Ben Mather , Dietmar Müller, Chris Alfonso, Nicky Wright, Maria Seton 350% increase in copper demand by 2050 for renewable energy plants and EVs. No significant copper discoveries in the last 10 years. Porphyry Cu distribution – Lee & Tang 2020, EPSL Largest Cu porphyries occur in thick crust > 45 km. Porphyry Cu requires shortening along the arc with > 45 km thick crust . No magmatic activity in flat subduction regime. Vigorous volcanism “overcooks” Cu deposits post slab delamination. Geodynamic regime diagram – Richards 2021, Geosphere
Ben Mather | EarthByte Group | The University of Sydney Mt Fuji, Japan Last Eruption: 1707 St Helens, USA Last Eruption: 1980 Mauna Loa, Hawaii Last Eruption: 1984
Dietmar Müller EarthByte Group, School of Geosciences, University of Sydney Geology and Geophysics Research Group at the University of Sydney established in 2002 www.earthbyte.org Philosophy: Build an experimental planet through open software and open-access data and models Home of plate tectonic software Today’s talk based on this paper: https:// www.e-education.psu.edu / After Kelemen and Manning (2015)
Ben Mather , Dietmar Müller, Chris Alfonso, Nicky Wright, Maria Seton 350% increase in copper demand by 2050 for renewable energy plants and EVs. No significant copper discoveries in the last 10 years. Porphyry Cu distribution – Lee & Tang 2020, EPSL Largest Cu porphyries occur in thick crust > 45 km. Porphyry Cu requires shortening along the arc with > 45 km thick crust . No magmatic activity in flat subduction regime. Vigorous volcanism “overcooks” Cu deposits post slab delamination. Geodynamic regime diagram – Richards 2021, Geosphere
Cold slabs can take water into the transition zone. Stored within Ringwoodite and Wadsleyite Excess water may predict locations of enigmatic intraplate volcanism Predict influx of water from cold, wet slabs by fusing plate reconstructions and thermodynamics Water reservoirs in sediments, crust, lithospheric mantle But how do we validate this against observations? Various global tomography models resolve the MTZ. Temperature and water are strongly correlated A region of high temperature looks like high water in tomography Vp /Vs ratio from GYPSUM
Fracture zones Sharp discontinuities in seafloor age Seamount trail LIP LIP conjugate Fracture zone (Synthetic) seamounts Tracks overriding plate motion above plumes (stream #2) Conjugate LIPs LIPs are formed by a plume head Reconstructed LIP conjugates (stream #2) Seamount trail LIP LIP conjugate Fracture zone Fracture zones Sharp discontinuities in seafloor age (Synthetic) seamounts Tracks overriding plate motion above plumes (stream #2) Conjugate LIPs LIPs are formed by a plume head Reconstructed LIP conjugates (stream #2) 96% of all deposits located within 800 km of a fracture zone 294 Cu deposits in the Americas reside within 500-800 km distance Positive samples Random samples 70% of all deposits within 250-650 km of synthetic seamount Equates to 242 of 347 Cu deposits in the Americas Not enough LIPs to determine if there is a statistically significant relationship
Constraining flow pathways across eastern Australia Ben Mather , Dietmar Müller, Adam Beall , Craig O’Neill, Willem Vervoort, Louis Moresi Whole-of-basin groundwater model No guessing side boundary conditions Integrates regional geological complexity Simulate groundwater flow field Simulate residence times Very good at estimating flow in deep aquifers Local geological structures that impact groundwater flow may not be resolved Some misfit to hydrological data is expected Cannot reliably resolve shallow alluvial sediments and short timescales We are geodynamicists working on large-scale groundwater flow. Please be gentle! Calf, 1978 Sophisticated parallel codes that are (relatively) easy to use Build models in a Jupyter notebook using Python Write documentation as you go Share online Deploy in a high-performance computing environment as a Python script Parallel version “just works” github.com / underworldcode
Ben Mather , Maria Seton, Simon Williams, Jo Whittaker, Rebecca Carey, Maëlis Arnould, Nicolas Coltice, Bob Duncan Iceland Ridge Plate motion driven by: Slab pull at subduction zones Plume push at mid-ocean ridges (MORs) Geometry and location of MORs are independent of lower mantle dynamics. But this fails to recognize the attraction between plumes and MORs. Zhang et al, 2018, Geosci . Frontiers LIPs repeatedly form at locations where plumes and ridges intersect. Ridge segments coupled to plumes migrate far less than adjacen t ridge segments. Whittaker et al. 2016, Nat Geo Slowly spreading MORs may jump towards mantle plumes Mittlestaedt et al. 2011, JGR May result in deviations in hotspot tracks predicted from plate motion Hawaiian-Emperor Chain Sun et al 2021, Science Bulletin
Ben Mather , Maria Seton, Simon Williams, Jo Whittaker, Rebecca Carey, Maëlis Arnould, Nicolas Coltice, Bob Duncan LIPs repeatedly form at locations where plumes and ridges intersect Slowly spreading MORs may jump towards mantle plumes Can lead to asymmetric spreading rates Whittaker et al. 2016, Nat Geo Mittlestaedt et al. 2011, JGR Yale & Morgan 1998, EPSL Arnould et al. 2 020, EPSL Plume-ridge coupling Plume-ridge de-anchoring