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Tian X, Behn MD, Ito G, Schierjott JC, Kaus BJP, Popov AA. Magmatism controls global oceanic transform fault topography. Nat Commun 2024; 15:1914. [PMID: 38429287 PMCID: PMC10907720 DOI: 10.1038/s41467-024-46197-9] [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: 08/22/2023] [Accepted: 02/16/2024] [Indexed: 03/03/2024] Open
Abstract
Oceanic transform faults play an essential role in plate tectonics. Yet to date, there is no unifying explanation for the global trend in broad-scale transform fault topography, ranging from deep valleys to shallow topographic highs. Using three-dimensional numerical models, we find that spreading-rate dependent magmatism within the transform domain exerts a first-order control on the observed spectrum of transform fault depths. Low-rate magmatism results in deep transform valleys caused by transform-parallel tectonic stretching; intermediate-rate magmatism fully accommodates far-field stretching, but strike-slip motion induces across-transform tension, producing transform strength dependent shallow valleys; high-rate magmatism produces elevated transform zones due to local compression. Our models also address the observation that fracture zones are consistently shallower than their adjacent transform fault zones. These results suggest that plate motion change is not a necessary condition for reproducing oceanic transform topography and that oceanic transform faults are not simple conservative strike-slip plate boundaries.
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Affiliation(s)
- Xiaochuan Tian
- Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, MA, USA.
| | - Mark D Behn
- Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, MA, USA
| | - Garrett Ito
- Department of Earth Sciences, University of Hawaii, Honolulu HI, USA
| | - Jana C Schierjott
- Department of Earth Sciences, University of Hawaii, Honolulu HI, USA
| | - Boris J P Kaus
- Institute of Geosciences, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Anton A Popov
- Institute of Geosciences, Johannes Gutenberg University Mainz, Mainz, Germany
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Wang Z, Singh SC. Seismic evidence for uniform crustal accretion along slow-spreading ridges in the equatorial Atlantic Ocean. Nat Commun 2022; 13:7809. [PMID: 36528618 PMCID: PMC9759516 DOI: 10.1038/s41467-022-35459-z] [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: 02/16/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
The crustal accretion along mid-ocean ridges is known to be spreading-rate dependent. Along fast-spreading ridges, two-dimensional sheet-like mantle upwelling creates relatively uniform crust. In contrast, the crust formed along slow-spreading ridges shows large along-axis thickness variations with thicker crust at segment centres, which is hypothesised to be due a three-dimensional plume-like mantle upwelling or due to focused melt migration to segment centres. Using wide-angle seismic data acquired from the equatorial Atlantic Ocean, here we show that the crustal thickness is nearly uniform (~5.5 km) across five crustal segments for crust formed at the slow-spreading Mid-Atlantic Ridge with age varying from 8 to 70 Ma. The crustal velocities indicate that this crust is predominantly of magmatic origin. We suggest that this uniform magmatic crustal accretion is due to a two-dimensional sheet-like mantle upwelling facilitated by the long-offset transform faults in the equatorial Atlantic region and the presence of a high concentration of volatiles in the primitive melt in the mantle.
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Affiliation(s)
- Zhikai Wang
- grid.9489.c0000 0001 0675 8101Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, 1 rue Jussieu, Paris, 75238 France
| | - Satish C. Singh
- grid.9489.c0000 0001 0675 8101Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, 1 rue Jussieu, Paris, 75238 France
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Marjanović M, Singh SC, Gregory EPM, Grevemeyer I, Growe K, Wang Z, Vaddineni V, Laurencin M, Carton H, Gómez de la Peña L, Filbrandt C. Seismic Crustal Structure and Morphotectonic Features Associated With the Chain Fracture Zone and Their Role in the Evolution of the Equatorial Atlantic Region. JOURNAL OF GEOPHYSICAL RESEARCH. SOLID EARTH 2020; 125:e2020JB020275. [PMID: 33282617 PMCID: PMC7685155 DOI: 10.1029/2020jb020275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/31/2020] [Accepted: 09/01/2020] [Indexed: 06/12/2023]
Abstract
Oceanic transform faults and fracture zones (FZs) represent major bathymetric features that keep the records of past and present strike-slip motion along conservative plate boundaries. Although they play an important role in ridge segmentation and evolution of the lithosphere, their structural characteristics, and their variation in space and time, are poorly understood. To address some of the unknowns, we conducted interdisciplinary geophysical studies in the equatorial Atlantic Ocean, the region where some of the most prominent transform discontinuities have been developing. Here we present the results of the data analysis in the vicinity of the Chain FZ, on the South American Plate. The crustal structure across the Chain FZ, at the contact between ∼10 and 24 Ma oceanic lithosphere, is sampled along seismic reflection and refraction profiles. We observe that the crustal thickness within and across the Chain FZ ranges from ∼4.6-5.9 km, which compares with the observations reported for slow-slipping transform discontinuities globally. We attribute this presence of close to normal oceanic crustal thickness within FZs to the mechanism of lateral dike propagation, previously considered to be valid only in fast-slipping environments. Furthermore, the combination of our results with other data sets enabled us to extend the observations to morphotectonic characteristics on a regional scale. Our broader view suggests that the formation of the transverse ridge is closely associated with a global plate reorientation that was also responsible for the propagation and for shaping lower-order Mid-Atlantic Ridge segmentation around the equator.
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Affiliation(s)
- Milena Marjanović
- Université de Paris, Institut de Physique du Globe de Paris, CNRSParisFrance
| | - Satish C. Singh
- Université de Paris, Institut de Physique du Globe de Paris, CNRSParisFrance
| | - Emma P. M. Gregory
- Université de Paris, Institut de Physique du Globe de Paris, CNRSParisFrance
| | - Ingo Grevemeyer
- GEOMAR Helmholtz Centre of Ocean Research Kiel, RD4—Marine GeodynamicsKielGermany
| | - Kevin Growe
- Applied Geophysics ProgramTU Delft, ETH Zürich, RWTH AachenAachenGermany
| | - Zhikai Wang
- Université de Paris, Institut de Physique du Globe de Paris, CNRSParisFrance
| | - Venkata Vaddineni
- Université de Paris, Institut de Physique du Globe de Paris, CNRSParisFrance
| | - Muriel Laurencin
- Université de Paris, Institut de Physique du Globe de Paris, CNRSParisFrance
| | - Hélène Carton
- Université de Paris, Institut de Physique du Globe de Paris, CNRSParisFrance
| | | | - Christian Filbrandt
- GEOMAR Helmholtz Centre of Ocean Research Kiel, RD4—Marine GeodynamicsKielGermany
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Schmid F, Schlindwein V, Koulakov I, Plötz A, Scholz JR. Magma plumbing system and seismicity of an active mid-ocean ridge volcano. Sci Rep 2017; 7:42949. [PMID: 28218270 PMCID: PMC5317165 DOI: 10.1038/srep42949] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/17/2017] [Indexed: 11/12/2022] Open
Abstract
At mid-ocean ridges volcanism generally decreases with spreading rate but surprisingly massive volcanic centres occur at the slowest spreading ridges. These volcanoes can host unexpectedly strong earthquakes and vigorous, explosive submarine eruptions. Our understanding of the geodynamic processes forming these volcanic centres is still incomplete due to a lack of geophysical data and the difficulty to capture their rare phases of magmatic activity. We present a local earthquake tomographic image of the magma plumbing system beneath the Segment 8 volcano at the ultraslow-spreading Southwest Indian Ridge. The tomography shows a confined domain of partial melt under the volcano. We infer that from there melt is horizontally transported to a neighbouring ridge segment at 35 km distance where microearthquake swarms and intrusion tremor occur that suggest ongoing magmatic activity. Teleseismic earthquakes around the Segment 8 volcano, prior to our study, indicate that the current magmatic spreading episode may already have lasted over a decade and hence its temporal extent greatly exceeds the frequent short-lived spreading episodes at faster opening mid-ocean ridges.
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Affiliation(s)
- Florian Schmid
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Vera Schlindwein
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Ivan Koulakov
- Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, Russia Novosibirsk State University, Pirogova 2, 630090, Novosibirsk, Russia
| | - Aline Plötz
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Institue of Geophysics and Geology, University of Leipzig, Germany
| | - John-Robert Scholz
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
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Cannat M, Cann J, Maclennan J. Some Hard Rock Constraints on the Supply of Heat to Mid-Ocean Ridges. MID-OCEAN RIDGES 2013. [DOI: 10.1029/148gm05] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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Demartin B, Hirth G, Evans B. Experimental Constraints on Thermal Cracking of Peridotite at Oceanic Spreading Centers. MID-OCEAN RIDGES 2013. [DOI: 10.1029/148gm07] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Searle RC, Escartín J. The Rheology and Morphology of Oceanic Lithosphere and Mid-Ocean Ridges. MID-OCEAN RIDGES 2013. [DOI: 10.1029/148gm03] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Crawford WC, Singh SC, Seher T, Combier V, Dusunur D, Cannat M. Crustal structure, magma chamber, and faulting beneath the Lucky Strike Hydrothermal Vent Field. GEOPHYSICAL MONOGRAPH SERIES 2010. [DOI: 10.1029/2008gm000726] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Honsho C, Dyment J, Tamaki K, Ravilly M, Horen H, Gente P. Magnetic structure of a slow spreading ridge segment: Insights from near-bottom magnetic measurements on board a submersible. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jb005915] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Gregg PM, Lin J, Behn MD, Montési LGJ. Spreading rate dependence of gravity anomalies along oceanic transform faults. Nature 2007; 448:183-7. [PMID: 17625563 DOI: 10.1038/nature05962] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Accepted: 05/24/2007] [Indexed: 11/09/2022]
Abstract
Mid-ocean ridge morphology and crustal accretion are known to depend on the spreading rate of the ridge. Slow-spreading mid-ocean-ridge segments exhibit significant crustal thinning towards transform and non-transform offsets, which is thought to arise from a three-dimensional process of buoyant mantle upwelling and melt migration focused beneath the centres of ridge segments. In contrast, fast-spreading mid-ocean ridges are characterized by smaller, segment-scale variations in crustal thickness, which reflect more uniform mantle upwelling beneath the ridge axis. Here we present a systematic study of the residual mantle Bouguer gravity anomaly of 19 oceanic transform faults that reveals a strong correlation between gravity signature and spreading rate. Previous studies have shown that slow-slipping transform faults are marked by more positive gravity anomalies than their adjacent ridge segments, but our analysis reveals that intermediate and fast-slipping transform faults exhibit more negative gravity anomalies than their adjacent ridge segments. This finding indicates that there is a mass deficit at intermediate- and fast-slipping transform faults, which could reflect increased rock porosity, serpentinization of mantle peridotite, and/or crustal thickening. The most negative anomalies correspond to topographic highs flanking the transform faults, rather than to transform troughs (where deformation is probably focused and porosity and alteration are expected to be greatest), indicating that crustal thickening could be an important contributor to the negative gravity anomalies observed. This finding in turn suggests that three-dimensional magma accretion may occur near intermediate- and fast-slipping transform faults.
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Affiliation(s)
- Patricia M Gregg
- Department of Geology and Geophysics, Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
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Engen Ø, Frazer LN, Wessel P, Faleide JI. Prediction of sediment thickness in the Norwegian-Greenland Sea from gravity inversion. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jb003924] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Øyvind Engen
- Department of Geosciences; University of Oslo; Oslo Norway
| | - L. Neil Frazer
- Department of Geology and Geophysics, School of Ocean and Earth Science and Technology; University of Hawai'i at Mānoa; Honolulu Hawaii USA
| | - Pål Wessel
- Department of Geology and Geophysics, School of Ocean and Earth Science and Technology; University of Hawai'i at Mānoa; Honolulu Hawaii USA
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Bonatti E, Ligi M, Brunelli D, Cipriani A, Fabretti P, Ferrante V, Gasperini L, Ottolini L. Mantle thermal pulses below the Mid-Atlantic Ridge and temporal variations in the formation of oceanic lithosphere. Nature 2003; 423:499-505. [PMID: 12774114 DOI: 10.1038/nature01594] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2002] [Accepted: 03/28/2003] [Indexed: 11/09/2022]
Abstract
A 20-Myr record of creation of oceanic lithosphere is exposed along a segment of the central Mid-Atlantic Ridge on an uplifted sliver of lithosphere. The degree of melting of the mantle that is upwelling below the ridge, estimated from the chemistry of the exposed mantle rocks, as well as crustal thickness inferred from gravity measurements, show oscillations of approximately 3-4 Myr superimposed on a longer-term steady increase with time. The time lag between oscillations of mantle melting and crustal thickness indicates that the mantle is upwelling at an average rate of approximately 25 mm x yr(-1), but this appears to vary through time. Slow-spreading lithosphere seems to form through dynamic pulses of mantle upwelling and melting, leading not only to along-axis segmentation but also to across-axis structural variability. Also, the central Mid-Atlantic Ridge appears to have become steadily hotter over the past 20 Myr, possibly owing to north-south mantle flow.
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Affiliation(s)
- Enrico Bonatti
- Istituto Scienze del Mare, Geologia Marina, CNR, Via Gobetti 101, 40129, Bologna, Italy.
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Cochran JR, Kurras GJ, Edwards MH, Coakley BJ. The Gakkel Ridge: Bathymetry, gravity anomalies, and crustal accretion at extremely slow spreading rates. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jb001830] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- James R. Cochran
- Lamont-Doherty Earth Observatory of Columbia University; Palisades New York USA
| | - Gregory J. Kurras
- Department of Geology and Geophysics, School of Ocean Earth Science and Technology; University of Hawaii; Honolulu Hawaii USA
| | - Margo H. Edwards
- Hawaii Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology; University of Hawaii; Honolulu Hawaii USA
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Escartín J, Cannat M, Pouliquen G, Rabain A, Lin J. Crustal thickness of V-shaped ridges south of the Azores: Interaction of the Mid-Atlantic Ridge (36°-39°N) and the Azores hot spot. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2001jb000224] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Barclay AH, Toomey DR, Solomon SC. Microearthquake characteristics and crustalVP/VSstructure at the Mid-Atlantic Ridge, 35°N. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000jb900371] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Canales JP, Collins JA, Escartín J, Detrick RS. Seismic structure across the rift valley of the Mid-Atlantic Ridge at 23°20′ (MARK area): Implications for crustal accretion processes at slow spreading ridges. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jb900301] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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