A5047073542- Clay minerals and soil interactions
- Geological and Geochemical Analysis
- Geology and Paleoclimatology Research
- Paleontology and Stratigraphy of Fossils
- Geological formations and processes
- Hydrocarbon exploration and reservoir analysis
- Geochemistry and Elemental Analysis
- Soil and Unsaturated Flow
- Iron oxide chemistry and applications
- Geochemistry and Geologic Mapping
- earthquake and tectonic studies
- Therapeutic Uses of Natural Elements
- Geological and Geophysical Studies Worldwide
- Methane Hydrates and Related Phenomena
- Geological Studies and Exploration
- Radioactive element chemistry and processing
- Evolution and Paleontology Studies
- Hydraulic Fracturing and Reservoir Analysis
- Mineralogy and Gemology Studies
- Geophysical and Geoelectrical Methods
- Paleontology and Evolutionary Biology
- Marine and environmental studies
- CO2 Sequestration and Geologic Interactions
- NMR spectroscopy and applications
- Building materials and conservation
Natural History Museum
2015-2025
East Sussex County Council
2016-2023
University of Greenwich
1999-2001
Imperial College London
1984-2000
BP (United Kingdom)
1986-1990
The late Early Jurassic Toarcian Stage represents the warmest interval of Period, with an abrupt rise in global temperatures up to ∼7 °C mid-latitudes at onset early Oceanic Anoxic Event (T-OAE; ∼183 Ma). T-OAE, which has been extensively studied marine and continental successions from both hemispheres, was marked by widespread expansion anoxic euxinic waters, geographically extensive deposition organic-rich black shales, climatic environmental perturbations. Climatic processes following...
Changes in the marine macro- and microfauna, sedimentary geochemistry surface-water palaeoproductivity through last 500 000 years of Cenomanian first 300 Turonian are documented. These based on succession at Eastbourne, thickest most complete section Late Early Anglo–Paris Basin. Two levels rapid faunal geochemical change identified, one coincident with a significant increase siliciclastic input base Plenus Marls Member, other marked drop surface water productivity near top same unit. Faunal...
Abstract: The Late Jurassic was a time of increasing aridity in NW Europe. Here, new clay mineral dataset is presented from 600 m thick composite core through the Kimmeridge Clay Formation, southern England. assemblages comprise mainly illite and kaolinite, with minor randomly interstratified illite–smectite mixed-layer clays. SEM observations indicate that minerals are detrital, except silty strata late Tithonian age, which contain abundant pore-filling kaolinite aggregates. Th/K ratios...
Following the investigations of Odin and others into distribution green granules, glaucony has been widely assumed to be a reliable indicator fully marine, open shelf environment with low sedimentation rate. We have investigated value as palaeoenvironmental through an investigation pellets, their reworking in predominantly brackish shallow marine Tertiary sediments Hampshire basin, together re-evaluation sedimentology. Glaucony apparently formed situ all lithofacies from estuarine. Of three...
Abstract The clay mineralogy and chemistry of a green lacustrine marl that has been pedogenically modified in the upper part was investigated order to better understand formation low-temperature Fe-rich 10 Å clay. Twelve samples vertical sequence have using X-ray diffraction (XRD), chemical analysis, scanning electron microscopy (SEM) laser particle size analysis. assemblage range overall illite-smectite (I-S) compositions (64–100%) resulting from several I-S phases that, for sake modelling,...
This article reviews recent advances made by the authors through evaluation of samples in museum collections, context our novel observations, cleavage a recrystallising ikaite crystal, that may guide future research understanding morphology ikaite, which traditional crystallography has so far not achieved, as cannot be applied to ikaite. Having reviewed over 1100 using combination and petrology, we are able define how can classified glendonite. The topics covered include: (1) historical...
ABSTRACT Glaucony occurs in abundance clinoform-top and clinoform-toe positions within Atlantic-margin depositional sequences (offshore New Jersey, U.S.A.; Oligocene to Pliocene). Thin section backscatter scanning electron microscope (BSEM) analyses indicate that grains of glaucony commonly formed situ burrows deep-water (600-1000 m), settings; fragmentation the matrix is most likely have occurred through animal disturbance (e.g., ingestion displacement by burrowers). Deep-water occurrences...
Variegated palaeosols, which formed from weathering of clays, silts, and brackish to freshwater limestones, are present in the late Eocene-early Oligocene Solent Group Hampshire Basin, southern U.K. The detrital clay mineral suite is dominated by illite illite-smectite with minor kaolinite chlorite. In pedogenically modified (palaeosol) evaporitic lacustrine clay-rich sediments, proportion greater than non-pedogenically where alteration most intense, chlorite absent. smectite transition has...
The magnetostratigraphy, clay mineralogy, cyclostratigraphy and sequence stratigraphy of the estuarine continental Solent Group (Isle Wight, Hampshire Basin, UK), which is Late Eocene–Early Oligocene age, were investigated. A new magnetostratigraphy for correlated to chronostratigraphic standard using limited biostratigraphical data, it concluded that base falls close Bembridge Limestone Formation. long time-series mineral XRD data was generated, shows striking variation in illitic...
ABSTRACT In this paper, the imaging of mineral grains in sedimentary rocks by atomic-number contrast using back-scattered electrons (BSE) SEM is discussed. The analyses polished thin sections a sandstone and shale are used to illustrate technique particularly demonstrate its usefulness petrographic studies fine-grained rocks. coupling energy or wavelength-dispersive X-ray elemental analysis allows minerals be readily identified paves way for detailed geochemical crystallochemical sediments.
Study of the composition and distribution derived lithoclast fossil suites collected from Selsey, Barton Becton Formations in Whitecliff Bay, Isle Wight has enabled a detailed reconstruction Mid-Late Eocene uplift 500 m + on northern limb Sandown Pericline. The stratigraphical clasts fossils older formations demonstrates erosion progressively Eocene, Palaeocene Cretaceous sediments during growth structure. presence delicate reworked clasts, together with limited palaeocurrent data support...
Reservoir sandstones in the Mid‐ and South Tapti gas fields Surat Depression (Mumbai Offshore Basin, western India) have been investigated using a range of petrographic techniques, isotope geochemistry basin modelling. Authigenic chlorite is abundant shallow‐marine Miocene Mahim Formation, major reservoir rock fields, which are described here terms their quality diagenetic characteristics. The currently at burial depths between ∼1500 2800m. authigenic has had significant impact on resulting...
Pristinely preserved mineral pseudomorphs called glendonites, up to 1.6 m long, from the Palaeogene strata of Denmark allow detailed crystallographic characterisation and add understanding transformation precursor mineral, ikaite (CaCO3·6H2O), calcite, which constitutes glendonite. We describe Danish after two localities formations: Early Eocene Fur Formation Late Oligocene Brejning Formation. This study highlights that key aspects such as morphology mode occurrence these ancient glendonites...
Petrography of recrystallised ikaite from Ocean Drilling Program material has been presented previously Nankai Trough and Congo (ex-Zaire) deep-sea fan. This paper expands on the observations, drawing evidence Laptev Sea, South Georgia, Okhotsk coastal lagoon Point Barrow. However, even though many glendonite sites occur at high latitudes, it cannot be that forms exclusively in polar environments, as demonstrated by occurrences low latitude temperature deep sea sediments offshore Gulf Guinea...
Abstract K-Ar ages of Eocene glauconite pellets from the Isle Wight are related to quantified amounts older and occurrences detrital mica/illite particles that might have been added synsedimentary during reworking processes. Addition did not significantly bias dates, as results most often provide expected stratigraphic reference or even lower ages. Alternatively, dates greater than those suggested by stratigraphy appear result non-glauconized mica in which is always removable, high-gradient...
Abstract The results of a microstructural study by backscattered scanning electron microscopy and microchemical using X-ray microprobe analysis phyllosilicate intergrowths from sandstones, shales, metagreywackes, low-grade schists are presented. revealed that the thicken become more coherent with metamorphic grade; change incoherent to in anchizone. increasing coherency is mirrored an increase crystallinity indices illites/phengites. Chemical individual intergrowth phases was difficult...
Abstract Glaucony is present in the Palaeocene sediments of London Basin, from Thanet Sand Formation to gravel beds at base Lower Mottled Beds Reading Formation. The Upnor glaucony a rare example formation warm, shallow, brackish water and this, combined with ready availability fresh material boreholes, make this study important developing our understanding mineral. comprises up 50% Formation, grey green sandstone, variable thickness composition, which was deposited awarm, marine estuarine...