Joao C. Duarte

University of Lisbon | UL · Department of Geology

Subduction zones and their associated slabs are the main drivers of plate tectonics and mantle flow, but how these zones initiate remains enigmatic. In the Scotia Sea region, subduction started in the Late Cretaceous/Early Cenozoic in a pristine ocean basin setting devoid of other subduction/collision zones. How this subduction zone initiated remai...

Subduction provides the primary driving force for plate tectonics. However, the mechanisms leading to the formation of new subduction zones remain debated. An example is the Lesser Antilles Arc in the Atlantic. Previous initiationmechanisms have implied the transmission of subduction from the Pacific Ocean or the impact of a plume head. Here, we us...

Dynamics of Plate Tectonics and Mantle Convection, written by specialists in the field, gathers state-of-the-art perspectives on the dynamics of plate tectonics and mantle convection. Plate tectonics is a unifying theory of solid Earth sciences. In its initial form, it was a kinematic theory that described how the planet’s surface is fragmented int...

Subduction initiation is a cornerstone of the Wilson cycle. It marks the turning point in an ocean’s lifetime, allowing its lithosphere to be recycled into the mantle. However, formation of new subduction zones in Atlantic-type oceans is challenging, given that it commonly involves the action of an external force, such as the slab pull from a nearb...

The severe "Snowball Earth" glaciations proposed to have existed during the Cryogenian period (720 to 635 million years ago) coincided with the breakup of one supercontinent and assembly of another. Whereas the presence of extensive continental ice sheets predicts a tidally energetic Snowball ocean due to the reduced ocean depth, the supercontinent...

Earthquake hazard analyses rely on seismogenic source models. These are designed in various fashions, such as point sources or area sources, but the most effective is the three-dimensional representation of geological faults. We here refer to such models as fault sources. This study presents the European Fault-Source Model 2020 (EFSM20), which was...

Continental collision occurs when two continents are dragged towards each other by the pull of the attached subducting oceanic lithosphere. Previous geodynamic modeling studies of collisional systems focused on first-order processes (such as coupled/decoupled regimes, continental delamination, slab break-off dynamics) and regional or even local sca...

Ophiolites are exposed remnants of oceanic lithosphere that are critical to our understanding of the structure, composition, and evolution of oceanic plates. Some ophiolites (e.g., some Tethyan-type ophiolites) originate in the oceanic forearc of an intra-oceanic subduction system (i.e., in the overriding plate). If the trailing edge of the subduct...

Subduction initiation is a cornerstone of the Wilson cycle. It marks the turning point in an ocean's lifetime, allowing its lithosphere to be recycled into the mantle. However, formation of subduction zones in Atlantic-type oceans is challenging, given it commonly involves the action of an external force, such as the slab pull from a nearby subduct...

Oceanic natural hazards pose threats to coastal communities worldwide. These include earthquakes, tsunamis, submarine landslide, volcanic eruptions, and tropical cyclones. Scientific ocean drilling can contribute to our understanding and assessment of these hazards through rapid response measurements of hazardous events, learning from past hazard r...

Earthquake hazard analyses rely on the availability of seismogenic source models. These are designed in different fashions, such as point sources or area sources, but the most effective is the three-dimensional representation of geological faults. We here refer to such models as fault sources. This study presents the European Fault-Source Model 202...

While subduction is known to be the primary driving force of plate tectonics, the mechanisms leading to the formation of new subduction zones remain debated. Here, we use large scale 3D geodynamic numerical models to simulate the evolution of the Cretaceous Caribbean region, a locus where the eastern Pacific subduction system triggered the formatio...

Numerical modelling of rifting has been focused on cases involving extension and breakup of the continental lithosphere. However, the oceanic lithosphere has also been known to undergo rifting in specific geo-tectonic settings, as in the case of the Terceira ridge in the Azores triple junction (N-Atlantic). The rift-to-drift evolution of a segment...

Ophiolites are exposed remnants of oceanic lithosphere that are emplaced onto a continental domain, and Tethyan-type ophiolites, specifically, are those that are emplaced within a continental passive margin. The emplacement process for this type of ophiolites occurs when a continental passive margin subducts, and subsequently exhumes, beneath an oc...

Evolution of the Caribbean region showing a subduction polarity reversal event (forming the Antilles arc), re-start of subduction zone at the back of the Caribbean plateau and the generation of a LIP (CLIP).

The Himalaya and the Tibetan plateau, the highest mountain range on Earth, have been growing continuously for the last 55 Myr since India collided with Eurasia. The forces driving this protracted mountain building process are still not fully understood. Although subduction zones are considered the main driving force for plate tectonics, mantle flow...

Plate tectonics is the unifying theory of solid earth sciences. It describes that the surface of the Earth is divided into several lithospheric tectonic plates that move in relation to each other and over the less viscous asthenosphere. Many of the fundamental geological phenomena occur along the plate's boundaries, such as earthquakes and volcanoe...

Because of tectonics, oceans change shape, leading to changes in the tides. We know that past tides have gone through a series of short-lived maxima above a low-energy state, but what will happen in the future? Here we present four scenarios of how the future might tectonically develop. In all four scenarios the Atlantic will continue to grow and t...

The relationship between tides and tectonics is an important part of the Earth system, but plate tectonics as we know it has not existed on Earth for its entire history. So, what did the tides look like in the period between the Moon forming event (4500 Ma) and the start of plate tectonics (around 2500 Ma)? This period was divided into the Hadean (...

Earth is ~ 4600 million years old. An immense time for human times scales. Since its formation, Earth has undergone many changes, including the formation of oceans, kick start of plate tectonics, climate changes, and the emergence of life. To study these past events, earth scientists have to rely on the observation of the geological record. Over th...

In this book, I have asked experts to write perspective papers on plate tectonics and mantle convection. Over the last century, our understanding of the solid Earth has completely revolutionized. It began with the continental drift theory of Wegener. Then everything changed with the discovery of ocean spreading and the formalization of the theory o...

A thorough exploration of the fascinating evolution of tides through the Earth’s history and their impacts on the Earth Did you know that the size of the full moon in the night sky is determined by how the continents have been arranged on Earth throughout its history? This is indeed the case, because the tides are largely controlled by the size of...

Subduction zones have recurrently formed on Earth. Previous studies have, however, suggested that they are unlikely to start in the interior of a pristine ocean. Instead, they seem to be more likely to form from another pre-existing subduction zone. One widely cited conceptual model to start new subduction zones is polarity reversal, resulting from...

Subduction zones have recurrently formed on Earth. Previous studies have, however, suggested that they are unlikely to start in the interior of a pristine ocean. Instead, they seem to be more likely to form from another pre-existing subduction zone. One widely cited conceptual model to start new subduction zones is polarity reversal, resulting from...

During the early stages of continental rift, two main grabens are often formed in the upper crust. This double graben structural pattern is typically short-lived, only briefly accommodating rift-related extension. Although the formation and evolution of this structural pattern could be related to the existence of different types of (pre-rift) inher...

Oceanic lithosphere worldwide is younger than ca. 200 Myr, suggesting that it must have been globally recycled by the recurrent formation of new subduction zones since the existence of subduction on Earth. However, postulated subduction zone initiation processes remain difficult to explain in many cases, and the specific geodynamic conditions under...

Processes within the Earth shape and influence the surface environment and the emergence and evolution of life. Our Editorial board members outline recent advances and future directions in our attempt to understand the history of our planet and its environment. Processes within the Earth shape and influence the surface environment and the emergence...

We explore two possible Earth climate scenarios, 200 and 250 million years into the future, using projections of the evolution of plate tectonics, solar luminosity, and rotation rate. In one scenario, a supercontinent forms at low latitudes, whereas in the other it forms at high northern latitudes with an Antarctic subcontinent remaining at the sou...

The Earth’s surface is constantly being recycled by plate tectonics. Subduction of oceanic lithosphere and delamination of continental lithosphere constitute the two most important mechanisms by which the Earth’s lithosphere is recycled into the mantle. Delamination or detachment in continental regions typically occurs below mountain belts due to a...

The study of extensional structures such as normal faults, grabens and rift systems using analogue modelling techniques has been widely used to understand the evolution of sedimentary basins. These have been particularly helpful to understand the generation of oil reservoirs and structural traps. The present work was inspired by the discussion on t...

Cruise No. M162 06.03.2020 – 11.04.2020 Ponta Delgada (Portugal) – Emden (Germany) GLORIA-FLOW

In typical subduction systems, plate convergence is subperpendicular to the trench. The Gibraltar Arc System is exceptional, with its narrow subduction arc oriented N‐S and laterally “squeezed” by the NNW‐SSE tectonic convergence between Nubia and Iberia. The extent to which the slab is still coupled to the surface and how it interacts actively wit...

The Earth is currently 180 Myr into a supercontinent cycle that began with the break-up of Pangaea and which will end around 200–250 Myr (million years) in the future, as the next supercontinent forms. As the continents move around the planet they change the geometry of ocean basins, and thereby modify their resonant properties. In doing so, oceans...

Extensional structures such as rift systems and grabens have been widely studied through analogue and numerical modelling, since these techniques started to be used by the oil industry to understand structural traps. We have performed a study using both analogue and numerical modelling that was inspired by the initial stage of development of the Ne...

Abstract. The Earth is currently 180 Ma into a supercontinent cycle that began with the breakup of Pangea, and will end in around 200–250 Ma (Mega-annum) in the future, as the next supercontinent forms. As the continents move around the planet, they change the geometry of ocean basins, and thereby modify their resonant properties. In doing so ocean...

The India-Asia collision has formed the highest mountains on Earth and is thought to account for extensive intraplate deformation in Asia. The prevailing explanation considers the role of the Pacific and Sunda subduction zones as passive during deformation. Here we test the hypothesis that subduction played an active role and present geodynamic exp...

Supporting GPlates files of the kinematic reconstructions of the four future tectonic scenarios presented in (Davies et al., 2018).

The Alpine orogeny is well recorded onshore and offshore by tectonic inversion of the Mesozoic rift basins. Large scale linear seamounts (more than 250 km long and with up to 5 km of uplift) involving oceanic and continental lithosphere were carried on top of thrusts, such as the Gorringe seamount and the Estremadura Spur in the SouthWest and West...

Crustal shearing of pre-tectonic weak bodies (e.g. salt pillows, igneous pockets) associated with basement strike-slip fault systems is common in nature. Yet the structural pattern arising from the interference between a brittle shear zone and such weak rheological heterogeneities is still not fully explained. In the present work, different sand-bo...

Deep time investigations have revealed that supercontinents formed periodically over Earth history. The dispersal and aggregation of supercontinents led to the opening and closing of oceanic basins, e.g., the Atlantic, which formed as the result of the breakup of the latest supercontinent, Pangea. Recently, we explored how the next supercontinent w...

Marine transform faults and associated fracture zones (MTFFZs) cover vast stretches of the ocean floor, where they play a key role in plate tectonics, accommodating the lateral movement of tectonic plates and allowing connections between ridges and trenches. Together with the continental counterparts of MTFFZs, these structures also pose a risk to...

Transform Plate Boundaries and Fracture Zones bridges the gap between the classic plate tectonic theory and new emerging ideas, offering an assessment of the state-of-the-art, pending questions, and future directions in the study of transform plate boundaries and fracture zones. The book includes a number of case studies and reviews on both oceanic...

On the 1st of November 1755, a giant 8.7 magnitude earthquake struck off the coast of Portugal, destroying the city of Lisbon. The seismic event and the following tsunami triggered the interest of philosophers and contributed to the development of modern seismology. In 1969, a 7.9 magnitude earthquake struck in the same region. This was the time wh...

While continental break-up, formation of Atlantic-type (i.e. passive) margins and subduction dynamics are now fairly well understood, a comprehensive understanding of the full dynamics of subduction initiation is yet to be achieved. This is mainly because there is no ongoing evidence of spontaneous subduction initiation (Stern and Gerya, 2017) and...

The Cryogenian (720-635 million years (Ma) ago) was a period in Earth's history of prolonged and severe glaciations, known as "Snowball Earth". The two main glaciations were probably near-global in extent, and the first of these (the Sturtian glaciation) lasted over 55 Ma, from about 715-660 Ma. The second, the Marinoan, "only" lasted 15 Ma, betwee...

We discuss crustal surface velocities in the Gibraltar Arc System derived from around 150 GPS sites in Iberia and Morocco operating between 1995 and 2018. The estimated velocity field shows patterns that are strongly correlated with other geophysical constraints (tomographically imaged velocity anomalies, SKS-splitting, etc.) including seismicity p...

The development of extensional structures such as rifts and grabens within the context of sedimentary basins has been studied through analogue modelling since it was first applied to understand structural traps by the oil industry. Several studies have been carried out since, to understand the evolution of sedimentary basins and some of the structu...

The geological relevance of rotating rigid inclusions embedded in a viscous matrix has been profusely addressed in the literature (e.g. Ghosh and Ramberg 1976; Passchier and Trouw 1996; Marques et al. 2014 and references therein), in which it has been shown that the mechanics of such systems bears within critical tectonic implications, since their...

The collision between India and Asia has pushed up the Himalayas and has been the main driver for formation of the Tibetan plateau. In the current paradigm, the collision is responsible for all intraplate continental deformation in East Asia covering ∼32 million square km, stretching from Indonesia in the south to eastern Siberia in the north, incl...

The theory of plate tectonics and the discovery of large scale, deep-time cycles, such as the Supercontinent cycle and Wilson cycle, has contributed to the identification of several supercontinents in Earth's history. Using the rules of plate tectonic theory, and the dynamics of subduction zones and mantle convection, it is possible to envisage sce...

One of the conundrums in plate tectonics is what the next supercontinent will look like. The idea of the existence of the past supercontinent Pangaea was a key element in the concept of continental drift proposed by Alfred Wegener. This implied that the Atlantic Ocean formed as a consequence of the breakup of Pangaea. During the advent of the plate...

Upper crustal propagation of sub-vertical strike-slip faults across relatively softer (i.e. low viscosity) bodies is investigated through a series of analogue modelling experiments. The low viscosity bodies are here generally considered in sensu lato and could potentially represent crustal magmatic chambers, evaporitic dome-like structures, or othe...

Earth is 180 Myr into the current Supercontinent cycle and the next Supercontinent is predicted to form in 250 Myr. The continuous changes in continental configuration can move the ocean between resonant states, and the semi‐diurnal tides are currently large compared to the past 252 Myr due to tidal resonance in the Atlantic. This leads to the hypo...

Overriding plate topography provides constraints on subduction zone geodynamics. We investigate its evolution using fully dynamic laboratory models of subduction with techniques of stereoscopic photogrammetry and particle image velocimetry. Model results show that the topography is characterized by an area of forearc dynamic subsidence, with a magn...

The NW-SE striking Otway Basin in southeastern Australia is part of the continental rift system that formed during the separation of Australia from Antarctica. The development of this sedimentary basin occurred in two phases of Late Jurassic-Early Cretaceous and Late Cretaceous rifting. The evolution of this basin is mainly associated with extensio...

The Gulf of Cadiz seismicity is characterized by persistent low to intermediate magnitude earthquakes, occasionally punctuated by high magnitude events such as the M ~ 8.7 1755 Great Lisbon earthquake and the M = 7.9 event of February 28th, 1969. Micro-seismicity was recorded during 11 months by a temporary network of 25 ocean bottom seismometers (...

We present new analogue modelling results of crustal thrust-systems in which a deformable (brittle) hanging wall is assumed to endure passive internal deformation during thrusting, i.e. exclusively as a consequence of having to adapt its shape to the variable geometry of a rigid footwall. Building on previous experimental contributions, we specific...

The editors of a new book on tectonics discuss the origins of the science and its importance in a new millennium.

Available online xxxx Editor: J. Brodholt Keywords: subduction mantle plume analog modelling mantle flow slab rollback We present three-dimensional deep-mantle laboratory models of a compositional plume within the vicinity of a buoyancy-driven subducting plate with a fixed trailing edge. We modelled front plumes (in the mantle wedge), rear plumes (...