Gianreto Manatschal

Gianreto Manatschal
University of Strasbourg | UNISTRA · IPGS

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413
Publications
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Publications

Publications (413)
Conference Paper
Full-text available
The salt-bearing conjugate rifted margins of Morocco and Nova Scotia contain one of the oldest stratigraphic records documenting the opening history of the Central Atlantic Ocean, starting in Late Triassic times. Although there is certain consensus on the Middle Jurassic to Present evolution of this ocean basin, the Early Jurassic rift to drift tra...
Article
Full-text available
The formation of a new plate boundary and creation of the first oceanic crust, two of the most important processes of plate tectonics, still remains little understood. While older studies used to assumed a sharp ocean-continent boundary between continent and ocean, recent studies suggest a progressive ocean-continent transition (OCT) between unequi...
Article
Full-text available
Based on a high-resolution seismic reflection dataset, we describe and map rift domains at the tip of the V-shaped NW-South China Sea (NW-SCS) Basin. We compare our rift domain map with seismic refraction, magnetic and gravity field data, and with previously mapped Continent-Ocean Boundaries (COB). We also define and map syn-breakup sedimentary and...
Conference Paper
Full-text available
Fluid-rock interactions in mantle rocks that turns peridotite into serpentinite has been widely documented during the past two decades, for geological settings such as mid-ocean ridges (MOR) and subduction zones. In contrast, serpentinization at rifted margins has received much less attention, while serpentinites at these settings are largely invol...
Chapter
This chapter provides a snapshot of the state of the research on the Alpine Tethys rift system and discusses some of the new concepts and ideas that have been recently developed. It explains how the Alpine Tethys margin template was built. The chapter describes the datasets and how they were used to build the so‐called “building blocks” (BB). It ex...
Article
Full-text available
The competition between the impact of inherited weaknesses and plate kinematics determines the location and style of deformation during rifting, yet the relative impacts of these “internal” and “external” factors remain poorly understood, especially in 3D. In this study we used brittle-viscous analogue models to assess how multiphase rifting, i.e.,...
Article
Necking zones, located between the proximal and distal domains of passive margins, are characterized by important crustal thinning and the occurrence of extensional detachment faults. Here we provide a petrographic, microstructural and geochemical study of an extensional detachment fault discovered in the Mont-Blanc massif, which was located in the...
Article
Full-text available
The source of metals involved in the formation of oceanic ultramafic-hosted hydrothermal Cu-Fe-Co-Zn-Ni mineralization remains poorly constrained. Here, we focus on a fossil ultramafic-hosted hydrothermal mineralized system preserved in the Platta nappe (SE Switzerland), where mantle rocks were exhumed along detachment faults to the seafloor during...
Article
Full-text available
This contribution reviews the challenges of imaging collisional orogens, focusing on the example of the Pyrenean domain. Indeed, important progresses have been accomplished regarding our understanding of the architecture of this mountain range over the last decades, thanks to the development of innovative passive imaging techniques, relying on a mo...
Data
This data set includes videos depicting the surface evolution (time-lapse photographs and Particle Image Velocimetry or PIV analysis) of 38 analogue models, in five model series (A-E), simulating rift tectonics. In these experiments we examined the influence of differently oriented mantle and crustal weaknesses on rift system development during mul...
Article
Full-text available
Carbonation of mantle rocks during mantle exhumation is reported in present-day oceanic settings, both at mid-ocean ridges and ocean-continent transitions (OCTs). However, the hydrothermal conditions of carbonation (i.e., fluid sources, thermal regimes) during mantle exhumation remain poorly constrained. We focus on an exceptionally well-preserved...
Article
Ongoing seafloor exploration highlights that ultramafic-hosted seafloor massive sulfide deposits (UM-SMS) are ubiquitous along slow to ultra-slow spreading ridges. These deposits are closely linked to low-angle detachment faults, are hosted in variably altered ultramafic rocks and are enriched in precious (Au-Ag), critical (Co) and base metals (Cu-...
Article
Full-text available
This study is based on a careful analysis of high-quality reflection seismic sections located at the tip of the NW South China Sea V-shaped rift basin. Using the CGN-1 section, a seismic line imaging the complete sedimentary and magmatic architecture of conjugate rifted margins, we: (1) provide a detailed description of the crustal architecture; (2...
Article
Full-text available
The tectono-stratigraphic evolution of rift systems is at present poorly understood, especially the one preceding the onset of oceanic seafloor spreading. Improving our understanding of the complex, polyphase tectonic evolution of the fossil Alpine Tethys, one of the best calibrated magma-poor rift systems worldwide, offers great potential for the...
Article
Full-text available
One fundamental lesson from the last decades research into rifted margins is that stratigraphic horizons cannot be simply correlated from the proximal into distal domain, which makes the interpretation of poorly calibrated and largely inaccessible distal margins difficult. In this contribution, we propose a new tectono‐stratigraphic model to help b...
Article
Full-text available
The present-day tectonic setting of the Western Mediterranean region, from the Pyrénées to the Betics and from the Alps to the Atlas, results from a complex 3-D geodynamic evolution involving the interactions between the Africa, Eurasia and Iberia plates and asthenospheric mantle dynamics underneath. In this paper, we review the main tectonic event...
Article
Full-text available
Large uncertainties remain about the architecture, timing and role of the structures responsible for high degrees of crustal thinning and the exhumation of mid-crustal granulites in the Pyrenean and Biscay rift systems. Both, Le Danois High in the North Iberian margin and the Labourd Massif in the Western Pyrenees preserve evidence of extensional d...
Article
This study is based on a careful analysis of high-quality reflection seismic sections located at the tip of the NW South China Sea rift propagator. Using the CGN-1 section, a seismic line imaging the complete sedimentary and magmatic architecture of conjugate rifted margins, we: (1) provide a detailed description of the crustal architecture; (2) de...
Article
Full-text available
The aim of this paper is to provide a conceptual framework that integrates the role of inheritance in the study of rifts, rifted margins and collisional orogens based on the work done in the OROGEN project, which focuses on the Biscay-Pyrenean system. The Biscay-Pyrenean rift system resulted from a complex multistage rift evolution that developed o...
Article
Full-text available
The architecture and nature of the continental lithosphere result from billions of years of tectonic and magmatic evolution. Continental deformation over broad regions form collisional orogens which evolution is controlled by the interactions between properties inherited from hits long-lasting evolution and plate kinematics. The analysis of present...
Article
Full-text available
This contribution investigates the role of a hyperextended rift system in the formation of the Basque – Cantabrian Pyrenees by discussing their present‐day architecture as well as the inherited rift template. Moreover, this work attempts to decipher the onset of reactivation of a hyperextended system and to discuss the related processes during coll...
Preprint
Full-text available
The competition between the impact of inherited weaknesses and plate kinematics determines the location and style of deformation during rifting, yet the relative impacts of these “internal” and “external” factors remain poorly understood, especially in 3D. In this study we used brittle-viscous analogue models to assess how multiphase rifting, i.e.,...
Article
Full-text available
During lithospheric extension, localization of deformation often occurs along structural weaknesses inherited from previous tectonic phases. Such weaknesses may occur in both the crust and mantle, but the combined effects of these weaknesses on rift evolution remain poorly understood. Here we present a series of 3D brittle–viscous analogue models t...
Data
This data set includes videos depicting the surface evolution (time laps photographs and Particle Image Velocimetry or PIV analsys) of 15 analogue models on rift tectonics, as well as 4D CT imagery (figures and videos) from four of these experiments. The experiments examined the influence of differently oriented mantle and crustal weaknesses on rif...
Article
Full-text available
Despite considerable progress in restoring rifted margins, none of the current kinematic models can restore the Mesozoic motion of the Iberian block in full agreement with the circum‐Iberian geology. This conflict requires a revision of the kinematic description at onset of divergence. The circum‐Iberian region has a unique geological dataset that...
Article
Full-text available
We investigate the present-day orogenic architecture of the Pyrenean-Cantabrian junction corresponding to a boundary between inverted rift segments using seismic interpretation, field data and borehole information. This junction was formerly attributed to a major NNE-SSW striking Pamplona transfer fault segmenting the Basque-Cantabrian and Mauléon...
Article
The Ocean-Continent Transition (OCT) located between the edge of the continental and unequivocal oceanic crusts is an ideal laboratory to understand one of the most fundamental processes of Plate Tectonics, namely the formation mechanism of a new plate boundary, also referred to as lithospheric breakup. However, the location and architecture of the...
Article
In this study, we explore the tectono-sedimentary and magma evolution of final rifting and continental breakup along the SW conjugate margins of the South China Sea (SCS). Based on new seismic observations, we define and map three rift domains, referred to as “box-shaped”, “wedging” and “proto-oceanic”. Each of these domains is characterized by: (1...
Article
In this study, we present an interpretation of a 3D depth-migrated dataset imaging the Ocean Continent-Transition (OCT) of the southern Gabon margin. Located in an area where salt is not strongly overflowing the OCT, it allows the geometrical relationships of salt deposition and its relative timing to breakup to be determined. The OCT is formed by...
Article
Using the example of the conjugate Mozambique-Antarctica rifted margins, we investigate how mantle plume magmatism interacts with extensional processes during lithospheric rifting and breakup. The presence of extensive plume related magmatic additions formed during rifting masks the edges of the continental margins, making it difficult to determine...
Article
In accretionary convergent margins, the subduction interface is formed by a lower plate décollement above which sediments are scraped off and incorporated into the accre¬tionary wedge. During subduction, the basal décollement is typically located within or at the base of the sedimentary pile. However, the transition to collision implies the accre¬t...
Article
Serpentinisation and concomitant reduction of CO2 to methane at modern hydrothermal vents has been observed to support methanotrophic biosystems at mid-ocean ridges. Exhumation of mantle within ocean regions and its subsequent serpentinisation is a common occurrence. It is possible that methanotrophy is not restricted to hydrothermal vents systems...
Preprint
Full-text available
During lithospheric extension, localization of deformation often occurs along structural weaknesses inherited from previous tectonic phases. Such weaknesses may occur in both the crust and mantle, but the combined effects of these weaknesses on rift evolution remains poorly understood. Here we present a series of 3D brittle-viscous analogue models...
Article
Full-text available
The interaction between magmatic and extensional processes related to the formation of rifted margins has been and still is highly debated. The interpretation of magmatic additions, timing of onset and budget of magma during rifting remains controversial and poorly constrained. In this study we explore the emplacement of magmatic additions in a rif...
Article
We analyzed high-quality seismic reflection profiles across the ocean-continent transition in the Enderby Basin between the Kerguelen Plateau and the Antarctic margin. There, we observe numerous high-amplitude dipping reflections in the lower oceanic crust which was accreted at a magmatic spreading center as testified by the almost uniform 6.4-7 km...
Article
The association of mafic extrusive rocks and serpentinized mantle rocks is a common feature encountered in numerous ultra-distal magma-poor rifted margins as well as in (ultra)slow-spreading oceanic settings where detachment faulting and mantle exhumation occur. Although seismic imaging and high-resolution TOBI radar allow imaging this association,...
Article
Current rift models propose polyphase rift evolutions that develop with the same kinematic framework and accommodate continuous and sequential extension, through the stacking of deformation modes. Several rifted margins show, however, evidence for multiple and out of sequence rift events, which developed within different kinematic frameworks, with...
Article
Full-text available
The Basque-Cantabrian junction corresponds to an inverted rift accommodation zone at the limit between the former hyperextended Pyrenean and Cantabrian rift segments. The recognition of an inherited rift segment boundary allows to investigate the reactivation associated with large-scale rift segmentation in an orogenic system. We use criteria from...
Article
Full-text available
The Grès Singuliers unit represents an anomalous occurrence of a siliciclastic-dominated sedimentary system typifying a restricted geographic area around the Mont Blanc massif. Deposited during Early Jurassic rifting, this unit was influenced by the tectonic processes responsible for its development. This contribution integrates and reconciles sedi...
Conference Paper
Full-text available
In this work, we address the problem of the formation and reactivation of multi-stage rifting based on the study of the central North Iberian margin, located at the southern Bay of Biscay triangular oceanic domain. This magma-poor rifted margin registered three major Mesozoic rift events and a subsequent Alpine compressional reactivation, represent...
Article
We used high-resolution (500 × 250 m) two-dimensional lithospheric-scale thermo-mechanical numerical modeling to unravel the unexpected topographic and thermal evolutions recorded during the necking phase of several rift systems worldwide. Through a systematic analysis we studied how the lithosphere rheology impacts the topographic and thermal evol...
Article
Lithospheric breakup is generally defined as the process that results in a new plate boundary and oceanic crust. However, how this process occurs in magma‐poor systems remains debated. As recently suggested, the J magnetic anomaly at the Iberia‐Newfoundland margins has polygenic sources and therefore cannot be interpreted as an isochron. However, t...
Article
Full-text available
The evolution of hyperextended rift systems is linked to complex tectonic processes in which fluid activity is much more important than previously thought. This study sheds light on the fluid-sediment interactions within the distalmost parts of the Mauléon-Arzacq hyperextended basin (Western Pyrenees) focusing on the post-depositional modifications...
Article
The mechanism by which seaward dipping reflectors (SDRs) are formed is a topic of debate. Two contrasting models exist for their formation, the volcanic-faulting model and the volcanic-loading model. Each of these models has important implications for the processes which control the structure and formation of magma-rich rifted continental margins....
Article
Rifted margins have been extensively studied, however there are still many important questions related to their formation processes. We use the Iberia-Newfoundland conjugate rifted margins as a natural laboratory to investigate how much extension is required to produce crustal rupture and separation. To achieve our aim we use; (i) gravity anomaly i...
Article
Full-text available
This contribution presents the analysis of a data set that was put together in the PhD thesis of Jordi Miró which is part of the OROGEN Project. The Basque – Cantabrian Pyrenees, that are the focus of this report, have been extensively studied over the last years. Several open debates in the Earth Science community aroused from this realm regarding...
Article
Full-text available
Mid‐Ocean Ridges host various types of hydrothermal systems including high‐T black‐smokers found in ultramafic rocks exhumed along slow spreading ridges. These systems are mostly described in two dimensions as their exposure on the present‐day seafloor lacks the vertical dimension. One way to understand these systems at depth is to study their foss...
Article
The Jurassic Chenaillet ophiolite in the Western Alps consists of a gabbro–mantle association exhumed to the seafloor through detachment faulting and partly covered by basaltic lavas. One of the Chenaillet gabbroic bodies includes mylonites that are transected by a network of felsic veins, thereby testifying to the interplay of ductile shearing and...
Article
Full-text available
Magma-poor ocean-continent transitions at distal rifted margins record complex stratigraphic interactions engendered by extreme crustal thinning and mantle exhumation. The Tasna ocean-continent transition, exposed in the Middle Penninic Tasna nappe in eastern Switzerland, is so far the only known example where the lateral transition from continenta...
Article
Basalts exposed in the Platta and Tasna nappes (SE Switzerland) derive from the Alpine‐Tethys Ocean‐Continent Transitions (OCT) and overlie SubContinental Lithospheric Mantle (SCLM). We show that the trace element signatures of these basalts differ from Mid‐Ocean Ridge Basalts (MORB). Two types of basalts occur in the OCT: a type‐1 showing a “garne...
Article
Full-text available
The South China Sea margins represent a critical natural laboratory to study the processes and parameters controlling the rift-to-drift transition. High quality seismic data previously suggested the occurrence of a relatively sharp transition between the continental and oceanic domains, a hypothesis recently validated by the results of the IODP Exp...
Article
High‐quality, long offset seismic data from many distal rifted margins show evidence for hyper‐extended, <10‐km‐thick crust. Direct observation of such domains is challenging as they lie, at great water depth, buried beneath thick sedimentary sequences and formed by rock‐assemblages that are hydrated and geophysically indistinguishable. Only a few...
Article
We investigate the thermal and structural evolution of asymmetric rifted margin using numerical modeling and geological observations derived from the Western Pyrenees. Our numerical model provides a self-consistent physical evolution of the top basement heat flow during asymmetric rifting. The model shows a pronounced thermal asymmetry that is caus...
Article
Despite the fact that many studies have investigated mantle exhumation at ultra-slow-spreading ridges and magma-poor rifted margins, there are still numerous questions concerning the 3D architecture, magmatic, fluid, and thermal evolution of these domains that remain unexplained. Indeed, it has been observed in seismic data from ultra-distal magma-...