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Articles 1441 - 1470 of 1536
Full-Text Articles in Geochemistry
Mining In Maine : Past, Present, And Future, Carolyn A. Lepage
Mining In Maine : Past, Present, And Future, Carolyn A. Lepage
Maine Collection
Mining in Maine : Past, Present, and Future
by Carolyn A. Lepage, Michael E. Foley, and Woodrow B. Thompson
Maine Geological Survey, Department of Conservation, Augusta, Me., 1990.
Contents: Introduction / The Early Years: Pre-Civil War / The Civil War to World War II / The War Years of the 1940's / The Postwar Years: 1940's to 1960 / The 1960's / The 1970's / Maine Mineral Resources Association / The 1980's / Current Mining and Exploration / Future Potential / Acknowledgments / References
Origin, Sedimentary Geochemistry, And Correlation Of Middle And Late Ordovician K-Bentonites: Constraints From Melt Inclusions And Zircon Morphology, Carsten Schirnick
Origin, Sedimentary Geochemistry, And Correlation Of Middle And Late Ordovician K-Bentonites: Constraints From Melt Inclusions And Zircon Morphology, Carsten Schirnick
Geology Theses and Dissertations
The present study of Paleozoic K-bentonites demonstrates that the geochemistry of melt inclusions and the morphology of zircons can be studied by inexpensive and simple-to-use methods, which rely on phenocrysts. Constraints are obtained that lead to (a) the origin of these altered volcanic ashes, (b) the geochemistry of ash-to-K-bentonite-alteration, and (c) the reliable correlation of extensively altered volcanic ashes (i.e. K-bentonites).
Silicic melt inclusions (i.e. non-devitrified) have been found in quartz and zircon phenocrysts contained within Ordovician and Devonian K-bentonites from New York State, the Upper Mississippi Valley, and Pennsylvania. Origin, source, and tectonic setting of the volcanism that produced …
Application Of A Trace Element Fractionation Model To Cumulate Gabbroic Xenoliths Of Mauna Kea, Hawaii, Ulrike Eberle
Application Of A Trace Element Fractionation Model To Cumulate Gabbroic Xenoliths Of Mauna Kea, Hawaii, Ulrike Eberle
Geology Theses and Dissertations
A trace element fractionation model originally designed to relate plutonic rocks containing a trapped glass component to a complementary volcanic rock suite was applied to olivine and opaque-oxide gabbroic xenoliths from the summit cone of Mauna Kea, Hawaii.
The mathematical model which is based on the Rayleigh Fractionation Law was extended to include the various phases present in these two groups of gabbros and was generalized to treat multiple trace elements, in this case four. These results were incorporated in a new FORTRAN program using the interval-bisection method to greatly improve the convergence time in the numerical solutions.
Calculated results …
Petrology And Major Element Geochemistry Of Basaltic Glasses From The Blanco Trough, Northeast Pacific, Glenn A. Gaetani
Petrology And Major Element Geochemistry Of Basaltic Glasses From The Blanco Trough, Northeast Pacific, Glenn A. Gaetani
Geology Theses and Dissertations
The original electron microprobe analyses of suite of basaltic glasses recovered in 1968 by W.G. Melson and co-workers from the Blanco Trough have extremely unusual characteristics. Their compositions plot in a region of the normative Ol-Di-Pl-SiO2 tetrahedron which suggests that they represent liquids in equilibrium with an upper mantle assemblage of olivine + orthopyroxene at 10-15 kb. Given the present state of controversy surrounding the composition and depth of origin of primary MORB, natural examples of such liquids would be very important. The major element variations observed in the suite imply that the dominant phases are olivine and an iron-aluminum …
Geochemistry Of Garnet Xenocrysts And Garnet-Bearing Xenoliths In Ordovician Bentonites, Barbara Bock
Geochemistry Of Garnet Xenocrysts And Garnet-Bearing Xenoliths In Ordovician Bentonites, Barbara Bock
Geology Theses and Dissertations
Within outcrops of the black Utica shales south of the Mohawk Valley narrow re-entrants parallel with stratification are visible, often accompanied -by a marked orange-staining of the underlying strata. These rentrant features indicate the presence of bentonites weathered back faster then the enclosing shales. These bentonites are presumably magmatic ashes related to extensive volcanism when an island arc collided with the North American continent in the late Ordovician about 450 million years ago (Taconic orogeny).
Bentonites are good stratigraphic markers because of the short time-interval they represent and the large area they cover. Therefore they are commonly used as correlation …
Identification And Quantitation Of Volatile Amines In Marine Sediments, Chuen Mei Huang
Identification And Quantitation Of Volatile Amines In Marine Sediments, Chuen Mei Huang
Chemistry & Biochemistry Theses & Dissertations
Pore waters which were taken from sediments of the Chesapeake Bay were analyzed to determine the presence of volatile amines. A purge-and-trap technique was used to concentrate the amines. Then, following derivatization with heptaflourobutyric anhydride, the HFBA-amines were analyzed by gas chromatography with electron capture detection and with mass spectrometric detection. One secondary amine, diethylamine with a concentration of 0.3-0.6 uM, was found in a total of three pore water samples from cores collected on two different dates. A primary amine, sec-butylamine with a concentration of O. 05 AIM, was also found in one of these same samples. Another primary …
A Geochemical Study Of The Eagle Creek Formation In The Columbia River Gorge, Oregon, Rachel Ann Carlin
A Geochemical Study Of The Eagle Creek Formation In The Columbia River Gorge, Oregon, Rachel Ann Carlin
Dissertations and Theses
The Early Miocene Eagle Creek Formation, a series of volcanic mudflows and debris flows, is exposed in the Columbia River Gorge about 64 kilometers east of Portland, Oregon. Eighty-seven samples were analyzed using instrumental neutron activation analysis for trace element concentrations. Eleven samples were analyzed by Dr. Peter Hooper at Washington State University using X-ray Fluorescence for major element chemistry. These data were used to determine that the Eagle Creek Formation compositionally ranges from andesite to dacite.
Geochemical Stratigraphy Of The Dooley Rhyolite Breccia And Tertiary Basalts In The Dooley Mountain Quadrangle, Oregon, David Neale Whitson
Geochemical Stratigraphy Of The Dooley Rhyolite Breccia And Tertiary Basalts In The Dooley Mountain Quadrangle, Oregon, David Neale Whitson
Dissertations and Theses
The Dooley Rhyolite Breccia in northeast Oregon was erupted between 12 and 16 million years ago, from central vents and linear feeder dikes within the Dooley Mountain quadrangle. The peraluminous, high-silica rhyolites of the formation were erupted over an irregular highland of eroded pre-Tertiary metamorphic rocks locally overlain by intracanyon, Eocene Clarno-type basalt flow(s). The Dooley Rhyolite Braccia is exposed in a tectonically disrupted, north-south trending graben across the Elkhorn Range. The formation is variable in thickness with maximum thickness exceeding 660 meters in the south and 600 meters in the north half of the quadrangle. Volumetrically the formation is …
Sedimentology, Structure, And Geochemistry Of The Galice Formation: Sediment Fill Of A Back-Arc Basin And Island Arc In The Western Klamath Mountains, Rosann Park-Jones
Sedimentology, Structure, And Geochemistry Of The Galice Formation: Sediment Fill Of A Back-Arc Basin And Island Arc In The Western Klamath Mountains, Rosann Park-Jones
Geology Theses and Dissertations
The western Jurassic belt of the Klamath Mountains is an ideal locale for the study of ophiolite genesis, island arc development, and study of flysch deposition from a nearby eroding island arc and continental margin. Closure and imbrication of an inferred back-arc basin coincided with the Late Jurassic Nevadan orogeny (ca 150 Ma). The Galice Formation is the youngest formation involved in the Nevadan orogeny (Lanphere et al., 1968). In the type section in southwestern Oregon, the Galice structurally overlies the Rogue Formation volcaniclastics. The Rogue Formation has been previously interpreted as an island arc assemblage (Garcia, 1979). The type …
Sulfide In Shelf/Slope Waters Of The Western Atlantic, Christian F. Krahforst
Sulfide In Shelf/Slope Waters Of The Western Atlantic, Christian F. Krahforst
OES Theses and Dissertations
Sulfide in the surface ocean has been recently considered as a source of hydrogen sulfide gas in the marine boundary layer. This "oxic" sulfide may also be important as a ligand in trace metal complexation. In the absence of actual data, the existence of sulfide in the ocean mixed layer remains speculative. The purpose of this study was to develop a sensitive technique (having picomolar detection limits) for the determination of sulfide in seawater, and to investigate the distribution of sulfide in the surface ocean.
In order to assess the abundance and distribution of sulfide in surface waters, samples were …
Discrimination Of Subparallel Beach Ridges Using Detrital Ilmenite Composition And Fourier Shape Analysis, Allen E. Evans Jr.
Discrimination Of Subparallel Beach Ridges Using Detrital Ilmenite Composition And Fourier Shape Analysis, Allen E. Evans Jr.
OES Theses and Dissertations
Elemental composition (Fe, Ti, Mn, Mg, V, Cu, Ni, Zn, and Cr) and Fourier shape analysis of magnetically separated detrital ilmenite from seven Pleistocene and modern beach sand deposits of the Southeastern Virginia Coastal Plain were used to distinguish each deposit. Geomorphic expression, crosscutting relationships and proximity to the present shoreline differentiates the relative age of the seven sampled beach deposits. Analysis of ilmenite elemental composition, independent of geomorphic expression, distinguished beach sands of
different age and was successful in determining that each beach contained ilmenite similar in composition. Of the seven beach ridges tested, subtle yet significant differences in …
Isotope Content And Temperature Of Precipitation In Southern Nevada, August 1983-August 1986, W. K. Milne, Larry Benson, P. W. Mckinley
Isotope Content And Temperature Of Precipitation In Southern Nevada, August 1983-August 1986, W. K. Milne, Larry Benson, P. W. Mckinley
United States Geological Survey: Publications
From August 1983 through August 1986, 429 precipitation samples of 112 precipitation events were collected at 12 stations in southern Nevada. Some of these samples were analyzed for oxygen-18, deuterium, and tritium. The results of these analyses as well as the air temperature and the precipitation measured at the collection sites are tabulated in this report. The sampling program provides a data base for future interpretive studies on the timing and origin of ground-water recharge in the Yucca Mountain region, of southern Nevada.
The stable-isotope composition of precipitation is the result of fractionation processes that occur in the atmosphere. Isotopic …
Identification Of Endmembers For Magma Mixing In Little Sitkin Volcano, Alaska, Douglas A. Wolf
Identification Of Endmembers For Magma Mixing In Little Sitkin Volcano, Alaska, Douglas A. Wolf
Geology Theses and Dissertations
Little Sitkin island is an Aleutian calc-alkalic volcanic center that has erupted a suite of lavas ranging from andesite through rhyodacite. Whole-rock chemistry of these lavas indicates contrasting evolutionary processes; major-oxide silica variation diagrams exhibit linear trends that are suggestive of magma-mixing while trace-element trends are largely controlled by accessory-phase fractionation.
Plagioclase, the dominant phenocryst phase in all lavas, commonly occurs in two distinct populations with markedly different compositions and textures. Both normal and reverse zonation is noted in the plagioclase and clinopyroxene of several samples. In addition, clinopyroxene is found as rims on orthopyroxene grains and as cores with …
Granitic Pegmatites In The Southeastern Adirondacks: Their Use As Indicators Of Temperature, Pressure, And Fluid Conditions During A Late Stage Of The Grenville Orogeny, John P. Mihalich
Geology Theses and Dissertations
Granitic pegmatites associated with the Grenville orogeny intrude a mid-Proterozoic, upper amphibolite to near granulite facies terrane in the southeastern Adirondack Mountains of New York State. The inferred anatectic, fluid-saturated, and minimum melt characteristics of the pegmatites suggest that they can be used as analogs of the "granite" or "haplogranite" system, and as indicators of crustal temperature, pressure, and fluid conditions during a late stage of the Grenville orogeny. Bulk chemical compositions of seven simple, undeformed pegmatites in the southeastern Adirondacks indicate that they are generally depleted in silica and sodium, and enriched in potassium, relative to experimental data on …
Geology, Geochemistry, And Geochronology Of The Lems Ridge Olistostrome, Klamath Mountains, California, Matthias Ohr
Geology, Geochemistry, And Geochronology Of The Lems Ridge Olistostrome, Klamath Mountains, California, Matthias Ohr
Geology Theses and Dissertations
The Lems Ridge olistostrome (LRO), located within the western Jurassic belt of the Klamath Mountains geologic province, is a melange unit showing a distinct block-in-matrix fabric. The conformable relationship to both an igneous basement and the overlying flysch of the Late Jurassic Galice Formation points to a sedimentary origin. The lack of pervasive deformation and the internal stratification also support a predominantly olistostromal origin of the LRO. The matrix of the LRO consists of pebbly mudstone which interfingers with tuffaceous greenstone and tuff-breccias. Subordinate beds of chert, argillite, and sandstone are also present. The matrix contains abundant ophiolitic clasts, fragments …
Structural, Remote Sensing And Multivariate Correlation Methods As Aids To Mineral Exploration, Central Ireland, D.W. Coller, M.F. Critchley, J.M. Dolan, Ciaran Mcdonnell, C.J. Murphy, W.E.A. Phillips, D.J. Sanderson
Structural, Remote Sensing And Multivariate Correlation Methods As Aids To Mineral Exploration, Central Ireland, D.W. Coller, M.F. Critchley, J.M. Dolan, Ciaran Mcdonnell, C.J. Murphy, W.E.A. Phillips, D.J. Sanderson
Books/Book chapters
This work discusses structural, remote sensing and multivariate correlation methods as aids to mineral exploration in West Central Ireland. The work was performed as part of the EU-funded CREST project.
Transient Electromagnetic Sounding For Groundwater, David V. Fitterman, Mark T. Stewart
Transient Electromagnetic Sounding For Groundwater, David V. Fitterman, Mark T. Stewart
Geology Faculty Publications
The feasibility of using the transient electromagnetic sounding (TS or TDEM) method for groundwater exploration can be studied by means of numerical models. As examples of its applicability to groundwater exploration, we study four groundwater exploration problems: (1) mapping of alluvial fill and gravel zones over bedrock; (2) mapping of sand and gravel lenses in till; (3) detection of salt or brackish water interfaces in freshwater aquifers; and (4) determination of hydrostratigraphy. These groundwater problems require determination of the depth to bedrock; location of resistive, high-porosity zones associated with fresh water; determination of formation resistivity to assess water quality; and …
On The Linear Relation Between Mb And Ms For Discrimination Between Explosions And Earthquakes, Ali A. Nowroozi
On The Linear Relation Between Mb And Ms For Discrimination Between Explosions And Earthquakes, Ali A. Nowroozi
OES Faculty Publications
Summary. The statistical capability of the mb :Ms, discriminant for the discrimination of earthquake and explosion populations is examined by application of discriminant functions to a group of 83 explosions and 72 earthquakes in Eurasia. Equations are derived for the probability that an event is an earthquake or an explosion. The positive sign of DIS in the decision index equation,
DIS, = 34.3383 - 11.9569 mbi, + 7.1 161 Msi,
indicates that the event i is an earthquake. Its negative sign indicates that event i is an explosion. The probability of …
Biomarker Geochemistry Of The Miocene Monterey Formation, West San Joaquin Basin, California: Implications For Petroleum Generation, Michael A. Kruge
Biomarker Geochemistry Of The Miocene Monterey Formation, West San Joaquin Basin, California: Implications For Petroleum Generation, Michael A. Kruge
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Much of the Miocene Monterey Formation of California is rich in biogenic sediment, especially organic matter and silica. Because of the geologic structure, the Monterey in the subsurface near Lost Hills in the San Joaquin Basin forms a natural laboratory for the study of the diagenetic responses of these materials. Rocks of similar age and lithology are buried to depths ranging between 500 and 3500 m, and are thus exposed to a temperature range of 45–130°C. The diagenetic progression of silica from opal-A to opal-CT to microquartz is well-documented in Monterey burial history studies. However, diagenetic indicators need to be …
A Stratigraphic-Geochemical Study Of The Troutdale Formation And Sandy River Mudstone In The Portland Basin And Lower Columbia River Gorge, Rodney Duane Swanson
A Stratigraphic-Geochemical Study Of The Troutdale Formation And Sandy River Mudstone In The Portland Basin And Lower Columbia River Gorge, Rodney Duane Swanson
Dissertations and Theses
Hyaloclastic sediment forms an identifiable stratigraphic interval within the Troutdale Formation that can be traced from the Bridal Veil channel to the Portland basin. Hyaloclastic sediment composed chiefly vitric sands is found interbedded with muds, sandy muds and gravels penetrated by wells in northeast Portland are correlated with the upper member of the Troutdale Formation. These beds are characteristic of the informal upper member of the Troutdale Formation in the Bridal Veil channel of the ancestral Columbia River (Tolan and Beeson, 1984) and the type area of the Troutdale Formation exposed along the Sandy River (Trimble, 1963). Fluvially deposited hyaloclastic …
The Geology, Geochemistry, And Alteration Of Red Butte, Oregon: A Precious Metal-Bearing Paleo Hot Spring System, Carol Susan Evans
The Geology, Geochemistry, And Alteration Of Red Butte, Oregon: A Precious Metal-Bearing Paleo Hot Spring System, Carol Susan Evans
Dissertations and Theses
Red Butte is located 60 km south of Vale, Oregon, about 20 km west of the Oregon/Idaho border. The butte is within the Owyhee Upland physiographic province of eastern Oregon which lies at the intersection of the Western Snake River Plain, the High Lava Plains, and the Northern Basin and Range provinces.
The butte is composed of Miocene to Pliocene lacustrine and fluvial volcaniclastic sediments. The topography of the butte is controlled by silicification of the sandstones and mudstones which cap it. Silicification and hydrothermal alteration are both structurally and stratigraphically controlled. North-trending normal faults dominate the area, and show …
Leachate Monitoring In Naturally Saline Groundwater Chesapeake Landfill Chesapeake Virginia, T. Britt Mcmillan
Leachate Monitoring In Naturally Saline Groundwater Chesapeake Landfill Chesapeake Virginia, T. Britt Mcmillan
OES Theses and Dissertations
Groundwater chemistry around the Chesapeake municipal landfill was monitored over a one year period. Ten sample sites as well as two surface water sites were used to monitor water quality. Two wells, one at 3 m and the other at 10 m were located at each site. Surface water samples were taken from the Elizabeth River, north of the landfill, and a tidal channel, west of the landfill. Seven groundwater sites were downgradient of the landfill and three sites were upgradient (control sites).
The landfill overlies a tidal marsh, approximately 100 m south of the intracoastal waterway (Elizabeth River). Dredge …
Geochemistry Of Alteration And Mineralization Of The Wind River Gold Prospect, Skamania County, Washington, Krista I. Mcgowan
Geochemistry Of Alteration And Mineralization Of The Wind River Gold Prospect, Skamania County, Washington, Krista I. Mcgowan
Dissertations and Theses
The Wind River gold prospect is located in TSN, R7E of Skamania County, Washington, and is an epithermal gold-quartz vein system hosted in volcanic rocks of the Ohanapecosh Formation, a late Eocene to middle Oligocene unit of calcalkaline chemical composition. Andesitic pyroclastic rocks of the Ohanapecosh Formation are the host of mineralization in the study area, and form the lowest of several stratigraphic subunits. These pyroclastic rocks are overlain by two sequences of lava flows which cap the ridges and are folded by an anticlinal warp over the length of Paradise Ridge, plunging gently to the southeast. Toward the west, …
Geology And Geochemistry Of Hydrothermal Alteration, Eastern Portion Of The North Santiam Mining Area, J. Michael Pollock
Geology And Geochemistry Of Hydrothermal Alteration, Eastern Portion Of The North Santiam Mining Area, J. Michael Pollock
Dissertations and Theses
The Ruth Mine is a base-metal vein deposit near the eastern margin of a reported porphyry copper deposit in the Western Cascade Range in Oregon. Uplift of the Western Cascade Range has resulted in a deeply dissected terrain in which more than a kilometer of the stratigraphy overlying the porphyry-style mineralization is preserved and exposed. The stratigraphic units, which are middle Tertiary in age, have been given arbitrary letter designations beginning with the lowest unit (Unit A) through the uppermost unit (Unit D).
Unit A is composed of fragmental rocks of andesitic composition. Overlying and interlayered with Unit A are …
The Continental Crust: Its Composition And Evolution, Stuart Ross Taylor, Scott M. Mclennan
The Continental Crust: Its Composition And Evolution, Stuart Ross Taylor, Scott M. Mclennan
Department of Geosciences Faculty Publications
Graduates in geology, geochemistry and geophysics will find this book a valuable reference text. The book begins by describing the known composition of the present upper crust, then deals with possible compositions for the total crust and the inferred composition of the lower crust. The question of the uniformity of crustal composition throughout geological time is discussed, the rate of growth of the crust and the effects of extraction of the crust on mantle compositions are considered. Finally, the question of early pre-geological crusts on Earth is debated and comparisons are given with crusts on the Moon, Mercury, Mars, Venus …
Chemical Composition Of Ground Water In The Yucca Mountain Area, Nevada, 1971-84, Larry Benson, P. W. Mckinley
Chemical Composition Of Ground Water In The Yucca Mountain Area, Nevada, 1971-84, Larry Benson, P. W. Mckinley
United States Geological Survey: Publications
Fifteen test wells in the Yucca Mountain area of southern Nevada have been sampled for chemical analysis at least once during 1971-84. Samples were obtained by pumping water from the entire well bore (composite sample), and, in three instances, by pumping from one or more isolated intervals within a well bore. Sodium was the most abundant cation, and bicarbonate was the most abundant anion in all water samples. Samples from the deep carbonate aquifer penetrated by well UE-25p#l contained higher relative concentrations of calcium and magnesium than did samples from overlying volcanic tuffs. Concentrations of the stable isotopes of oxygen …
The Use Of Ilmenite Element Composition For The Determination Of Provenance, Yu W. Tsang
The Use Of Ilmenite Element Composition For The Determination Of Provenance, Yu W. Tsang
OES Theses and Dissertations
Fifty three samples were taken from three major rivers and their tributaries in Virginia: the James, Roanoke. and Potomac-Shenandoah Rivers. Samples were obtained from the Valley and Ridge. Blue Ridge and Piedmont provinces. The possible source rock types for these samples were determined by comparison of tributary ilmenite composition with drainage basin rock types. Ilmenite element concentration varied with different rock types. Ti was usually high for the ilmenite derived from non-mafic igneous rocks. Mg and Cr were high for the ilmenite from mafic igneous rocks. Zn was low for metamorphic ilmenite. The ilmenite from sedimentary rocks tended to have …
Fault Movements And Tectonics Of Eastern Iran: Boundaries Of The Lut Plate, Ali A. Nowroozi, A. Mohajer-Ashjai
Fault Movements And Tectonics Of Eastern Iran: Boundaries Of The Lut Plate, Ali A. Nowroozi, A. Mohajer-Ashjai
OES Faculty Publications
Summary. From 1977 March 21 to 1981 July 28, about 15 earthquakes with Ms ≥6.0 and many earthquakes with Ms≥4.5 have occurred in Iran. The upsurge of seismic activity started following the Khorqu earthquake of 1977 March 21, M,=7.0, south-east of the Fars folded series of Zagros. This shock had a thrust focal mechanism solution indicating the general northward movement of the Arabian plate with respect to the Iranian landmass. It was followed by six major damaging earthquakes in eastern Iran. The earthquakes are associated with extensive faulting which surrounds the Lut plate. (1) The Zarand earthquake …
A Bacteriological And Chemical Analysis Of Nonpoint Source Pollution In A Karst Aquifer Bowling Green, Kentucky, Wayne Green
A Bacteriological And Chemical Analysis Of Nonpoint Source Pollution In A Karst Aquifer Bowling Green, Kentucky, Wayne Green
Masters Theses & Specialist Projects
Monthly water samples collected from four sites in the Lost River Groundwater Basin, a shallow karst aquifer in the Bowling Green-Warren County area of Kentucky, represented samples from sites receiving conduit and diffuse flow. All sites were severely contaminated with bacteria, and on some occasions the surface water criteria for some heavy metals were exceeded.
Of the total 334 bacterial colonies identified 92.1% were verified as Escherichia coli by the API20E system. Acinetobacter calcoaceticus var. anitratum accounted for 2.10% of colonies; Citrobacter freundii for 0.30% Klebsiella pneumoniae for 0.90%; Klebsiella oxytoca, 0.90%; Citrobacter amalonaticus 0.30%; Enterobacter cloacae, 1.20%; …
The Aquatic Geochemistry Of The Particle-Reactive Radionuclides Po-210, Pb-210, And Be-7, James Forrest Todd
The Aquatic Geochemistry Of The Particle-Reactive Radionuclides Po-210, Pb-210, And Be-7, James Forrest Todd
OES Theses and Dissertations
Integrated monthly wet-only and bulk precipitation samples for Be-7 and Pb-210 analysis were collected from November 1982 through October 1983 at two sites in lower Chesapeake Bay. Atmospheric deposition fluxes for Be-7 in wet-only and bulk precipitation averaged 0.013 and 0.014 pCi/cm2/d, respectively, and for Pb-210 averaged 0.36 and 0.40 pCi/cm2/yr, respectively, suggesting that dry deposition makes only a minor contribution to the total fluxes.
A seasonal trend was observed in the depositional flux of Be-7, with a pronounced maximum in the Spring. Approximately 40 percent of the annual Be-7 deposition occurred between February and April, …