Abstract The extent of continental rifts and subduction zones through deep geological time provides insights into the mechanisms behind supercontinent cycles and the long term evolution of the mantle. However, previous compilations have stopped short of mapping the locations of rifts and subduction zones continuously since the Neoproterozoic and within a self-consistent plate kinematic framework. … Read more…
Abstract The motion of diverging tectonic plates is typically constrained by geophysical data from preserved ocean crust. However, constraining plate motions during continental rifting and the breakup process relies on balancing evidence from a diverse range of geological and geophysical observations, often subject to differing interpretations. Reconstructing the evolution of rifting and breakup between Australia and Antarctica epitomizes the challenges involved in … Read more…
Abstract A complex history of subduction, back-arc basin formation, terrane accretion and transpressional shearing characterizes the evolution of the Caribbean and northern South American margin since Jurassic times. Quantitative plate tectonic reconstructions of the area do not include Jurassic-Cretaceous back-arc terranes of which there are both geological and geophysical observations. We developed a revised plate … Read more…
Abstract: Movements of tectonic plates often induce oblique deformation at divergent plate boundaries. This is in striking contrast with traditional conceptual models of rifting and rifted margin formation, which often assume 2-D deformation where the rift velocity is oriented perpendicular to the plate boundary. Here we quantify the validity of this assumption by analysing the kinematics … Read more…
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…
Abstract: The CO2 liberated along subduction zones through intrusive/extrusive magmatic activity and the resulting active and diffuse outgassing influences global atmospheric CO2. However, when melts derived from subduction zones intersect buried carbonate platforms, decarbonation reactions may cause the contribution to atmospheric CO2 to be far greater than segments of the active margin that lacks buried carbon-rich rocks and … Read more…
Abstract: Assemblages of corals characterise specific reef biozones and the environmental conditions that change spatially across a reef and with depth. Drill cores through fossil reefs record the time and depth distribution of assemblages, which captures a partial history of the vertical growth response of reefs to changing palaeoenvironmental conditions. The effects of environmental factors on … Read more…
Abstract: Detailed global plate motion models that provide a continuous description of plate boundaries through time are an effective tool for exploring processes both at and below the Earth’s surface. A new generation of numerical models of mantle dynamics pre- and post-Pangea timeframes requires global kinematic descriptions with full plate reconstructions extending into the Paleozoic … Read more…
Abstract: Although many sources of atmospheric CO2 have been estimated, the major sinks are poorly understood in a deep-time context. Here we combine plate reconstructions, the eruption ages and outlines of Large Igneous Provinces (LIPs), and the atmospheric CO2 proxy record to investigate how their eruptions and weathering within the equatorial humid zone impacted global … Read more…
The pyBacktrack software package allows the backtracking of the paleo-water depth of ocean drill sites, providing a framework for reconstructing the accumulation history of sediment components through time. The software incorporates the effects of decompaction of common marine lithologies and allows backtracking of sites on both oceanic and continental crust. Backtracking on ocean crust is based on … Read more…
Abstract Abstract: Volcanism of Late Cretaceous–Miocene age is more widespread across the Zealandia continent than previously recognized. New age and geochemical information from widely spaced northern Zealandia seafloor samples can be related to three volcanotectonic regimes: (1) age-progressive, hotspot-style, low-K, alkali-basalt-dominated volcanism in the Lord Howe Seamount Chain. The northern end of the chain (c. … Read more…
Abstract Contourite drifts are anomalously high sediment accumulations that form due to reworking by bottom currents. Due to the lack of a comprehensive contourite database, the link between vigorous bottom water activity and drift occurrence has yet to be demonstrated on a global scale. Using an eddy-resolving ocean model and a new georeferenced database of 267 contourites, we show that the … Read more…
Abstract Understanding Earth surface responses in terms of sediment dynamics to climatic variability and tectonics forcing is hindered by limited ability of current models to simulate long-term evolution of sediment transfer and associated morphological changes. This paper presents pyBadlands, an open-source python-based framework which computes over geological time (1) sediment transport from landmasses to coasts, … Read more…
Climatic variability like precipitation changes or increase in extreme events such as storms and tropical cyclones is known to significantly modify the Earth’s surface. Yet, our understanding of how sediment dynamics and reef evolution might respond to these changes is still limited. In a recent study, a team of researchers from the University of Sydney’s … Read more…
Citation: Cao, W., Williams, S., Flament, N., Zahirovic, S., Scotese, C., and Müller, R. D., 2018. Paleolatitudinal distribution of lithologic indicators of climate in a paleogeographic framework. Geological Magazine, 1-24. Abstract: Whether the latitudinal distribution of climate-sensitive lithologies is stable through greenhouse and icehouse regimes remains unclear. Previous studies suggest that the palaeolatitudinal distribution of palaeoclimate … Read more…
Author List: Nicky M. Wright , Howie D. Scher , Maria Seton , Claire E. Huck , and Brian D. Duggan Citation: Wright, N. M., Scher, H. D., Seton, M., Huck, C. E., & Duggan, B. D. (2018). No change in Southern Ocean circulation in the Indian Ocean from the Eocene through late Oligocene. Paleoceanography … Read more…
Citation: Müller, R.D. and Dutkiewicz, A., 2018, Oceanic crustal carbon cycle drives 26 million-year atmospheric carbon dioxide periodicities, Science Advances, 4:eaaq0500, 1-7. Atmospheric carbon dioxide (CO2) data for the last 420 million years (My) show long-term fluctuations related to supercontinent cycles as well as shorter cycles at 26–32 My whose origin is unknown. Periodicities of 26–30 … Read more…
In a recent paper in JGR-Solid Earth, EarthByter Ömer Faruk Bodur and colleagues show that mantle lithosphere rheology has a primary control on the subduction style (i.e., one-sided vs. double-sided subduction) and strongly affects the pressure-temperature conditions of metamorphic rocks that can be buried >100 km depth and exhume to the surface! This long journey … Read more…
Citation: Dutkiewicz, A., Müller, R.D., Wang, X., O’Callaghan, S., Cannon, J., Wright, N.M., 2017. Predicting sediment thickness on vanished ocean crust since 200 Ma. Geochemistry, Geophysics, Geosystems, 18, 4586–4603. Tracing sedimentation through time on existing and vanished seafloor is imperative for constraining long-term eustasy and for calculating volumes of subducted deep-sea sediments that contribute to global … Read more…
Author List: Wenchao Cao, Sabin Zahirovic, Nicolas Flament, Simon Williams, Jan Golonka, Dietmar Müller Citation: Cao, W., Zahirovic, S., Flament, N., Williams, S., Golonka, J., and Müller, R. D., 2017, Improving global paleogeography since the late Paleozoic using paleobiology: Biogeosciences, v. 14, no. 23, p. 5425-5439. Paleogeographic maps, linked to plate tectonic reconstructions, are key components required for climate models … Read more…
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…
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…
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…
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…
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…
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…
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…
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 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…
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…