Plate Tectonics & Geodynamics

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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…

Continental arcs dominate global chemical weathering

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Earth’s plate-tectonic activity regulates the carbon cycle and, hence, climate, via volcanic outgassing and silicate-rock weather- ing. Mountain building, arc–continent collisions and clustering of continents in the tropics have all been invoked as controlling the weathering flux, with arcs also acting as a major contributor of carbon dioxide to the atmosphere. However, these processes have … Read more…

Chatting about reconstructing 1 billion years of Earth evolution in Geology Bites podcast

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In the latest Geology Bites podcast series, Dietmar Muller talks about the challenges and benefits of reconstructing Earth evolution over a billion years with Oliver Strimpel, former astrophysicist and museum director, and Visiting Professor at the Department of Earth Sciences at Oxford University.  https://www.geologybites.com/ A transcript of the podcast can be found here.

A global dataset of present-day oceanic crustal age and seafloor spreading parameters

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Abstract: We present an updated oceanic crustal age grid and a set of complementary grids including spreading rate, asymmetry, direction and obliquity. Our dataset is based on a selected set of magnetic anomaly identifications and the plate tectonic model of Müller et al. (2019). We find the mean age of oceanic crust is 64.2 Myrs, … Read more…

Kinematic and geodynamic evolution of the Isthmus of Panama region: Implications for Central American Seaway closure

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Abstract: A major topic of debate in Earth and climate science surrounds the timing of closure of the Central American Seaway. While it is clear that the gateway was closed by ~2.8 Ma, recent studies based on geological and marine molecular evidence have suggested an earlier closing time of early to mid-Miocene. Here, we examine … Read more…

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

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Abstract: 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 … Read more…

A Quantitative Tomotectonic Plate Reconstruction of Western North America and the Eastern Pacific Basin

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Abstract: Plate reconstructions since the breakup of Pangaea are mostly based on the preserved spreading history of ocean basins, within absolute reference frames that are constrained by a combination of age-progressive hotspot tracks and palaeomagnetic data. The evolution of destructive plate margins is difficult to constrain from surface observations as much of the evidence has … Read more…

Muller et al. (2019) deforming plate reconstructions and associated digital supplements (Tectonics)

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A Global Plate Model Including Lithospheric Deformation Along Major Rifts and Orogens Since the Triassic R. Dietmar Müller, Sabin Zahirovic, Simon E. Williams, John Cannon, Maria Seton, Dan J. Bower, Michael G. Tetley, Christian Heine, Eline Le Breton, Shaofeng Liu, Samuel H. J. Russell, Ting Yang, Jonathon Leonard, and Michael Gurnis Journal: Tectonics (open access) … Read more…

Tectonic evolution and deep mantle structure of the eastern Tethys since the latest Jurassic

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Sabin Zahirovic, Kara J. Matthews, Nicolas Flament, R. Dietmar Müller, Kevin C. Hill, Maria Seton, Michael Gurnis Earth-Science Reviews Citation: Zahirovic, S., Matthews, K.J., Flament, N., Müller, R.D., Hill, K.C., Seton, M. and Gurnis, M., 2016, Tectonic evolution and deep mantle structure of the eastern Tethys since the latest Jurassic, Earth Science Reviews, 162, 293-337. The … Read more…

GESSS NSW Conference

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Congratulations to the EarthByte students who recently represented the School of Geosciences, University of Sydney at the student-run GSA Earth Sciences Student Symposium (GESSS) NSW conference. The event aims to bring together Honours, Masters and PhD students from across NSW to present and discuss their research in a relaxed, supportive environment; a primary goal of GESSS is … Read more…

Continental breakup triggered massive CO2 emissions

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Plate Models

Currently, human activity is the primary driver of elevating atmospheric CO2, but the Earth fluctuated from greenhouse to icehouse conditions and back long before humans existed. The question is:  what triggered these long-term climate cycles? Now research at the University of Sydney’s EarthByte Group, in collaboration with the German Research Centre for Geosciences, reveals how … Read more…

A reconstruction of the Eurekan Orogeny incorporating deformation constraints

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Author List:  Austin Gion, Simon Williams, Dietmar Müller Citation: Gion, A.M., Williams, S.E. and Müeller, R.D., 2017. A reconstruction of the Eurekan Orogeny incorporating deformation constraints. Tectonics, 36(2), pp.304-320. Abstract: The Eurekan Orogeny records Paleogene convergence between Greenland and the Canadian Arctic. The complexity of the region, well represented by the disputed magnitude of Cenozoic sinistral displacement of … Read more…

A global review and digital database of large-scale extinct spreading centers

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Author List: Sarah MacLeod, Simon Williams, Kara Matthews, Dietmar Müller and Xiaodong Qin Citation: MacLeod, S.J., Williams, S.E., Matthews, K.J., Müller, R.D. and Qin, X., 2017. A global review and digital database of large-scale extinct spreading centers. Geosphere, pp.GES01379-1. Abstract: Extinct mid-ocean ridges record past plate boundary reorganizations, and identifying their locations is crucial to developing a better understanding of the … Read more…

Kinematic constraints on the Rodinia to Gondwana transition

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Author List: Andrew Merdith, Simon Williams, Dietmar Müller & Alan Collins. Citation: Merdith, Andrew & Williams, Simon & Müller, Dietmar & Collins, Alan. (2017). Kinematic constraints on the Rodinia-Gondwana transition. Precambrian Research. 299. . 10.1016/j.precamres.2017.07.013. Abstract: Earth’s plate tectonic history during the breakup of the supercontinent Pangea is well constrained from the seafloor spreading record, but evolving plate configurations during … Read more…

Influence of mantle flow on the drainage of eastern Australia since the Jurassic period

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Author List: Tristan Salles, Nicolas Flament & Dietmar Müller. Citation: Salles, Tristan & Flament, Nicolas & Müller, Dietmar. (2017). Influence of mantle flow on the drainage of eastern Australia since the Jurassic Period. Geochemistry, Geophysics, Geosystems. 18. . 10.1002/2016GC006617. Abstract:  Recent studies of the past eastern Australian landscape from present-day longitudinal river profiles and from mantle flow models … Read more…

Dynamic topography and eustasy controlled the paleogeographic evolution of northern Africa since the mid-Cretaceous

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Author List: Nicholas Barnett-Moore, Rakib Hassan, Dietmar Müller, Simon Williams & Nicolas Flament. Citation: Barnett-Moore, Nicholas & Hassan, Rakib & Müller, Dietmar & Williams, Simon & Flament, Nicolas. (2017). Dynamic topography and eustasy controlled the paleogeographic evolution of northern Africa since the mid Cretaceous. Tectonics. . 10.1002/2016tc004280. Abstract: Northern Africa underwent widespread inundation during the Late Cretaceous. Changes … Read more…

Origin and evolution of the deep thermochemical structure beneath Eurasia

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Author List: Nicolas Flament, Simon Williams, Dietmar Müller, Michael Gurnis & Dan Bower. Citation: Flament, Nicolas & Williams, Simon & Müller, Dietmar & Gurnis, Michael & J. Bower, Dan. (2017). Origin and evolution of the deep thermochemical structure beneath Eurasia. Nature Communications. 8. . 10.1038/ncomms14164. Abstract: A unique structure in the Earth’s lowermost mantle, the Perm Anomaly, was … Read more…

The origin of contractional structures in extensional gneiss domes

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Author List: Patrice Rey, Luke Mondy, Guillaume Duclaux, Christian Teyssier, Donna Whitney, Marie Bocher, cécile Prigent. Citation: Rey, Patrice & Mondy, L & Duclaux, G & Teyssier, Christian & Whitney, Donna & Bocher, Marie & Prigent, cécile. (2017). The origin of contractional structures in extensional gneiss domes. 45. 263-266. 10.1130/G38595. Abstract: The juxtaposition of domains of shortening and extension at different … Read more…

The Encyclopedia of Marine Geosciences

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The Encyclopedia of Marine Geosciences was selected for the 2017 Mary B. Ansari Best Geoscience Research Resource Work Award of The Geoscience Information Society (GSIS). The formal award will be given at the GSA 2017 conference in October in Seattle/USA. EarthByters Dietmar Muller and Maria Seton contributed two chapters on “Paleophysiography of Ocean Basins” and “Plate Motion”. This Encyclopedia … Read more…

Global patterns in Earth’s dynamic topography since the Jurassic: the role of subducted slabs

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Author List: Michael Rubey, Sascha Brune, Christian Heine, Rhodri Davies, Simon Williams, and Dietmar Müller. Citation: Rubey, M., Brune, S., Heine, C., Davies, D. R., Williams, S. E., and Müller, R. D.: Global patterns in Earth’s dynamic topography since the Jurassic: the role of subducted slabs, Solid Earth, 8, 899-919, https://doi.org/10.5194/se-8-899-2017, 2017. Abstract: We evaluate the spatial … Read more…

Tectonic speed limits from plate kinematic reconstructions

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Abstract The motion of plates and continents on the planet’s surface are a manifestation of long-term mantle convection and plate tectonics. Present-day plate velocities provide a snapshot of this ongoing process, and have been used to infer controlling factors on the speeds of plates and continents. However, present-day velocities do not capture plate behaviour over … Read more…

Earth is estimated to be around 4.5 billion years old, with life first appearing around 3 billion years ago.

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EarthByter Andrew Merdith, Alan Collins from the Univ. of Adelaide and colleagues produced an animated plate tectonic map that changes the history of our planet as we know it. Of course it’s not just an animation, it’s an elaborate computer model that took years to be built, assimilating tons of geological and geophysical observations, in a … Read more…

The deep Earth origin of the Iceland plume and its effects on regional surface uplift and subsidence

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Abstract The present-day seismic structure of the mantle under the North Atlantic Ocean indicates that the Iceland hotspot represents the surface expression of a deep mantle plume, which is thought to have erupted in the North Atlantic domain during the Palaeocene. The spatial and temporal evolution of the plume since its eruption is still highly … Read more…