1
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Clerc F, Behn MD, Minchew BM. Deglaciation-enhanced mantle CO 2 fluxes at Yellowstone imply positive climate feedback. Nat Commun 2024; 15:1526. [PMID: 38378722 PMCID: PMC10879189 DOI: 10.1038/s41467-024-45890-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 02/06/2024] [Indexed: 02/22/2024] Open
Abstract
Mantle melt generation in response to glacial unloading has been linked to enhanced magmatic volatile release in Iceland and global eruptive records. It is unclear whether this process is important in systems lacking evidence of enhanced eruptions. The deglaciation of the Yellowstone ice cap did not observably enhance volcanism, yet Yellowstone emits large volumes of CO2 due to melt crystallization at depth. Here we model mantle melting and CO2 release during the deglaciation of Yellowstone (using Iceland as a benchmark). We find mantle melting is enhanced 19-fold during deglaciation, generating an additional 250-620 km3. These melts segregate an additional 18-79 Gt of CO2 from the mantle, representing a ~3-15% increase in the global volcanic CO2 flux (if degassed immediately). We suggest deglaciation-enhanced mantle melting is important in continental settings with partially molten mantle - including Greenland and West Antarctica - potentially implying positive feedbacks between deglaciation and climate warming.
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Affiliation(s)
- Fiona Clerc
- Previously at: MIT-WHOI Joint Program in Oceanography/Applied Ocean Science & Engineering, Cambridge, MA, USA.
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA.
| | - Mark D Behn
- Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, MA, USA
| | - Brent M Minchew
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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2
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Li J, Sun D, Bower DJ. Slab control on the mega-sized North Pacific ultra-low velocity zone. Nat Commun 2022; 13:1042. [PMID: 35210453 PMCID: PMC8873298 DOI: 10.1038/s41467-022-28708-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/24/2022] [Indexed: 11/09/2022] Open
Abstract
Ultra-low velocity zones (ULVZs) are localized small-scale patches with extreme physical properties at the core-mantle boundary that often gather at the margins of Large Low Velocity Provinces (LLVPs). Recent studies have discovered several mega-sized ULVZs with a lateral dimension of ~900 km. However, the detailed structures and physical properties of these ULVZs and their relationship to LLVP edges are not well constrained and their formation mechanisms are poorly understood. Here, we break the degeneracy between the size and velocity perturbation of a ULVZ using two orthogonal seismic ray paths, and thereby discover a mega-sized ULVZ at the northern edge of the Pacific LLVP. The ULVZ is almost double the size of a previously imaged ULVZ in this region, but with half of the shear velocity reduction. This mega-sized ULVZ has accumulated due to stable mantle flow converging at the LLVP edge driven by slab-debris in the lower mantle. Such flow also develops the subvertical north-tilting edge of the Pacific LLVP.
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Affiliation(s)
- Jiewen Li
- Laboratory of Seismology and Physics of Earth's Interior, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China.,CAS Center for Excellence in Comparative Planetology, China, Hefei, Anhui, 233500, China
| | - Daoyuan Sun
- Laboratory of Seismology and Physics of Earth's Interior, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China. .,CAS Center for Excellence in Comparative Planetology, China, Hefei, Anhui, 233500, China.
| | - Dan J Bower
- Center for Space and Habitability, University of Bern, Gesellschaftsstrasse 6, 3012, Bern, Switzerland
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3
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Shellnutt JG, Dostal J, Lee TY. Linking the Wrangellia flood basalts to the Galápagos hotspot. Sci Rep 2021; 11:8579. [PMID: 33883628 PMCID: PMC8060428 DOI: 10.1038/s41598-021-88098-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/30/2021] [Indexed: 02/02/2023] Open
Abstract
The Triassic volcanic rocks of Wrangellia erupted at an equatorial to tropical latitude that was within 3000 km of western North America. The mafic and ultramafic volcanic rocks are compositionally and isotopically similar to those of oceanic plateaux that were generated from a Pacific mantle plume-type source. The thermal conditions, estimated from the primitive rocks, indicate that it was a high temperature regime (TP > 1550 °C) consistent with elevated temperatures expected for a mantle plume. The only active hotspot currently located near the equator of the eastern Pacific Ocean that was active during the Mesozoic and produced ultramafic volcanic rocks is the Galápagos hotspot. The calculated mantle potential temperatures, trace elemental ratios, and Sr-Nd-Pb isotopes of the Wrangellia volcanic rocks are within the range of those from the Caribbean Plateau and Galápagos Islands, and collectively have similar internal variability as the Hawaii-Emperor island chain. The paleogeographic constraints, thermal estimates, and geochemistry suggests that it is possible that the Galápagos hotspot generated the volcanic rocks of Wrangellia and the Caribbean plateau or, more broadly, that the eastern Pacific (Panthalassa) Ocean was a unique region where anomalously high thermal conditions either periodically or continually existed from ~ 230 Ma to the present day.
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Affiliation(s)
- J. Gregory Shellnutt
- grid.412090.e0000 0001 2158 7670Department of Earth Sciences, National Taiwan Normal University, 88 Tingzhou Road Section 4, Taipei, 11677 Taiwan
| | - Jaroslav Dostal
- grid.412362.00000 0004 1936 8219Department of Geology, Saint Mary’s University, 923 Robie Street, Halifax, NS B3H 3C3 Canada
| | - Tung-Yi Lee
- grid.412090.e0000 0001 2158 7670Department of Earth Sciences, National Taiwan Normal University, 88 Tingzhou Road Section 4, Taipei, 11677 Taiwan
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4
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Castellanos JC, Perry-Houts J, Clayton RW, Kim Y, Stanciu AC, Niday B, Humphreys E. Seismic anisotropy reveals crustal flow driven by mantle vertical loading in the Pacific NW. SCIENCE ADVANCES 2020; 6:eabb0476. [PMID: 32832611 PMCID: PMC7439309 DOI: 10.1126/sciadv.abb0476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 05/26/2020] [Indexed: 06/11/2023]
Abstract
Buoyancy anomalies within Earth's mantle create large convective currents that are thought to control the evolution of the lithosphere. While tectonic plate motions provide evidence for this relation, the mechanism by which mantle processes influence near-surface tectonics remains elusive. Here, we present an azimuthal anisotropy model for the Pacific Northwest crust that strongly correlates with high-velocity structures in the underlying mantle but shows no association with the regional mantle flow field. We suggest that the crustal anisotropy is decoupled from horizontal basal tractions and, instead, created by upper mantle vertical loading, which generates pressure gradients that drive channelized flow in the mid-lower crust. We then demonstrate the interplay between mantle heterogeneities and lithosphere dynamics by predicting the viscous crustal flow that is driven by local buoyancy sources within the upper mantle. Our findings reveal how mantle vertical load distribution can actively control crustal deformation on a scale of several hundred kilometers.
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Affiliation(s)
- Jorge C. Castellanos
- Seismological Laboratory, Department of Earth and Planetary Sciences, Caltech, Pasadena, CA 91125, USA
| | | | - Robert W. Clayton
- Seismological Laboratory, Department of Earth and Planetary Sciences, Caltech, Pasadena, CA 91125, USA
| | - YoungHee Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | | | - Bart Niday
- Department of Geological Sciences, University of Oregon, Eugene, OR 97403, USA
| | - Eugene Humphreys
- Department of Geological Sciences, University of Oregon, Eugene, OR 97403, USA
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5
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Kolínský P, Schneider FM, Bokelmann G. Surface Wave Diffraction Pattern Recorded on AlpArray: Cameroon Volcanic Line Case Study. JOURNAL OF GEOPHYSICAL RESEARCH. SOLID EARTH 2020; 125:e2019JB019102. [PMID: 32999803 PMCID: PMC7507139 DOI: 10.1029/2019jb019102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 05/07/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Stripe-like patterns of surface wave arrival angle deviations have been observed by several seismological studies around the world, but this phenomenon has not been explained so far. Here we test the hypothesis that systematic arrival angle deviations observed at the AlpArray broadband seismic network in Europe are interference patterns caused by diffraction of surface waves at single small-scaled velocity anomalies. We use the observed pattern of Rayleigh waves from two earthquakes under the Southern Atlantic Ocean, and we fit this pattern with theoretical arrival angles derived by a simple modeling approach describing the interaction of a seismic wavefield with small anomalies. A grid search inversion scheme is implemented, which indicates that the anomaly is located in Central Africa, with its head under Cameroon. Moreover, the inversion enables the characterization of the anomaly: The anomaly is inferred to be between 320 and 420 km wide, matching in length the 2,500 km long upper mantle low-velocity region under the volcano-capped swells of the Cameroon volcanic line. We show that this approach can be generally used for studying the upper mantle anomalies worldwide.
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Affiliation(s)
- Petr Kolínský
- Department of Meteorology and GeophysicsUniversity of ViennaViennaAustria
| | - Felix M. Schneider
- Department of Meteorology and GeophysicsUniversity of ViennaViennaAustria
- Section “Seismology”Helmholtz Centre Potsdam—German Research Centre for Geosciences (GFZ)PotsdamGermany
| | - Götz Bokelmann
- Department of Meteorology and GeophysicsUniversity of ViennaViennaAustria
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6
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Kim D, Lekić V, Ménard B, Baron D, Taghizadeh-Popp M. Sequencing seismograms: A panoptic view of scattering in the core-mantle boundary region. Science 2020; 368:1223-1228. [PMID: 32527827 DOI: 10.1126/science.aba8972] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 05/04/2020] [Indexed: 11/03/2022]
Abstract
Scattering of seismic waves can reveal subsurface structures but usually in a piecemeal way focused on specific target areas. We used a manifold learning algorithm called "the Sequencer" to simultaneously analyze thousands of seismograms of waves diffracting along the core-mantle boundary and obtain a panoptic view of scattering across the Pacific region. In nearly half of the diffracting waveforms, we detected seismic waves scattered by three-dimensional structures near the core-mantle boundary. The prevalence of these scattered arrivals shows that the region hosts pervasive lateral heterogeneity. Our analysis revealed loud signals due to a plume root beneath Hawaii and a previously unrecognized ultralow-velocity zone beneath the Marquesas Islands. These observations illustrate how approaches flexible enough to detect robust patterns with little to no user supervision can reveal distinctive insights into the deep Earth.
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Affiliation(s)
- D Kim
- Department of Geology, University of Maryland, College Park, MD 20742, USA.
| | - V Lekić
- Department of Geology, University of Maryland, College Park, MD 20742, USA
| | - B Ménard
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA
| | - D Baron
- School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel
| | - M Taghizadeh-Popp
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA
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7
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New Candidate Ultralow-Velocity Zone Locations from Highly Anomalous SPdKS Waveforms. MINERALS 2020. [DOI: 10.3390/min10030211] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ultralow-velocity zones (ULVZs) at the core–mantle boundary (CMB) represent some of the most preternatural features in Earth’s mantle. These zones most likely contain partial melt, extremely high iron content ferropericlase, or combinations of both. We analyzed a new collection of 58,155 carefully processed and quality-controlled broadband recordings of the seismic phase SPdKS in the epicentral distance range from 106° to 115°. These data sample 56.9% of the CMB by surface area. From these recordings we searched for the most anomalous seismic waveforms that are indicative of ULVZ presence. We used a Bayesian approach to identify the regions of the CMB that have the highest probability of containing ULVZs, thereby identifying sixteen regions of interest. Of these regions, we corroborate well-known ULVZ existence beneath the South China Sea, southwest Pacific, the Samoa hotspot, the southwestern US/northern Mexico, and Iceland. We find good evidence for new ULVZs beneath North Africa, East Asia, and north of Papua New Guinea. We provide further evidence for ULVZs in regions where some evidence has been hinted at before beneath the Philippine Sea, the Pacific Northwest, and the Amazon Basin. Additional evidence is shown for potential ULVZs at the base of the Caroline, San Felix and Galapagos hotspots.
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8
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Bono RK, Tarduno JA, Bunge HP. Hotspot motion caused the Hawaiian-Emperor Bend and LLSVPs are not fixed. Nat Commun 2019; 10:3370. [PMID: 31358746 PMCID: PMC6662702 DOI: 10.1038/s41467-019-11314-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 07/01/2019] [Indexed: 11/13/2022] Open
Abstract
Controversy surrounds the fixity of both hotspots and large low shear velocity provinces (LLSVPs). Paleomagnetism, plate-circuit analyses, sediment facies, geodynamic modeling, and geochemistry suggest motion of the Hawaiian plume in Earth's mantle during formation of the Emperor seamounts. Herein, we report new paleomagnetic data from the Hawaiian chain (Midway Atoll) that indicate the Hawaiian plume arrived at its current latitude by 28 Ma. A dramatic decrease in distance between Hawaiian-Emperor and Louisville chain seamounts between 63 and 52 Ma confirms a high rate of southward Hawaiian hotspot drift (~47 mm yr-1), and excludes true polar wander as a relevant factor. These findings further indicate that the Hawaiian-Emperor chain bend morphology was caused by hotspot motion, not plate motion. Rapid plume motion was likely produced by ridge-plume interaction and deeper influence of the Pacific LLSVP. When compared to plate circuit predictions, the Midway data suggest ~13 mm yr-1 of African LLSVP motion since the Oligocene. LLSVP upwellings are not fixed, but also wander as they attract plumes and are shaped by deep mantle convection.
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Affiliation(s)
- Richard K Bono
- Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY, 14627, USA.
- Geomagnetism Laboratory, University of Liverpool, Liverpool, L69 3GP, UK.
| | - John A Tarduno
- Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY, 14627, USA.
- Department of Physics and Astronomy, University of Rochester, Rochester, NY, 14627, USA.
| | - Hans-Peter Bunge
- Department of Earth and Environmental Sciences (Geophysics), Ludwig-Maximilians-University, Munich, 80333, Germany
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9
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Arnould M, Ganne J, Coltice N, Feng X. Northward drift of the Azores plume in the Earth's mantle. Nat Commun 2019; 10:3235. [PMID: 31324813 PMCID: PMC6642178 DOI: 10.1038/s41467-019-11127-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 06/21/2019] [Indexed: 11/19/2022] Open
Abstract
Mantle plume fixity has long been a cornerstone assumption to reconstruct past tectonic plate motions. However, precise geochronological and paleomagnetic data along Pacific continuous hotspot tracks have revealed substantial drift of the Hawaiian plume. The question remains for evidence of drift for other mantle plumes. Here, we use plume-derived basalts from the Mid-Atlantic ridge to confirm that the upper-mantle thermal anomaly associated with the Azores plume is asymmetric, spreading over ~2,000 km southwards and ~600 km northwards. Using for the first time a 3D-spherical mantle convection where plumes, ridges and plates interact in a fully dynamic way, we suggest that the extent, shape and asymmetry of this anomaly is a consequence of the Azores plume moving northwards by 1-2 cm/yr during the past 85 Ma, independently from other Atlantic plumes. Our findings suggest redefining the Azores hotspot track and open the way for identifying how plumes drift within the mantle.
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Affiliation(s)
- Maëlis Arnould
- Laboratoire de Géologie, École Normale Supérieure, CNRS UMR 8538, PSL Research University, 75005, Paris, France.
- Laboratoire de Géologie de Lyon, Terre, Planètes, Environnement, École Normale Supérieure de Lyon, Université de Lyon, Université Claude Bernard, CNRS UMR 5276, 2 rue Raphaël Dubois, 69622, Villeurbanne, France.
- EarthByte Group, School of Geosciences, Madsen Building F09, University of Sydney, Sydney, 2006, NSW, Australia.
| | - Jérôme Ganne
- IRD, CNRS, GET, Université Toulouse III, 14 Avenue Edouard Belin, 31400, Toulouse, France
| | - Nicolas Coltice
- Laboratoire de Géologie, École Normale Supérieure, CNRS UMR 8538, PSL Research University, 75005, Paris, France
| | - Xiaojun Feng
- School of Safety Engineering, China University of Mining and Technology, Jiangsu, 221116, China
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10
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Nikogosian IK, Bracco Gartner AJJ, van Bergen MJ, Mason PRD, van Hinsbergen DJJ. Mantle Sources of Recent Anatolian Intraplate Magmatism: A Regional Plume or Local Tectonic Origin? TECTONICS 2018; 37:4535-4566. [PMID: 31007340 PMCID: PMC6472637 DOI: 10.1029/2018tc005219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 10/18/2018] [Accepted: 11/21/2018] [Indexed: 06/09/2023]
Abstract
We present an extensive study of rehomogenized olivine-hosted melt inclusions, olivine phenocrysts, and chromian spinel inclusions to explore the link between geodynamic conditions and the origin and composition of Pliocene-Quaternary intraplate magmatism in Anatolia at Kula, Ceyhan-Osmaniye, and Karacadağ. Exceptional compositional variability of these products reveals early and incomplete mixing of distinct parental melts in each volcanic center, reflecting asthenospheric and lithospheric mantle sources. The studied primitive magmas consist of (1) two variably enriched ocean island basalt (OIB)-type melts in Kula; (2) both OIB-type and plume mid-ocean ridge basalt (P-MORB)-like melts beneath Toprakkale and Üçtepeler (Ceyhan-Osmaniye); and (3) two variably enriched OIB-type melts beneath Karacadağ. Estimated conditions of primary melt generation are 23-9 kbar, 75-30 km, and 1415-1215 °C for Kula; 28-19 kbar, 90-65 km, and 1430-1350 °C for Toprakkale; 23-18 kbar, 75-60 km, and 1400-1355 °C for Üçtepeler; and 35-27 kbar, 115-90 km, and 1530-1455 °C for Karacadağ, the deepest levels of which correspond to the depth of the lithosphere-asthenosphere boundary in all regions. Although magma ascent was likely facilitated by local deformation structures, recent Anatolian intraplate magmatism seems to be triggered by large-scale mantle flow that also affects the wider Arabian and North African regions. We infer that these volcanics form part of a much wider Arabian-North African intraplate volcanic province, which was able to invade the Anatolian upper plate through slab gaps.
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Affiliation(s)
- I. K. Nikogosian
- Department of Earth SciencesVrije Universiteit AmsterdamAmsterdamThe Netherlands
- Department of Earth SciencesUtrecht UniversityUtrechtThe Netherlands
| | - A. J. J. Bracco Gartner
- Department of Earth SciencesVrije Universiteit AmsterdamAmsterdamThe Netherlands
- Department of Earth SciencesUtrecht UniversityUtrechtThe Netherlands
| | - M. J. van Bergen
- Department of Earth SciencesUtrecht UniversityUtrechtThe Netherlands
| | - P. R. D. Mason
- Department of Earth SciencesUtrecht UniversityUtrechtThe Netherlands
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11
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Strak V, Schellart WP. A subduction and mantle plume origin for Samoan volcanism. Sci Rep 2018; 8:10424. [PMID: 29992964 PMCID: PMC6041271 DOI: 10.1038/s41598-018-28267-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 06/20/2018] [Indexed: 11/13/2022] Open
Abstract
The origin of Samoan volcanism in the southwest Pacific remains enigmatic. Whether mantle melting is solely caused by a mantle plume is questionable because some volcanism, here referred to as non-hotspot volcanism, defies the plume model and its linear age-progression trend. Indeed, non-hotspot volcanism occurred as far as 740 km west of the predicted Samoan hotspot after 5 Ma. Here we use fully-dynamic laboratory subduction models and a tectonic reconstruction to show that the nearby Tonga-Kermadec-Hikurangi (TKH) subduction zone induces a broad mantle upwelling around the northern slab edge that coincides with the non-hotspot volcanic activity after 5 Ma. Using published potential mantle temperatures for the ambient mantle and Samoan mantle plume, we find that two geodynamic processes can explain mantle melting responsible for intraplate volcanism in the Samoan region. We propose that before 5 Ma, the volcanism is consistent with the plume model, whereas afterwards non-hotspot volcanism resulted from interaction between the Subduction-Induced Mantle Upwelling (SIMU) and Samoan mantle plume material that propagated west from the hotspot due to the toroidal component of slab rollback-induced mantle flow. In this geodynamic scenario, the SIMU drives decompression melting in the westward-swept plume material, thus producing the non-hotpot volcanism.
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Affiliation(s)
- Vincent Strak
- School of Earth, Atmosphere and Environment, Monash University, Melbourne, VIC, 3800, Australia. .,Department of Earth Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. .,Instituto Dom Luiz, Lisbon University, Lisbon, Portugal.
| | - Wouter P Schellart
- School of Earth, Atmosphere and Environment, Monash University, Melbourne, VIC, 3800, Australia.,Department of Earth Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
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12
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On the relative motions of long-lived Pacific mantle plumes. Nat Commun 2018; 9:854. [PMID: 29487287 PMCID: PMC5829163 DOI: 10.1038/s41467-018-03277-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 02/01/2018] [Indexed: 11/16/2022] Open
Abstract
Mantle plumes upwelling beneath moving tectonic plates generate age-progressive chains of volcanos (hotspot chains) used to reconstruct plate motion. However, these hotspots appear to move relative to each other, implying that plumes are not laterally fixed. The lack of age constraints on long-lived, coeval hotspot chains hinders attempts to reconstruct plate motion and quantify relative plume motions. Here we provide 40Ar/39Ar ages for a newly identified long-lived mantle plume, which formed the Rurutu hotspot chain. By comparing the inter-hotspot distances between three Pacific hotspots, we show that Hawaii is unique in its strong, rapid southward motion from 60 to 50 Myrs ago, consistent with paleomagnetic observations. Conversely, the Rurutu and Louisville chains show little motion. Current geodynamic plume motion models can reproduce the first-order motions for these plumes, but only when each plume is rooted in the lowermost mantle. Using mantle plumes to reconstruct past plate motion is complicated, because plumes may not be fixed. Here, the authors demonstrate using 40Ar/39Ar ages that the Rurutu plume is relatively stable compared to the rapidly moving Hawaiian plume, yet it has a similar deep mantle origin.
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13
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Ficini E, Dal Zilio L, Doglioni C, Gerya TV. Horizontal mantle flow controls subduction dynamics. Sci Rep 2017; 7:7550. [PMID: 28790325 PMCID: PMC5548891 DOI: 10.1038/s41598-017-06551-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 06/14/2017] [Indexed: 12/03/2022] Open
Abstract
It is generally accepted that subduction is driven by downgoing-plate negative buoyancy. Yet plate age –the main control on buoyancy– exhibits little correlation with most of the present-day subduction velocities and slab dips. “West”-directed subduction zones are on average steeper (~65°) than “East”-directed (~27°). Also, a “westerly”-directed net rotation of the lithosphere relative to the mantle has been detected in the hotspot reference frame. Thus, the existence of an “easterly”-directed horizontal mantle wind could explain this subduction asymmetry, favouring steepening or lifting of slab dip angles. Here we test this hypothesis using high-resolution two-dimensional numerical thermomechanical models of oceanic plate subduction interacting with a mantle flow. Results show that when subduction polarity is opposite to that of the mantle flow, the descending slab dips subvertically and the hinge retreats, thus leading to the development of a back-arc basin. In contrast, concordance between mantle flow and subduction polarity results in shallow dipping subduction, hinge advance and pronounced topography of the overriding plate, regardless of their age-dependent negative buoyancy. Our results are consistent with seismicity data and tomographic images of subduction zones. Thus, our models may explain why subduction asymmetry is a common feature of convergent margins on Earth.
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Affiliation(s)
- E Ficini
- Department of Earth Sciences, Sapienza University of Rome, Rome, Italy.
| | - L Dal Zilio
- Institute of Geophysics, ETH Zurich, Zürich, Switzerland
| | - C Doglioni
- Department of Earth Sciences, Sapienza University of Rome, Rome, Italy.,Istituto Nazionale di Geofisica e Vulcanologia, INGV, Rome, Italy
| | - T V Gerya
- Institute of Geophysics, ETH Zurich, Zürich, Switzerland
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14
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Sea level fall during glaciation stabilized atmospheric CO 2 by enhanced volcanic degassing. Nat Commun 2017; 8:15867. [PMID: 28681844 PMCID: PMC5504290 DOI: 10.1038/ncomms15867] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 05/09/2017] [Indexed: 11/08/2022] Open
Abstract
Paleo-climate records and geodynamic modelling indicate the existence of complex interactions between glacial sea level changes, volcanic degassing and atmospheric CO2, which may have modulated the climate system's descent into the last ice age. Between ∼85 and 70 kyr ago, during an interval of decreasing axial tilt, the orbital component in global temperature records gradually declined, while atmospheric CO2, instead of continuing its long-term correlation with Antarctic temperature, remained relatively stable. Here, based on novel global geodynamic models and the joint interpretation of paleo-proxy data as well as biogeochemical simulations, we show that a sea level fall in this interval caused enhanced pressure-release melting in the uppermost mantle, which may have induced a surge in magma and CO2 fluxes from mid-ocean ridges and oceanic hotspot volcanoes. Our results reveal a hitherto unrecognized negative feedback between glaciation and atmospheric CO2 predominantly controlled by marine volcanism on multi-millennial timescales of ∼5,000-15,000 years.
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15
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Jackson MG, Konter JG, Becker T. Primordial helium entrained by the hottest mantle plumes. Nature 2017; 542:340-343. [DOI: 10.1038/nature21023] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 11/24/2016] [Indexed: 11/09/2022]
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16
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A rapid burst in hotspot motion through the interaction of tectonics and deep mantle flow. Nature 2016; 533:239-42. [PMID: 27172048 DOI: 10.1038/nature17422] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 02/09/2016] [Indexed: 11/08/2022]
Abstract
Volcanic hotspot tracks featuring linear progressions in the age of volcanism are typical surface expressions of plate tectonic movement on top of narrow plumes of hot material within Earth's mantle. Seismic imaging reveals that these plumes can be of deep origin--probably rooted on thermochemical structures in the lower mantle. Although palaeomagnetic and radiometric age data suggest that mantle flow can advect plume conduits laterally, the flow dynamics underlying the formation of the sharp bend occurring only in the Hawaiian-Emperor hotspot track in the Pacific Ocean remains enigmatic. Here we present palaeogeographically constrained numerical models of thermochemical convection and demonstrate that flow in the deep lower mantle under the north Pacific was anomalously vigorous between 100 million years ago and 50 million years ago as a consequence of long-lasting subduction systems, unlike those in the south Pacific. These models show a sharp bend in the Hawaiian-Emperor hotspot track arising from the interplay of plume tilt and the lateral advection of plume sources. The different trajectories of the Hawaiian and Louisville hotspot tracks arise from asymmetric deformation of thermochemical structures under the Pacific between 100 million years ago and 50 million years ago. This asymmetric deformation waned just before the Hawaiian-Emperor bend developed, owing to flow in the deepest lower mantle associated with slab descent in the north and south Pacific.
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Davies DR, Rawlinson N, Iaffaldano G, Campbell IH. Lithospheric controls on magma composition along Earth’s longest continental hotspot track. Nature 2015; 525:511-4. [DOI: 10.1038/nature14903] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 07/07/2015] [Indexed: 11/09/2022]
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18
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Broad plumes rooted at the base of the Earth's mantle beneath major hotspots. Nature 2015; 525:95-9. [DOI: 10.1038/nature14876] [Citation(s) in RCA: 504] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 06/19/2015] [Indexed: 11/08/2022]
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19
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Low-buoyancy thermochemical plumes resolve controversy of classical mantle plume concept. Nat Commun 2015; 6:6960. [PMID: 25907970 PMCID: PMC4421820 DOI: 10.1038/ncomms7960] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 03/18/2015] [Indexed: 11/24/2022] Open
Abstract
The Earth's biggest magmatic events are believed to originate from massive melting when hot mantle plumes rising from the lowermost mantle reach the base of the lithosphere. Classical models predict large plume heads that cause kilometre-scale surface uplift, and narrow (100 km radius) plume tails that remain in the mantle after the plume head spreads below the lithosphere. However, in many cases, such uplifts and narrow plume tails are not observed. Here using numerical models, we show that the issue can be resolved if major mantle plumes contain up to 15–20% of recycled oceanic crust in a form of dense eclogite, which drastically decreases their buoyancy and makes it depth dependent. We demonstrate that, despite their low buoyancy, large enough thermochemical plumes can rise through the whole mantle causing only negligible surface uplift. Their tails are bulky (>200 km radius) and remain in the upper mantle for 100 millions of years. The classic mantle plume concept explains large igneous provinces and hotspot magmatism, but often contradicts observed surface uplift and plume morphology. Here, the authors present a plume model that better supports observations by considering low-buoyancy plumes containing up to 15% of recycled oceanic crust.
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French S, Lekic V, Romanowicz B. Waveform Tomography Reveals Channeled Flow at the Base of the Oceanic Asthenosphere. Science 2013; 342:227-30. [PMID: 24009355 DOI: 10.1126/science.1241514] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Scott French
- Berkeley Seismological Laboratory, 209 McCone Hall, Berkeley, CA 94720, USA
| | - Vedran Lekic
- Department of Geology, University of Maryland, College Park, MD 20742, USA
| | - Barbara Romanowicz
- Berkeley Seismological Laboratory, 209 McCone Hall, Berkeley, CA 94720, USA
- Collège de France, 11 Place Marcelin Berthelot, 75005 Paris, France
- Institut de Physique du Globe de Paris, 1 rue Jussieu, 752382 Paris Cedex 05, France
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21
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Doubrovine PV, Steinberger B, Torsvik TH. Absolute plate motions in a reference frame defined by moving hot spots in the Pacific, Atlantic, and Indian oceans. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jb009072] [Citation(s) in RCA: 197] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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22
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Wu B, Driscoll P, Olson P. A statistical boundary layer model for the mantleD″ region. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jb008511] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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23
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Zhang H, Zhao J, Xu Q. Seismic P-wave tomography in eastern Tibet: Formation of the rifts. CHINESE SCIENCE BULLETIN-CHINESE 2011. [DOI: 10.1007/s11434-011-4577-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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24
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Maresch WV, Kluge R, Baumann A, Pindell JL, Krückhans-Lueder G, Stanek K. The occurrence and timing of high-pressure metamorphism on Margarita Island, Venezuela: a constraint on Caribbean-South America interaction. ACTA ACUST UNITED AC 2009. [DOI: 10.1144/sp328.28] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractThe metamorphic rock sequences exposed on the Island of Margarita, Venezuela, located in the southeastern corner of the Caribbean Plate margin, are composed of a high-pressure/low-temperature (HP/LT) nucleus subducted to at least 50 km depth, now structurally overlain by lower-grade greenschist-facies units lacking any sign of high-pressure subduction-zone metamorphism. The HP/LT nucleus involves protoliths of both oceanic (metabasalts and intimately associated carbonaceous schists of the La Rinconada unit; peridotite massifs) and continental affinity (metapelites, marbles and gneisses of the Juan Griego unit). All HP/LT units were joined together prior to the peak of high-pressure metamorphism, as shown by their matching metamorphic pressure–temperature evolution. The metamorphic grade attained produced barroisite as the regional amphibole. Glaucophane is not known from Margarita. Contrary to a widely propagated assumption, there are nomajornappe structurespost-datingHP/LT metamorphism anywherewithinthe high-pressure nucleus of Margarita Island. U–Pb zircon dating of key tonalitic to granitic intrusive rocks provides the following constraints: (1) the Juan Griego unit is heterogeneous and contains Palaeozoic as well as probable Mesozoic protolith; (2) the peak of HP/LT metamorphism, that is maximum subduction, is younger than 116–106 Ma and older than 85 Ma, most probablyc.100–90 Ma, a time span during which the southeastern Caribbean/South American border was clearly a passive margin. The assembly of Margaritan protoliths and their HP/LT overprint occurred far to the west in northwestern South America, a scenario completely in accord with the details of the Pacific-origin model outlined by Pindell & Kennan. Juxtaposition of the greenschist-facies units occurred after exhumation into mid-crustal levels afterc.80 Ma.
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Affiliation(s)
- Walter V. Maresch
- Institute of Geology, Mineralogy & Geophysics, Ruhr-University Bochum, 44780 Bochum, Germany
| | - Rolf Kluge
- Institute of Mineralogy, Münster University, Corrensstrasse 24, 48149 Münster, Germany
- Present address: AQUANTA Hydrogeologie GmbH & Co. KG, Kirchplatz 1, 48301 Nottuln, Germany
| | - Albrecht Baumann
- Institute of Mineralogy, Münster University, Corrensstrasse 24, 48149 Münster, Germany
| | - James L. Pindell
- Tectonic Analysis Ltd. Chestnut House, Duncton, Sussex GU28 0LH, UK
- Department of Earth Science, Rice University, Houston, TX 77002, USA
| | - Gabriela Krückhans-Lueder
- Institute of Mineralogy, Münster University, Corrensstrasse 24, 48149 Münster, Germany
- Present address: Tornescher Weg 150, 25436 Uetersen, Germany
| | - Klaus Stanek
- Institute of Geology, TU Bergakademie Freiberg, 09596 Freiberg, Germany
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25
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Pindell JL, Kennan L. Tectonic evolution of the Gulf of Mexico, Caribbean and northern South America in the mantle reference frame: an update. ACTA ACUST UNITED AC 2009. [DOI: 10.1144/sp328.1] [Citation(s) in RCA: 301] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractWe present an updated synthesis of the widely accepted ‘single-arc Pacific-origin’ and ‘Yucatán-rotation’ models for Caribbean and Gulf of Mexico evolution, respectively. Fourteen palaeogeographic maps through time integrate new concepts and alterations to earlier models. Pre-Aptian maps are presented in a North American reference frame. Aptian and younger maps are presented in an Indo-Atlantic hot spot reference frame which demonstrates the surprising simplicity of Caribbean–American interaction. We use the Mülleret al.(Geology21: 275–278, 1993) reference frame because the motions of the Americas are smoothest in this reference frame, and because it does not differ significantly, at least sincec.90 Ma, from more recent ‘moving hot spot’ reference frames. The Caribbean oceanic lithosphere has moved little relative to the hot spots in the Cenozoic, but moved north atc.50 km/Ma during the Cretaceous, while the American plates have drifted west much further and faster and thus are responsible for most Caribbean–American relative motion history. New or revised features of this model, generally driven by new data sets, include: (1) refined reconstruction of western Pangaea; (2) refined rotational motions of the Yucatán Block during the evolution of the Gulf of Mexico; (3) an origin for the Caribbean Arc that invokes Aptian conversion to a SW-dipping subduction zone of a trans-American plate boundary from Chortís to Ecuador that was part sinistral transform (northern Caribbean) and part pre-existing arc (eastern, southern Caribbean); (4) acknowledgement that the Caribbean basalt plateau may pertain to the palaeo-Galapagos hot spot, the occurrence of which was partly controlled by a Proto-Caribbean slab gap beneath the Caribbean Plate; (5) Campanian initiation of subduction at the Panama–Costa Rica Arc, although a sinistral transform boundary probably pre-dated subduction initiation here; (6) inception of a north-vergent crustal inversion zone along northern South America to account for Cenozoic convergence between the Americas ahead of the Caribbean Plate; (7) a fan-like, asymmetric rift opening model for the Grenada Basin, where the Margarita and Tobago footwall crustal slivers were exhumed from beneath the southeast Aves Ridge hanging wall; (8) an origin for the Early Cretaceous HP/LT metamorphism in the El Tambor units along the Motagua Fault Zone that relates to subduction of Farallon crust along western Mexico (and then translated along the trans-American plate boundary prior to onset of SW-dipping subduction beneath the Caribbean Arc) rather than to collision of Chortis with Southern Mexico; (9) Middle Miocene tectonic escape of Panamanian crustal slivers, followed by Late Miocene and Recent eastward movement of the ‘Panama Block’ that is faster than that of the Caribbean Plate, allowed by the inception of east–west trans-Costa Rica shear zones. The updated model integrates new concepts and global plate motion models in an internally consistent way, and can be used to test and guide more local research across the Gulf of Mexico, the Caribbean and northern South America. Using examples from the regional evolution, the processes of slab break off and flat slab subduction are assessed in relation to plate interactions in the hot spot reference frame.
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Affiliation(s)
- James L. Pindell
- Tectonic Analysis Ltd, Chestnut House, Duncton, West Sussex GU28 0LH, UK
- Department of Earth Science, Rice University, Houston, TX 77002, USA
| | - Lorcan Kennan
- Tectonic Analysis Ltd, Chestnut House, Duncton, West Sussex GU28 0LH, UK
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26
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Kreemer C. Absolute plate motions constrained by shear wave splitting orientations with implications for hot spot motions and mantle flow. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2009jb006416] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Wessel P, Kroenke LW. Pacific absolute plate motion since 145 Ma: An assessment of the fixed hot spot hypothesis. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jb005499] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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28
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Schmerr N, Garnero EJ. Upper mantle discontinuity topography from thermal and chemical heterogeneity. Science 2007; 318:623-6. [PMID: 17962558 DOI: 10.1126/science.1145962] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Using high-resolution stacks of precursors to the seismic phase SS, we investigated seismic discontinuities associated with mineralogical phase changes approximately 410 and 660 kilometers (km) deep within Earth beneath South America and the surrounding oceans. Detailed maps of phase boundary topography revealed deep 410- and 660-km discontinuities in the down-dip direction of subduction, inconsistent with purely isochemical olivine phase transformation in response to lowered temperatures. Mechanisms invoking chemical heterogeneity within the mantle transition zone were explored to explain this feature. In some regions, multiple reflections from the discontinuities were detected, consistent with partial melt near 410-km depth and/or additional phase changes near 660-km depth. Thus, the origin of upper mantle heterogeneity has both chemical and thermal contributions and is associated with deeply rooted tectonic processes.
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Affiliation(s)
- Nicholas Schmerr
- Arizona State University, School of Earth and Space Exploration, Box 871404, Tempe, AZ 85287-1404, USA.
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29
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Waite GP, Schutt DL, Smith RB. Models of lithosphere and asthenosphere anisotropic structure of the Yellowstone hot spot from shear wave splitting. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jb003501] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Gregory P. Waite
- Department of Geology and Geophysics; University of Utah; Salt Lake City Utah USA
| | - Derek L. Schutt
- Department of Geology and Geophysics; University of Wyoming; Laramie Wyoming USA
| | - Robert B. Smith
- Department of Geology and Geophysics; University of Utah; Salt Lake City Utah USA
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30
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Rost S, Garnero EJ, Williams Q, Manga M. Seismological constraints on a possible plume root at the core-mantle boundary. Nature 2005; 435:666-9. [PMID: 15931220 DOI: 10.1038/nature03620] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Accepted: 04/06/2005] [Indexed: 11/09/2022]
Abstract
Recent seismological discoveries have indicated that the Earth's core-mantle boundary is far more complex than a simple boundary between the molten outer core and the silicate mantle. Instead, its structural complexities probably rival those of the Earth's crust. Some regions of the lowermost mantle have been observed to have seismic wave speed reductions of at least 10 per cent, which appear not to be global in extent. Here we present robust evidence for an 8.5-km-thick and approximately 50-km-wide pocket of dense, partially molten material at the core-mantle boundary east of Australia. Array analyses of an anomalous precursor to the reflected seismic wave ScP reveal compressional and shear-wave velocity reductions of 8 and 25 per cent, respectively, and a 10 per cent increase in density of the partially molten aggregate. Seismological data are incompatible with a basal layer composed of pure melt, and thus require a mechanism to prevent downward percolation of dense melt within the layer. This may be possible by trapping of melt by cumulus crystal growth following melt drainage from an anomalously hot overlying region of the lowermost mantle. This magmatic evolution and the resulting cumulate structure seem to be associated with overlying thermal instabilities, and thus may mark a root zone of an upwelling plume.
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Affiliation(s)
- Sebastian Rost
- Department of Geological Sciences, Arizona State University, Box 871404, Tempe , Arizona 85287-1404, USA.
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31
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Koppers AAP, Staudigel H. Asynchronous Bends in Pacific Seamount Trails: A Case for Extensional Volcanism? Science 2005; 307:904-7. [PMID: 15705846 DOI: 10.1126/science.1107260] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Gilbert Ridge and Tokelau Seamounts are the only seamount trails in the Pacific Ocean with a sharp 60 degrees bend, similar to the Hawaii-Emperor bend (HEB). These two bends should be coeval with the 47-million-year-old HEB if they were formed by stationary hot spots, and assuming Pacific plate motion only. New 40Ar/39Ar ages indicate that the bends in the Gilbert Ridge and Tokelau seamount trail were formed much earlier than the HEB at 67 and 57 million years ago, respectively. Such asynchronous bends cannot be reconciled with the stationary hot spot paradigm, possibly suggesting hot spot motion or magmatism caused by short-term local lithospheric extension.
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Affiliation(s)
- Anthony A P Koppers
- Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0225, USA.
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32
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Neukum G, Jaumann R, Hoffmann H, Hauber E, Head JW, Basilevsky AT, Ivanov BA, Werner SC, van Gasselt S, Murray JB, McCord T. Recent and episodic volcanic and glacial activity on Mars revealed by the High Resolution Stereo Camera. Nature 2005; 432:971-9. [PMID: 15616551 DOI: 10.1038/nature03231] [Citation(s) in RCA: 390] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2004] [Accepted: 11/30/2004] [Indexed: 11/08/2022]
Abstract
The large-area coverage at a resolution of 10-20 metres per pixel in colour and three dimensions with the High Resolution Stereo Camera Experiment on the European Space Agency Mars Express Mission has made it possible to study the time-stratigraphic relationships of volcanic and glacial structures in unprecedented detail and give insight into the geological evolution of Mars. Here we show that calderas on five major volcanoes on Mars have undergone repeated activation and resurfacing during the last 20 per cent of martian history, with phases of activity as young as two million years, suggesting that the volcanoes are potentially still active today. Glacial deposits at the base of the Olympus Mons escarpment show evidence for repeated phases of activity as recently as about four million years ago. Morphological evidence is found that snow and ice deposition on the Olympus construct at elevations of more than 7,000 metres led to episodes of glacial activity at this height. Even now, water ice protected by an insulating layer of dust may be present at high altitudes on Olympus Mons.
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Affiliation(s)
- G Neukum
- Institut fuer Geologische Wissenschaften, Freie Universitaet Berlin, Malteserstrasse 74-100, Bldg D, 12249 Berlin, Germany.
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33
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Van Ark E, Lin J. Time variation in igneous volume flux of the Hawaii-Emperor hot spot seamount chain. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003jb002949] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Emily Van Ark
- Massachusetts Institute of Technology-Woods Hole Oceanographic Institution Joint Program; Cambridge Massachusetts USA
| | - Jian Lin
- Department of Geology and Geophysics; Woods Hole Oceanographic Institution; Woods Hole Massachusetts USA
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34
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Conrad CP, Lithgow-Bertelloni C. The temporal evolution of plate driving forces: Importance of “slab suction” versus “slab pull” during the Cenozoic. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004jb002991] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Clinton P. Conrad
- Department of Geological Sciences; University of Michigan; Ann Arbor Michigan USA
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35
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Thorne MS, Garnero EJ. Inferences on ultralow-velocity zone structure from a global analysis ofSPdKSwaves. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004jb003010] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Michael S. Thorne
- Department of Geological Sciences; Arizona State University; Tempe Arizona USA
| | - Edward J. Garnero
- Department of Geological Sciences; Arizona State University; Tempe Arizona USA
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36
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Steinberger B, Sutherland R, O'Connell RJ. Prediction of Emperor-Hawaii seamount locations from a revised model of global plate motion and mantle flow. Nature 2004; 430:167-73. [PMID: 15241405 DOI: 10.1038/nature02660] [Citation(s) in RCA: 279] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2004] [Accepted: 05/12/2004] [Indexed: 11/09/2022]
Abstract
The bend in the Hawaiian-Emperor seamount chain is a prominent feature usually attributed to a change in Pacific plate motion approximately 47 Myr ago. However, global plate motion reconstructions fail to predict the bend. Here we show how the geometry of the Hawaiian-Emperor chain and other hotspot tracks can be explained when we combine global plate motions with intraplate deformation and movement of hotspot plumes through distortion by global mantle flow. Global mantle flow models predict a southward motion of the Hawaiian hotspot. This, in combination with a plate motion reconstruction connecting Pacific and African plates through Antarctica, predicts the Hawaiian track correctly since the date of the bend, but predicts the chain to be too far west before it. But if a reconstruction through Australia and Lord Howe rise is used instead, the track is predicted correctly back to 65 Myr ago, including the bend. The difference between the two predictions indicates the effect of intraplate deformation not yet recognized or else not recorded on the ocean floor. The remaining misfit before 65 Myr ago can be attributed to additional intraplate deformation of similar magnitude.
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Affiliation(s)
- Bernhard Steinberger
- Institute for Frontier Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.
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37
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Vidal V. Variations of the Hawaiian hot spot activity revealed by variations in the magma production rate. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003jb002559] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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38
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Antretter M, Riisager P, Hall S, Zhao X, Steinberger B. Modelled palaeolatitudes for the Louisville hot spot and the Ontong Java Plateau. ACTA ACUST UNITED AC 2004. [DOI: 10.1144/gsl.sp.2004.229.01.03] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractFormation of the Ontong Java Plateau (OJP), a large igneous province in the western Pacific, has been attributed to a rising plume head in the initial stage of the Louisville hot spot, approximately 120–125 Ma ago. However, the Neal et al. plate reconstruction suggests that the plateau formed approximately 9° north of the current location of this hot spot at 51°S. The magnetization of the plateau’s basement records a palaeolatitude of approximately 25°S which further increases the discrepancy with the plume-head model. Modelling the motion of the Louisville hot spot for the last 120 Ma yields a possible southward motion of up to about 6°. True polar wander (TPW) models also shift the predicted palaeolatitudes of the plateau farther north. Taking into account both hot-spot motion and TPW, formation of the OJP by the Louisville not spot remains a possibility.
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Affiliation(s)
- Maria Antretter
- Department of Earth and Environmental Sciences, University of Munich
Theresienstrasse 41, D-80333 München, Germany
| | - Peter Riisager
- Danish Lithosphere Centre
Øster Voldgade 10, DK-1350 Copenhagen K, Denmark
| | - Stuart Hall
- Department of Geosciences, University of Houston
Houston, TX 77204-5007, USA
| | - Xixi Zhao
- Earth Sciences Department, University of California at Santa Cruz
Santa Cruz, CA 95064, USA
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39
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Nishiyama N, Yagi T. Phase relation and mineral chemistry in pyrolite to 2200°C under the lower mantle pressures and implications for dynamics of mantle plumes. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jb002216] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Takehiko Yagi
- Institute for Solid State Physics; University of Tokyo; Kashiwa Japan
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40
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The convective mantle flow signal in rates of true polar wander. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/gd029p0233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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41
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Kuo BY, Garnero EJ, Lay T. Tomographic inversion ofS-SKStimes for shear velocity heterogeneity in D″: Degree 12 and hybrid models. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jb900334] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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42
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Castle JC, Creager KC, Winchester JP, van der Hilst RD. Shear wave speeds at the base of the mantle. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jb900193] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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