V. Vandeginste - Academia.edu (original) (raw)

Papers by V. Vandeginste

Archaeological Prospection, 2017

Geophysical techniques are widely applied in archaeological exploration, providing rapid and noni... more Geophysical techniques are widely applied in archaeological exploration, providing rapid and noninvasive site appraisal. Geochemical analyses contribute significantly in archaeometry, but conventional laboratory apparatus requires that samples are removed from their in situ context. Recent advances in field-portable apparatus facilitate in situ geochemical analysis, and this apparatus is deployed in this paper alongside conventional geophysical analysis to characterize the archaeological prospectivity of a site. The target is subsurface debris at the crash site of a World War II Mosquito aircraft. A 100 m long transect of magnetic, electromagnetic (EM) and in situ X-ray fluorescence (XRF) measurements was acquired in November 2014, with soil samples also collected for laboratory validation. A subset of XRF measurements was repeated in August 2015 alongside a targeted grid, 900 m2 in area, of magnetic gradiometry profiles. Built chiefly from wood, the Mosquito responds weakly in magnetic and EM data; magnetic gradient anomalies of ±10 nT/m are instead attributed to thermoremanence in a burnt layer at 0.2-0.4 m depth, produced by the impact fire following the crash. XRF spectrometry reveals co-located enrichments in copper (Cu) and zinc (Zn) ions (400% and 200%, respectively, above background). These metals are alloyed into brass, present in abundance in the ammunition on board the Mosquito. Records from the in situ XRF sampling compare well with laboratory validated data, although a bespoke calibration for the local soil type would improve the reliability of absolute geochemical concentrations. XRF responses vary significantly with ground conditions: the November 2014 acquisition was performed soon after ploughing at the site, potentially providing a fresh charge of metallic contaminants to the ground surface. Where the chemistry of a target is anomalous with respect to host soil and a source-to-surface transport mechanism is present, in situ XRF analysis offers improved understanding of a target compared to geophysical interpretation alone. KEYWORDS air crash, conflict archaeology, geochemistry, geophysics, magnetometry, XRF spectrometry 1 | INTRODUCTION The detection and delineation of archaeological targets is often based on contrasts in the subsurface distribution of physical properties (density, electrical conductivity, magnetic susceptibility, etc.). The chemical composition of the target is typically of secondary importance, and it usually suffices to observe a response consistent with

Mineralium Deposita, 2007

Two Mississippi Valley-type (MVT) ore deposits, Kicking Horse and Monarch, have been studied with... more Two Mississippi Valley-type (MVT) ore deposits, Kicking Horse and Monarch, have been studied with the aim of comparing the ores at the two localities and to characterize the origin of the mineralizing fluids and the ore formation process(es). Both deposits are hosted by the Middle Cambrian Cathedral Formation carbonate host rocks, Kicking Horse on the north and Monarch on the south flank of the Kicking Horse valley near Field (SE British Columbia). The ore bodies are situated at the transition of (western) basinal to (eastern) shallow-water strata of the paleo-Pacific passive margin succession in the Cordilleran Foreland Province of the Western Canada Sedimentary Basin. Both deposits are related spatially to normal faults. In both localities, the ore minerals are dominated by pyrite, sphalerite, and galena. Dolomite, minor quartz, and calcite are also present in close association with the ores. The salinity (21-30 wt% NaCl eq.) and homogenization temperatures (63-182°C) measured in fluid inclusions in carbonate, quartz, and sphalerite lie within the typical range of MVT fluid conditions. The good stoichiometry (50-53 mol% CaCO 3), low δ 18 O values (−21 to −14‰ Vienna Peedee belemnite) and relatively high homogenization temperatures (>95°C) of the dolomite suggest the dolomites were formed under burial diagenesis. The oreforming fluids probably interacted with siliciclastic units, based on elevated Li contents and 87 Sr/ 86 Sr ratios, which are highest in the dolomite type after the main ore stage. We propose that the ores formed from the mixing of a downward-infiltrating, sulfur-bearing halite-dissolution fluid with an upward-migrating, metal-rich evaporated seawater fluid, which had already undergone minor mixing with a dilute fluid.

searchanddiscovery.com

The study of foreland fold and thrust belts (FFTB) is not only of interest with respect to hydroc... more The study of foreland fold and thrust belts (FFTB) is not only of interest with respect to hydrocarbon and ore exploration, but also for example to refine kinematic models and to onravel for example groundwater circulation mechanisms, … . In order to make predictive models, a good ...

Journal of Geochemical Exploration, 2006

Because of their economic importance as hydrocarbon reservoirs, the Upper Devonian dolomitized ca... more Because of their economic importance as hydrocarbon reservoirs, the Upper Devonian dolomitized carbonate reefs in southwest Alberta have been the subject of several studies. Still, there is no consensus on the process of matrix dolomitization and furthermore, the process of vug development is not often addressed. The studied outcrops show features of an early diagenetic matrix-selective dolomitization by a Late Devonian seawater-derived fluid. Seepage reflux dolomitization combined with latent reflux is proposed, which best explains most chemical characteristics. The cements in the vugs are precipitated from warm saline, 87 Sr-enriched fluids and testify to thermogenic sulphate reduction based on the presence of sulphur, CO 2 and H 2 S in inclusions, relatively high homogenization temperatures and depleted δ 13 C values, which sets constraints on the timing of vug formation. Secondary porosity may be created by the mixing of formation water with a tectonically and topographically driven fluid and by the dissolution of anhydrite nodules.

Mineral Deposits at the Beginning of the 21st Century

82nd EAGE Annual Conference & Exhibition, 2021

Geological Society of America Bulletin, 2015

Understanding the authigenesis of carbon ate fluorapatite through isotopic geochem istry can yiel... more Understanding the authigenesis of carbon ate fluorapatite through isotopic geochem istry can yield important information on fundamental geologic processes occurring on continental margins around the world. This is particularly true for phosphatic hardgrounds, which are often found in regions of upwell ing, but of which questions remain about the initial formation and subsequent diagen esis. Here, we apply standard isotopes (δ 13 C, δ 18 O) alongside the novel clumped isotope (Δ 47) used in this study for the first time to reconstruct the temperature of formation of carbonate ions within the lattice of sedimen tary carbonate fluorapatite. We investigated phosphatic hardgrounds of Miocene age (12.7-10.8 Ma) sampled at El Capitan State Beach in the Monterey Formation. The range of isotopic signatures observed is between +1.5‰ and +8.0‰ for δ 13 C relative to the Vienna Peedee belemnite (VPDB) standard and-9.5‰ and-6.0‰ VPDB for δ 18 O, and val ues range between 0.599‰ and 0.615‰ for Δ 47. The enriched δ 13 C and depleted δ 18 O signa tures are suggestive of recrystallization within the methanogenic zone. Clumped isotope geo chemistry further constrains this transforma tion as having taken place at a temperature of 61-66 °C ± 5 °C, in line with previous esti mates for maximum burial of the Monterey Formation based on the silica phase transi tion. The calculated δ 18 O for the connate fluid shows an expected range for seawater composition for the Miocene, suggesting only minor contribution of silicaderived oxygen to the δ 18 O of carbonate fluorapatite. The combined conventional and clumped isotope data set also points out that methanogenesis took place deeper within the sediment in the middle Miocene than at present day within the Santa Barbara Basin. This study fur thers our understanding of phosphogenesis and potential links to burial processes in the Monterey Formation, and it shows for the first time that the clumped isotope paleother mometer could be used to under stand funda mental geochemical processes in authigenic sedimentary phosphates.

Sedimentary Geology, 2016

Carbonate sedimentology. Diagenesis of carbonate sediments and rocks with particular emphasis on ... more Carbonate sedimentology. Diagenesis of carbonate sediments and rocks with particular emphasis on microscale processes. Analysis of spring deposits.

Journal of Analytical Atomic Spectrometry, 2015

In situ rapid quantitative geochemical measurements of carbonate using handheld XRF.

Carbonate reservoirs contain more than half the world's oil reserves, including highly produc... more Carbonate reservoirs contain more than half the world's oil reserves, including highly productive reservoirs in Cretaceous and Cenozoic carbonates from the Middle East and Southeastern Asia. They are usually characterized by the complexity both of their internal architecture and of the distribution of their diagenetic fabrics which hampers crosshole correlations at various scales, and predictions regarding flow paths and volumes of fluids. Reservoir analogs can have the advantage of easier accessibility and sampling and less severe diagenetic alteration. Their study often provides information complementary to the knowledge of hydrocarbon reservoirs and it leads to a better understanding of carbonate systems, important to make better predictions on other potential reservoirs. Significant advances can be made from joint research in natural laboratories integrating outcrops and shallow boreholes, with extensive control on geophysical, geological and petrophysical parameters. The so...

An inversion structure located in the northern Adriatic foreland (Italy) has been investigated to... more An inversion structure located in the northern Adriatic foreland (Italy) has been investigated to understand the relationship between geometry, age of deformation and dolomitization process. The geometry of the inversion structure and the relationship between the tectonic deformation and the dolomitization have been investigated producing isochron maps, isopach maps, amplitude and continuity extractions. The structure is delineated by NE trending SE dipping reverse faults reactivated on older Mesozoic extensional faults during Cenozoic compression (Fig. 1A). The inversion structure is defined by two culminations, Agata culmination located to the south and Amira culmination to the north. The isopach maps showed that the growth of the structure was mostly pronounced on Agata culmination and that the culmination is an older Mesozoic extensional basin reactivated during Upper Cretaceous to Eocene inversion (Fig. 1B). The structure showed pervasive dolomitization on its higher Agata culm...

Geologica Belgica

Until recently, only four authentic meteorites have been recovered in Belgium. They are all ordin... more Until recently, only four authentic meteorites have been recovered in Belgium. They are all ordinary chondrite falls. Sint-Denijs-Westrem (also spelled St. Denis Westrem) is a L6 chondrite that was observed to fall in 1855 (Duprez, 1855). The L6 chondrite Tourinnes-la-Grosse fell in 1863 (Van Beneden, 1863), and the L6 chondrite Lesves fell 1896 (Renard, 1896). Finally, the H3-6 brecciated chondrite Hainaut (also called Bettrechies) fell in 1934 (Lecompte, 1935). The Hautes Fagnes meteorite is not an observed fall. It was found around 1965 during a school excursion through the Hautes Fagnes area (High Fens, a raised bog with sphagnum moss in Liège province, eastern Belgium). The approximate geographical coordinates of this area are 50°35' ± 5' N latitude and 6°10' ± 5' E longitude. The stone was kept by a teacher, who was intrigued by its peculiar characteristics. Only in 2007, after visiting an exposition on meteorites, the teacher guessed its true nature, and consulted Vincent Jacques, an experienced meteorite collector, who acquired the meteorite specimen and donated half of it to the Royal Belgian Institute of Natural Sciences for further investigation and curation. The Hautes Fagnes meteorite was officially recognised by the Meteorite Nomenclature Committee in December 2010. The salient features of the specimen are summarized in the Meteoritical Bulletin N°99 (De Vos, 2011). The present paper supplements this short note and deals with a more comprehensive study of the mineralogy, and of the mineral and bulk chemical composition. A determination of chemical group, metamorphic/petrologic type and shock grade not only meets curatorial needs, but also provides useful information for studies of the frequency distribution of the various types and subtypes of chondrites. 2. Methodology The original stone consisted of a single piece. It was cut in two halves, of which the major half (itself broken in two pieces) is in the possession of Vincent Jacques, whereas the other part and two smaller pieces that broke off during cutting, are held at the Royal Belgian Institute of Natural Sciences (RBINS). The macroscopic description is based on the original single piece as well as on the meteorite pieces (and their cut surfaces) that are present at the RBINS (Fig. 1A). The mineralogical and petrographical analysis was performed on two thin sections and a polished section. XRD powder diffraction analysis with a Philips Analytical PW3830 spectrometer provided additional information on the mineralogy. The XRD spectrometer operated with FeKα radiation at 40 kV and 30 mA. A SEM-EDXA (JEOL JSM-6340F) at VITO (Vlaamse Instelling voor Technologisch Onderzoek, Flemish Institut for Technological Research) was used to characterize small phases, difficult to determine by optical microscopy, on a polished section. An Environmental Scanning Electron Microscope (ESEM Quanta 600 of FEI) equipped with an Energy Dispersive System (EDS of EDAX) was used at the Royal Belgian Institute of Natural Sciences, to realise point analyses of mineral grains and also to perform element mapping, in low-vacuum conditions, on two polished sections. This mapping was also used to estimate mineral abundances. Electron microprobe analyses were performed at the Université Catholique de Louvain with a Cameca France SX50 microprobe. By this method, the concentrations of Si, Fe, Mg, Ca, Al, Ti, Mn, Cr, Na, K and Ni were determined in olivine and orthopyroxene. Whole rock chemical analysis of aliquots of a ground, homogenised powder of a meteorite fragment was carried out at the Katholieke Universiteit Leuven with a Varian 720ES ICP-OES spectrometer, after (1) fusion with LiBO 2 and (2) microwave digestion in strong acids (HF, HNO 3 ,HClO 4 , and aqua regia). Calibration was based on the analysis of reference rock powders USGS DTS-1 (dunite), USGS BCR-2 (basalt) and ANRT BR (basalt). The first procedure is an adaptation and enhancement of the method of Bankston et al. (1979). 100 mg aliquots of two meteorite samples and of the three standards were fused with 500 mg LiBO 2 (Alfa Aesar/ Johnson Matthey Spectroflux 100A) in high purity graphite crucibles. The fusion bead was dissolved in 50 mL 0.4 M HNO 3 and diluted GEOLOGICA BELGICA (2012) 15/1-2: 96-104

International Petroleum Technology Conference, 2014

Petroleum geologists working in carbonate plays are facing two common and inter-connected challen... more Petroleum geologists working in carbonate plays are facing two common and inter-connected challenges linked to optimizing production. First, constraining the geometry, spatial distribution and inter-connectivity of reservoir geobodies is crucial as these properties can control the permeability anisotropy of reservoirs zones. This is difficult to do at the inter-well scale due to the limited resolution of seismic methods (20 meters or higher) compared to the size of typical reservoir geobodies (tens of centimers to meters and higher) and the very heterogeneous nature of carbonate reservoirs. Furthermore, diagenetic transformations are very important in carbonate reservoirs. Being able to fingerprint the process and timing of diagenetic transformation is crucial to a correct assessement of the distribution of cemented zones in the subsurface. The issue of diagenesis is also important for organic matter maturation and the timing of oil migration, and therefore the second challenge face...

Qatar Foundation Annual Research Forum Proceedings, 2010

Page 1. Author Institution This study, carried out in the Qatar Carbonates and Carbon Storage Res... more Page 1. Author Institution This study, carried out in the Qatar Carbonates and Carbon Storage Research Centre (QCCSRC) at Imperial College focuses on the interplay between fractures, diagenetic fluid flow and precipitation ...

Qatar Foundation Annual Research Forum Proceedings, 2010

This study addresses the brand repositioning of Banco Intermedium. The objective of the study was... more This study addresses the brand repositioning of Banco Intermedium. The objective of the study was to understand what the brand positioning was like for some years and how it has been working its repositioning since 2017. We also seek to investigate how the repositioning contributed to the improvement of the institution's image and performance in the marketplace. As a methodology, secondary data searches were adopted through the Internet, through the brand's websites and online social networks, and as a method for obtaining primary data, interviews were conducted with clients, and with a branding specialist and employee of Banco Inter, in order to understand the internal and external perception of the brand.

Qatar Foundation Annual Research Forum Proceedings, 2010

ABSTRACT The analysis of stable carbon and oxygen isotope composition is one of the most commonly... more ABSTRACT The analysis of stable carbon and oxygen isotope composition is one of the most commonly used techniques in stratigraphic and diagenetic research of carbonate rocks. The wide-spread use and easy access of this long-established method has the side effect that little attention is paid to fundamental calibrations. Dolomite is often measured against a calcite standard (NBS19), and the acid fractionation factor used to calibrate is based on the one for calcite. To date, no reference material exists for dolomite. In this study, which is part of dolomite research in the Qatar Carbonates and Carbon Storage Research Centre project, we focus on two main goals. First, we characterize a current standard of dolomite used for major and minor elemental geochemistry, and assess its suitability as a new dolomite standard for delta18O and delta13C. Second, we attempt to better constrain the acid fractionation factor for dolomite and assess the influence of different dolomite types on this fractionation factor. As only two third of the total oxygen in the carbonate is released in the form of CO2 during acid reaction, a fractionation between the reacting carbonate and the resulting gas will occur. A recent study by Kim et al. (2007) improved on the acid fractionation factors for calcite and aragonite. Often, the acid fractionation factor for dolomite is used to calculate delta18O and delta13C from the values obtained by calibration with the calcite standard. Only two studies (from the 1980's) have attempted to constrain the acid fractionation factor for dolomite, of which only Rosenbaum and Sheppard (1986) did experiments not only at 25°C, but also at 50 and 100°C. The dataset of the latter authors is, however, very limited and contains only two dolomite samples. We aim at improving the constraints on the acid fractionation factor of dolomite by reacting a wide range of different types of dolomite at a wide range of acid temperature, and compare this to the absolute isotopic composition of the samples measured on a fluorination line.

Archaeological Prospection, 2017

Geophysical techniques are widely applied in archaeological exploration, providing rapid and noni... more Geophysical techniques are widely applied in archaeological exploration, providing rapid and noninvasive site appraisal. Geochemical analyses contribute significantly in archaeometry, but conventional laboratory apparatus requires that samples are removed from their in situ context. Recent advances in field-portable apparatus facilitate in situ geochemical analysis, and this apparatus is deployed in this paper alongside conventional geophysical analysis to characterize the archaeological prospectivity of a site. The target is subsurface debris at the crash site of a World War II Mosquito aircraft. A 100 m long transect of magnetic, electromagnetic (EM) and in situ X-ray fluorescence (XRF) measurements was acquired in November 2014, with soil samples also collected for laboratory validation. A subset of XRF measurements was repeated in August 2015 alongside a targeted grid, 900 m2 in area, of magnetic gradiometry profiles. Built chiefly from wood, the Mosquito responds weakly in magnetic and EM data; magnetic gradient anomalies of ±10 nT/m are instead attributed to thermoremanence in a burnt layer at 0.2-0.4 m depth, produced by the impact fire following the crash. XRF spectrometry reveals co-located enrichments in copper (Cu) and zinc (Zn) ions (400% and 200%, respectively, above background). These metals are alloyed into brass, present in abundance in the ammunition on board the Mosquito. Records from the in situ XRF sampling compare well with laboratory validated data, although a bespoke calibration for the local soil type would improve the reliability of absolute geochemical concentrations. XRF responses vary significantly with ground conditions: the November 2014 acquisition was performed soon after ploughing at the site, potentially providing a fresh charge of metallic contaminants to the ground surface. Where the chemistry of a target is anomalous with respect to host soil and a source-to-surface transport mechanism is present, in situ XRF analysis offers improved understanding of a target compared to geophysical interpretation alone. KEYWORDS air crash, conflict archaeology, geochemistry, geophysics, magnetometry, XRF spectrometry 1 | INTRODUCTION The detection and delineation of archaeological targets is often based on contrasts in the subsurface distribution of physical properties (density, electrical conductivity, magnetic susceptibility, etc.). The chemical composition of the target is typically of secondary importance, and it usually suffices to observe a response consistent with

Mineralium Deposita, 2007

Two Mississippi Valley-type (MVT) ore deposits, Kicking Horse and Monarch, have been studied with... more Two Mississippi Valley-type (MVT) ore deposits, Kicking Horse and Monarch, have been studied with the aim of comparing the ores at the two localities and to characterize the origin of the mineralizing fluids and the ore formation process(es). Both deposits are hosted by the Middle Cambrian Cathedral Formation carbonate host rocks, Kicking Horse on the north and Monarch on the south flank of the Kicking Horse valley near Field (SE British Columbia). The ore bodies are situated at the transition of (western) basinal to (eastern) shallow-water strata of the paleo-Pacific passive margin succession in the Cordilleran Foreland Province of the Western Canada Sedimentary Basin. Both deposits are related spatially to normal faults. In both localities, the ore minerals are dominated by pyrite, sphalerite, and galena. Dolomite, minor quartz, and calcite are also present in close association with the ores. The salinity (21-30 wt% NaCl eq.) and homogenization temperatures (63-182°C) measured in fluid inclusions in carbonate, quartz, and sphalerite lie within the typical range of MVT fluid conditions. The good stoichiometry (50-53 mol% CaCO 3), low δ 18 O values (−21 to −14‰ Vienna Peedee belemnite) and relatively high homogenization temperatures (>95°C) of the dolomite suggest the dolomites were formed under burial diagenesis. The oreforming fluids probably interacted with siliciclastic units, based on elevated Li contents and 87 Sr/ 86 Sr ratios, which are highest in the dolomite type after the main ore stage. We propose that the ores formed from the mixing of a downward-infiltrating, sulfur-bearing halite-dissolution fluid with an upward-migrating, metal-rich evaporated seawater fluid, which had already undergone minor mixing with a dilute fluid.

searchanddiscovery.com

The study of foreland fold and thrust belts (FFTB) is not only of interest with respect to hydroc... more The study of foreland fold and thrust belts (FFTB) is not only of interest with respect to hydrocarbon and ore exploration, but also for example to refine kinematic models and to onravel for example groundwater circulation mechanisms, … . In order to make predictive models, a good ...

Journal of Geochemical Exploration, 2006

Because of their economic importance as hydrocarbon reservoirs, the Upper Devonian dolomitized ca... more Because of their economic importance as hydrocarbon reservoirs, the Upper Devonian dolomitized carbonate reefs in southwest Alberta have been the subject of several studies. Still, there is no consensus on the process of matrix dolomitization and furthermore, the process of vug development is not often addressed. The studied outcrops show features of an early diagenetic matrix-selective dolomitization by a Late Devonian seawater-derived fluid. Seepage reflux dolomitization combined with latent reflux is proposed, which best explains most chemical characteristics. The cements in the vugs are precipitated from warm saline, 87 Sr-enriched fluids and testify to thermogenic sulphate reduction based on the presence of sulphur, CO 2 and H 2 S in inclusions, relatively high homogenization temperatures and depleted δ 13 C values, which sets constraints on the timing of vug formation. Secondary porosity may be created by the mixing of formation water with a tectonically and topographically driven fluid and by the dissolution of anhydrite nodules.

Mineral Deposits at the Beginning of the 21st Century

82nd EAGE Annual Conference & Exhibition, 2021

Geological Society of America Bulletin, 2015

Understanding the authigenesis of carbon ate fluorapatite through isotopic geochem istry can yiel... more Understanding the authigenesis of carbon ate fluorapatite through isotopic geochem istry can yield important information on fundamental geologic processes occurring on continental margins around the world. This is particularly true for phosphatic hardgrounds, which are often found in regions of upwell ing, but of which questions remain about the initial formation and subsequent diagen esis. Here, we apply standard isotopes (δ 13 C, δ 18 O) alongside the novel clumped isotope (Δ 47) used in this study for the first time to reconstruct the temperature of formation of carbonate ions within the lattice of sedimen tary carbonate fluorapatite. We investigated phosphatic hardgrounds of Miocene age (12.7-10.8 Ma) sampled at El Capitan State Beach in the Monterey Formation. The range of isotopic signatures observed is between +1.5‰ and +8.0‰ for δ 13 C relative to the Vienna Peedee belemnite (VPDB) standard and-9.5‰ and-6.0‰ VPDB for δ 18 O, and val ues range between 0.599‰ and 0.615‰ for Δ 47. The enriched δ 13 C and depleted δ 18 O signa tures are suggestive of recrystallization within the methanogenic zone. Clumped isotope geo chemistry further constrains this transforma tion as having taken place at a temperature of 61-66 °C ± 5 °C, in line with previous esti mates for maximum burial of the Monterey Formation based on the silica phase transi tion. The calculated δ 18 O for the connate fluid shows an expected range for seawater composition for the Miocene, suggesting only minor contribution of silicaderived oxygen to the δ 18 O of carbonate fluorapatite. The combined conventional and clumped isotope data set also points out that methanogenesis took place deeper within the sediment in the middle Miocene than at present day within the Santa Barbara Basin. This study fur thers our understanding of phosphogenesis and potential links to burial processes in the Monterey Formation, and it shows for the first time that the clumped isotope paleother mometer could be used to under stand funda mental geochemical processes in authigenic sedimentary phosphates.

Sedimentary Geology, 2016

Carbonate sedimentology. Diagenesis of carbonate sediments and rocks with particular emphasis on ... more Carbonate sedimentology. Diagenesis of carbonate sediments and rocks with particular emphasis on microscale processes. Analysis of spring deposits.

Journal of Analytical Atomic Spectrometry, 2015

In situ rapid quantitative geochemical measurements of carbonate using handheld XRF.

Carbonate reservoirs contain more than half the world's oil reserves, including highly produc... more Carbonate reservoirs contain more than half the world's oil reserves, including highly productive reservoirs in Cretaceous and Cenozoic carbonates from the Middle East and Southeastern Asia. They are usually characterized by the complexity both of their internal architecture and of the distribution of their diagenetic fabrics which hampers crosshole correlations at various scales, and predictions regarding flow paths and volumes of fluids. Reservoir analogs can have the advantage of easier accessibility and sampling and less severe diagenetic alteration. Their study often provides information complementary to the knowledge of hydrocarbon reservoirs and it leads to a better understanding of carbonate systems, important to make better predictions on other potential reservoirs. Significant advances can be made from joint research in natural laboratories integrating outcrops and shallow boreholes, with extensive control on geophysical, geological and petrophysical parameters. The so...

An inversion structure located in the northern Adriatic foreland (Italy) has been investigated to... more An inversion structure located in the northern Adriatic foreland (Italy) has been investigated to understand the relationship between geometry, age of deformation and dolomitization process. The geometry of the inversion structure and the relationship between the tectonic deformation and the dolomitization have been investigated producing isochron maps, isopach maps, amplitude and continuity extractions. The structure is delineated by NE trending SE dipping reverse faults reactivated on older Mesozoic extensional faults during Cenozoic compression (Fig. 1A). The inversion structure is defined by two culminations, Agata culmination located to the south and Amira culmination to the north. The isopach maps showed that the growth of the structure was mostly pronounced on Agata culmination and that the culmination is an older Mesozoic extensional basin reactivated during Upper Cretaceous to Eocene inversion (Fig. 1B). The structure showed pervasive dolomitization on its higher Agata culm...

Geologica Belgica

Until recently, only four authentic meteorites have been recovered in Belgium. They are all ordin... more Until recently, only four authentic meteorites have been recovered in Belgium. They are all ordinary chondrite falls. Sint-Denijs-Westrem (also spelled St. Denis Westrem) is a L6 chondrite that was observed to fall in 1855 (Duprez, 1855). The L6 chondrite Tourinnes-la-Grosse fell in 1863 (Van Beneden, 1863), and the L6 chondrite Lesves fell 1896 (Renard, 1896). Finally, the H3-6 brecciated chondrite Hainaut (also called Bettrechies) fell in 1934 (Lecompte, 1935). The Hautes Fagnes meteorite is not an observed fall. It was found around 1965 during a school excursion through the Hautes Fagnes area (High Fens, a raised bog with sphagnum moss in Liège province, eastern Belgium). The approximate geographical coordinates of this area are 50°35' ± 5' N latitude and 6°10' ± 5' E longitude. The stone was kept by a teacher, who was intrigued by its peculiar characteristics. Only in 2007, after visiting an exposition on meteorites, the teacher guessed its true nature, and consulted Vincent Jacques, an experienced meteorite collector, who acquired the meteorite specimen and donated half of it to the Royal Belgian Institute of Natural Sciences for further investigation and curation. The Hautes Fagnes meteorite was officially recognised by the Meteorite Nomenclature Committee in December 2010. The salient features of the specimen are summarized in the Meteoritical Bulletin N°99 (De Vos, 2011). The present paper supplements this short note and deals with a more comprehensive study of the mineralogy, and of the mineral and bulk chemical composition. A determination of chemical group, metamorphic/petrologic type and shock grade not only meets curatorial needs, but also provides useful information for studies of the frequency distribution of the various types and subtypes of chondrites. 2. Methodology The original stone consisted of a single piece. It was cut in two halves, of which the major half (itself broken in two pieces) is in the possession of Vincent Jacques, whereas the other part and two smaller pieces that broke off during cutting, are held at the Royal Belgian Institute of Natural Sciences (RBINS). The macroscopic description is based on the original single piece as well as on the meteorite pieces (and their cut surfaces) that are present at the RBINS (Fig. 1A). The mineralogical and petrographical analysis was performed on two thin sections and a polished section. XRD powder diffraction analysis with a Philips Analytical PW3830 spectrometer provided additional information on the mineralogy. The XRD spectrometer operated with FeKα radiation at 40 kV and 30 mA. A SEM-EDXA (JEOL JSM-6340F) at VITO (Vlaamse Instelling voor Technologisch Onderzoek, Flemish Institut for Technological Research) was used to characterize small phases, difficult to determine by optical microscopy, on a polished section. An Environmental Scanning Electron Microscope (ESEM Quanta 600 of FEI) equipped with an Energy Dispersive System (EDS of EDAX) was used at the Royal Belgian Institute of Natural Sciences, to realise point analyses of mineral grains and also to perform element mapping, in low-vacuum conditions, on two polished sections. This mapping was also used to estimate mineral abundances. Electron microprobe analyses were performed at the Université Catholique de Louvain with a Cameca France SX50 microprobe. By this method, the concentrations of Si, Fe, Mg, Ca, Al, Ti, Mn, Cr, Na, K and Ni were determined in olivine and orthopyroxene. Whole rock chemical analysis of aliquots of a ground, homogenised powder of a meteorite fragment was carried out at the Katholieke Universiteit Leuven with a Varian 720ES ICP-OES spectrometer, after (1) fusion with LiBO 2 and (2) microwave digestion in strong acids (HF, HNO 3 ,HClO 4 , and aqua regia). Calibration was based on the analysis of reference rock powders USGS DTS-1 (dunite), USGS BCR-2 (basalt) and ANRT BR (basalt). The first procedure is an adaptation and enhancement of the method of Bankston et al. (1979). 100 mg aliquots of two meteorite samples and of the three standards were fused with 500 mg LiBO 2 (Alfa Aesar/ Johnson Matthey Spectroflux 100A) in high purity graphite crucibles. The fusion bead was dissolved in 50 mL 0.4 M HNO 3 and diluted GEOLOGICA BELGICA (2012) 15/1-2: 96-104

International Petroleum Technology Conference, 2014

Petroleum geologists working in carbonate plays are facing two common and inter-connected challen... more Petroleum geologists working in carbonate plays are facing two common and inter-connected challenges linked to optimizing production. First, constraining the geometry, spatial distribution and inter-connectivity of reservoir geobodies is crucial as these properties can control the permeability anisotropy of reservoirs zones. This is difficult to do at the inter-well scale due to the limited resolution of seismic methods (20 meters or higher) compared to the size of typical reservoir geobodies (tens of centimers to meters and higher) and the very heterogeneous nature of carbonate reservoirs. Furthermore, diagenetic transformations are very important in carbonate reservoirs. Being able to fingerprint the process and timing of diagenetic transformation is crucial to a correct assessement of the distribution of cemented zones in the subsurface. The issue of diagenesis is also important for organic matter maturation and the timing of oil migration, and therefore the second challenge face...

Qatar Foundation Annual Research Forum Proceedings, 2010

Page 1. Author Institution This study, carried out in the Qatar Carbonates and Carbon Storage Res... more Page 1. Author Institution This study, carried out in the Qatar Carbonates and Carbon Storage Research Centre (QCCSRC) at Imperial College focuses on the interplay between fractures, diagenetic fluid flow and precipitation ...

Qatar Foundation Annual Research Forum Proceedings, 2010

This study addresses the brand repositioning of Banco Intermedium. The objective of the study was... more This study addresses the brand repositioning of Banco Intermedium. The objective of the study was to understand what the brand positioning was like for some years and how it has been working its repositioning since 2017. We also seek to investigate how the repositioning contributed to the improvement of the institution's image and performance in the marketplace. As a methodology, secondary data searches were adopted through the Internet, through the brand's websites and online social networks, and as a method for obtaining primary data, interviews were conducted with clients, and with a branding specialist and employee of Banco Inter, in order to understand the internal and external perception of the brand.

Qatar Foundation Annual Research Forum Proceedings, 2010

ABSTRACT The analysis of stable carbon and oxygen isotope composition is one of the most commonly... more ABSTRACT The analysis of stable carbon and oxygen isotope composition is one of the most commonly used techniques in stratigraphic and diagenetic research of carbonate rocks. The wide-spread use and easy access of this long-established method has the side effect that little attention is paid to fundamental calibrations. Dolomite is often measured against a calcite standard (NBS19), and the acid fractionation factor used to calibrate is based on the one for calcite. To date, no reference material exists for dolomite. In this study, which is part of dolomite research in the Qatar Carbonates and Carbon Storage Research Centre project, we focus on two main goals. First, we characterize a current standard of dolomite used for major and minor elemental geochemistry, and assess its suitability as a new dolomite standard for delta18O and delta13C. Second, we attempt to better constrain the acid fractionation factor for dolomite and assess the influence of different dolomite types on this fractionation factor. As only two third of the total oxygen in the carbonate is released in the form of CO2 during acid reaction, a fractionation between the reacting carbonate and the resulting gas will occur. A recent study by Kim et al. (2007) improved on the acid fractionation factors for calcite and aragonite. Often, the acid fractionation factor for dolomite is used to calculate delta18O and delta13C from the values obtained by calibration with the calcite standard. Only two studies (from the 1980's) have attempted to constrain the acid fractionation factor for dolomite, of which only Rosenbaum and Sheppard (1986) did experiments not only at 25°C, but also at 50 and 100°C. The dataset of the latter authors is, however, very limited and contains only two dolomite samples. We aim at improving the constraints on the acid fractionation factor of dolomite by reacting a wide range of different types of dolomite at a wide range of acid temperature, and compare this to the absolute isotopic composition of the samples measured on a fluorination line.