Chrystèle Verati

Chrystèle Verati
University of Nice Sophia Antipolis | UNS · Géoazur UMR 7329

PhD

About

69
Publications
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Publications

Publications (69)
Article
Exposed parts of the Central Atlantic Magmatic Province (CAMP) plumbing system, including huge doleritic sills and numerous dykes, are widespread in the northern flank of the Tindouf basin (Algeria). Doleritic pipes, that have never been studied so far, are spatially associated with these sills and dykes and thus supposed of CAMP origin. We present...
Article
Full-text available
Ar/³⁹Ar geochronology is one of the most important techniques for constraining the timing of basaltic events due to the paucity of suitable minerals in basalts for other geochronological techniques such as U–Pb (e.g., zircon, baddeleyite). Among a variety of materials from basaltic rocks that have been used for ⁴⁰Ar/³⁹Ar dating, plagioclase is the...
Article
We investigate the potential of ⁴⁰Ar-³⁹Ar systematics in secondary K-bearing minerals developed at the expense of hydrothermally altered volcanic pyroxenes from a fossil geothermal system located in the Saintes archipelago (Lesser Antilles magmatic arc). Our work reports the first example of dating hydrothermal muscovite crystallization developed d...
Article
The Neolithisation of the North-Western Mediterranean is still an open issue. New data has recently enriched the chronological and cultural archaeological framework, providing more precise absolute dates and revealing a new and more complex process of expansion of farming in Southern Europe. The Mediterranean route of colonization (6000–5600 BCE),...
Article
Full-text available
Structural and microstructural analyses are carried out in two sites of the Argentera-Mercantour Massif, Valscura and Val du Haut Boréon, where swarms of lamprophyres intruded into Variscan migmatites and early Permian granitoids. Efforts aim at defining the structural relationships between lamprophyres and country rocks, and at constraining the st...
Article
Numerous mafic dykes, sills and laccoliths crop out in the southern part of the Tafilalt basin (Eastern Anti-Atlas, Morocco). These rocks intrude the mildly folded Ordovician to Early Carboniferous formations, consisting mainly of lamprophyric dolerites and camptonites with minor gabbros and syenodiorites. Previous geochemical studies have shown th...
Conference Paper
Full-text available
Des cheminées doléritiques sont connues dans le bassin de Tindouf en Algérie depuis les travaux de Jaqcuemont (1952) et Gevin (1960), et sont supposées appartenir à la Province Magmatique de l’Atlantique Central (CAMP). Le bassin de Tindouf est caractérisé par une abondance de formations magmatiques appartenant à la CAMP (Chabou, 2008; Bersi, 2016)...
Article
Full-text available
In order to decipher the tectono-metamorphic evolution of shallow crustal levels of the active volcanic arc of the Guadeloupe archipelago (Lesser Antilles) we present new geochemical, geochronological, mineralogical and structural investigations of the so-called Basal Complex, the oldest and most eroded volcanic complex of Basse-Terre in Guadeloupe...
Article
Full-text available
The Sidi El Hemissi region, Souk-Ahras, is part of the Tellian Atlas where the Triassic sediments tectonically outcrop under the Tellian nappes of the Maghrebide chain. Mafic rocks, mainly gabbros and dolerites, called “ophites,” are interbedded as a ~ 200 × 30-m lenticular body within the Triassic gypsum-rich formation. These rocks show granular,...
Chapter
Sited in Souk-Ahras, the Sidi El Hemissi region stands as part of the Tellian Atlas, where the Triassic formation tectonically outcrops under the Tellian nappes of the Maghrebide chain. Dubbed ‘ophites’, mafic rocks, mainly gabbros and dolerites are interbedded in ~200 × 30 m lenticular body within the Triassic gypsum-rich formation. These rocks ar...
Conference Paper
Full-text available
As part of the GEOTREF research project, a cost-effective approach, relying on innovative software tools, is proposed to carry out prefeasibility studies prior drilling based on numerical conceptual models associated with phenomenological modelling and well layout optimization. The numerical conceptual models are intended to be 3D structural, geolo...
Poster
Full-text available
Datation d'un des plus anciens sites préhistoriques de France par la méthode U-Pb sur les spéléothèmes en relation avec les niveaux archéologiques. Présence de l'activité humaine attestée par la mise en évidence de traces de découpe sur les os de grands mammifères et par la présence d'outils taillés.
Article
We unravel for the first time the expression of a low-grade metamorphic event affecting the deepest exposures of the Guadeloupe Island, central Lesser Antilles, Caribbean plate. The work offers a novel insight for the presence of young (<3 Ma) sub-greenschist facies metamorphism in the Lesser Antilles active arc and is consistent with the elevated...
Article
The results of the GEOTREF project presented here aim to develop high enthalpy geothermal energy in fractured reservoirs. They focus on active volcanic islands, especially the Basse-Terre Island (Guadeloupe Archipelago). As part of this project we measured several petrophysical properties to better understand how fluids flow in the hydrothermal sys...
Conference Paper
Full-text available
The 615-540 Ma Central Iapetus Magmatic Province (CIMP) was emplaced in multiple pulses during Ediacaran-Cambrian times, and has been linked to the disruption of the Rodinia supercontinent leading to the opening of the Central Iapetus Ocean. It is well represented in Laurentia and Baltica but also present on other formerly attached blocks such as t...
Presentation
Full-text available
This survey takes part in the GEOTREF project (high enthalpy geothermal energy in fractured reservoirs), supported by the French government program "Investments for the future". The program focuses on the exploration of geothermal resource in the Lesser Antilles volcanic arc. An exclusive license has been issued in the Vieux-Habitants area (Basse-T...
Article
In the N.-W. Mediterranean area, the development of the Neolithic way of life during the 6th millennium cal. BCE is related to the spread of sailing pioneer groups. In the course of the 5th millennium cal. BCE, more stable agro-pastoral settlements expand their hold on the hinterland and exchange networks increase in complexity (obsidian, flints, c...
Article
We welcome the comment by Michard et al. (2013) as it gives us the opportunity to better discuss the Jurassic-Cretaceous magmatism of the High Atlas (Morocco). In their comment, Michard et al. (2013) focus on three main points which are: (i) the age of the basalts from Naour, (ii) the structural history of the Central High Atlas and (iii) the geody...
Article
In this paper, we provide the first structural map of Les Saintes archipelago (Guadeloupe, Lesser Antilles). The finite strain pattern displays four families of fault systems characterized by their statistical structural orientations: N000-N020, N050-N070, N090-N110 and N130-N140 trending fault systems. Our onshore results thus underline a fault ne...
Article
In the N.W.-Mediterranean area, exchange networks and social relationships gain an increasing complexity in the course of the Neolithic: varied goods diffuse in considerable quantities and distances. In particular, obsidian, Bedoulian and Oligocene flints, jadeite and eclogite are known to have been exchanged over long distances as shown by researc...
Poster
Full-text available
Materials procurement studies provide key data for determining territories, mobility systems and socio-cultural relationships. The transition to sedentary agricultural societies during Neolithic is often associated with a considerable increase in the complexity of exchange networks: varied goods diffuse in considerable quantities and distances. In...
Article
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An integrated stratigraphic study was conducted on the shallow water carbonate platforms of the Guadeloupe archipelago to refine the tectonic evolution of the Lesser Antilles forearc. The carbonate platforms are now dated to the Zanclean–Calabrian interval, and their demise occurred between 1.5 and 1.07 Ma. The precise chronostratigraphy allows dat...
Article
Full-text available
Space missions and thermal infrared observations have shown that small asteroids (kilometre-sized or smaller) are covered by a layer of centimetre-sized or smaller particles, which constitute the regolith. Regolith generation has traditionally been attributed to the fall back of impact ejecta and by the break-up of boulders by micrometeoroid impact...
Article
Full-text available
Mineral separates of adularia have been extracted from three samples of highly silicified hydrothermal breccias, newly discovered in the active Bouillante geothermal field (Guadeloupe archipelago), and investigated by 40Ar/39Ar geochronology in order to constrain the timing of geothermal activity in this part of the active Lesser Antilles island ar...
Article
Full-text available
The 40Ar/39Ar technique is the most commonly used technique to date basaltic rocks. For basaltic rocks older than about 30 Ma, the dating of plagioclase separates is preferred over groundmass as the latter is susceptible to containing cryptic alteration due to fluid circulations, difficult if not impossible to remove during sample preparation. Alte...
Article
Full-text available
Decoding the complete history of Earth and our solar system is a daunting task. This requires the placing of the scattered pages of Earth history in a precise chronological order. Currently the best approach to date a particular event is to use naturally occurring radioactive elements (i.e. parent-daughter isotopic ratios) with known rates of decay...
Article
Full-text available
Refined radio-isotopic dating techniques have been applied to Orgnac 3, a Late Acheulean and Early Middle Palaeolithic site in France. Evidence of Levallois core technology appeared in level 4b in the middle of the sequence, became predominant in the upper horizons, and was best represented in uppermost level 1, making the site one of the oldest ex...
Article
Full-text available
This work presents a synthesis of the present-day knowledge on both emerged and submerged carbonate platforms of the Guadeloupe archipelago. Onshore and offshore data acquired during the KaShallow project are presented. Since the early Zanclean, some isolated platforms developed onto a Jurassic to Tortonian basement which displayed reliefs inherite...
Article
Full-text available
In this paper we present and discuss new investigations performed on both the magmatic basement and the sedimentary formations of La Désirade. We report structural and sedimentary evidences for several episodes of deformation and displacement occurring prior to the present day tectonics. The main faults, respectively N130 ± 10°, N040 ± 10° and N090...
Article
Full-text available
Surficial indicators of recent to present geothermal activity are present around Bouillante (Guadeloupe, French West Indies). Until lately, most mineralogical parageneses identified in this area were typical of low temperature alteration (< 100°C) with the occurrence of dioctahedral aluminous smectites accompanied by zeolites (heulandite-clinoptilo...
Article
Space-based [12] and remote sensing observations [4] reveal that regolith - a layer of loose unconsolidated material - is present on all asteroids, including very small, sub km-sized near-Earth asteroids (NEAs) such as (25143) Itokawa [7]. Classically, regolith is believed to be produced by impacts of small particles hitting asteroid surfaces. Such...
Poster
Full-text available
Colouring materials are a privileged medium to approach prehistoric symbolic systems, via the study of technical systems. However, the knowledge on the chaîne opératoire of these highly-varied geo-materials remains limited, particularly for the end of prehistorical times. In the franco-italian area, within “liguro-provençal” bow, as well as Baux-de...
Conference Paper
Full-text available
The so-called Central Iapetus Magmatic Province (CIMP) was emplaced during Ediacaran-Cambrian times, and has been linked to the disruption of the supercontinent of Rodinia (Pannotia) leading to the initial opening of the Central Iapetus Ocean in the triple junction Laurentia, Baltica, and Amazonia or northwestern Africa. As for the Central Atlantic...
Article
This article presents the dating results recently obtained on three archaeological sites in Europe. At Orgnac 3 (Ardèche, France) from where the last Homo heidelbergensis fossils are associated with the first evidence of levallois technique, two speleothem formations from the 5b–6–7th layers were U-Th dated with MC-ICPMS, giving an age range of 319...
Article
Full-text available
Space-based [12] (Fig. 1) and remote sensing observations [4] reveal that regolith - a layer of loose unconsolidated material - is present on all asteroids, including very small, sub km-sized near-Earth asteroids (NEAs) such as (25143) Itokawa [7] (See Fig. 2). Classically, regolith is believed to be produced by impacts of small particles hitting a...
Article
Full-text available
Located east of Guadeloupe, the island of La DÈsirade exhibits the oldest rocks of the Lesser Antilles arc and the eastern Caribbean plate. An old magmatic basement is composed of (1) late Jurassic ophiolitic complex with meta-basaltic pillow lavas and interbedded radiolarites, (2) acid igneous complex comprising meta-quartz-diorite and meta-rhyoli...
Article
Full-text available
In order to date low-temperature deformation, intensely strained muscovite porphyroclasts and neocrystallized shear band phengite from greenschist-facies shear zones have been dated by 40Ar/39Ar method in the Argentera-Mercantour massif. Shear zones are featured by gradual mylonitization of a Variscan granite, gneiss and Permian pelite protolith (3...
Article
Full-text available
The Bouillante geothermal field, located on the west coast of Guadeloupe (Lesser Antilles), was explored in the 1970s, developed in the 1980s, brought into production in 1986, and expanded in 2005 to currently produce up to 15 MWe. In addition to its electricity-producing role, the Bouillante field is an outstanding research laboratory for improvin...
Article
The Central Atlantic Magmatic Province (CAMP), emplaced at the Triassic–Jurassic (T–J) boundary (~200Ma), is among the largest igneous provinces on Earth. The Maranhão basin in NE Brazil is located around 700km inland and 2000km from the site of the earliest Pangea disruption. The CAMP tholeiites occur only in the western part of the basin and have...
Article
Keywords: Mediterranean Sardinia Early Miocene Magnetostratigraphy Biostratigraphy 40 Ar/ 39 Ar Rifting The chronostratigraphy of the lower Miocene deposits of northwestern Sardinia is refined in the Castelsardo Basin. The combination of new 40 Ar/ 39 Ar isotopic datings, 19 micropalaeontological datings (calcareous nannofossils, planktonic and lar...
Article
In the Lesser Antilles, the Plio-Pleistocene carbonate platforms have developped in a fore-arc setting on the top of a ancient (Oligo ?-Miocene) abandonned arc (Bouysse et al., 1990). These platforms are cut by normal faults and provide index beds or units that are usefull for studying the arc-parallel extension (Feuillet et al., 2001 ; 2002 ;2004)...
Article
The identification of a large OIB-type volcanic sequence on top of an obducted nappe in the Lesser Caucaus of Armenia helps us explain the obduction processes in the Caucasus region that are related to dramatic change in the global tectonics of the Tethyan region in the late Lower Cretaceous. The ophiolitic nappe preserves three distinct magmatic s...
Article
In the Lesser Caucausus the Sevan-Akera ophiolites of N Armenia have lithological features of a slow-spreading oceanic lithosphere: serpentinites are frequently exposed and hydrothermalized at sea-floor level, plutonic rocks and dykes are rare. A complete differentiation trend is observed from mafic norites evolving to diorites and plagiogranites....
Article
1. The camp and the T–J boundary The interpretation and significance of events at the Triassic– Jurassic (T–J) boundary are investigated in numerous research papers (e.g. those recently published in a special volume of this journal; Hesselbo et al., 2007), and are still matter of considerable scientific debate. The end of the Triassic is characteri...
Article
Full-text available
Eight articles are presented on the role of forests in carbon sequestration, and 5 of these are also noticed separately in CAB ABSTRACTS. Article (1) (Drenou, C. ; pp. 10-11) carries the title of the dossier, and is an introductory discussion to the topic. The next 3 papers, which are all noticed separately, are as follows: (2) Do you speak carbon?...
Article
The Central Atlantic Magmatic Province (CAMP) is among the largest igneous provinces on Earth, emplaced synchronously with or just prior to the Triassic–Jurassic (T–J) boundary ca. 200 Ma. In great part due to the controversial connection between the occurrence of CAMP and the events of the T–J boundary, the demand for better constraints on the dur...
Article
The Central Atlantic Magmatic Province (CAMP) is the world's largest known continental igneous province and is contemporaneous with the Triassic–Jurassic (T–J) boundary that marks one of the five largest biological extinctions in the last 600 Ma. Although constraints on the duration of the CAMP volcanism remain yet poorly defined, the assumption th...
Article
The 40Ar/39Ar dating technique is based on the knowledge of the age of neutron fluence monitors (standards). Recent investigations have improved the accuracy and precision of the ages of most of the Phanerozoic-aged standards (e.g. Fish Canyon Tuff sanidine (FCs), Alder Creek sanidine, GA1550 biotite and LP-6 biotite); however, no specific study ha...
Conference Paper
Full-text available
Dados preliminares sobre o magmatismo do Jurássico superior-Cretácico inferior da zona sinclinal do Oued El-Abid (Alto Atlas, Marrocos): vulcanologia, geoquímica e implicações geodinâmicas Preliminary data on the Upper Jurassic-Early Cretaceous magmatism of the Oued El-Abid synclinal zone (Central High Atlas, Morocco): volcanology, geochemistry and...
Article
Full-text available
The Central Atlantic Magmatic Province (CAMP) is among the largest igneous provinces on Earth, emplaced synchronously with or just previous to the Triassic-Jurassic boundary ca. 200 Ma. In great part due to the controversial connection between the occurrence of CAMP and the events of the Triassic-Jurassic boundary, the demand for better constraints...
Article
The Central Atlantic Magmatic Province (CAMP) is among the largest igneous provinces on Earth, emplaced synchronously with or just prior to the Triassic-Jurassic boundary ca. 200 Ma. In great part due to the controversial connection between the occurrence of CAMP and the events of the Triassic-Jurassic boundary, the demand for better constraints on...
Article
The Taoudenni basin dike swarm (northern Mali) is one of the densest dike complexes of the Central Atlantic Magmatic Province (CAMP). A combined geometrical (dike directions), geochemical (major and trace elements, Sr and Nd isotopes), and geochronological (40Ar/39Ar dating) study is presented for the first time on the dikes and sills in this area....
Article
Full-text available
The evolution of life on Earth is marked by catastrophic extinction events, one of which occurred ca. 200 Ma at the transition from the Triassic Period to the Jurassic Period (Tr-J boundary), apparently contemporaneous with the eruption of the world's largest known continental igneous province, the Central Atlantic magmatic province. The temporal r...
Conference Paper
Full-text available
A broad temporal correlation between major mass extinction events and continental flood basalt provinces has been widely recognized. In order to establish a causal link between flood volcanism and biotic turnovers, a very precise knowledge of the absolute ages is necessary. However, analytical errors (including those due to uncertainties of the dec...
Article
With the Ar-Ar method, the best way to date precisely basaltic volcanic events, is to analyze plagioclases (when possible), rather than the whole rocks for which various problems may occur (alteration, recoil of 39Ar). Plagioclases have been then widely used for Ar-Ar dating of major flood basalt volcanism such as Deccan traps or Central Atlantic M...
Article
We report the observation of an external layer, less than 20 μm thick, attached to hydrothermal chimney fragments of black smokers collected from the Pito Seamount site on the Easter microplate. Scanning electron microscope observations revealed bacterial imprints located on and within the layer, which was associated with underlying layers of thin...
Article
Previous studies of hydrothermal deposits on active sediment-starved spreading centers have shown that the lead isotope compositions of the oceanic crust are homogenized by the circulation of high temperature fluids. This averaging effect is confirmed by the homogeneity of the sulphide isotopic values at numerous sites in the Pacific ocean. Our stu...
Article
Pb isotope compositions were determined on sulfides collected from hydrothermal vent fields on the North Fiji Basin spreading ridge. On Pb-Pb diagrams, the compositions are within both the MORB field and the least radiogenic part of the NFB basalt domain. Compared with the rather large variation of Pb isotope composition of the NFB basalts, the dat...

Projects

Projects (4)
Project
A multidisciplinary platform for innovation and demonstration activities for the exploration and development of high geothermal energy in fractured reservoirs (GEOTREF). A project that seeks to improve the understanding of how fractured geothermal reservoirs function in: The exploration phase: controlling the risk of significant drilling investment without the certainty of being able to demonstrate an economically exploitable geothermal resource, The production phase: ensure sustainable exploitation of the reservoir. GEOTREF is a tool for excellence and innovation in industrial development: as such it enjoys the support of the French State through the Future Investments funds.