Geology: Recent submissions
Now showing items 121-140 of 315
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Pesticide occurrence in Irish groundwater
(Trinity College (Dublin, Ireland). Department of Geology, 2012)Groundwater pesticide occurrence was investigated within agricultural catchments and at the national scale across Ireland. Seven intensive agricultural catchments were selected, each with different physical characteristics ... -
Evaluating UK natural hazards: the national risk assessment
(UK Parliament, 2019)Despite its relatively temperate climate and stable geography, natural hazards present multiple risks to human activity in the UK. These range from small-scale local occurrences, such as landslides, through regional ... -
Chlorite-white Mica Pairs' composition as a micro-chemical guide to fingerprint massive sulfide deposits of the Bathurst Mining Camp, Canada
(2019)The compositions of phyllosilicates, with a focus on fluid-mobile elements, were evaluated as a means to fingerprint the Middle Ordovician metamorphosed (greenschist facies) volcanogenic massive sulfide deposits of the ... -
Chemostratigraphy Across the Triassic–Jurassic Boundary
(John Wiley & Sons, Inc, 2019)The Triassic‐Jurassic transition (~201.5 Ma) is marked by one of the largest mass extinctions in Earth’s history. This was accompanied by significant perturbations in ocean and atmosphere geochemistry, ... -
A route for the direct crystallization of dolomite
(2015)The direct crystallization of dolomite from an aqueous solution at temperatures between 60–220 °C was followed in situ through time-resolved synchrotron-based energy-dispersive X-ray diffraction combined with offline ... -
The role of amorphous precursors in the crystallization of La and Nd carbonates
(2015)Crystalline La and Nd carbonates can be formed from poorly-ordered nanoparticulate precursors, termed amorphous lanthanum carbonate (ALC) and amorphous neodymium carbonate (ANC). When reacted in air or in aqueous solutions ... -
Citrate Effects on Amorphous Calcium Carbonate (ACC) Structure, Stability, and Crystallization
(2015)Understanding the role of citrate in the crystallization kinetics of amorphous calcium carbonate (ACC) is essential to explain the formation mechanisms, stabilities, surface properties, and morphologies of CaCO3 biominerals. ... -
Biomineralisation by earthworms - an investigation into the stability and distribution of amorphous calcium carbonate
(2015)BACKGROUND: Many biominerals form from amorphous calcium carbonate (ACC), but this phase is highly unstable when synthesised in its pure form inorganically. Several species of earthworm secrete calcium carbonate granules ... -
Neutron and X-ray diffraction and empirical potential structure refinement modelling of magnesium stabilised amorphous calcium carbonate
(2014)Amorphous calcium carbonate (ACC) plays a key role in biomineralisation processes in sea organisms. Neutron and X-ray diffraction have been performed for a sample of magnesium-stabilised ACC, which was prepared with a Mg:Ca ... -
The effect of aspartic acid and glycine on amorphous calcium carbonate (ACC) structure, stability and crystallization
(Elsevier, 2014)The effect of organic molecules on CaCO3 crystallization, in particular on the formation of the initial amorphous calcium carbonate (ACC) phase, is poorly understood despite this knowledge being crucial for designing ... -
The effect of heating on the morphology of crystalline neodymium hydroxycarbonate, NdCO3OH
(2014)The crystallization of hexagonal NdCO3OH through hydrothermal synthesis carried out at slow (reaching the desired temperature within 100 min) and quick (50 min) rates of heating but at variable temperatures (165–220ºC) are ... -
The role of REE3+ in the crystallization of lanthanites
(2014)The formation of crystalline rare earth element (REE) (e.g. La, Ce, Pr, Nd) carbonates from aqueous solutions was examined at ambient temperature using UV-Vis spectrophotometry, combined with X-ray diffraction, high-resolution ... -
Amorphous dysprosium carbonate: characterization, stability, and crystallization pathways
(2013)The crystallization of amorphous dysprosium carbonate (ADC) has been studied in air (21–750 °C) and in solution (21–250 °C). This poorly ordered precursor, Dy2(CO3)3·4H2O, was synthesized in solution at ambient temperature. ... -
Structural properties and transformations of precipitated FeS
(2012)Nanocrystalline iron sulfides form in diverse anoxic environments. The initial precipitate is commonly referred to as nanocrystalline mackinawite (FeS) or amorphous FeS. In order to better understand the structure of the ... -
Formation of calcium sulfate through the aggregation of sub-3 nanometre primary species
(2016)The formation pathways of gypsum remain uncertain. Here, using truly in situ and fast time-resolved small-angle X-ray scattering, we quantify the four-stage solution-based nucleation and growth of gypsum (CaSO4·2H2O), an ... -
Inhibition of Calcite Growth: Combined Effects of Mg2+ and SO42–
(2016)Magnesium and sulfate are each known to affect calcite growth and dissolution, but little is known about their combined effects on calcite growth rates. We grew calcite using the constant composition approach at ambient ... -
Is bicarbonate stable in and on the calcite surface?
(2016)We have used density functional theory with the COSMO-RS implicit solvent model to predict the pKa for the deprotonation of bicarbonate to carbonate, i.e. HCO3− <=> CO32− + H+, when HCO3− is included in, and adsorbed on, ... -
An experimental study of hydroxylbastnasite solubility in aqueous solutions at 25 °C
(2016)The mobility of rare earth elements (REEs) in natural aqueous solutions is of increasing interest due to their application in numerous high-tech and renewable energy technologies (e.g., wind turbines and electric vehicles), ... -
ACC and vaterite as metastable intermediates in the solution based crystallization of CaCO3
(Springer International Publishing, 2017)Amorphous calcium carbonate (ACC) and vaterite are not very common in abiotic systems, but they play a very significant role in biomineralization processes and are key in the global carbon cycle. Despite their importance, ... -
Physicochemical and Additive Controls on the Multistep Precipitation Pathway of Gypsum
(MDPI, 2017)Synchrotron-based small- and wide-angle X-ray scattering (SAXS/WAXS) was used to examine in situ the precipitation of gypsum (CaSO4·2H2O) from solution. We determined the role of (I) supersaturation, (II) temperature and ...
