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Geology topics

Owen P. Bricker

Publications and source records attributed to Owen P. Bricker.

At least 19 recordsLinked to original sources
USGS2024

Crystal structure refinement and Mössbauer spectroscopy of an ordered, triclinic clinochlore

The crystal structure of a natural, ordered IIb-4 triclinic clinochlore has been refined in space group C 1¯ from 4282 unique X-ray intensity measurements of which 3833 are greater than 3 times the statistical counting error (3σ). Unit cell parameters are a = 5.3262(6) Å; b = 9.226(1) Å; c = 14.334(3) Å; α = 90.56(2)°; β = 97.47(2)°; and γ = 89.979(9)°, which represents the greatest deviation from monoclinic symmetry yet recorded for a triclinic chlorite. The final weighted R is 0.059 for reflections with I > 3σ and 0.064 for all reflections. The chemical formula is (Mg 0.966 Fe 0.034 ) M1 (Mg 0.962 Fe 0.038 ) M2 2 (Si 2.96 Al 1.04 )O 10 (OH) 2 (Mg 0.996 Fe 0.004 ) M3 2 (Al 0.841 Fe III 0.102 Cr 0.004 Ti 0.004 ) M4 (OH) 6 , which is consistent with electron microprobe (EMP), wet chemical analyses, Mössbauer spectroscopy and X-ray structure refinement. The high degree of ordering of the divalent versus trivalent octahedral cations in the interlayer is noteworthy, with Fe III and Al in M4 and virtually no Fe in M3. In the 2:1 layer, M1 and M2 each contain similar amounts of Fe. The 2 tetrahedral sites have nearly identical mean oxygen distances and volumes, and thus show no evidence of long-range cation ordering.

Clays and Clay Minerals↗
USGS2022

Geochemical investigations of selected Eastern United States watersheds affected by acid deposition

The effects of acid deposition on surface waters in eastern United States watersheds having similar size, physiography, climate and land use are related to the composition of the underlying bedrock. Watersheds developed on greenstone, calcareous shale, sandstone, granite, and schist differ in their ability to neutralize acid deposition. Surface waters in watersheds developed on greenstone and calcareous shale are not discernably affected by acidification. Wastersheds developed on sand-stone have little capacity to neutralize acid rain; consequently, stream acidity is similar to that of precipitation. Watersheds developed on granite and schist are intermediate in their capacity to neutralize acid deposition. Bedrock composition appears to be the major property controlling surface-water chemistry in these systems; hydrologic flow paths and the nature of surficial materials and vegetation also influence chemical responses to acid deposition in watersheds.

Journal of the Geological Society↗
USGS2014

From headwaters to coast: Influence of human activities on water quality of the Potomac River Estuary

The natural aging process of Chesapeake Bay and its tributary estuaries has been accelerated by human activities around the shoreline and within the watershed, increasing sediment and nutrient loads delivered to the bay. Riverine nutrients cause algal growth in the bay leading to reductions in light penetration with consequent declines in sea grass growth, smothering of bottom-dwelling organisms, and decreases in bottom-water dissolved oxygen as algal blooms decay. Historically, bay waters were filtered by oysters, but declines in oyster populations from overfishing and disease have led to higher concentrations of fine-sediment particles and phytoplankton in the water column. Assessments of water and biological resource quality in Chesapeake Bay and tributaries, such as the Potomac River, show a continual degraded state. In this paper, we pay tribute to Owen Bricker’s comprehensive, holistic scientific perspective using an approach that examines the connection between watershed and estuary. We evaluated nitrogen inputs from Potomac River headwaters, nutrient-related conditions within the estuary, and considered the use of shellfish aquaculture as an in-the-water nutrient management measure. Data from headwaters, nontidal, and estuarine portions of the Potomac River watershed and estuary were analyzed to examine the contribution from different parts of the watershed to total nitrogen loads to the estuary. An eutrophication model was applied to these data to evaluate eutrophication status and changes since the early 1990s and for comparison to regional and national conditions. A farm-scale aquaculture model was applied and results scaled to the estuary to determine the potential for shellfish (oyster) aquaculture to mediate eutrophication impacts. Results showed that (1) the contribution to nitrogen loads from headwater streams is small (about 2 %) of total inputs to the Potomac River Estuary; (2) eutrophic conditions in the Potomac River Estuary have improved in the upper estuary since the early 1990s, but have worsened in the lower estuary. The overall system-wide eutrophication impact is high, despite a decrease in nitrogen loads from the upper basin and declining surface water nitrate nitrogen concentrations over that period; (3) eutrophic conditions in the Potomac River Estuary are representative of Chesapeake Bay region and other US estuaries; moderate to high levels of nutrient-related degradation occur in about 65 % of US estuaries, particularly river-dominated low-flow systems such as the Potomac River Estuary; and (4) shellfish (oyster) aquaculture could remove eutrophication impacts directly from the estuary through harvest but should be considered a complement—not a substitute—for land-based measures. The total nitrogen load could be removed if 40 % of the Potomac River Estuary bottom was in shellfish cultivation; a combination of aquaculture and restoration of oyster reefs may provide larger benefits.

Maryland, Pennsylvania, Virginia, West Virginia↗
USGS2010

Comparison of episodic acidification of Mid-Atlantic Upland and Coastal Plain streams

Episodic acidification was examined in five mid-Atlantic watersheds representing three physiographic provinces: Coastal Plain, Valley and Ridge, and Blue Ridge. Each of the watersheds receives a similar loading of atmospheric pollutants (SO 4 2− and NO 3 − ) and is underlain by different bedrock type. The purpose of this research was to quantify and compare the episodic variability in storm flow chemistry in Reedy Creek, Virginia (Coastal Plain), Mill Run and Shelter Run, Virginia (Valley and Ridge), and Fishing Creek Tributary and Hunting Creek, Maryland (Blue Ridge). Because episodic responses were similar from storm to storm in each of the watersheds, a representative storm from each watershed was discussed. Acidification, defined as the loss of acid-neutralizing capacity (ANC), was observed in all streams except Mill Run. Mill Run chemistry showed little episodic variability. During storms in the other streams, p H decreased while SO 4 2− , NO 3 − , and K + concentrations increased. Concentrations of Mg 2+ and Ca 2+ increased in Reedy Creek and Fishing Creek Tributary, but decreased in Shelter Run and Hunting Creek. Therefore the net effect of episodic changes on the acid-base status differed among the streams. In general, greater losses of ANC were observed during storms at Shelter Run and Hunting Creek, watersheds underlain by reactive bedrock (carbonate, metabasalt); comparatively smaller losses in ANC were observed at Reedy Creek and Fishing Creek Tributary, watersheds underlain by quartzites and unconsolidated quartz sands and cobbles. Increased SO 4 2− concentrations were most important during storms at Reedy Creek and Fishing Creek Tributary, but organic anions (inferred by anion deficit) were also a factor in causing the loss of ANC. Dilution of base cations was the most important factor in the loss of ANC at Shelter Run. Both increased sulfate and dilution of base flow were important in causing the episodic acidification at Hunting Creek. The role of SO 4 2− in contributing to episodic acidification in these watersheds is similar to that documented in studies conducted in other regions of the United States, Scandinavia, Canada, and the United Kingdom. The importance of SO 4 2− in mid-Atlantic United States streams contrasts with northeastern United States streams, in which increased NO 3 - derived from snowpack is more important in causing episodic acidification. Results support the importance of shallow subsurface processes in determining storm flow chemistry, regional climatic characteristics in determining the different sources of acidity during episodes, and the importance of bedrock geology in determining the amount of ANC loss.

Maryland, Virginia, West Virginia↗
USGS2006

Geologic map of the Colonial Beach South 7.5-minute quadrangle, Virginia

The Open-File Report includes a geologic map with cross section, and composite stratigraphic section of the Tertiary stratigraphy and of the Quaternary stratigraphy. The Tertiary map units are presented and interpreted for erodability and derived surficial deposits. The map area contains the George Washington Birthplace National Monument. The map facilitates the interpretation of the natural history of the Park including processes such as bog (wetlands) formation and coastal erosion. Two cores of Holocene estuarine deposits are sited on the map. They present the transition from terrestrial to estuarine depositional environments.

Open-File Report↗
USGS2003

Bog iron formation in the Nassawango Watershed, Maryland

Introduction Bog iron deposits occur at a number of localities in the Pocomoke River basin. The most extensive deposits are situated along Nassawango Creek northwest of Snow Hill, a town on the Pocomoke River. After the discovery of these deposits an iron furnace was built in 1830 on the west side of Nassawango Creek, five miles northwest of Snow Hill, at a location known as the Furnace. The furnace exclusively smelted bog iron obtained along Nassawango Creek for a mile or so north of the furnace site; iron was produced from 1830 to 1850 at a rate of approximately 700 tons per year. Smelting technology of that period used mollusc shells for lime flux and locally burned charcoal for fuel; they were unable to remove phosphorous and the iron was rendered brittle when cold ("cold short") because of the high phosphorous content inherited from the ore. For that reason, and because of the limited size of the deposits and the discovery of the much larger and higher quality ore deposits in other parts of the country, production ceased about 1850. The bog iron deposits have been forming throughout the Holocene and are still forming today. Singewald (1911) stated, that their chief interest today lies in the fact that the deposits are now forming and at such a rate as to be observable. "Deposits which were once exhausted are again workable after an interval of a few years" (for more on rate of formation of bog ore at different locations see Starkey, 1962 and Moore, 1910). In general, bog ores consist primarily of iron oxyhydroxides, commonly goethite (FeO(OH)). The ores in the Nassawango, in addition to goethite and other ferric oxyhydroxides, contain a significant amount of magnetite.

Maryland↗
USGS2002

Acidic deposition to streams: A geology-based method predicts their sensitivity

All water that reaches watershed systems comes directly or indirectly from precipitation. Normally, this water contains very small amounts of dissolved solids and is only slightly acidic. As a result of chemical reactions in watersheds, however, stream water generated from precipitation normally is less acidic and contains larger concentrations of dissolved solids than does the precipitation falling onto the watershed.

Environmental Science & Technology↗
USGS2002

The U.S. Geological Survey and the Chesapeake Bay – The role of science in environmental restoration

The Chesapeake Bay is the Nation's largest estuary and historically supported one of the most productive fisheries in the world. In addition to supporting aquatic communities and wildlife, the bay's watershed serves the economic and recreational needs of 15 million people. The fertile soils of the watershed support significant agricultural production. Unfortunately, the commercial, economic, and recreational value of the bay and its watershed has been degraded by poor water quality, loss of habitat, and overharvesting of living resources. Since the early 1980's, the Chesapeake Bay Program, which is a partnership among Maryland, Virginia, Pennsylvania, the District of Columbia, the Federal Government, and the Chesapeake Bay Commission, has been formulating and implementing restoration goals to restore living resources, minimize habitat loss, and reduce the amount of nutrients, sediment, and toxic substances entering the bay. The U.S. Geological Survey has the critical role of providing unbiased scientific information to be used in helping to formulate, implement, and assess the effectiveness of restoration goals in the bay and its watershed.

Chesapeake Bay watershed↗
USGS1999

An Overview of the Factors Involved in Evaluating the Geochemical Effects of Highway Runoff on the Environment

Materials washed by rain and snowmelt from highways into adjacent surface waters, ground waters, and ecosystems can pollute water and affect biota. To understand the chemical behavior of any one of these materials and its effects on the environment requires knowledge of the chemistry of the material and how it interacts with other components in the local geochemical system. An integrated watershed approach, therefore, would be the most effective method to assess the effects of highway runoff on local receiving waters. Analysis of one or a few specific contaminants will provide limited and incomplete information and may be misleading in terms of environmental effects. This report addresses the background geochemistry required to model highway runoff and to make realistic assessments of the potential effects of runoff on the environment.

Open-File Report↗
USGS1998

Transmission of atmospherically deposited trace elements through an undeveloped, forested Maryland watershed

Retention and transmission of atmospherically-derived major (H + , Na + , K + , Ca 2+ , Mg 2+ , HCO 3 - , NO 3 - , SO 4 -2 , Cl - , SiO 2 ) and trace (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn) species were evaluated in an undeveloped forested watershed underlain by a rather inert quartzite lithology (Bear Branch, Catoctin State Forest, Thrumont, Maryland). These comparisons were based on atmospheric input to stream export over a period of 16 months. Both wet (precipitation) and total (bulk, including vegetative throughfall) atmospheric loading to the catchment were determined. Stream export was gauged based on systematic sampling of the stream under varied flow regimes. Additionally, watershed export of both dissolved and particulate trace element phases was examined during three high run-off intensives associated with summer storms.

Maryland↗
USGS1997

Use of geochemical mass balance modelling to evaluate the role of weathering in determining stream chemistry in five mid-Atlantic watersheds on different lithologies

The importance of mineral weathering was assessed and compared for five mid-Atlantic watersheds receiving similar atmospheric inputs but underlain by differing bedrock. Annual solute mass balances and volume-weighted mean solute concentrations were calculated for each watershed for each year of record. In addition, primary and secondary mineralogy were determined for each of the watersheds through analysis of soil samples and thin sections using petrographic, scanning electron microscope, electron microprobe and X-ray diffraction techniques. Mineralogical data were also compiled from the literature. These data were input to NETPATH, a geochemical program that calculates the masses of minerals that react with precipitation to produce stream water chemistry. The feasibilities of the weathering scenarios calculated by NETPATH were evaluated based on relative abundances and reactivities of minerals in the watershed. In watersheds underlain by reactive bedrocks, weathering reactions explained the stream base cation loading. In the acid-sensitive watersheds on unreactive bedrock, calculated weathering scenarios were not consistent with the abundance of reactive minerals in the underlying bedrock, and alternative sources of base cations are discussed.

Hydrological Processes↗
USGS1997

Acid Rain

Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S0 2 and NO x to the atmosphere during the combustion of fossil fuels. Oxidation of these compounds in the atmosphere forms strong acids - H 2 SO 4 and HNO 3 - which are returned to the Earth in rain, snow, fog, cloud water, and as dry deposition. Although acid deposition has only recently been recognized as an environmental problem in the U.S., it is not a new phenomenon (Cogbill & Likens 1974). As early as the middle of the 17th century in England, the deleterious effects of industrial emissions on plants, animals, and humans, and the atmospheric transport of pollutants between England and France had become issues of concern (Evelyn 1661, Graunt 1662). It is interesting that well over three hundred years ago in England, recommendations were made to move industry outside of towns and build higher chimneys to spread the pollution into "distant parts." Increasing the height of smokestacks has helped alleviate local problems, but has exacerbated others. In the U.S. the height of the tallest smokestack has more than doubled, and the average height of smokestacks has tripled since the 1950s (Patrick et al 1981). This trend occurred in most industrialized nations during the 20th century and has had the effect of transforming acid rain from a local urban problem into a problem of global scale.

Book chapter↗
USGS1996

Hydrologic and water-quality data for two small watersheds on Catoctin Mountain, North-Central Maryland, 1987-93

Hydrologic and water-quality data were collected from a precipitation-collection station and from two small watersheds on Catoctin Mountain, north-central Maryland, as part of investigations of acidic deposition and episodic acidification, and their effects on streamwater quality. Detailed descriptions of the site instrumentation in the watersheds, field data-collection techniques, and laboratory methods used to conduct the studies are included. Data that were collected on precipitation, throughfall, soil water, ground water, streamwater, and other surface and ground waters sampled during biannual synoptic surveys are given in tables. Data collected since October 1987 from one of the streamwater-quality monitoring sites and data collected since March 1988 from one of the ground-water quality monitoring sites are presented. Additional data collected since January 1987 from the precipitation station and data collected since June 1990 from all of the other water-quality monitoring sites are presented. Hydrologic data include tables of precipitation and throughfall quantities, streamflow, and synoptic measurements of ground-water levels. Selected hydrologic data are shown in graphs.

Maryland↗
USGS1996

Hydrologic and geochemical factors affecting the chemistry of small headwater streams in response to acidic deposition on Catoctin Mountain, north-central Maryland

Hydrologic and water-quality data were collected at a precipitation-collection station and from two small watersheds on Catoctin Mountain, north- central Maryland, as part of an investigation of episodic acidification and its effects on streamwater quality. Data were collected from June 1990 through December 1993. Descriptions of the water shed instrumentation, data-collection techniques, and laboratory methods used to conduct the studies are included. Data that were collected on precipitation, throughfall, soil water, ground water, and streamwater during base flow and stormflow indicate that the streams undergo episodic acidification during storms. Both streams showed decreases in pH to less than 5.0 standard units during stormflow. The acid-neutralizing capacity (ANC) of both streams decreased during stormflow, and the ANC of one of the streams, Bear Branch, became negative. The chemistries of the different types of waters that were sampled indicate that shallow subsurface water with minimal residence time in the watersheds is routed to the streams to become stormflow and is the cause of the episodic acidification observed. Three-component hydrograph separations were performed on the data collected during several storms in each watershed. The hydrograph separations of all of the storms indicate that throughfall contributed 0 to 50 percent of the stormflow, soil water contributed 0 to 80 percent, and ground water contributed 20 to 90 percent. The results of the hydrograph separations indicate that, in general, the watershed with higher hydraulic gradients tends to have shallower and shorter flow paths than the watershed with lower hydraulic gradients.

Maryland↗
USGS1995

Seasonal cycles of dissolved constituents in streamwater in two forested catchments in the mid-Atlantic region of the eastern U.S.A.

Streamwater discharge and chemistry of two small catchments on Catoctin Mountain in north-central Maryland have been monitored since 1982. Repetitive seasonal cycles in stream-water chemistry have been observed each year, along with seasonal cycles in the volume of stream discharge and in groundwater levels. The hypothesis that the observed streamwater chemical cycles are related to seasonal changes in the hydrological flow paths that contribute to streamflow is examined using a combination of data on groundwater levels, shallow and deep groundwater chemistry, streamwater discharge, streamwater chemistry, soil-water chemistry, and estimates of water residence times. The concentrations of constituents derived from rock weathering, particularly bicarbonate and silica, increase in streamwater during the summer when the water table is below the regolith-bedrock interface and stream discharge consists primarily of deep groundwater from the fractured-bedrock aquifer. Conversely, the concentrations in streamwater of atmospherically derived components, particularly sulfate, increase in winter when the water table is above the regolith-bedrock interface and stream discharge consists primarily of shallow groundwater from the regolith. Tritium and chlorofluorocarbon (CFC) measurements suggest that the groundwater in these systems is young, with a residence time of less than several years. The results of this study have implications for the design of large-scale water-quality monitoring programs.

Maryland↗
USGS1995

Seasonal cycles in streamwater quality on Catoctin Mountain, Maryland

In 1980, the U.S. Congress mandated the National Acid Precipitation Assessment Program (NAPAP) to study the effects of acidic precipitation (acid rain). In 1982, the U.S. Geological Survey (USGS) was selected to be the lead Federal agency under NAPAP to monitor the composition of precipitation and its effects on the environment. In 1982, the USGS began to monitor precipitation and streamwater on Catoctin Mountain in north-central Maryland (fig. 1); the effort has continued through the present. Beginning in 1990, funding for these data-collection and interpretation activities was supplemented by the Maryland Department of the Environment and the Maryland Department of Natural Re- sources. The collection and interpretation of long-term precipitation and streamwater-quality records, such as those at Catoctin Mountain, provide valuable information for management decisions. At the local level, the information can be used to identify periods when streamwater quality may pose a danger to aquatic resources, such as finfish; at the national level, the information can be used to assess the effectiveness of the Clean Air Act Amendments.

Maryland↗
USGS1995

Acid Rain

Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

Conference Paper↗