Publications

Evolution of Mantle Plumes and Lower Mantle Structure in Numerical Models Using Tectonic Reconstructions as Boundary Conditions

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We evaluate four mantle convection models that use tectonic reconstructions to specify kinematic boundary conditions to explore the development of the lower mantle large low shear velocity provinces (LLSVP) structures and their relationship with mantle plumes. Evolution of mantle plumes in our spherical models is broadly consistent with observations including the number of plumes generated … Read more…

Science: Hundred million years of landscape dynamics from catchment to global scale

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Our capability to reconstruct past landscapes and the processes that shape them underpins our understanding of paleo-Earth. We take advantage of a global-scale landscape evolution model assimilating paleoelevation and paleoclimate reconstructions over the past 100 million years. This model provides continuous quantifications of metrics critical to the understanding of the Earth system, from global physiography … Read more…

Nature Reviews Earth and Environment: Deconstructing plate tectonic reconstructions

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The evolving mosaic of tectonic plates across the surface of the Earth sets boundary conditions for the evolution of biotic and abiotic processes and helps shape the dynamics of its interior. Reconstructing plate tectonics back through time allows scientists from a range of disciplines (such as palaeobiology, palaeoclimate, geodynamics and seismology) to investigate Earth evolution … Read more…

Geology: The role of surface processes in basin inversion and breakup unconformity

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In the context of continental extension, transient compressional episodes (stress inversion) and phases of uplift (depth inversion) are commonly recorded with no corresponding change in plate motion. Changes in gravitational potential energy during the rifting process have been invoked as a possible source of compressional stresses, but their magnitude, timing, and relationship with depth inversions … Read more…

Terra Nova: Brief immersion of southern Australia by change in relative plate speed

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Dynamic subsidence and uplift of plates are often explained by the vertical motion of density anomalies in the mantle. Such models predict surface vertical motion rates of less than 100 m Myr−1 at long-wavelengths with a timespan of tens of Myr. However, during periods of relative sea-level stability, some of the phases of vertical motion … Read more…

J. Struct. Geol.: Microstructural and textural modification of columnar calcite under increasing shear strain (Evia Island, Greece)

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We studied the microstructural and textural modification of columnar calcite naturally deformed at increasing shear strain. The studied marbles were sampled from different structural levels of the Basal Unit of the Cycladic Massif on Evia Island, Greece. The marbles have experienced high pressure metamorphism at peak temperatures around 350 °C. The long axes of the columnar calcite grains and their c-axes were … Read more…

Geol. Soc. London Mem.: Effects of melt-percolation, refertilization and deformation on upper mantle seismic anisotropy: constraints from peridotite xenoliths, Marie Byrd Land, West Antarctica

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We report on the petrology, microstructure and seismic properties of 44 peridotite xenoliths extracted from the upper mantle beneath Marie Byrd Land (MBL), West Antarctica. The aim of this work is to understand how melt-rock reaction, refertilization, and deformation affected the seismic properties (velocities, anisotropy) of the West Antarctic upper mantle, in the context of … Read more…

Scientific Reports: Javanese Homo erectus on the move in SE Asia circa 1.8 Ma

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The migration of Homo erectus in Southeast Asia during Early Pleistocene is cardinal to our comprehension of the evolution of the genus Homo. However, the limited consideration of the rapidly changing physical environment, together with controversial datings of hominin bearing sites, make it challenging to secure the robust timeline needed to unveil the behavior of early humans. Here, … Read more…

Marine Geology: Tidal dynamics drive ooid formation in the Capricorn Channel since the Last Glacial Maximum

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Relative sea-level changes can dramatically alter coastal geomorphology and coastlines, which, in turn, can fundamentally alter tidal regimes. The Great Barrier Reef (GBR) has undergone around 120 m of relative sea level (RSL) rise since the Last Glacial Maximum, ∼20,000 years ago (ka). Ooid grains (sand sized carbonate sediment) that formed in shallow water (>5 m depth) … Read more…

Geoscience Letters: Geophysical model generation with generative adversarial networks

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With the rapid development of deep learning technologies, data-driven methods have become one of the main research focuses in geophysical inversion. Applications of various neural network architectures to the inversion of seismic, electromagnetic, gravity and other types of data confirm the potential of these methods in real-time parameter estimation without dependence on the starting subsurface … Read more…

Nature Reviews Earth and Environment: A glimpse into a possible geomorphic future of Tibet

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The Tibetan Plateau plays a central role in global atmospheric circulation, acts as a key biodiversity hotspot, and delivers fresh water for more than 20% of the global population. Projecting its future uplift and erosion trajectory over geological time can offer potential testable hypotheses into interactions between tectonic and surface processes. Rey, P., Salles, T., … Read more…

Geochemistry, Geophysics, Geosystems: The history of Cenozoic carbonate flux in the Atlantic Ocean constrained by multiple regional carbonate compensation depth reconstructions

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The Atlantic is the only ocean basin almost entirely surrounded by passive margins, and a major global long-term sink of carbonate carbon that has evaded subduction. Quantifying the history of carbonate accumulation in the Atlantic has been limited by the absence of well-defined regional carbonate compensation depth (CCD) models. We determine the CCD for the … Read more…

The formation of atolls: new insights from numerical simulations

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Several theories have been proposed to explain atoll formation. While karst dissolution during glacial periods and preferential coral reef accretion along raised bank margins during deglaciations and interglacials have been invoked to explain atoll formation, the respective roles of karst dissolution and reef margin construction in atoll formation have not been adequately evaluated by simulations. … Read more…

Nature Communications: Coupled influence of tectonics, climate, and surface processes on landscape evolution in southwestern North America

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The Cenozoic landscape evolution in southwestern North America is ascribed to crustal isostasy, dynamic topography, or lithosphere tectonics, but their relative contributions remain controversial. Here we reconstruct landscape history since the late Eocene by investigating the interplay between mantle convection, lithosphere dynamics, climate, and surface pro- cesses using fully coupled four-dimensional numerical models. Our quantified … Read more…

Nature: Post-extinction recovery of the Phanerozoic oceans and biodiversity hotspots

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The fossil record of marine invertebrates has long fuelled the debate as to whether or not there are limits to global diversity in the sea. Ecological theory states that, as diversity grows and ecological niches are filled, the strengthening of biological interactions imposes limits on diversity. However, the extent to which biological interactions have constrained … Read more…

Solid Earth: A tectonic-rules-based mantle reference frame since 1 billion years ago – implications for supercontinent cycles and plate–mantle system evolution

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Understanding the long-term evolution of Earth’s plate-mantle system is reliant on absolute plate motion models in a mantle reference frame, but such models are both difficult to construct and controversial. We present a tectonic rules-based optimisation approach to construct a plate motion model in a mantle reference frame covering the last billion years and use … Read more…

G-cubed: Slow Geodynamics and Fast Morphotectonics in the Far East Tethys

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How can the sluggish, long-wavelength mantle convection be expressed by so many time and space scales of morphotectonic activity? To investigate these relationships, we explore the Java-Banda subduction zone, where geodynamic records cluster. In the far-East Tethys, the exceptionally arcuate Banda subduction zone circumscribes the deepest oceanic basin on Earth, seismotectonic activity slices the upper … Read more…

Front Earth Sci: Two-step Gravity Inversion Reveals Variable Architecture of African Cratons

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The lithospheric build-up of the African continent is still to a large extent unexplored. In this contribution, we present a new Moho depth model to discuss the architecture of the three main African cratonic units, which are: West African Craton, Congo Craton, and Kalahari Craton. Our model is based on a two-step gravity inversion approach … Read more…

Extending full-plate tectonic models into deep time: Linking the Neoproterozoic and the Phanerozoic

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Recent progress in plate tectonic reconstructions has seen models move beyond the classical idea of continental drift by attempting to reconstruct the full evolving configuration of tectonic plates and plate boundaries. A particular problem for the Neoproterozoic and Cambrian is that many existing interpretations of geological and palaeomagnetic data have remained disconnected from younger, better-constrained … Read more…

Evolution of Earth’s tectonic carbon conveyor belt

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This video shows plate motions, carbon storage within tectonic plates and carbon degassing along mid-ocean ridges and subduction zones through time. Our carbon model shows these processes alone cannot explain global cooling in the Cenozoic Era. The effects of rock erosion, not shown here, played a key role. Arrows indicate plate motion speed relative to … Read more…

Terra Nova: Timing of partial melting and granulite formation during the genesis of high to ultra-high temperature terranes: Insight from numerical experiments

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Long-lived high to ultra-high temperature (HT-UHT) granulitic terranes formed throughout Earth’s history. Yet, the detailed processes involved in their formation re- main unresolved and notably the sequence of appearance and duration of migmatisa- tion and granulites conditions in the orogenic cycle. These processes can be evaluated by analytical and numerical models. First, solving the steady-state … Read more…

Earth Science Reviews: Sea-level fluctuations driven by changes in global ocean basin volume following supercontinent break-up

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Long-term variations in eustatic sea level in an ice-free world, which existed through most of the Mesozoic and early Cenozoic eras, are partly driven by changes in the volume of ocean basins. Previous studies have determined ocean basin volume changes from plate tectonic reconstructions since the Mesozoic; however, these studies have not considered a number … Read more…

Identifying Characteristic and Anomalous Mantle From the Complex Relationship Between Abyssal Hill Roughness and Spreading Rates

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The dependence of abyssal hill roughness on mid-ocean ridge (MOR) spreading rate is an important indicator for faulting and volcanism. I reanalyze this relationship using a global gravity-based prediction of root-mean-square (RMS) heights, enabling dense sampling of RMS/spreading rate space and thus a far more detailed examination than possible with bathymetric data. RMS histograms are … Read more…

Nature Commmunications: Impact of green clay authigenesis on element sequestration in marine settings

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Retrograde clay mineral reactions (reverse weathering), including glauconite formation, are first-order controls on element sequestration in marine sediments. Here, we report substantial element sequestration by glauconite formation in shallow marine settings from the Triassic to the Holocene, averaging 3 ± 2 mmol·cm−²·kyr−1 for K, Mg and Al, 16 ± 9 mmol·cm−²·kyr−1 for Si and 6 ± 3 mmol·cm−²·kyr−1 for Fe, which is ~2 orders of magnitude higher … Read more…

Geology: Deep-sea hiatuses track the vigor of Cenozoic ocean bottom currents

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The deep-sea stratigraphic record is full of gaps. These hiatuses track changes in ocean circulation and chemistry, but determining their timing and causes has been limited by sparse data and incomplete knowledge of ocean gateway evolution in earlier studies. We combine a significantly expanded, age-calibrated deep-sea stratigraphic database with a global tectonic and paleo–water depth … Read more…

Scientific Reports: Constraining the response of continental‐scale groundwater flow to climate change

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Numerical models of groundwater flow play a critical role for water management scenarios under climate extremes. Large‐scale models play a key role in determining long-range flow pathways from continental interiors to the oceans, yet struggle to simulate the local flow patterns offered by small‐scale models. We have developed a highly scalable numerical framework to model … Read more…

EPSL: Long-term Phanerozoic sea level change from solid Earth processes

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The sedimentary rock record suggests that global sea levels may have fluctuated by hundreds of meters throughout Phanerozoic times. Long-term (10–80 Myr) sea level change can be inferred from paleogeographic reconstructions and stratigraphic methods can be used to estimate sea level change over 1–10 Myr in tectonically quiescent regions assumed to be stable. Plate tectonic … Read more…

Remote Sensing: A Comparative Study of Convolutional Neural Networks and Conventional Machine Learning Models for Lithological Mapping Using Remote Sensing Data

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Lithological mapping is a critical aspect of geological mapping that can be useful in studying the mineralization potential of a region and has implications for mineral prospectivity mapping. This is a challenging task if performed manually, particularly in highly remote areas that require a large number of participants and resources. The combination of machine learning … Read more…

Journal of Asian Earth Sciences: The roles and seismic expressions of turbidites and mass transport deposits using stratigraphic forward modeling and seismic forward modeling

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Turbidity currents and mass transport are two principal processes in deepwater settings. However, their roles in shaping deepwater depositional systems and interpreting their deposits in seismic profiles have not been fully settled due to the lack of extensive well data and high-quality seismic data in comparison with onshore oil fields. Therefore, this study integrated stratigraphic … Read more…

The efficiency of fractal techniques in geochemical anomaly delineation within BLEG and <180 μm stream sediments in Western Turkey

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A new article published recently by Huseyin Yilmaz (Dokuz Eylul University, Turkey), Behnam Sadeghi (EarthByte Group, USYD), and David Cohen (UNSW) in Journal of Geochemical Exploration (JGE): Abstract: In regional exploration for Au mineralization using stream sediment geochemistry, multielement analysis following cyanide leaching of bulk samples or aqua regia digestion of the <180 μm fraction are the two most common … Read more…