Papers by Antoni Milodowski
Lake Ohrid (Macedonia/Albania) is an ancient lake with a unique biodiversity and a site of global... more Lake Ohrid (Macedonia/Albania) is an ancient lake with a unique biodiversity and a site of global significance for investigating the influence of climate, geological and tectonic events on the generation of endemic populations. Here, we present oxygen (δ 18 O) and carbon (δ 13 C) isotope data on carbonate from the upper ca. 248 m of sediment cores
Proceedings, Oct 13, 2015
We present findings from a series of transport and consolidation tests conducted on well-preserve... more We present findings from a series of transport and consolidation tests conducted on well-preserved samples taken from within the Mercia Mudstone Group. Observations include baseline geotechnical properties and hydraulic conductivities. In addition, sample response to changing effective stress conditions is given in terms of changes in void ratio and hydraulic permeability. Whilst initial hydraulic conductivities and the form of sample response to loading display a degree of variability, estimated values for yield appear relatively consistent (~30-35MPa). Test results will be combined with additional experimental data to define the critical state failure envelope for, delineating material response in p-q space. Future testing and expansion of the data-set will focus on examining the lithological controls on variation in sample response.
This review considers the geological and geomorphological context of tufa barrages that occupy bu... more This review considers the geological and geomorphological context of tufa barrages that occupy buried valley settings in the Wye catchment, Derbyshire. It describes the potential relationship of the tufa with locations of hypothesised river captures and inception horizon-guided groundwater flow paths. Tufa barrage development is associated with steps in the bedrock, which may be related to knick-point recession during river capture. Broad estimates of valley incision have been calculated from previously dated deposits. These support current interpretations of particularly significant effective base-level lowering during the Anglian and Devensian stages of the Quaternary and have the potential to add to the knowledge of regional uplift histories.
Proceedings, Jun 5, 1996
The Fulmar Formation is a major reservoir in the UK Central Graben HPHT province. Often, reservoi... more The Fulmar Formation is a major reservoir in the UK Central Graben HPHT province. Often, reservoirs are buried to depths of more than 5 km. The general environment of deposition is shallow marine shelfal, and bioturbation is the dominant preserve d sedimentary structure.
Thermochimica Acta, Dec 1, 1981
ABSTRACT Ankerites and ferroan dolomites [Ca(Mg,Fe)(CO3)2] dissociate in three stages to give cha... more ABSTRACT Ankerites and ferroan dolomites [Ca(Mg,Fe)(CO3)2] dissociate in three stages to give characteristic three-endothermic-peaked DTA curves which correspond to three weight loss steps on TG curves. Pure dolomite decomposes in only two steps. The definition of these phenomena is greatly enhanced by determination in flowing CO2. During this investigation a series of well-characterized minerals covering the dolomite-ferroan dolomite-ankerite series was studied using TG-DTG, DTA-EGA, TM and continuous heating X-ray powder photography (“continuous XRD”), backed up by X-ray diffractometry of products cooled from intermediate temperatures (“static” XRD). Limited Mössbauer spectroscopic determinations (reported in detail elsewhere) were also made on intermediate products.The first stage of the thermal decomposition of dolomite results in the formation of Mg-calcite ((CaMg)CO3) and periclase (MgO), with the liberation of CO2. In the cases of ankerite and ferroan dolomite, the initial reaction is similar except that a ferroan periclase or magnesian wustite ((Mg,Fe)O) is produced respectively. However, this phase is rapidly oxidized by CO2 to magnesioferrite (MgFe2O4). A ferrous spinel (Fe3O4 - MgFe2O4 solid solution) may also be formed as an unstable transient intermediate compound during this oxidation, depending on experimental conditions. As a result, CO is liberated by reduction of CO2. The second decomposition step arises out of a solid-state reaction between calcite and magnesioferrite to produce dicalcium ferrite (2CaO · Fe2O3) and periclase with the evolution of CO2. The remaining unreacted calcium carbonate dissociates to CaO and CO2 in the third decomposition step.
Chemical Geology, Aug 1, 2022
Journal of Geochemical Exploration, Nov 1, 1992
The highly alkahne spnngs of the Maqann area of northern Jordan are currently under examination a... more The highly alkahne spnngs of the Maqann area of northern Jordan are currently under examination as part of an mternauonal project testing the models used to analyse the safety of repositories for low and intermediate level radioactive waste (L/ILW) The Maqann area contains a rock-groundwater system which is an 1deal natural analogue of a concrete-filled L/ILW repository emplaced m a sedimentary host rock The high pH (12 5) groundwaters at this site are the product of interaction with naturally oecumng cement minerals and not of the alteration of ultramafic minerals Stable isotope data for the hyperalkalme groundwaters he below both the local meteoric water hne and the eastern Mediterranean water hne At least part of the shift appears to be the result of groundwater interaction vath the cement minerals This paper introduces the site of the natural analogue study and, m presenting novel data on the chemtstry and stable ~sotoplc slguature of the groundwater, prowdes background reformation which is used m a compamon paper (Alexander et at, 1992) on testing the predictive capabilities of geochemical thermodynamic codes (and their assocmted databases) which will be utlhsed as part of the safety assessment ofa L/ILW repository
Applied Geochemistry, Mar 1, 2023
Clay Minerals, Dec 1, 2001
AB ST R ACT : Studies of the subsurface microbiology of the Ä spö Hard Rock Laboratory, Sweden ha... more AB ST R ACT : Studies of the subsurface microbiology of the Ä spö Hard Rock Laboratory, Sweden have revealed the presence of many different bacteria in the deep groundwaters which appear to maintain reducing conditions. Experiments were conducted to study the rock-water and microbial interactions. These used crushed Ä spö diorite, Ä spö groundwater and iron-and sulphate-reducing bacteria in flowing systems under anaerobic conditions. In column experiments, there was evidence of loss and mobilization of fine-grained crushed material (<5 mm) which had originally adhered to grain surfaces in the starting material. The mobilized fines were trapped between grains. The degree of mineralogical alteration was greater in the experiments when bacteria were present. In both column and continuously stirred reactor experiments, there is evidence for the formation of a secondary clay. These experiments have shown that microbial activity can influence rock-water interactions even in nutrient-poor conditions.
Geochimica et Cosmochimica Acta, Aug 1, 2007
This study aimed to develop a methodology for assessing the evolution of the long-term groundwate... more This study aimed to develop a methodology for assessing the evolution of the long-term groundwater system, using fracture-filling calcite. Fracture-filling calcite mineralization in deep (to ca. 1000 m) granitic rocks in Mizunami area, Japan, was studied. Four generations (I to IV) of calcite precipitation can be differentiated based on their paragenetic relationships, morphological and isotopic characteristics. Carbon and oxygen isotopic ratios suggest that the Calcite I is of hydrothermal origin. On the other hand, Calcite II, IV and III were precipitated from freshwater and marine water, respectively. The Mizunami Group strata (Tertiary), which overly the basement Toki granite (Cretaceous), were initially deposited in a lacustrine environment but later became marine. Lacustrine conditions were re-established during the deposition of the upper Seto Group (Quaternary). It is suggested that both of deposition of the marine upper part of the Mizunami Group and the precipitation of Calcite III were possibly related to the same transgression event. This was followed by the precipitation of Calcite IV during subsequent fresh water flushing of the earlier marine groundwater. In summary, integrated morphological, mineralogical, microchemical and isotopic analysis of multilayered calcite fracture mineralization provides valuable information to evaluate the long-term evolution of groundwater system.
Mineralogical Magazine
The diffusive exchange of dissolved material between fluid flowing in a fracture and the enclosin... more The diffusive exchange of dissolved material between fluid flowing in a fracture and the enclosing wallrocks (rock matrix diffusion) has been proposed as a mechanism by which radionuclides derived from a radioactive waste repository may be removed from groundwater and incorporated into the geosphere. To test the effectiveness of diffusive exchange in igneous and metamorphic rocks, we have carried out an investigation of veins formed at low temperatures (<100°C), comparing the oxygen isotopic composition of vein calcite with that of secondary calcite in the wallrocks. Two examples of veins from the Borrowdale Volcanic Group, Cumbria, and one from the Mountsorrel Granodiorite, Leicestershire, UK, have remarkably similar vein calcite compositions, ca. +20‰(SMOW) or greater, substantially heavier than the probable compositions of the host rocks, and these vein calcite compositions are inferred to reflect the infiltrating fluid and the temperature of vein formation. Calcites from the ...
Materials and Corrosion, 2020
The materials corrosion test (MaCoTe) is a long‐term, multinational in situ corrosion experiment ... more The materials corrosion test (MaCoTe) is a long‐term, multinational in situ corrosion experiment setup at the Grimsel Test Site, Switzerland. The experiment has been operating since 2014 with a focus on the corrosion behaviour of container materials for the disposal of high‐level waste and spent nuclear fuel under conditions representing a granitic deep geological repository. The experiment consists of eight modules containing metal coupons and bentonite. Two of the modules, each with a different bentonite density, have been retrieved after 394 days of exposure and have been analysed using a range of techniques aimed at studying the corrosion behaviour of the metals and the mineralogical evolution of the bentonite. Weight loss measurements show that carbon steel had a relatively low average corrosion rate (~2 µm year−1). Much lower average corrosion rates were measured for the various types of copper (0.13–0.32 µm year−1). No detectable corrosion was measured on stainless steel coup...
Materials and Corrosion, 2020
Since 2012, a long-term in situ corrosion experiment (IC-A) is being conducted in the Mont Terri ... more Since 2012, a long-term in situ corrosion experiment (IC-A) is being conducted in the Mont Terri Underground Research Laboratory in Switzerland to investigate the corrosion behaviour of candidate canister materials in conditions representative of the Swiss concept for the disposal of high-level waste and spent nuclear fuel. To date, carbon steel and various types of copper coatings have been retrieved after different exposure periods of up to three years, and characterized to establish the composition of the corrosion product, the morphology of the corroded surface, the nature of the interaction between the metal and the surrounding bentonite, and the microbial populations in the bentonite and surrounding porewater. For carbon steel specimens, a complex corrosion product was identified, consisting predominantly of magnetite. Much less alteration on either the metal or the bentonite was observed in the case of copper samples. Low average anaerobic corrosion rates were measured for carbon steel and a very modest amount of alteration was identified on copper. The density and the initial form of the 2 bentonite had a small influence on the rate of corrosion, across all materials. This paper summarises the results of the experimental programme obtained to date and discusses the relationship observed between exposure time and the evolution of the metal-bentonite interface for both carbon steel and copper.
Construction and Building Materials, 2018
Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 2018
ABSTRACTGeochemical and related studies have been made of near-surface sediments from the River C... more ABSTRACTGeochemical and related studies have been made of near-surface sediments from the River Clyde estuary and adjoining areas, extending from Glasgow to the N, and W as far as the Holy Loch on the W coast of Scotland, UK. Multibeam echosounder, sidescan sonar and shallow seismic data, taken with core information, indicate that a shallow layer of modern sediment, often less than a metre thick, rests on earlier glacial and post-glacial sediments. The offshore Quaternary history can be aligned with onshore sequences, with the recognition of buried drumlins, settlement of muds from quieter water, probably behind an ice dam, and later tidal delta deposits. The geochemistry of contaminants within the cores also indicates shallow contaminated sediments, often resting on pristine pre-industrial deposits at depths less than 1m. The distribution of different contaminants with depth in the sediment, such as Pb (and Pb isotopes), organics and radionuclides, allow chronologies of contaminati...
Quarterly Journal of Engineering Geology and Hydrogeology, 2018
Large-scale compressed air ene using solution-mined caverns in salt lithologies. For optimum gas ... more Large-scale compressed air ene using solution-mined caverns in salt lithologies. For optimum gas storage efficiency, cavern geometry should ideally be smooth: spherical to cylindrical with a circular cross-section. However, such caverns are often irregular with marked asymmetry or ellipticity, and whilst the reasons for non-circular crosssections developing during solution-mining in some caverns can be related to e.g. the presence of interbedded lithologies, in other instances they are not fully understood. Cavities from dissolution experiments using five main end-member salt facies fabrics from the Triassic Preesall and Northwich Halite formations have been assessed to determine factors affecting cavity geometry, formation and variability in dissolution behaviour. Identical sets of experiments were performed on each fabric type, using two solution concentration strengths: brine and synthetic seawater. Comparison of experimental results using a combination of analytical and imaging techniques show the extent to which the salt fabric and enhancement of features within the salt influences the resulting dissolution cavity. Observations show a visible increase in micropores within the adjacent halite matrix following dissolution. Smaller-scale features provide further insights into the dissolution processes, and salt fabric behaviour under different dissolution conditions.
MRS Advances, 2017
This study details the characterization of a glass sample exposed to hyperalkaline water and calc... more This study details the characterization of a glass sample exposed to hyperalkaline water and calcium-rich sediment for an extended time period (estimated as 2 - 70 years) at a lime (CaO) waste site in the UK. We introduce this site, known as Peak Dale, in reference to its use as a natural analogue for nuclear waste glass dissolution in the high pH environment of a cementitious engineered barrier of a geological disposal facility. In particular, a preliminary assessment of alteration layer chemistry and morphology is described and the initiation of a long-term durability assessment is outlined.
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Papers by Antoni Milodowski