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Geochemistry

2013

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Articles 31 - 60 of 76

Full-Text Articles in Earth Sciences

Investigations Into The Potential For Hypogene Speleogenesis In The Cumberland Plateau Of Southeast Kentucky, U.S.A., Lee J. Florea Jul 2013

Investigations Into The Potential For Hypogene Speleogenesis In The Cumberland Plateau Of Southeast Kentucky, U.S.A., Lee J. Florea

Lee J Florea, PhD, P.G.

This manuscript offers preliminary geochemical evidence that investigates the potential for hypogene speleogenesis in the Cumberland Plateau of southeastern Kentucky, U.S.A. The region was traditionally considered a classic example of epigenic karst, but new insights have uncovered tantalizing observations that suggest alternatives to simple carbonic acid speleogenesis. Such first-order observations have included natural petroleum seeps at the surface and in caves, occasional cave morphologies consistent with action of hypogene fluids, and prolific gypsum within cave passages. To this point, geochemical data from caves and springs verify carbonic acid as the primary dissolutional agent; however, these same analyses cannot rule out …


Lower Aptian Comparative Stratigraphy Of The Basco-Cantabrian Region (Spain) And Eastern Cordillera (Colombia): Implications For Local Factors In The Depositional Record Of Oceanic Anoxic Event 1a (Oae-1a), Tatiana Gaona Narvaez Jun 2013

Lower Aptian Comparative Stratigraphy Of The Basco-Cantabrian Region (Spain) And Eastern Cordillera (Colombia): Implications For Local Factors In The Depositional Record Of Oceanic Anoxic Event 1a (Oae-1a), Tatiana Gaona Narvaez

FIU Electronic Theses and Dissertations

An important episode of carbon sequestration, Oceanic Anoxic Event 1a (OAE-1a), characterizes the Lower Aptian worldwide, and is mostly known from deeper-water settings. The present work of two Lower Aptian deposits, Madotz (N Spain) and Curití Quarry (Colombia), is a multiproxy study that includes fossil assemblages, microfacies, X-ray diffraction bulk and clay mineralogy, elemental analyses (major, minor, trace elements), Rock-Eval pyrolysis, biomarkers, inorganic and organic carbon content, and stable carbon isotopes. The results provide baseline evidence of the local and global controlling environmental factors influencing OAE-1a in shallow-water settings. The data also improve our general understanding of the conditions under …


Oil-Source Rock Correlation In The Late Paleozoic, Denver Basin, Nebraska -The Search For A Negative Δ¹³C Anomaly In Pennsylvanian-Permian Cyclothems, John P. Still Jun 2013

Oil-Source Rock Correlation In The Late Paleozoic, Denver Basin, Nebraska -The Search For A Negative Δ¹³C Anomaly In Pennsylvanian-Permian Cyclothems, John P. Still

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Late Paleozoic sedimentation in the Denver basin occurred in two environmentally distinct depocenters. The northern-most Alliance Basin has been interpreted to have a restricted character: anhydrite-bearing mudstones are present in cyclothems comprising wackestone, packstone and mudstone. The source of petroleum produced from these intervals is considered to be organic-rich units within these cyclothems. Oil recovered from late Paleozoic reservoirs has δ13C values that range from -30.8‰ to -28.8‰: values that are lower than those reported previously for prospective source rocks from this interval. Cores from seven wells that penetrate upper Pennsylvanian to lower Permian rocks have been chosen for analysis. …


Determination Of The Cec In Srs Soils And The Capability Of Epa Model 9081 For Cec Of Acidic Soils, Alexandra Simpson May 2013

Determination Of The Cec In Srs Soils And The Capability Of Epa Model 9081 For Cec Of Acidic Soils, Alexandra Simpson

Alexandra M Simpson

No abstract provided.


Determination Of The Cec In Srs Soils And The Capability Of Epa Model 9081 For Cec Of Acidic Soils, Alexandra Simpson May 2013

Determination Of The Cec In Srs Soils And The Capability Of Epa Model 9081 For Cec Of Acidic Soils, Alexandra Simpson

Alexandra M Simpson

No abstract provided.


Origins Of Stable Isotopic Variations In Late Pleistocene Horse Enamel And Bone From Alberta, Nicolle S. Bellissimo May 2013

Origins Of Stable Isotopic Variations In Late Pleistocene Horse Enamel And Bone From Alberta, Nicolle S. Bellissimo

Electronic Thesis and Dissertation Repository

Oxygen and carbon isotopic measurements of coevally formed bone and tooth enamel bioapatite from a modern equid show that these tissues record drinking water and diet isotopic signals in an identical fashion. Hence, data for both tissues can be combined to track movement, dietary changes, and seasonal variability over the animal’s lifetime, and climatic variability over longer time periods. This tool was tested for horses using ten paired tooth and bone samples to reconstruct conditions in Alberta during the Late Pleistocene. While post-mortem isotopic alteration confounded interpretation of the results, two key findings emerged: (i) pre- and post-Last Glacial Maximum …


Readily Available Acidity In Schwertmannite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton May 2013

Readily Available Acidity In Schwertmannite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Associate Professor Edward D Burton

Schwertmannite and jarosite are considered as less soluble ironhydroxy sulfate minerals which are present in highly acidic environments (pH < 3). These minerals release acidity in the long run as they weather by hydrolysis [1]. However, 1M KCl extraction of soil samples (Clarence and Quartz) spiked with those two minerals showed that schwertmannite has some acidity that may be readily available.


Hydro-Geochemical Coupling In Seawater Inundation Acid Sulfate Soils: Mobilisation Of Arsenic And Hysteresis In Iron And Sulfur Cycling, Scott Johnston, Annabelle Keene, Edward Burton, Richard Bush, Leigh Sullivan May 2013

Hydro-Geochemical Coupling In Seawater Inundation Acid Sulfate Soils: Mobilisation Of Arsenic And Hysteresis In Iron And Sulfur Cycling, Scott Johnston, Annabelle Keene, Edward Burton, Richard Bush, Leigh Sullivan

Associate Professor Edward D Burton

A large-scale field trial indicates that tidal seawater inundation of coastal acid sulfate soils (CASS) stimulates iron and sulfate reducing conditions, leading to the generation of internal alkalinity and greatly decreasing soil / groundwater acidity. This remediation technique can be considered highly effective from the relatively narrow perspective of decreasing acidity and raising pH. However, a broader perspective reveals that tidal seawater inundation initiates complex and tightly coupled hydrological and geochemical processes within sediments and porewaters. These processes have had a profound effect on the mobilisation, redistribution and transformation of Fe minerals in the landscape (Johnston et al., 2011a) – …


Metamorphic Phase Equilibria In A Contact Aureole: Tres Hermanas Mountains, Luna County, New Mexico., Carissa Dawn Snyder May 2013

Metamorphic Phase Equilibria In A Contact Aureole: Tres Hermanas Mountains, Luna County, New Mexico., Carissa Dawn Snyder

Masters Theses

To characterize the metamorphism in the Tres Hermanas Mountains contact–metamorphic aureole in Luna County, New Mexico, I mapped and collected samples of the Paleozoic strata near the quartz monzonite pluton along the northeast flank of North Peak. Stratigraphy in this area includes the Pennsylvanian undivided unit that is composed of thin-medium interbedded limestone, shale, and sandstone and the Hueco Formation that could be broken out into four members: a pebble–cobble conglomerate marks the base, a medium to massive bedded siliceous limestone is next, followed by a pure limestone member and topped by a breccia bed in places marking the fault …


Adsorption Of Antimony By Birnessite And The Impact Of Antimony On The Electrostatic Surface Properties Of Variable-Charge Soil Minerals, Kalyn Alaine Vergeer May 2013

Adsorption Of Antimony By Birnessite And The Impact Of Antimony On The Electrostatic Surface Properties Of Variable-Charge Soil Minerals, Kalyn Alaine Vergeer

Masters Theses

Antimony (Sb) is a toxin that can be found in high concentrations in the soil due to anthropogenic sources. Antimony exists in soil as Sb(V) in the monovalent antimonate hydroxyanion. The adsorption mechanisms of Sb(V) are not well-characterized. The objective of this study was to further elucidate Sb(V) adsorption mechanisms by examining the impact of adsorption on surface charging characteristics of gibbsite, goethite, birnessite, and kaolinite. Also examined was Sb(V), SO4 [sulfate], and PO4 [phosphate] adsorption by birnessite. Electrophoretic mobility and potentiometric titrations were employed to examine the ζ-potential [zeta-potential] and net proton surface charge density as a …


Magnesium Isotopic Compositions Of The Moon And Achondrites: Implications For Their Origin And Evolution, Fatemeh Sedaghatpour May 2013

Magnesium Isotopic Compositions Of The Moon And Achondrites: Implications For Their Origin And Evolution, Fatemeh Sedaghatpour

Graduate Theses and Dissertations

The main objectives of this thesis are to estimate Mg isotopic compositions of the Moon and achondrites, to understand the behavior of Mg isotopes during magmatic differentiation processes in different planetary bodies, and to evaluate the extent of Mg isotopic heterogeneity in the solar system. In order to achieve these goals, Mg isotopes have been measured for 47 well-characterized lunar samples and 22 differentiated meteorites by MC-ICPMS. The limited Mg isotopic variations among mare and highland regolith, mare breccias, and highland impact-melt rocks reflect negligible Mg isotope fractionation during lunar surface processes (e.g. solar wind, cosmic rays, micrometeorite bombardments, meteorite …


Dissolution Rates Of Amorphous Al- And Fe-Phosphates And Their Relevance To Phosphate Mobility On Mars, Valerie Tu May 2013

Dissolution Rates Of Amorphous Al- And Fe-Phosphates And Their Relevance To Phosphate Mobility On Mars, Valerie Tu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Phosphate is an essential element for life on Earth, and therefore if life exists or ever existed on Mars it may have required phosphate. Amorphous Al- and Fe-phosphates rapidly precipitate from acidic solutions and amorphous Al-phosphates likely control phosphate concentrations in some natural waters on Earth. Amorphous phases may be even more important on Mars than on Earth, and amorphous phosphates are therefore likely important in the phosphate cycle on Mars. Despite this importance, however, few dissolution rates exist for amorphous Al- and Fe- phosphates. In this study, dissolution rates of amorphous Al- and Fe-phosphates were measured in flow-through reactors …


Arsenic Mobilization And Iron Transformations During Sulfidization Of As(V)-Bearing Jarosite, Scott Johnston, Edward Burton, Annabelle Keene, Britta Planer-Friedrich, Andreas Voegelin, Mark Blackford, Greg Lumpkin Apr 2013

Arsenic Mobilization And Iron Transformations During Sulfidization Of As(V)-Bearing Jarosite, Scott Johnston, Edward Burton, Annabelle Keene, Britta Planer-Friedrich, Andreas Voegelin, Mark Blackford, Greg Lumpkin

Associate Professor Edward D Burton

Jarosite (KFe3(SO4) 2(OH)6) is an important host-phase for As in acid mine drainage (AMD) environments and coastal acid sulfate soils (CASS). In AMD and CASS wetlands, jarosite may encounter S(−II) produced by sulfate reducing bacteria. Here, we examine abiotic sulfidization of As(V)-bearing K-jarosite at pH 4.0, 5.0, 6.5 and 8.0. We quantify the mobilization and speciation of As and identify corresponding Fe mineral transformations. Sulfide-promoted dissolution of jarosite caused release of co-precipitated As and the majority of mobilized As was re-partitioned to a readily exchangeable surface complex (AsEx). In general, maximum As mobilization occurred in the highly sulfidized end-members of …


Mapping And Zircon Geochronology Of The Lyon Inlet Boundary Zone, Nunavut; A Crustal Scale Break In The Churchill Province, Nikolas B. Ganderton Apr 2013

Mapping And Zircon Geochronology Of The Lyon Inlet Boundary Zone, Nunavut; A Crustal Scale Break In The Churchill Province, Nikolas B. Ganderton

Electronic Thesis and Dissertation Repository

An important aspect of geology is the understanding of processes that created and modified continents and their resources. Knowledge of the age of formation and metamorphism of crystalline crust is thus important, and has been pursued in a recently discovered crustal-scale boundary on the southern Melville Peninsula (Nunavut, Canada) through field mapping, U-Pb zircon geochronology and electron beam analysis. This >250km-long crustal feature is termed here the Lyon Inlet Boundary Zone (LIBZ). Three samples from a 15 by 20 km map area reveal a complex Archean history with the dominant granitoid unit crystallizing at 2770±38 Ma and metamorphosed at 2670±36 …


Paleoecology Of Nebraska’S Ungulates During The Eocene-Oligocene Climate Transition, Grant S. Boardman Apr 2013

Paleoecology Of Nebraska’S Ungulates During The Eocene-Oligocene Climate Transition, Grant S. Boardman

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The White River Group (WRG) preserves the Eocene-Oligocene climate transition (EOCT), an interval of global cooling and drying during the onset of Antarctic glaciation. In the Great Plains, a shift from forested conditions to drier woodland-savanna biomes is hypothesized to have occurred at this time. I test this hypothesis through the analyses of several paleoenvironmental proxies on the teeth of 12 WRG ungulate species: stable carbon and oxygen isotopes from tooth enamel, and mesowear and microwear texture. The EOCT shift toward more open habitats and lower vegetation density under drying climates should have resulted in an increase in mean carbon …


Adsorption Of Hexavalent Chromium On Hydrous Manganese Oxide, Andrew K. Macleod Apr 2013

Adsorption Of Hexavalent Chromium On Hydrous Manganese Oxide, Andrew K. Macleod

Masters Theses

Hexavalent chromium is a very common contaminant most often associated with industrial processes, it is quite mobile in the subsurface and a better understanding of its mobility and interactions with soil constituents will help ongoing remediation efforts.

Hydrous manganese oxides (HMO) are a very common soil constituent and thus would be likely to interact with Cr(VI) in contaminated shallow subsurface environments. The goal of this study is to develop a working model that can improve predictions of Cr(VI) mobility in natural systems. A diffuse double layer surface complexation model (DLM) was developed by deriving reaction stoichiometries and stability constants for …


Application Of Boron Isotopes To Constrain The Depositional Environment Of The Precursors To Proterozoic Granulite-Facies Borosilicate Paragneisses, Larsemann Hills, Antarctica, Edward Grew Mar 2013

Application Of Boron Isotopes To Constrain The Depositional Environment Of The Precursors To Proterozoic Granulite-Facies Borosilicate Paragneisses, Larsemann Hills, Antarctica, Edward Grew

University of Maine Office of Research Administration: Grant Reports

Intellectual Merit. Major challenges in understanding high P-T granulite facies terranes are identifying the original protolith rocks and the tectonic environment in which they were originally deposited. This project focuses on granulitic gneisses exposed in the Larsemann Hills, Prydz Bay (East Antarctica). These rocks are considered to be metasediments (paragneisses), but, despite more than 20 years of intense study, the tectonic framework of deposition of the original rocks is still debated. However the origin of these rocks has important implications for determining the assembly of the ancient Gondwana continent. The unique B-rich character of the rocks offers potential insight into …


Determination Of The Cec In Srs Soils And The Capability Of Epa Model 9081 For Cec Of Acidic Soils, Alexandra M. Simpson Mar 2013

Determination Of The Cec In Srs Soils And The Capability Of Epa Model 9081 For Cec Of Acidic Soils, Alexandra M. Simpson

Georgia State Undergraduate Research Conference

No abstract provided.


Petrogenetic Characteristics Of Oyaca – Kedi̇kayasi – Boyalik Adakites In Sw Ankara (Central Anatolia, Turkey): Evidence For Slab Melt Metasomatism, Pınar Şen, Erdal Şen Mar 2013

Petrogenetic Characteristics Of Oyaca – Kedi̇kayasi – Boyalik Adakites In Sw Ankara (Central Anatolia, Turkey): Evidence For Slab Melt Metasomatism, Pınar Şen, Erdal Şen

Bulletin of the Mineral Research and Exploration

The Early Miocene Oyaca, Kedikayası and Boyalık dacites, situated approximately 50-60 km southwest of Ankara have affinities similar to adakitic rocks. They have porphyritic texture with a variable amount of plagioclase feldspar, hornblende and lesser biotite phenocrysts and a groundmass of plagioclase and quartz microcrysts. They have high Sr/Y (55-79 ppm) and (La/Yb)n (21-32 ppm) ratios, and low Y (10-19 ppm) and heavy rare earth element contents. According to their SiO2 (62.3-69.70 % wt.) and MgO (0.62-2.23 % wt) contents, they are referred to as high silica adakites, indicating the effects of slab-derived melts in their genesis. The adakites in …


Hydrogeochemical And Isotopic Investigation Of Nasrettin Hoca Springs, Eski̇şehi̇r, Turkey, Mehmet Çeli̇k, Uğur Erdem Dokuz, Pakize Elif Türköz, Özlem Güllü, Şebnem Arslan Mar 2013

Hydrogeochemical And Isotopic Investigation Of Nasrettin Hoca Springs, Eski̇şehi̇r, Turkey, Mehmet Çeli̇k, Uğur Erdem Dokuz, Pakize Elif Türköz, Özlem Güllü, Şebnem Arslan

Bulletin of the Mineral Research and Exploration

No abstract provided.


Holocene Paleo-Environmental Variability Reconstructed From A Lake Sediment Record From Southeast Greenland, Gregory A. De Wet Jan 2013

Holocene Paleo-Environmental Variability Reconstructed From A Lake Sediment Record From Southeast Greenland, Gregory A. De Wet

Masters Theses 1911 - February 2014

Arctic climate variability over the Holocene has been both extensive and, at times, abrupt. Current understanding of these changes is still quite limited with few high-resolution paleoclimate records available for this period. In order to place observed and predicted 21st century climate change in perspective, reliable and highly resolved paleo-reconstructions of Arctic climate are essential. Using an 8.5 m sediment core from Nanerersarpik Lake, this project will characterize climate changes during the Holocene, including the deglacial transition, the rapid changes that are known to have occurred around 8,200 years ago, the transition from Holocene thermal maximum (HTM) to the …


7700 Years Of Holocene Climatic Variability In Sermilik Valley, Southeast Greenland Inferred From Lake Sediments, Samuel H. Davin Jan 2013

7700 Years Of Holocene Climatic Variability In Sermilik Valley, Southeast Greenland Inferred From Lake Sediments, Samuel H. Davin

Masters Theses 1911 - February 2014

During the latter half of the 20th century until present day there has been an unprecedented rise in global annual mean temperatures accompanied by rising sea levels and a decrease in Northern Hemisphere snow cover, which if it continues will lead to widespread disruption of climate patterns, ecosystems, and present-day landscapes. It is therefore of critical importance to establish an expanded network of paleoclimate records across the globe in order to better assesses how the global climate system has changed in the past, that we may create a metric by which to address modern change. Herein is presented a7,700 …


Distribution And Impacts Of Petroleum Hydrocarbons In Louisiana Tidal Marsh Sediments Following The Deepwater Horizon Oil Spill, Rachel S. Hatch Jan 2013

Distribution And Impacts Of Petroleum Hydrocarbons In Louisiana Tidal Marsh Sediments Following The Deepwater Horizon Oil Spill, Rachel S. Hatch

Theses and Dissertations--Earth and Environmental Sciences

Following the 2010 Deepwater Horizon (DWH) spill, sediment cores were analyzed from marshes at various levels of oiling to determine how deeply oil penetrated sediment in these marsh environments, and if at these sites it had quantifiably affected benthic ecosystems. Minimum mixing depths were determined from penetration of the lithogenic radionuclide 234Th, which ranged from 0.25 to 4.5 cm. Sediment accumulation rates were determined using 210Pb, with verification from 137Cs in selected cores. Lead-210 profiles revealed long-term (decadal) mixing. Bay Jimmy, Louisiana was significantly affected by the DWH oil spill, as indicated by total polycyclic aromatic hydrocarbon …


Epistemology And Synthesis: Instrumental Neutron Activation Analysis And The Caddo Tradition, Robert Z. Selden Jr. Jan 2013

Epistemology And Synthesis: Instrumental Neutron Activation Analysis And The Caddo Tradition, Robert Z. Selden Jr.

CRHR: Archaeology

The statistical groupings illustrated herein represent the current iteration of Caddo INAA compositional groups based upon the chemical composition of archaeologically-recovered ceramics. For some time, a number of Caddo archaeologists have thought these results to be lacking. This poster symbolizes the first step toward a new interpretation of chemical composition groups, and the initial instancce within which GIS has been employed as an analytical tool.


Consilience: Radiocarbon, Instrumental Neutron Activation Analysis, And Litigation In The Ancestral Caddo Region, Robert Z. Selden Jr. Jan 2013

Consilience: Radiocarbon, Instrumental Neutron Activation Analysis, And Litigation In The Ancestral Caddo Region, Robert Z. Selden Jr.

CRHR: Archaeology

Through the creation and analysis of databases for radiocarbon, instrumental neutron activation analysis (INAA), and law, macro-level trends are exposed that form the framework of a broader research program aimed at advancing ideas of craft specialization and archaeological theory in the ancestral Caddo region of Southwest Arkansas, Northwest Louisiana, Northeast Texas, and Southeast Oklahoma. The findings of this investigation illustrate the research potential that remains buried within the context of cultural resource management (CRM) reports and legal databases (Westlaw and LexisNexis) that is awaiting consumption within regional research designs aimed at exploring the nuances and trends that appear through synthetic …


Chemostratigraphy Of The Early Pliocene Diatomite Interval From Mis And-1b Core (Antarctica): Paleoenvironment Implications, Giovanna Scopelliti, Adriana Bellanca, Donata Monien, Gerhard Kuhn Jan 2013

Chemostratigraphy Of The Early Pliocene Diatomite Interval From Mis And-1b Core (Antarctica): Paleoenvironment Implications, Giovanna Scopelliti, Adriana Bellanca, Donata Monien, Gerhard Kuhn

ANDRILL Research and Publications

The AND-1B drill core (1285 m-long) was recovered, inside the ANDRILL (ANtarctic geological DRILLing) Program, during the austral summer of 2006/07 from beneath the floating McMurdo Ice Shelf. Drilling recovered a stratigraphic succession of alternating diamictites, diatomites and volcaniclastic sediments spanning about the last 14 Ma. A core portion between 350 and 480 mbsf, including a 80 m-thick diatomite interval recording the early Pliocene warming event, was investigated in term of opal biogenic content and element geochemistry. Across the diatomite interval, in spite of the lithological uniformity, a fluctuating biogenic opal profile mirrors the δ18O record, testifying a decrease in …


Five Year Carbon Storage Analysis In The Gordon Natural Area, Joy Fritschle, Chad Hudson, Catherine Spahr, Andy Tamez Jan 2013

Five Year Carbon Storage Analysis In The Gordon Natural Area, Joy Fritschle, Chad Hudson, Catherine Spahr, Andy Tamez

Forest Carbon Storage Study Documents

The Gordon Natural Area (GNA) serves as a natural laboratory for a range of class research projects. In a Geography Field Methods course led by Dr. Fritschle, students established five permanent carbon-study plots in 2008. Since then, students have returned to these plots to measure the carbon stock of standing trees in five plots located along a topographic gradient: floodplain, ridge-top, lower mid-slope, mid-slope and upper mid-slope. Using U.S. Forest Service established guidelines, all trees greater than 5 cm and up to 73 cm in diameter at breast height (DBH) were measured and identified within each 40 m circular plot. …


Geo402/585: Field Methods; Labs 4-5 Gordon Natural Area Carbon Stock Pilot Study, Joy Fritschle Jan 2013

Geo402/585: Field Methods; Labs 4-5 Gordon Natural Area Carbon Stock Pilot Study, Joy Fritschle

Gordon Natural Area-related Curricula Documents

No abstract provided.


In-Situ, Integrated U-Pb, Hf And O Isotopic Study Of Igneous, Metamorphic And Detrital Zircons. Implications To Crustal Evolution And Geodynamics, Munazzam Ali Mahar Jan 2013

In-Situ, Integrated U-Pb, Hf And O Isotopic Study Of Igneous, Metamorphic And Detrital Zircons. Implications To Crustal Evolution And Geodynamics, Munazzam Ali Mahar

Open Access Theses & Dissertations

Zircon data from South Karakoram gneiss dome provide evidence for Proterozoic inherited cores (1.8-1.9 Ga and 2.3-.2.5 Ga) surrounded by migmatitic overgrowth with ages ranging from ~6 to ~20Ma. Oxygen isotopic data of Neogene migmatite and inherited core is similar and indistinguishable ranging from 7.5 to 9.5 /. However, Neogene overgrowth is significantly less evolved than the inherited core in terms of Hf composition. This implies that the Hf composition of the migmatitic zircons is not controlled exclusively by the dissolution of the inherited cores and that contamination by external melts is likely. Isotopic data from the Baltoro plutonic unit …


Natural And Anthropogenic Factors Which Influence Aerosol Distribution In Ingleborough Show Cave, Uk, Andrew C. Smith B.S.C, Peter M. Wynn, Philip A. Barker Professor Jan 2013

Natural And Anthropogenic Factors Which Influence Aerosol Distribution In Ingleborough Show Cave, Uk, Andrew C. Smith B.S.C, Peter M. Wynn, Philip A. Barker Professor

International Journal of Speleology

Monitoring in Ingleborough Show Cave (N. Yorkshire, UK) reveals the influence of tourism and cave management techniques on different parameters of the cave atmosphere. Exploratory aerosol monitoring identified a 0.015 ± 0.03 mg/m³ (≈70%) reduction in airborne particulates within the first 75 meters of cave passage and two major aerosol sources within this artificially ventilated show cave. Autogenic aerosol production was identified close to active stream ways (increases of