Publications 2022

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…

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…

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…

Geochemical anomaly definition using stream sediments landscape modeling

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A new research paper published in Ore Geology Reviews based on a collaboration between Dr. Behnam Sadeghi from EarthByte Group, USYD, and several research institutes in China, including: China University of Geosciences: State Key Laboratory of Geological Processes and Mineral Resources Hebei GEO University: 1) Institute of Resource and Environmental Engineering, 2) Hebei Key Laboratory … Read more…