Behnam Sadeghi has recently published a research paper about urban geochemistry in Cyprus, based on soil data, and using fractal models and statistical analysis. A part of this paper is from his PhD thesis. This is a collaborative project with the Geological Survey of Cyprus and UNSW School of Biological, Earth and Environmental Sciences. ABSTRACT: This … Read more…
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…
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…
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…
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…
A book chapter in: New Caledonia: Geology, Geodynamic Evolution and Mineral Resources. Geological Society, London, Memoirs, 51, 13–26, https://doi.org/10.1144/M51-2018-5 has finally been published. The book chapter, which gives a brief overview of the geodynamics of New Caledonia, was a collaboration between colleagues from New Caledonia, New Zealand, Australia and France. Abstract below: The SW Pacific … Read more…
Abstract: An International Ocean Discovery Program (IODP) workshop was held at Sydney University, Australia, from 13 to 16 June 2017 and was attended by 97 scientists from 12 countries. The aim of the workshop was to investigate future drilling opportunities in the eastern Indian Ocean, southwestern Pacific Ocean, and the Indian and Pacific sectors of the … Read more…
Abstract: The extraction of tectonic lineaments from digital satellite data is a fundamental application in remote sensing. The location of tectonic lineaments such as faults and dykes are of interest for a range of applications, particularly because of their association with hydrothermal mineralization. Although a wide range of applications have utilized computer vision techniques, a … Read more…
Abstract: Global sea level change can be inferred from sequence stratigraphic and continental flooding data. These methods reconstruct sea level from peri-cratonic and cratonic basins that are assumed to be tectonically stable and sometimes called reference districts, and from spatio-temporal correlations across basins. However, it has been understood that long-wavelength (typically hundreds of km) and low-amplitude … Read more…
Abstract: The absolute motion of tectonic plates since Pangea can be derived from observations of hotspot trails, paleomagnetism, or seismic tomography. However, fitting observations is typically carried out in isolation without consideration for the fit to unused data or whether the resulting plate motions are geodynamically plausible. Through the joint evaluation of global hotspot track … Read more…
Abstract: Bayesian inference provides a rigorous methodology for estimation and uncertainty quantification of unknown parameters in geophysical forward models. Badlands is a landscape evolution model that simulates topography development at various space and time scales. Badlands consists of a number of geophysical parameters that needs estimation with appropriate uncertainty quantification; given the observed present-day ground truth … Read more…
Abstract: Accurately mapping plate boundary types and locations through time is essential for understanding the evolution of the plate-mantle system and the exchange of material between the solid Earth and surface environments. However, the complexity of the Earth system and the cryptic nature of the geological record make it difficult to discriminate tectonic environments through … Read more…
Abstract: Stream sediment surveying is a geochemical sampling method which is typically applied in the preliminary stages of mineral prospecting. Both continuous and discrete mapping approaches have been proposed to delineate geochemical anomalies at large scales using stream sediment samples. We aim to enhance the efficiency of a recent discrete mapping method called Weighted Drainage … Read more…
Abstract: Today the eastern highlands of Australia are significantly more elevated than western Australia, but the continent’s geodynamic evolution suggests that the opposite was the case during Cretaceous times, when the Eromanga Sea dominated the eastern Australian landscape. Previous geodynamic and surface processes models have been used to simulate the evolution of this seaway, but … Read more…
Abstract: Carbon is a key control on the surface chemistry and climate of Earth. Significant volumes of carbon are input to the oceans and atmosphere from deep Earth in the form of degassed CO2 and are returned to large carbon reservoirs in the mantle via subduction or burial. Different tectonic settings (e.g., volcanic arcs, mid-ocean … Read more…
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…
Abstract–The circa 14 km diameter Pantasma circular structure in Oligocene volcanic rocks in Nicaragua is here studied for the first time to understand its origin. Geomorphology, field mapping, and petrographic and geochemical investigations all are consistent with an impact origin for the Pantasma structure. Observations supporting an impact origin include outward-dipping volcanic flows, the presence … Read more…
Abstract: Global sea level change can be inferred from sequence stratigraphic and continental flooding data. These methods reconstruct sea level from peri-cratonic and cratonic basins that are assumed to be tectonically stable and sometimes called reference districts, and from spatio-temporal correlations across basins. However, it has been understood that long-wavelength (typically hundreds of km) and … Read more…
Citation: Seton, M, Williams, S.E., Mortimer, N., Meffre, S., Micklethwaite, S., Zahirovic, S., 2019, Magma production along the Lord Howe Seamount Chain, northern Zealandia, Geological Magazine, 1-13, https://doi.org/10.1017/S0016756818000912 Abstract: One of the world’s most notable intraplate volcanic regions lies on the eastern Australian plate and includes two age-progressive trails offshore (Tasmantid and Lord Howe seamount chains) and the … Read more…
Citation: Merdith, Andrew & Williams, Simon & Brune, Sascha & Collins Alan, S & Müller, Dietmar. (2018). Rift and plate boundary evolution across two supercontinent cycles. Global and Planetary Change. 173. 10.1016/j.gloplacha.2018.11.006. 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. … Read more…
Citation: Dutkiewicz, Adriana & Müller, Dietmar & Cannon, John & Vaughan, Sioned & Zahirovic, Sabin. (2018). Sequestration and subduction of deep-sea carbonate in the global ocean since the Early Cretaceous. Geology. 10.1130/G45424.1. Abstract Deep-sea carbonate represents Earth’s largest carbon sink and one of the least-known components of the long-term carbon cycle that is intimately linked … Read more…
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…