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Wang J, Lekić V, Schmerr NC, Gu YJ, Guo Y, Lin R. Mesozoic intraoceanic subduction shaped the lower mantle beneath the East Pacific Rise. SCIENCE ADVANCES 2024; 10:eado1219. [PMID: 39331711 PMCID: PMC11430487 DOI: 10.1126/sciadv.ado1219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 08/22/2024] [Indexed: 09/29/2024]
Abstract
The Pacific large low-shear-velocity province (LLSVP), as revealed by cluster analysis of global tomographic models, hosts multiple internal anomalies, including a notable gap (~20° wide) between the central and eastern Pacific. The cause of the structural gap remains unconstrained. Directly above this structural gap, we identify an anomalously thick mantle transition zone east of the East Pacific Rise, the fastest-spreading ocean ridge in the world, using a dense set of SS precursors. The area of the thickened transition zone exhibits faster-than-average velocities according to recent tomographic images, suggesting perturbed postolivine phase boundaries shifting in response to lowered temperatures. We attribute this observation to episodes of Mesozoic-aged (250 to 120 million years ago) intraoceanic subduction beneath the present-day Nazca Plate. The eastern portion of the Pacific LLSVP was separated by downwelling because of this ancient oceanic slab. Our discovery provides a unique perspective on linking deep Earth structures with surface subduction.
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Affiliation(s)
- Jingchuan Wang
- Department of Geology, University of Maryland, College Park, MD 20742, USA
| | - Vedran Lekić
- Department of Geology, University of Maryland, College Park, MD 20742, USA
| | - Nicholas C Schmerr
- Department of Geology, University of Maryland, College Park, MD 20742, USA
| | - Yu J Gu
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Yi Guo
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Rongzhi Lin
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
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2
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Fouquet A, Kok PJR, Recoder RS, Prates I, Camacho A, Marques-Souza S, Ghellere JM, McDiarmid RW, Rodrigues MT. Relicts in the mist: Two new frog families, genera and species highlight the role of Pantepui as a biodiversity museum throughout the Cenozoic. Mol Phylogenet Evol 2024; 191:107971. [PMID: 38000706 DOI: 10.1016/j.ympev.2023.107971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 11/21/2023] [Accepted: 11/21/2023] [Indexed: 11/26/2023]
Abstract
The iconic mountains of the Pantepui biogeographical region host many early-diverging endemic animal and plant lineages, concurring with Conan Doyle's novel about an ancient "Lost World". While this is the case of several frog lineages, others appear to have more recent origins, adding to the controversy around the diversification processes in this region. Due to its remoteness, Pantepui is challenging for biological surveys, and only a glimpse of its biodiversity has been described, which hampers comprehensive evolutionary studies in many groups. During a recent expedition to the Neblina massif on the Brazil-Venezuela border, we sampled two new frog species that could not be assigned to any known genus. Here, we perform phylogenetic analyses of mitogenomic and nuclear loci to infer the evolutionary relationships of the new taxa and support their description. We find that both species represent single lineages deeply nested within Brachycephaloidea, a major Neotropical clade of direct-developing frogs. Both species diverged >45 Ma from their closest relatives: the first is sister to all other Brachycephaloidea except for Ceuthomantis, another Pantepui endemic, and the second is sister to Brachycephalidae, endemic to the Brazilian Atlantic Forest. In addition to these considerable phylogenetic and biogeographic divergences, external morphology and osteological features support the proposition of two new family and genus-level taxa to accommodate these new branches of the amphibian tree of life. These findings add to other recently described ancient vertebrate lineages from the Neblina massif, providing a bewildering reminder that our perception of the Pantepui's biodiversity remains vastly incomplete. It also provides insights into how these mountains acted as "museums" during the diversification of Brachycephaloidea and of Neotropical biotas more broadly, in line with the influential "Plateau theory". Finally, these discoveries point at the yet unknown branches of the tree of life that may go extinct, due to global climate change and zoonotic diseases, before we even learn about their existence, amphibians living at higher elevations being particularly at risk.
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Affiliation(s)
- Antoine Fouquet
- Laboratoire Évolution et Diversité Biologique, UMR 5174, CNRS, IRD, Université Paul Sabatier, Bâtiment 4R1 31062 cedex 9, 118 Route de Narbonne, 31077 Toulouse, France.
| | - Philippe J R Kok
- Department of Ecology and Vertebrate Zoology, Faculty of Biology and Environmental Protection, University of Łódź, 12/16 Banacha Str., Łódź 90-237, Poland; Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom.
| | - Renato Sousa Recoder
- Universidade de São Paulo, Instituto de Biociências, Departamento de Zoologia, São Paulo, SP, Brazil.
| | - Ivan Prates
- Department of Ecology and Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, MI, USA
| | - Agustin Camacho
- Universidade de São Paulo, Instituto de Biociências, Departamento de Zoologia, São Paulo, SP, Brazil
| | - Sergio Marques-Souza
- Universidade de São Paulo, Instituto de Biociências, Departamento de Zoologia, São Paulo, SP, Brazil
| | - José Mario Ghellere
- Universidade de São Paulo, Instituto de Biociências, Departamento de Zoologia, São Paulo, SP, Brazil
| | - Roy W McDiarmid
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, PO Box 37012, Washington, DC 20013, USA
| | - Miguel Trefaut Rodrigues
- Universidade de São Paulo, Instituto de Biociências, Departamento de Zoologia, São Paulo, SP, Brazil
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3
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Mather BR, Müller RD, Alfonso CP, Seton M, Wright NM. Kimberlite eruptions driven by slab flux and subduction angle. Sci Rep 2023; 13:9216. [PMID: 37280326 DOI: 10.1038/s41598-023-36250-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 05/30/2023] [Indexed: 06/08/2023] Open
Abstract
Kimberlites are sourced from thermochemical upwellings which can transport diamonds to the surface of the crust. The majority of kimberlites preserved at the Earth's surface erupted between 250 and 50 million years ago, and have been attributed to changes in plate velocity or mantle plumes. However, these mechanisms fail to explain the presence of strong subduction signatures observed in some Cretaceous kimberlites. This raises the question whether there is a subduction process that unifies our understanding of the timing of kimberlite eruptions. We develop a novel formulation for calculating subduction angle based on trench migration, convergence rate, slab thickness and density to connect the influx of slab material into the mantle with the timing of kimberlite eruptions. We find that subduction angles combined with peaks in slab flux predict pulses of kimberlite eruptions. High rates of subducting slab material trigger mantle return flow that stimulates fertile reservoirs in the mantle. These convective instabilities transport slab-influenced melt to the surface at a distance inbound from the trench corresponding to the subduction angle. Our deep-time slab dip formulation has numerous potential applications including modelling the deep carbon and water cycles, and an improved understanding of subduction-related mineral deposits.
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Affiliation(s)
- Ben R Mather
- EarthByte Group, School of Geosciences, The University of Sydney, Sydney, 2006, Australia.
| | - R Dietmar Müller
- EarthByte Group, School of Geosciences, The University of Sydney, Sydney, 2006, Australia
| | - Christopher P Alfonso
- EarthByte Group, School of Geosciences, The University of Sydney, Sydney, 2006, Australia
| | - Maria Seton
- EarthByte Group, School of Geosciences, The University of Sydney, Sydney, 2006, Australia
| | - Nicky M Wright
- EarthByte Group, School of Geosciences, The University of Sydney, Sydney, 2006, Australia
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Gianni GM, Likerman J, Navarrete CR, Gianni CR, Zlotnik S. Ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction. Nat Commun 2023; 14:2083. [PMID: 37045842 PMCID: PMC10097660 DOI: 10.1038/s41467-023-37799-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 03/27/2023] [Indexed: 04/14/2023] Open
Abstract
The Southern Atlantic-Southwest Indian ridges (SASWIR) host mid-ocean ridge basalts with a residual subduction-related geochemical fingerprint (i.e., a ghost-arc signature) of unclear origin. Here, we show through an analysis of plate kinematic reconstructions and seismic tomography models that the SASWIR subduction-modified mantle source formed in the Jurassic close to the Georgia Islands slab (GI) and remained near-stationary in the mantle reference frame. In this analysis, the GI lies far inboard the Jurassic Patagonian-Antarctic Peninsula active margin. This was formerly attributed to a large-scale flat subduction event in the Late Triassic-Early Jurassic. We propose that during this flat slab stage, the subduction-modified mantle areas beneath the Mesozoic active margin and surrounding sutures zones may have been bulldozed inland by >2280 km. After the demise of the flat slab, this mantle anomaly remained near-stationary and was sampled by the Karoo mantle plume 183 Million years (Myr) ago and again since 55 Myr ago by the SASWIR. We refer to this process as asthenospheric anomaly telescoping. This study provides a hitherto unrecognized geodynamic effect of flat subduction, the viability of which we support through numerical modeling.
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Affiliation(s)
- Guido M Gianni
- Instituto Geofísico Sismológico Ing. Fernando Volponi (IGSV), Universidad Nacional de San Juan, San Juan, Argentina
- National Scientific and Technical Research Council (CONICET), Capital Federal, Argentina
| | - Jeremías Likerman
- National Scientific and Technical Research Council (CONICET), Capital Federal, Argentina
- Instituto de Estudios Andinos Don Pablo Groeber, Universidad de Buenos Aires, Capital Federal, Argentina
| | - César R Navarrete
- National Scientific and Technical Research Council (CONICET), Capital Federal, Argentina
- Laboratorio Patagónico de Petro-Tectónica, Universidad Nacional de la Patagonia "San Juan Bosco", Comodoro Rivadavia, Chubut, Argentina
| | - Conrado R Gianni
- Instituto Geofísico Sismológico Ing. Fernando Volponi (IGSV), Universidad Nacional de San Juan, San Juan, Argentina
| | - Sergio Zlotnik
- Laboratori de Cálcul Numéric, Escola Técnica Superior d'Enginyers de Camins, Canals i Ports, Universitat Politécnica de Catalunya, Barcelona, Spain.
- Centre Internacional de Métodes Numérics a l'Enginyeria (CIMNE), Barcelona, Spain.
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Cycles of Andean mountain building archived in the Amazon Fan. Nat Commun 2022; 13:6983. [PMID: 36379929 PMCID: PMC9666610 DOI: 10.1038/s41467-022-34561-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/27/2022] [Indexed: 11/16/2022] Open
Abstract
Cordilleran orogenic systems have complex, polycyclic magmatic and deformation histories, and the timescales and mechanisms of episodic orogenesis are still debated. Here, we show that detrital zircons (DZs) in terrigenous sediment from the late Pleistocene Amazon Fan, found at the terminus of the continent-scale Amazon River-fan system, record multiple, distinct modes of U-Pb crystallization ages and U-Th/He (ZHe) cooling ages that correlate to known South American magmatic and tectonic events. The youngest ZHe ages delineate two recent phases of Andean orogenesis; one in the Late Cretaceous - Paleogene, and another in the Miocene. Frequency analyses of the deep-time Phanerozoic record of DZ U-Pb and ZHe ages demonstrate a strong 72 Myr period in magmatic events, and 92 Myr and 57 Myr periods in crustal cooling. We interpret these results as evidence of changes in upper and lower plate coupling, associated with multiple episodes of magmatism and crustal deformation along the subduction-dominated western margin of South America.
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Pérez-Escobar OA, Zizka A, Bermúdez MA, Meseguer AS, Condamine FL, Hoorn C, Hooghiemstra H, Pu Y, Bogarín D, Boschman LM, Pennington RT, Antonelli A, Chomicki G. The Andes through time: evolution and distribution of Andean floras. TRENDS IN PLANT SCIENCE 2022; 27:364-378. [PMID: 35000859 DOI: 10.1016/j.tplants.2021.09.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 09/03/2021] [Accepted: 09/30/2021] [Indexed: 05/12/2023]
Abstract
The Andes are the world's most biodiverse mountain chain, encompassing a complex array of ecosystems from tropical rainforests to alpine habitats. We provide a synthesis of Andean vascular plant diversity by estimating a list of all species with publicly available records, which we integrate with a phylogenetic dataset of 14 501 Neotropical plant species in 194 clades. We find that (i) the Andean flora comprises at least 28 691 georeferenced species documented to date, (ii) Northern Andean mid-elevation cloud forests are the most species-rich Andean ecosystems, (iii) the Andes are a key source and sink of Neotropical plant diversity, and (iv) the Andes, Amazonia, and other Neotropical biomes have had a considerable amount of biotic interchange through time.
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Affiliation(s)
| | - Alexander Zizka
- Biodiversity of Plants, Philipps University Marburg, 35043 Marburg, Germany; German Center for Integrative Biodiversity Research Halle-Jena-Leipzig (iDiv), 04103 Leipzig, Germany
| | - Mauricio A Bermúdez
- Escuela de Ingeniería Geológica, Universidad Pedagógica y Tecnológica de Colombia, Tunja, Colombia
| | - Andrea S Meseguer
- Real Jardín Botánico de Madrid (RJB)-Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Fabien L Condamine
- Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de l'Evolution de Montpellier (Université de Montpellier), 34095 Montpellier, France
| | - Carina Hoorn
- Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, 1098XH Amsterdam, The Netherlands
| | - Henry Hooghiemstra
- Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, 1098XH Amsterdam, The Netherlands
| | - Yuanshu Pu
- German Center for Integrative Biodiversity Research Halle-Jena-Leipzig (iDiv), 04103 Leipzig, Germany
| | - Diego Bogarín
- Jardín Botánico Lankester, Universidad de Costa Rica, Cartago, Costa Rica; Naturalis Biodiversity Center, 2333 CR Leiden, The Netherlands
| | - Lydian M Boschman
- Department of Environmental Systems Science, Eidgenössische Technische Hochschule (ETH) Zurich, 8092 Zurich, Switzerland
| | - R Toby Pennington
- Department of Geography, University of Exeter, Exeter EX4 4RJ, UK; Royal Botanic Garden, Edinburgh EH3 5LR, UK
| | - Alexandre Antonelli
- Royal Botanic Gardens, Kew TW9 3AB, Surrey, UK; Gothenburg Global Biodiversity Centre, Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden; Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, UK
| | - Guillaume Chomicki
- Ecology and Evolutionary Biology, University of Sheffield, Sheffield S10 2TN, UK.
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7
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Growth of Neogene Andes linked to changes in plate convergence using high-resolution kinematic models. Nat Commun 2022; 13:1339. [PMID: 35292661 PMCID: PMC8924272 DOI: 10.1038/s41467-022-29055-4] [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: 02/02/2021] [Accepted: 02/18/2022] [Indexed: 11/22/2022] Open
Abstract
The Andean cordillera was constructed during compressive tectonic events, whose causes and controls remain unclear. Exploring a possible link to plate convergence has been impeded by the coarse temporal resolution of existing plate kinematic models. Here we show that the Neogene evolution of the Andean margin is primarily related to changes in convergence as observed in new high-resolution plate reconstructions. Building on a compilation of plate finite rotations spanning the last 30 million years and using noise-mitigation techniques, we predict several short-term convergence changes that were unresolved in previous models. These changes are related to main tectono-magmatic events and require forces that are compatible with a range of geodynamic processes. These results allow to revise models of ongoing subduction orogeny at its type locality, emphasizing the role of upper plate deformation in the balance between kinematic energy associated with plate motion and gravitational potential energy stored in orogenic crustal roots. A high-resolution model of the motion between Nazca and South American plates is presented. The work shows rapid changes that help explaining tectono-magmatic events via a balance between kinematic energy and gravitational potential energy stored in the roots of the Andes.
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8
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Gianni GM, Navarrete CR. Catastrophic slab loss in southwestern Pangea preserved in the mantle and igneous record. Nat Commun 2022; 13:698. [PMID: 35121740 PMCID: PMC8817029 DOI: 10.1038/s41467-022-28290-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 01/11/2022] [Indexed: 11/16/2022] Open
Abstract
The Choiyoi Magmatic Province represents a major episode of silicic magmatism in southwestern Pangea in the mid-Permian-Triassic, the origin of which remains intensely debated. Here, we integrate plate-kinematic reconstructions and the lower mantle slab record beneath southwestern Pangea that provide clues on late Paleozoic-Mesozoic subducting slab configurations. Also, we compile geochronological information and analyze geochemical data using tectono-magmatic discrimination diagrams. We demonstrate that this magmatic event resulted from a large-scale slab loss. This is supported by a paleogeographic coincidence between a reconstructed 2,800-3,000-km-wide slab gap and the Choiyoi Magmatic Province and geochemical data indicating a slab break-off fingerprint in the latter. The slab break-off event is compatible with Permian paleogeographic modifications in southwestern Pangea. These findings render the Choiyoi Magmatic Province the oldest example of a geophysically constrained slab loss event and open new avenues to assess the geodynamic setting of silicic large igneous provinces back to the late Paleozoic. The origin of the Permian-Triassic Choiyoi silicic large igneous province (SLIP) is assessed by linking the igneous record, plate-kinematic reconstructions, and the deep mantle. This study suggests an origin related to a massive slab loss in Pangea.
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Southward expanding plate coupling due to variation in sediment subduction as a cause of Andean growth. Nat Commun 2021; 12:7271. [PMID: 34907198 PMCID: PMC8671423 DOI: 10.1038/s41467-021-27518-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 11/22/2021] [Indexed: 11/08/2022] Open
Abstract
Growth of the Andes has been attributed to Cenozoic subduction. Although climatic and tectonic processes have been proposed to be first-order mechanisms, their interaction and respective contributions remain largely unclear. Here, we apply three-dimensional, fully-dynamic subduction models to investigate the effect of trench-axial sediment transport and subduction on Andean growth, a mechanism that involves both climatic and tectonic processes. We find that the thickness of trench-fill sediments, a proxy of plate coupling (with less sediments causing stronger coupling), exerts an important influence on the pattern of crustal shortening along the Andes. The southward migrating Juan Fernandez Ridge acts as a barrier to the northward flowing trench sediments, thus expanding the zone of plate coupling southward through time. Consequently, the predicted history of Andean shortening is consistent with observations. Southward expanding crustal shortening matches the kinematic history of inferred compression. These results demonstrate the importance of climate-tectonic interaction on mountain building.
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10
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Baker CM, Buckman-Young RS, Costa CS, Giribet G. Phylogenomic Analysis of Velvet Worms (Onychophora) Uncovers an Evolutionary Radiation in the Neotropics. Mol Biol Evol 2021; 38:5391-5404. [PMID: 34427671 PMCID: PMC8662635 DOI: 10.1093/molbev/msab251] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Onychophora ("velvet worms") are charismatic soil invertebrates known for their status as a "living fossil," their phylogenetic affiliation to arthropods, and their distinctive biogeographic patterns. However, several aspects of their internal phylogenetic relationships remain unresolved, limiting our understanding of the group's evolutionary history, particularly with regard to changes in reproductive mode and dispersal ability. To address these gaps, we used RNA sequencing and phylogenomic analysis of transcriptomes to reconstruct the evolutionary relationships and infer divergence times within the phylum. We recovered a fully resolved and well-supported phylogeny for the circum-Antarctic family Peripatopsidae, which retains signals of Gondwanan vicariance and showcases the evolutionary lability of reproductive mode in the family. Within the Neotropical clade of Peripatidae, though, we found that amino acid-translated sequence data masked nearly all phylogenetic signal, resulting in highly unstable and poorly supported relationships. Analyses using nucleotide sequence data were able to resolve many more relationships, though we still saw discordant phylogenetic signal between genes, probably indicative of a rapid, mid-Cretaceous radiation in the group. Finally, we hypothesize that the unique reproductive mode of placentotrophic viviparity found in all Neotropical peripatids may have facilitated the multiple inferred instances of over-water dispersal and establishment on oceanic islands.
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Affiliation(s)
- Caitlin M Baker
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Rebecca S Buckman-Young
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Cristiano S Costa
- Laboratório de Sistemática e Taxonomia de Artrópodes Terrestres, Departamento de Biologia e Zoologia, Instituto de Biociências, Universidade Federal de Mato Grosso, Cuiabá, Brazil
| | - Gonzalo Giribet
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
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Bedford JR, Moreno M, Deng Z, Oncken O, Schurr B, John T, Báez JC, Bevis M. Months-long thousand-kilometre-scale wobbling before great subduction earthquakes. Nature 2020; 580:628-635. [PMID: 32350476 DOI: 10.1038/s41586-020-2212-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 02/05/2020] [Indexed: 11/10/2022]
Abstract
Megathrust earthquakes are responsible for some of the most devastating natural disasters1. To better understand the physical mechanisms of earthquake generation, subduction zones worldwide are continuously monitored with geophysical instrumentation. One key strategy is to install stations that record signals from Global Navigation Satellite Systems2,3 (GNSS), enabling us to track the non-steady surface motion of the subducting and overriding plates before, during and after the largest events4-6. Here we use a recently developed trajectory modelling approach7 that is designed to isolate secular tectonic motions from the daily GNSS time series to show that the 2010 Maule, Chile (moment magnitude 8.8) and 2011 Tohoku-oki, Japan (moment magnitude 9.0) earthquakes were preceded by reversals of 4-8 millimetres in surface displacement that lasted several months and spanned thousands of kilometres. Modelling of the surface displacement reversal that occurred before the Tohoku-oki earthquake suggests an initial slow slip followed by a sudden pulldown of the Philippine Sea slab so rapid that it caused a viscoelastic rebound across the whole of Japan. Therefore, to understand better when large earthquakes are imminent, we must consider not only the evolution of plate interface frictional processes but also the dynamic boundary conditions from deeper subduction processes, such as sudden densification of metastable slab.
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Affiliation(s)
- Jonathan R Bedford
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany.
| | - Marcos Moreno
- Departamento de Geofísica, Universidad de Concepción, Concepción, Chile
| | - Zhiguo Deng
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany
| | - Onno Oncken
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany.,Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - Bernd Schurr
- Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany
| | - Timm John
- Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - Juan Carlos Báez
- University of Chile, National Seismological Centre, Santiago, Chile
| | - Michael Bevis
- School of Earth Sciences, Ohio State University, Columbus, OH, USA
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Zhou X, Li ZH, Gerya TV, Stern RJ. Lateral propagation-induced subduction initiation at passive continental margins controlled by preexisting lithospheric weakness. SCIENCE ADVANCES 2020; 6:eaaz1048. [PMID: 32181357 PMCID: PMC7056308 DOI: 10.1126/sciadv.aaz1048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 12/10/2019] [Indexed: 06/10/2023]
Abstract
Understanding the conditions for forming new subduction zones at passive continental margins is important for understanding plate tectonics and the Wilson cycle. Previous models of subduction initiation (SI) at passive margins generally ignore effects due to the lateral transition from oceanic to continental lithosphere. Here, we use three-dimensional numerical models to study the possibility of propagating convergent plate margins from preexisting intraoceanic subduction zones along passive margins [subduction propagation (SP)]. Three possible regimes are achieved: (i) subducting slab tearing along a STEP fault, (ii) lateral propagation-induced SI at passive margin, and (iii) aborted SI with slab break-off. Passive margin SP requires a significant preexisting lithospheric weakness and a strong slab pull from neighboring subduction zones. The Atlantic passive margin to the north of Lesser Antilles could experience SP if it has a notable lithospheric weakness. In contrast, the Scotia subduction zone in the Southern Atlantic will most likely not propagate laterally.
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Affiliation(s)
- Xin Zhou
- Key Laboratory of Computational Geodynamics, College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Geophysics, Department of Earth Sciences, ETH-Zurich, Zürich 8092, Switzerland
| | - Zhong-Hai Li
- Key Laboratory of Computational Geodynamics, College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Taras V. Gerya
- Institute of Geophysics, Department of Earth Sciences, ETH-Zurich, Zürich 8092, Switzerland
| | - Robert J. Stern
- Geosciences Department, University of Texas at Dallas, Richardson, TX 75080, USA
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