitrate, NO3; phosphate, PO4) and Escherichia coli contamination that compromises its water quality. The watershed covers a substantial portion of Madison County and consists of Lake Reba, Dreaming Creek, and east and west forks, all of which enter the trunk of Otter Creek before flowing into the Kentucky River. Suspected contaminate sources include leaky sewage system pipes, runoff from pasture land, and septic system leachate. We collected 330 water samples on three occasions during summer 2014 to determine the extent and sources of contamination. Nutrients …


Sources Of Nutrient And Fecal Microbe Pollution In Otter Creek, Madison County, Kentucky, Kandice L. Smith, Walter S. Borowski Nov 2013

Sources Of Nutrient And Fecal Microbe Pollution In Otter Creek, Madison County, Kentucky, Kandice L. Smith, Walter S. Borowski

EKU Faculty and Staff Scholarship

We measured nutrient (nitrate, ammonium, phosphate) and fecal microbe concentrations in surface waters of the Otter Creek watershed, Madison County, Kentucky to access sources of these contaminants. The watershed is approximately 12.5 miles long covering ~169 km2 (41,832 acres). The watershed includes East Fork, West Fork, and Dreaming Creek, all tributaries to the main trunk of Otter Creek. The upper portion of the main trunk and Dreaming Creek drain urban areas of Richmond, but 85% of total watershed area is agricultural land, used mainly for grazing cattle. Rural residential areas and woodlands also occur.

The principle contaminants are nutrients …


Are 34s-Enriched Authigenic Sulfide Minerals A Proxy For Elevated Methane Flux And Gas Hydrates In The Geologic Record?, Walter S. Borowski, Nancy M. Rodriguez, Charles K. Paull, William Ussler Iii Jan 2013

Are 34s-Enriched Authigenic Sulfide Minerals A Proxy For Elevated Methane Flux And Gas Hydrates In The Geologic Record?, Walter S. Borowski, Nancy M. Rodriguez, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

The sulfate–methane transition (SMT) zone is a diagenetic transition within anoxic marine sediments created by the metabolic activity of a consortium of sulfate-reducing bacteria and methane-oxidizing Archaea. As interstitial dissolved sulfate is consumed by microbially mediated sulfate reduction of sedimentary organic matter (SOM) and anaerobic oxidation of methane (AOM) large enrichments of 34S occur in the interstitial sulfate pool. These isotopic enrichments are transmitted to the dissolved sulfide pool (∑HS) and subsequently into sulfide minerals (So, ∼FeS, FeS2).

We investigate the sulfur isotopic composition of pore-water sulfate and sulfide minerals at three sites underlain …


Point Source And Non-Point Source Pollution In A Secondary Stream: Nutrient Concentration And Fecal Microbe Counts In Tates Creek, Madison County, Kentucky, Walter S. Borowski, Krisopher H. Carroll, Bethany Gabbard Nov 2012

Point Source And Non-Point Source Pollution In A Secondary Stream: Nutrient Concentration And Fecal Microbe Counts In Tates Creek, Madison County, Kentucky, Walter S. Borowski, Krisopher H. Carroll, Bethany Gabbard

EKU Faculty and Staff Scholarship

Nutrient concentration and fecal microbe counts are elevated in Tates Creek, a stream that emanates from the town of Richmond, KY, passes by a conventional sewage treatment plant that discharges into the stream, and winds for 13 miles through pastureland and a series of small communities on septic systems before entering the Kentucky River. The sewage treatment plant shut-down operations during our study and we monitored dissolved nutrients (ammonium, nitrate, and phosphate), fecal microbes (total coliform and Escherichia coli), and stream biota before and after treatment operations ceased. Sampling occurred 4 times in both 2011 and 2012 between May …


Nutrient And Fecal Microbe Assessment Of The Water Quality Of Tates Creek, Madison County, Kentucky, Walter S. Borowski, Kristopher H. Carroll Mar 2012

Nutrient And Fecal Microbe Assessment Of The Water Quality Of Tates Creek, Madison County, Kentucky, Walter S. Borowski, Kristopher H. Carroll

EKU Faculty and Staff Scholarship

Tates Creek is a significant tributary to the Kentucky River that has shown high levels of microbial and nutrient pollution in the past (Kentucky River Watershed Watch). We sampled the waters of Tates Creek more comprehensively by collecting stream water at 25 stations along its 13-mile length from its headwaters to the Kentucky River. Most samples were collected at the confluence of major tributaries to also access the water quality of tributary streams. Samples were collected four times between May and August 2011 during dry periods as well as immediately after a rainfall event. We measured ammonium (NH4+ …


Suspended Sediment Concentration In The Brushy Creek Watershed, Kentucky, Tyler Wade, Walter S. Borowski Nov 2011

Suspended Sediment Concentration In The Brushy Creek Watershed, Kentucky, Tyler Wade, Walter S. Borowski

EKU Faculty and Staff Scholarship

Suspended sediment concentration (SSC) can be used as a proxy for environmental health of stream water. For example, large sediment loads can cause harm to aquatic life and are a mechanism for introducing and transporting fecal microbes. We measure SSC of the Brushy Creek watershed, located in Rockcastle, Pulaski, and Lincoln Counties, where the Eastern Kentucky Environmental Research Institute (EK-ERI) has been conducting an assessment of the watershed. Two auto sampling units were placed in Brushy Creek to collect water samples for determination of SSC. The units collect samples every 14 hours for a two-week period, then samples are retrieved …


Nutrient And Fecal Microbe Assessment Of The Water Quality Of Tates Creek, Madison County, Kentucky, Krisopher H. Carroll, Walter S. Borowski Nov 2011

Nutrient And Fecal Microbe Assessment Of The Water Quality Of Tates Creek, Madison County, Kentucky, Krisopher H. Carroll, Walter S. Borowski

EKU Faculty and Staff Scholarship

Tates Creek is a significant tributary to the Kentucky River that has shown high levels of microbial and nutrient pollution. We sampled the waters of Tates Creek comprehensively by occupying 25 stations along its 13-mile length, collecting stream water at the confluence of major tributaries from its headwaters to the Kentucky River. Samples were collected four times between May and August 2011 during dry periods as well as immediately after rainfall events.

We measured ammonium (NH4+), nitrate (NO3-) and phosphate (PO4-) concentrations using colorimetry. Microbial samples were measured for total coliform …


Determination Of Caffeine As A Marker For Septic Tank Contamination Of Wilgreen Lake, Rosemary Onjiko, Susan Godbey, Walter S. Borowski, Darrin Smith, Lori Wilson Mar 2011

Determination Of Caffeine As A Marker For Septic Tank Contamination Of Wilgreen Lake, Rosemary Onjiko, Susan Godbey, Walter S. Borowski, Darrin Smith, Lori Wilson

EKU Faculty and Staff Scholarship

Wilgreen Lake in Richmond, Kentucky, has been listed by both the state and the Environmental Protection Agency as an “impaired” lake due to excess nutrients, which may be in part contributed by domestic septic systems. Caffeine can be used as an anthropogenic marker to estimate the contribution of septic tank effluent to the lake. We have modified existing analytical methods to produce a viable method for the determination of caffeine in environmental water samples and applied the method to water samples collected from Wilgreen Lake. The modified method allows determination of caffeine in a concentration range of 75 to 10,000 …


Concentration Of Heavy Metals In The Waters And Surface Sediments Of Wilgreen Lake, Madison County, Kentucky: An Evaluation Of Plausible Sources, Chad Von Gruenigen, Walter S. Borowski Mar 2011

Concentration Of Heavy Metals In The Waters And Surface Sediments Of Wilgreen Lake, Madison County, Kentucky: An Evaluation Of Plausible Sources, Chad Von Gruenigen, Walter S. Borowski

EKU Faculty and Staff Scholarship

Heavy metal pollution remains a problem in natural waters, particularly for localities near plausible anthropogenic sources. We assayed the level of heavy metals in surface waters and within surface sediments of Wilgreen Lake, whose watershed drains industrial, urban, agricultural, and residential areas near Richmond, Kentucky. We sampled both surface (oxic) and deep waters (anoxic) when the lake was stratified over Summer 2010. Water samples were treated according to U.S. Environmental Protection Agency (EPA) protocols and were digested with trace-metal-grade nitric and hydrochloric acids. Sediment samples were collected with a grab sampler and digested using established EPA procedures with trace-metal-grade nitric …


Patterns Of Heavy Metal Concentration In Core Sediments, Wilgreen Lake, Madison County, Clint Mcmaine, Walter S. Borowski Mar 2011

Patterns Of Heavy Metal Concentration In Core Sediments, Wilgreen Lake, Madison County, Clint Mcmaine, Walter S. Borowski

EKU Faculty and Staff Scholarship

Accumulation of heavy metals in ecosystems is a known environmental problem, and several possible industry sources occur within the watershed of Wilgreen Lake, which is fed its two major tributaries, Taylor Fork and Old Town Branch. Elevated levels of cadmium, copper, lead, and nickel were found within the waters of Wilgreen Lake during a preliminary survey in 2007. A possible source of these contaminant occurrences is diffusion from lake sediments, which record past and present activities within their drainage basins.

To obtain a history of anthropogenic practices within the drainage basin, we took 1-meter-long cores of lake sediment in each …


Heavy Metal Concentrations In Water And Surface Sediments Of Wilgreen Lake, Madison County, Kentucky, Chad Von Gruenigen, Walter S. Borowski Dec 2010

Heavy Metal Concentrations In Water And Surface Sediments Of Wilgreen Lake, Madison County, Kentucky, Chad Von Gruenigen, Walter S. Borowski

EKU Faculty and Staff Scholarship

Heavy metal pollution remains problematic in natural waters, particularly for localities near plausible anthropogenic sources. We assayed the level of heavy metals in surface waters and within surface sediments of Wilgreen Lake, whose watershed drains industrial, urban, agricultural, and residential areas near Richmond, Kentucky. Water samples were treated according to Environmental Protection Agency (EPA) protocols and digested with trace-metal-grade nitric and hydrochloric acids. Sediment samples were collected with a grab sampler and digested using established EPA procedures with hydrogen peroxide and trace-metal-grade nitric acid. Both water samples and sediment samples were sent to Activation Laboratories for analysis, and were measured …


Heavy Metal Concentrations In Water And Surface Sediments Of Wilgreen Lake, Madison County, Kentucky, Chad Von Gruenigen, Walter S. Borowski Nov 2010

Heavy Metal Concentrations In Water And Surface Sediments Of Wilgreen Lake, Madison County, Kentucky, Chad Von Gruenigen, Walter S. Borowski

EKU Faculty and Staff Scholarship

Heavy metal pollution remains a problem in natural waters, particularly for localities near plausible anthropogenic sources. We assayed the level of heavy metals in surface waters and within surface sediments of Wilgreen Lake, whose watershed drains industrial, urban, and residential areas near Richmond, Kentucky.

Water samples were treated according to Environmental Protection Agency (EPA) protocols and digested with trace-metal-grade nitric and hydrochloric acids. Sediment samples were collected with a grab sampler and digested using established EPA procedures with hydrogen peroxide and trace-metal-grade nitric acid. Both water samples and sediment samples were sent to Activation Laboratories for analysis, and were measured …


Patterns Of Heavy Metal Concentration In Core Sediments, Wilgreen Lake, Madison County, Kentucky, Clint Mcmaine, Walter S. Borowski Nov 2010

Patterns Of Heavy Metal Concentration In Core Sediments, Wilgreen Lake, Madison County, Kentucky, Clint Mcmaine, Walter S. Borowski

EKU Faculty and Staff Scholarship

Elevated levels of cadmium, copper, lead, and nickel were found within the waters of Wilgreen Lake during a preliminary survey in 2007. Accumulation of heavy metals in freshwater systems is a known problem. Heavy metals enter the lake in the dissolved phase or adsorbed onto sediment particles and may be linked to industries within the lake’s watershed. Under certain geochemical conditions such as anoxia, heavy metals may detach from sediment particles and diffuse into overlying lake waters, causing a renewed influx of heavy metals into the ecosystem. We hypothesize that heavy metals should decrease in concentration upcore as a result …


Enrichments Of Heavy Sulfur (34s) In Sulfide Minerals: Gas Hydrates, Methane Delivery, And Anaerobic Methane Oxidation, Walter S. Borowski, Namcy M. Rodriguez, Charles K. Paull, William Ussler Iii Jun 2010

Enrichments Of Heavy Sulfur (34s) In Sulfide Minerals: Gas Hydrates, Methane Delivery, And Anaerobic Methane Oxidation, Walter S. Borowski, Namcy M. Rodriguez, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

The sulfur isotopic composition of authigenic, sedimentary sulfide minerals is largely controlled by sulfate reduction and related processes within sedimentary environments. Histograms show that that d34S values of sulfide minerals forming in depositional and diagenetic environments are most often negative (d34S < 0o/oo CDT) reflecting the original isotopic composition of seawater sulfate (now ~21o/oo), microbially-mediated fractionations of ~-8 to -40o/oo (a = 1.029-1.059) during sulfate reduction, and more extreme fractionations caused by sulfur disproportionation. Enrichments of heavy sulfur (d34S > 0o/oo) in sulfide …


Changing Depositional Environments In An Upper Ordovician Stratigraphic Sequence, Ashlock Formation, Madison County, Kentucky, Kevin G. Greff, Walter S. Borowski Apr 2010

Changing Depositional Environments In An Upper Ordovician Stratigraphic Sequence, Ashlock Formation, Madison County, Kentucky, Kevin G. Greff, Walter S. Borowski

EKU Faculty and Staff Scholarship

We investigate the sedimentology, stratigraphy, and depositional environments of a 7-meter, Upper Ordovician limestone sequence cropping out in Richmond, Madison County, Kentucky. The stratigraphic section lies within the Ashlock Formation with good lateral exposure stretching along 200 meters of a highway roadcut. We took approximately 20 samples from the measured section, focusing on representative samples and lithologic transitions. We use standard laboratory procedures in slabbing rock samples and making thin sections.

The Ashlock Formation here consists of alternating layers of limey mudstone and limestone (field units A through F). Megafossils - brachiopods, bryozoans, trilobites, gastropods, ostracodes, coralline algae, and bivalves …


Nutrient And Fecal Microbe Sources For A Eutrophic Lake And Recommended Remediation Steps, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Theresa A. Aguiar, Jill Hunter, Erin C. Jolly, Richard D. Stockwell Mar 2009

Nutrient And Fecal Microbe Sources For A Eutrophic Lake And Recommended Remediation Steps, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Theresa A. Aguiar, Jill Hunter, Erin C. Jolly, Richard D. Stockwell

EKU Faculty and Staff Scholarship

Wilgreen Lake is a man-made lake, classified as nutrient-impaired (303d list) by the EPA and State of Kentucky. The lake drains a watershed with residential developments, cattle pasture, modified woodlands, and some industrial/urban usage in the city of Richmond. The principal tributaries are Taylor Fork and Old Town Branch that meet to form the trunk of the lake approximately one mile in length. The upper reaches of Taylor Fork are adjacent to a densely-packed (quarter-acre lots) housing development with septic systems, and its watershed drains some portions of southern Richmond. Old Town Branch drains cattle pasture and residential areas of …


Seasonal Changes In A Eutrophic Lake (Wilgreen Lake, Madison County, Kentucky) From Summer Stratification Through Fall Turnover, Richard D. Stockwell, Walter S. Borowski Dec 2008

Seasonal Changes In A Eutrophic Lake (Wilgreen Lake, Madison County, Kentucky) From Summer Stratification Through Fall Turnover, Richard D. Stockwell, Walter S. Borowski

EKU Faculty and Staff Scholarship

No abstract provided.


Tracing Nutrient Inputs Into A Eutrophic Lake Using Nitrogen Isotopes, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Theresa A. Aguiar Apr 2008

Tracing Nutrient Inputs Into A Eutrophic Lake Using Nitrogen Isotopes, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Theresa A. Aguiar

EKU Faculty and Staff Scholarship

Wilgreen Lake is a dammed lake that has been classified as nutrient-impaired (303d list) by the EPA and State of Kentucky. The lake is moderately-sized covering 169 acres (0.7 km2), and drains a watershed with residential developments, cattle pasture, modified woodlands, and some industrial/urban usage in the city of Richmond. The principal tributaries are Taylor Fork and Old Town Branch that meet to form the trunk of the lake approximately one mile in length. The upper reaches of Taylor Fork are adjacent to a densely-packed (quarter-acre lots) housing development with septic systems. Old Town Branch drains cattle pasture …


Using E. Coli And Bacteroides Distribution And Abundance In A Eutrophic Lake As A Tracer For Nutrient Inputs, Wilgreen Lake, Madison County, Kentucky, Theresa A. Aguiar, Walter S. Borowski, Alice C. Layton, Larry Mckay Mar 2008

Using E. Coli And Bacteroides Distribution And Abundance In A Eutrophic Lake As A Tracer For Nutrient Inputs, Wilgreen Lake, Madison County, Kentucky, Theresa A. Aguiar, Walter S. Borowski, Alice C. Layton, Larry Mckay

EKU Faculty and Staff Scholarship

Wilgreen Lake is a eutrophic lake that has been listed on the EPA’s 303d list as nutrient impaired. Potential sources of this impairment are likely from humans, cattle manure, and fertilizers. We suspect that the majority of nutrients originate from human sources, namely from septic tank effluent emanating from key housing developments ringing the lakeshore. We test our hypothesis with conventional microbial assays (Escherichia coli) and RT-PCR techniques (Bacteroides).

We took water samples at 19 sampling locations on 4 occasions, and measured the abundance of Escherichia coli using IDEXX methods. Corresponding sub-samples slated for potential PCR …


Seasonal Changes In Stratification And Oxygen Content Of A Eutrophic Lake, Wilgreen Lake, Madison County, Kentucky, Jill Hunter, Walter S. Borowski Mar 2008

Seasonal Changes In Stratification And Oxygen Content Of A Eutrophic Lake, Wilgreen Lake, Madison County, Kentucky, Jill Hunter, Walter S. Borowski

EKU Faculty and Staff Scholarship

Wilgreen Lake (Madison County, Kentucky) is listed by the Environmental Protection Agency as nutrient-impaired. The overabundance of nutrients is likely linked to the land-use practices in this area. Cattle pasture, residential developments served by septic systems, and urban/industrial areas lie in the lake’s watershed. We have studied the lake for two years to characterize its physical and chemical characteristics, and to identify nutrient sources.

The 2007 field season began in March and continued through October. We measured temperature and oxygen levels along with other parameters at 1-meter depth intervals at 19 stations distributed along the length of the lake and …


Fecal Microbe Distribution And Abundance Used As A Possible Proxy For Nutrient Source Identification In Eutrophic Wilgreen Lake, Madison County, Kentucky, Theresa A. Aguiar, Walter S. Borowski Nov 2007

Fecal Microbe Distribution And Abundance Used As A Possible Proxy For Nutrient Source Identification In Eutrophic Wilgreen Lake, Madison County, Kentucky, Theresa A. Aguiar, Walter S. Borowski

EKU Faculty and Staff Scholarship

Wilgreen Lake is a eutrophic lake that has been listed on the EPA’s 303d list as nutrient impaired. Potential sources of this impairment are from humans, cattle manure and fertilizers. We suspect that the majority of nutrients originate from human sources. As a possible proxy for nutrient input, we test our hypothesis by examining fecal microbe distribution and abundance in the lake.

We took water samples at 19 sampling locations on 4 occasions. Sampling spanned 26 June to 15 August with the last 3 sampling events occurring at roughly two-week intervals. These samples were then processed using IDEXX methods, which …


Preliminary Results Of A Fecal Microbe Survey In An Eutrophic Lake, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Michael S. Albright Mar 2007

Preliminary Results Of A Fecal Microbe Survey In An Eutrophic Lake, Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Michael S. Albright

EKU Faculty and Staff Scholarship

Wilgreen Lake is a small (~14 mi2) eutrophic lake formed by damming several tributary streams to Silver Creek, Madison County, Kentucky. The lake receives runoff from industrial and urban areas (Richmond) that comprise ~10% of the total watershed area; most runoff is from cattle pasture or human developments encircling the lake. Present and past developments are on septic systems, and effluent from these systems is known qualitatively to seep into lake waters.

Our research group is currently conducting a study of the lake in order to identify major nutrient sources, and one possible tracer method is to quantitatively …


Sulfur Geochemistry And Diagenesis In A Gas Hydrate Terrane, Cascadia Margin, Offshore Oregon: Role Of Anaerobic Methane Oxidation, David Deigert, Walter S. Borowski Mar 2007

Sulfur Geochemistry And Diagenesis In A Gas Hydrate Terrane, Cascadia Margin, Offshore Oregon: Role Of Anaerobic Methane Oxidation, David Deigert, Walter S. Borowski

EKU Faculty and Staff Scholarship

We present sulfide mineral data from south Hydrate Ridge located in a gas hydrate terrane, offshore Oregon. Sulfide sulfur concentration and the isotopic composition of sulfur (d34S) in authigenic sulfide minerals are analyzed from sediment samples collected on Ocean Drilling Project (ODP) Leg 204. Shallow sediment samples (<25 >mbsf) assess the relative importance of anaerobic methane oxidation (AMO) as a biogeochemical process, both here and at the Blake Ridge, another well known gas hydrate terrane offshore southeastern United States. Deep samples (>25 mbsf) are used to evaluate sulfur diagenesis and its controls from early Pleistocene to the …


A Preliminary Study Of Sulfide Mineral Formation In Methane-Rich, Marine Sediments Associated With Anaerobic Methane Oxidation, Cascadia Continental Margin, Offshore Oregon, David Deigert, Walter S. Borowski Nov 2006

A Preliminary Study Of Sulfide Mineral Formation In Methane-Rich, Marine Sediments Associated With Anaerobic Methane Oxidation, Cascadia Continental Margin, Offshore Oregon, David Deigert, Walter S. Borowski

EKU Faculty and Staff Scholarship

Within gas hydrate settings, sulfide mineralization in marine sediments is likely controlled by two microbially-mediated, sulfate-depleting processes: anaerobic methane oxidation (AMO) and sulfate reduction. If large amounts of methane are delivered to the sulfate-methane interface (SMI), predominantly by diffusion, larger amounts of solid sulfide sulfur should occur there as dissolved sulfide combines with iron, forming an authigenic precipitate. We measure the amount of diagenetic sulfide sulfur at three locations in the Hydrate Ridge vicinity by extracting the bulk sedimentary sulfide-phase minerals (So, FeS, and FeS2) through chromium reduction, precipitating sulfide sulfur as silver sulfide, and gravimetrically …


Preliminary Results Of A Nutrient Source Study In Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Erin C. Jolly Nov 2006

Preliminary Results Of A Nutrient Source Study In Wilgreen Lake, Madison County, Kentucky, Walter S. Borowski, Erin C. Jolly

EKU Faculty and Staff Scholarship

Wilgreen Lake (Madison County, Kentucky) is an eutrophic lake formed by damming Taylor Fork, part of the Silver Creek watershed. Two principal tributaries drain urban areas of the city of Richmond, agricultural land typified by cattle grazing, and a high-density residential area using septic systems. The lake is “nutrient impaired,” so it is likely that anthropogenic nutrient loading is affecting water quality. Our study aims to first characterize the physical characteristics and water quality of the lake (2006), and then determine the specific proportion of nutrient inputs (2007) to the lake with the aim of remediating any possible degradation of …


Data Report: Dissolved Sulfide Concentration And Sulfur Isotopic Composition Of Sulfide And Sulfate In Pore Waters, Odp Leg 204, Hydrate Ridge And Vicinity, Cascadia Margin, Offshore Oregon, Walter S. Borowski Sep 2006

Data Report: Dissolved Sulfide Concentration And Sulfur Isotopic Composition Of Sulfide And Sulfate In Pore Waters, Odp Leg 204, Hydrate Ridge And Vicinity, Cascadia Margin, Offshore Oregon, Walter S. Borowski

EKU Faculty and Staff Scholarship

We report dissolved sulfide sulfur concentrations and the sulfur isotopic composition of dissolved sulfate and sulfide in pore waters from sediments collected during Ocean Drilling Program Leg 204. Porewater sulfate is depleted rapidly as the depth to the sulfate/methane interface (SMI) occurs between 4.5 and 11 meters below seafloor at flank and basin locations. Dissolved sulfide concentration reaches values as high as 11.3 mM in Hole 1251E. Otherwise, peak sulfide concentrations lie between 3.2 and 6.1 mM and occur immediately above the SMI. The sulfur isotopic composition of interstitial sulfate generally becomes enriched in 34 S with increasing sediment depth. …


A Geologic Record Of Competing Sulfate-Depletion Processes Within Continental-Rise Sediments Overlying Methane Gas Hydrates Of The Blake Ridge Region (Continental Rise, Offshore Southeastern United States), Walter S. Borowski, Kathryn G. Takacs, Matthew K. Thompson Mar 2006

A Geologic Record Of Competing Sulfate-Depletion Processes Within Continental-Rise Sediments Overlying Methane Gas Hydrates Of The Blake Ridge Region (Continental Rise, Offshore Southeastern United States), Walter S. Borowski, Kathryn G. Takacs, Matthew K. Thompson

EKU Faculty and Staff Scholarship

Geochemical signals locked within sediments and sedimentary rocks record geochemical processes through geologic time. Sulfide minerals (elemental sulfur, iron monosulfides, and pyrite) are formed within marine sediments as dissolved sulfide is produced by various geochemical processes, which include sulfate reduction and anaerobic methane oxidation (AMO). The concentration and sulfur isotopic composition (d34S) of sulfide minerals gives clues about the relative importance of these competing geochemical processes, and consequently about sedimentation rates and upward methane transport.

Marine sediments of the Blake Ridge(offshore South Carolina and Georgia) contain sulfide minerals that point to AMO as an important diagenetic process both …