Research Articles, Department of Geosciences
Browse by
Recent Submissions
-
Evaluating Geologic Sources of Arsenic in Well Water in Virginia (USA)
(MDPI, 2018-04-18)We investigated if geologic factors are linked to elevated arsenic (As) concentrations above 5 μg/L in well water in the state of Virginia, USA. Using geologic unit data mapped within GIS and two datasets of measured ... -
A new rauisuchid (Archosauria, Pseudosuchia) from the Upper Triassic (Norian) of New Mexico increases the diversity and temporal range of the clade
(PeerJ, 2016-09-06)Rauisuchids are large (2–6 m in length), carnivorous, and quadrupedal pseudosuchian archosaurs closely related to crocodylomorphs. Though geographically widespread, fossils of this clade are relatively rare in Late Triassic ... -
The Tissint Martian meteorite as evidence for the largest impact excavation
(Nature, 2013-01-29)High-pressure minerals in meteorites provide clues for the impact processes that excavated, launched and delivered these samples to Earth. Most Martian meteorites are suggested to have been excavated from 3 to 7 km diameter ... -
A unifying model for Neoproterozoic–Palaeozoic exceptional fossil preservation through pyritization and carbonaceous compression
(Nature, 2014-12-17)Soft-tissue fossils capture exquisite biological detail and provide our clearest views onto the rise of animals across the Ediacaran–Cambrian transition. The processes contributing to fossilization of soft tissues, however, ... -
Effect of water activity on rates of serpentinization of olivine
(Nature, 2017-07-14)The hydrothermal alteration of mantle rocks (referred to as serpentinization) occurs in submarine environments extending from mid-ocean ridges to subduction zones. Serpentinization affects the physical and chemical properties ... -
A Short-Snouted, Middle Triassic Phytosaur and its Implications for the Morphological Evolution and Biogeography of Phytosauria
(Nature, 2017-04-10)Following the end-Permian extinction, terrestrial vertebrate diversity recovered by the Middle Triassic, and that diversity was now dominated by reptiles. However, those reptilian clades, including archosaurs and their ... -
Record of massive upwellings from the Pacific large low shear velocity province
(Nature, 2016-11-08)Large igneous provinces, as the surface expression of deep mantle processes, play a key role in the evolution of the planet. Here we analyse the geochemical record and timing of the Pacific Ocean Large Igneous Provinces ... -
Chemical, experimental, and morphological evidence for diagenetically altered melanin in exceptionally preserved fossils
(NAS, 2015-10-13)In living organisms, color patterns, behavior, and ecology are closely linked. Thus, detection of fossil pigments may permit inferences about important aspects of ancient animal ecology and evolution. Melanin-bearing ... -
Cell adhesion of Shewanella oneidensis to iron oxide minerals: Effect of different single crystal faces
(American Institute of Physics, 2005-12-30)The results of experiments designed to test the hypothesis that near-surface molecular structure of iron oxide minerals influences adhesion of dissimilatory iron reducing bacteria are presented. These experiments involved ... -
Nanotechnology: Nature's Gift or Scientists' Brainchild?
(The Royal Society of Chemistry, 2014-12-02)In the field of environmental nanotechnology, opinions on the novelty of engineered nanomaterials vary; some scientists believe that many engineered nanomaterials are indeed unique, while others are convinced that we are ... -
Texture and structural refinement using neutron diffraction data from molybdite (MoO3) and calcite (CaCO3) powders and a Ni-rich Ni50.7Ti49.30 alloy
(Cambridge University Press, 2009-12)Preferred orientation or texture is a common feature of experimental powder patterns. The mathematics of two commonly used models for preferred orientation-the March-Dollase and the generalized spherical-harmonic models-is ... -
Structural refinement of neutron powder diffraction data of two-stage martensitic phase transformations in Ti50.75Ni47.75Fe1.50 shape memory alloy
(Cambridge University Press, 2007-09)Transformation behaviors of the technologically important polycrystalline Ti50.75Ni47.75Fe1.50 shape memory alloy were investigated using differential scanning calorimeter (DSC) and powder diffraction techniques. DSC ... -
In situ structural and texture analyses of monoclinic phase for polycrystalline Ni-rich T49.86Ni50.14 alloy from neutron diffraction data
(Cambridge University Press, 2008-03)Phase transformation temperatures of a polycrystalline Ni-rich Ti49.86Ni50.14 shape memory alloy were investigated using a differential scanning calorimeter. In situ structural and texture analyses of the monoclinic ... -
Stability of zircon u-pb systematics in a greenschist-grade mylonite - an example from the rockfish valley fault zone, central Virginia, USA
(University of Chicago Press, 1992-09)The mid-Paleozoic, greenschist-grade Rockfish Valley Fault Zone (RVFZ) of central Virginia cuts the Grenville-aged Pedlar River Charnockite Suite (PRCS) and contains zircons that underwent brittle failure during ductile ... -
New Ediacara fossils preserved in marine limestone and their ecological implications
(Nature Publishing Group, 2014-02)Ediacara fossils are central to our understanding of animal evolution on the eve of the Cambrian explosion, because some of them likely represent stem-group marine animals. However, some of the iconic Ediacara fossils have ... -
Climate model boundary conditions for four Cretaceous time slices
(Copernicus Publications, 2007)General circulation models (GCMs) are useful tools for investigating the characteristics and dynamics of past climates. Understanding of past climates contributes significantly to our overall understanding of Earth's climate ... -
Cell adhesion of Shewanella oneidensis to iron oxide minerals: Effect of different single crystal faces
(American Institute of Physics, 2005-12)The results of experiments designed to test the hypothesis that near-surface molecular structure of iron oxide minerals influences adhesion of dissimilatory iron reducing bacteria are presented. These experiments involved ... -
Pressure impact on the structure, elasticity, and electron density distribution of CaSi2O5
(American Physical Society, 2013-05)Ab initio molecular dynamics simulations were used to reveal the mechanism of the fivefold to sixfold transition in Si coordination numbers of CaSi2O5. The longest first-neighbor Si-O distance drops from 2.8 to 1.8 angstrom ... -
Structural state of relaxor ferroelectrics PbSc0.5Ta0.5O3 and PbSc0.5Nb0.5O3 at high pressures up to 30 GPa
(American Physical Society, 2011-11-07)The pressure-induced structural changes in perovskite-type (ABO(3)) Pb-based relaxor ferroelectrics are studied on the basis of in situ single-crystal synchrotron x-ray diffraction and Raman scattering experiments on ... -
Pressure-induced structural transformations in pure and Ru-doped 0.9PbZn(1/3)Nb(2/3)O(3)-0.1PbTiO(3) near the morphotropic phase boundary
(American Physical Society, 2012-01-17)Pressure-induced structural transformations in relaxor-based perovskite-type (ABO(3)) 0.9PbZn(1/3)Nb(2/3)O(3)-0.1PbTiO(3) single crystals which have a very high piezoelectric response were studied by single-crystal x-ray ...
RSS 1.0