Arnauld Heuret

Arnauld Heuret
Université de Guyane - UMR5243 Géosciences Montpellier · DFR Sciences et Technologies

About

80
Publications
13,389
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2,653
Citations
Citations since 2016
42 Research Items
1366 Citations
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200

Publications

Publications (80)
Article
Full-text available
At subduction zones, fluid circulation and elevated pore pressure are key factors controlling the seismogenic behavior along the plate interface by reducing absolute fault strength, increasing the time return of high magnitude co-seismic rupture and favoring aseismic slip. The Lesser Antilles is an end-member subduction zone where the slow subducti...
Preprint
Full-text available
The Great Amazon Reef System is a living biogenic mesophotic reef ecosystem that has been recently described along the shelf break of Brazil. An exploration mission was carried out in 2019 along the outer edge of the French Guiana Shelf. A side-scan sonar survey was conducted to locate reef outcrops and allowed twelve in situ 80 to 120 m depth dive...
Preprint
Full-text available
The Great Amazon Reef System is a living biogenic mesophotic reef ecosystem that has been recently described along the shelf break of Brazil. An exploration mission was carried out in 2019 along the outer edge of the French Guiana Shelf. A side-scan sonar survey was conducted to locate reef outcrops and allowed twelve in situ 80 to 120 m depth dive...
Article
The prison heritage of French Guiana and New-Caledonia consists of remains of great value, both for their integrity and the fact that they reflect a shared history to those two territories. The prison colonisation of these two old colonies by France from 1852 to 1953 has led to the sending of more than 100,000 convicts with the aim to encourage the...
Article
Full-text available
On Earth, the velocity at which subducting plates are consumed at their trenches (termed “subduction rate” herein) is typically 3 times higher than trench migration velocities. The subduction rate is also 5 times higher than estimated lower mantle slab sinking rates. Using simple kinematic analyses, we show that if this present‐day “kinematic state...
Article
As operational concept, geodiversity implies a measurement and its application narrowed to a given spatial area, allowing the identification of clusters for prioritization and planning purposes. This study proposes a first geodiversity index assessment for French Guiana, a French Oversea territory located within the Guiana Shield (South America). A...
Conference Paper
Full-text available
As operational concept, geodiversity implies a measurement and its application narrowed to a given spatial area. However, such concept is often integrated to support planning perspectives that focus mostly on geoconservation. Furthermore, diversity alone might not account for the contribution of abiotic and interfacial resources to socio-ecological...
Preprint
Full-text available
On Earth, the velocity at which subducting plates are consumed at their trenches (termed `subduction rate' herein) is typically 3 times higher than trench migration velocities. The subduction rate is also 5 times higher than estimated lower mantle slab sinking rates. Using simple kinematic analyses, we show that if this present-day ``kinematic stat...
Article
Transform marginal Plateaus (TMPs) are large and flat structures commonly found in deep oceanic domains, but origin and relationship to adjacent oceanic lithosphere remain poorly understood. This paper focuses on two conjugate TMPs, the Demerara Plateau off Suriname and French Guiana and the Guinea Plateau, located at the junction of the Jurassic C...
Article
During the end of the lower Cretaceous, the connection between the South and the Central Atlantic accretionary axis led to the oblique opening of the Equatorial Atlantic, and to the separation of Africa and South America by alternating transform and rift margins. At the western end of the Equatorial Atlantic, we investigate the structure of the Cre...
Article
The mineral system concept, which combines integrated information from all kinds of geological and geophysical studies, is a very useful approach to predict and locate structures and lithologies potentially associated with gold mineralization at all scales (i.e., upscaling from craton-to district-to camp-to deposit-scale). This is demonstrated in t...
Article
The Couriège prospect (French Guiana) provides key examples of the diversity of gold distribution related to supergene processes. The nature of gold in two contrasted weathering profiles is examined as a function of the weathering lithofacies. The autochthonous profile hosts weathered Au-bearing quartz veins whereas the pediment profile is enriched...
Article
The Yaou deposit, located in French Guiana within the Guiana Shield, is one of the most promising gold deposits of the regional Palaeoproterozoic greenstone belt. It displays numerous quartz monzodiorite bodies aligned along a sinistral shear zone where a five-deformation phases model is established at the camp scale. The ductile D 1/2YA phase is r...
Article
The Grenada Basin separates the active Lesser Antilles Arc from the Aves Ridge, described as a Cretaceous‐Paleocene remnant of the “Great Arc of the Caribbean.” Although various tectonic models have been proposed for the opening of the Grenada Basin, the data on which they rely are insufficient to reach definitive conclusions. This study presents,...
Poster
Full-text available
A precise 1/125e geological mapping together with multiapproach study (deformation, back-scattered imaging, U-Pb and Ar-Ar dating, petro-geochemistry) of amphibolite, métrondhjemite, metagabbro and tonalitic units outcropping in French Guiana. These samples are part of the Amazonian Carton and provides strong constraints on the early evolution of t...
Article
Full-text available
Subduction megathrusts host the Earth’s greatest earthquakes as the 1960 Valdivia (M w 9.5, Chile), the largest earthquake instrumentally recorded, and the recent 2004 Sumatra-Andaman (M w 9.2, Indonesia), 2010 Maule (M w 8.8, Chile), and 2011 Tohoku-Oki (M w 9.1, Japan) earthquakes triggering devastating tsunamis and representing a major hazard to...
Article
French Guiana is well endowed with gold, yet it has no industrial mines, and most of the current production comes from illegal Brazilian miners (garimpeiros). This situation is rooted in its extractive frontier history, beginning with the first gold discovery in 1855. Two gold rushes, influenced primarily by gold prices, took place in the late 19th...
Article
Full-text available
We report the discovery of 173.4 Ma hotspot-related magmatic rocks in the basement of the Demerara Plateau, offshore French Guiana and Suriname. According to plate reconstructions, a single hotspot may be responsible for the magmatic formation of (1) both the Demerara Plateau (between 180 and 170 Ma) and the Guinea Plateau (circa 165 Ma) during the...
Article
Numerous submarine plateaus form highstanding bathymetric highs at continent to ocean transitions. Due to their proximity to continents, they have been frequently labelled “marginal plateaus”, although this term has not been clearly defined or associated with a specific geology or geodynamic process. Until now, these elevations have been interprete...
Article
The role of seafloor roughness on the seismogenic behavior of subduction zones has been increasingly addressed over the past years, although their exact relationship remains unclear. Do subducting features like seamounts, fracture zones, or submarine ridges act as barriers, preventing ruptures from propagating, or do they initiate megathrust earthq...
Article
We have developed a new approach to characterize the seafloor roughness seaward of the trenches, as a proxy for estimating the roughness of the subduction interface. We consider that abrupt elevation changes over given wavelengths play a larger role in the seismogenic behavior of the subduction interface than the amplitude of bathymetric variations...
Article
The observed maximum magnitude of subduction megathrust earthquakes is highly variable worldwide. One key question is which conditions, if any, favor the occurrence of giant earthquakes (Mw ≥ 8.5). Here we carry out a multivariate statistical study in order to investigate the factors affecting the maximum magnitude of subduction megathrust earthqua...
Article
Full-text available
Les écosystèmes des Guyanes comptent aujourd’hui parmi les plus riches et complexes sur Terre, mais qu’en était-il dans le passé ? De récentes avancées dans l’analyse des restes fossiles découverts en Amazonie permettent une plongée dans les profondeurs du temps, à la découverte d’organismes étonnants, parfois aux frontières de l’imaginable.
Chapter
Subduction zones are characterized by multiple behaviors, dynamics, or geometries. Most of them results from the complex interplay between various parameters. In this article, we define the most common parameters used by scientists and then mention the studies where (set of) parameters are tested empirically, or experimentally. We also focus on the...
Conference Paper
Full-text available
Heat-flow measurements acquired during the Antithesis Cruise in the Northern Lesser Antilles reveal an atypical heat-flow trend, from the trench to the margin forearc, where the subducting crust consists of exhumed and serpentinized mantle rocks (see Marcaillou et al. same session). We investigate the thermal structure of the Lesser Antilles subduc...
Article
Giant earthquakes (MW?8.5) usually occur on the boundary between subducting and overriding plates of converging margins, but it is not yet clear which (if any) subduction zones are more prone to produce such a kind of events. Here we show that subduction zones may have different capabilities to produce giant earthquakes. We analyze the frequency-ma...
Article
Full-text available
The IGUANES cruise took place in May 2013 on the R/V L’Atalante along the Demerara passive transform margin off French Guiana and Surinam. Seismic, multibeam and chirp acquisitions were made. Piston cores were collected for pore geochemistry and sedimentology. A mooring was deployed on the sea-bottom for 10 months (temperature, salinity, turbidity...
Article
Full-text available
Les fonds marins du Plateau des Guyanes sont nés lorsque le supercontinent du Gondwana s’est déchiré, il y a près de 100 millions d’années. Les géologues s’intéressent aujourd’hui particulièrement à une zone charnière de cette déchirure continentale, le plateau sous-marin de Demerara, exploré au cours de la mission océanographique IGUANES. Publish...
Article
The Demerara plateau, located offshore French Guiana and Suriname, is part of a passive transform continental margin particularly prone to develop slope instabilities, probably in relation to the presence of a free distal border along its steep continental slope. Slope failure occurred at different periods (Cretaceous to Neogene) and shows an overa...
Conference Paper
Full-text available
Past studies have shown that high coastal uplift rates are restricted to active areas, especially in a subduction context. The origin of coastal uplift in subduction zones, however, has not yet been globally investigated. Quaternary shorelines correlated to the last interglacial maximum (MIS 5e) were defined as a global tectonic benchmark (Pedoja e...
Article
Full-text available
Past studies have shown that high coastal uplift rates are restricted to active areas, especially in a subduction context. The origin of coastal uplift in subduction zones, however, has not yet been globally investigated. Quaternary shorelines correlated to the last interglacial maximum (MIS 5e) were defined as a global tectonic benchmark (Pedoja e...
Article
The majority of global seismicity originates at subduction zones, either within the converging plates or along the plate interface. In particular, events with Mw ≥ 8.0 usually occur at the subduction megathrust, which is the frictional interface between subducting and overriding plates. Consequently, seismicity at subduction megathrusts is responsi...
Article
Full-text available
At a subduction zone the amount of friction between the incoming plate and the forearc is an important factor in controlling the dip angle of subduction and the structure of the forearc. In this paper, we investigate the role of the frictional strength of sediments and of the serpentinized peridotite on the evolution of convergent margins. In numer...
Article
In the framework of the EURYI Project 'Convergent margins and seismogenesis: defining the risk of great earthquakes by using statistical data and modelling', a global collection of recent intraslab seismicity has been performed. Based on EHB hypocenter and CMT Harvard catalogues, the hypocenters, nodal planes and seismic moments of worldwide subduc...
Article
The occurrence of the last mega-thrust earthquake in Japan has clearly remarked the high risk posed to society by such events in terms of social and economic losses even at large spatial scale. The primary component for a balanced and objective mitigation of the impact of these earthquakes is the correct forecast of where such kind of events may oc...
Article
Subduction zones are the site of the largest and most dangerous seismic events occurring on the Earth. The interface of converging plates is comprised of major fault zones where most of the total seismic moment is released due to the global seismicity. Despite first order similarities between convergent margins, the statistical distribution of inte...
Article
Full-text available
1] Giant earthquake (moment magnitude M w ≥ 8.5) forecasts for subduction zones have been empirically related to both tectonic stresses and geometrical irregularities along the subduction interface. Both of these controls have been suggested as able to tune the ability of rupture to propagate laterally and, in turn, exert an important control on gi...
Article
The occurrence of the last mega-thrust earthquake in Japan has clearly remarked the high risk posed to society by such events in terms of social and economic losses even at large spatial scale. The primary component for a balanced and objective mitigation of the impact of these earthquakes is the correct forecast of where such kind of events may oc...
Article
In the framework of the EURYI Project 'Convergent margins and seismogenesis: defining the risk of great earthquakes by using statistical data and modelling', a global collection of recent intraslab seismicity has been performed. Based on EHB hypocenter and CMT Harvard catalogues, the hypocenters, nodal planes and seismic moments of worldwide subduc...
Article
Extreme seismic events (Mw 8.5 and higher) are uniformly characterized by trench-parallel rupture lengths longer than about 250 km, whereas downdip rupture width ranges from less than 70 km (e.g., Central Aleutians) to more than 200 km (e.g., Andaman-Sumatra). The ability of rupture to propagate in the trench-parallel direction thus appears to play...
Article
The subduction interplate domain (considered either as a plane or a channel, depending on the setting), is an interface of seismogenic coupling at the scale of one seismic cycle but also of kinematic decoupling on long-term time scales. The properties of this very particular interface is likely to affect not only the seismogenic potential of the su...
Article
Gelatin and sand paper as analogs of lithosphere and subduction faultFriction dynamics depends on loading rate, normal load and roughnessFriction rate parameter is negative for specific roughness amplitude/spacing values
Article
Estimates of slab curvature from 133 profiles across 12 major subduction zones are obtained by fitting splines through earthquakes locations. Several geometric quantities are computed from the spline fits, including the minimum radius of curvature. We also introduce a quantity called the equivalent radius of curvature to precisely define the bendin...
Article
Full-text available
1] Based on global earthquake catalogs, the hypocenters, nodal planes, and seismic moments of worldwide subduction plate interface earthquakes were extracted for the period between 1900 and 2007. Assuming that the seismogenic zone coincides with the distribution of 5.5 ≤ M < 7 earthquakes, the subduction inter-face seismogenic zones were mapped for...
Article
Based on the Centennial earthquake catalog, the revised 1964-2007 EHB hypocenters catalog and the 1976-2007 CMT Harvard catalog, we have extracted the hypocenters, nodal planes and seismic moments of worldwide subduction earthquakes for the 1900-2007 period. For the 1976-2007 period, we combine the focal solutions provided by Harvard and the revise...
Article
Deformation of both subducting and overriding at convergent plate boundaries tends to dissipate energy that would otherwise be used to drive plate motions. For subducting plates, the magnitude of the bending deformation is not known because of poor constraints on slab strength. For overriding plates, back-arc orogeny results from upper plate shorte...
Data
Full-text available
Laboratory models have been conducted to improve our understanding of the role that the resistance of the slab to bending and its coupling to the ambient mantle play in subduction dynamics over geological time scales. Our models are set up with a viscous plate of silicone (lithosphere) subducting under negative buoyancy in a viscous layer of glucos...
Article
Although subducting slabs undergo a bending deformation that resists tectonic plate motions, the magnitude of this resistance is not known because of poor constraints on slab strength. However, because slab bending slows the relatively rapid motions of oceanic plates, observed plate motions constrain the importance of bending. We estimated the slab...
Article
Laboratory models have been conducted to improve our understanding of the role that the resistance of the slab to bending and its coupling to the ambient mantle play in subduction dynamics over geological time scales. Our models are set up with a viscous plate of silicone (lithosphere) subducting under negative buoyancy in a viscous layer of glucos...
Article
Full-text available
1] New estimates of trench migration rates allow us to address the dynamics of trench migration and back-arc strain. We show that trench migration is primarily controlled by the subducting plate velocity V sub , which largely depends on its age at the trench. Using the hot and weak arc to back-arc region as a strain sensor, we define neutral arcs c...
Article
The motion of oceanic plates is commonly related to the subduction of cold and dense oceanic material into the mantle. These models predict plate velocities from subduction velocities but the trench motion is not directly included in the computation. Here, using a recent compilation of a global data set, we found that the motion of trenches (either...