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Sauter D, Manatschal G, Kusznir N, Masquelet C, Werner P, Ulrich M, Bellingham P, Franke D, Autin J. Ignition of the southern Atlantic seafloor spreading machine without hot-mantle booster. Sci Rep 2023; 13:1195. [PMID: 36681722 PMCID: PMC9867738 DOI: 10.1038/s41598-023-28364-y] [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: 09/29/2022] [Accepted: 01/17/2023] [Indexed: 01/22/2023] Open
Abstract
The source of massive magma production at volcanic rifted margins remains strongly disputed since the first observations of thick lava piles in the 1980s. However, volumes of extruded and intruded melt products within rifted continental crust are still not accurately resolved using geophysical methods. Here we investigate the magma budget alongside the South Atlantic margins, at the onset of seafloor spreading, using high-quality seismic reflection profiles to accurately estimate the oceanic crustal thickness. We show that, along ~ 75% of the length of the Early-Cretaceous initial spreading centre, the crustal thickness is similar to regular oceanic thickness with an age > 100 Ma away from hot spots. Thus, most of the southernmost Atlantic Ocean opened without anomalously hot mantle, high magma supply being restricted to the Walvis Ridge area. We suggest that alternative explanations other than a hotter mantle should be favoured to explain the thick magmatic layer of seaward dipping reflectors landward of the initial mid-oceanic ridge.
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Affiliation(s)
- Daniel Sauter
- Institut Terre et Environnement de Strasbourg (ITES), Université de Strasbourg, 5 Rue Descartes, 67084, Strasbourg, France.
| | - Gianreto Manatschal
- Institut Terre et Environnement de Strasbourg (ITES), Université de Strasbourg, 5 Rue Descartes, 67084, Strasbourg, France
| | - Nick Kusznir
- School of Environmental Sciences, Liverpool University, Liverpool, L69 3GP, UK
| | - Charles Masquelet
- Institut des Sciences de la Terre de Paris (ISTeP), Sorbonne Université, 4 Place Jussieu, 75005, Paris, France
| | - Philippe Werner
- Institut Terre et Environnement de Strasbourg (ITES), Université de Strasbourg, 5 Rue Descartes, 67084, Strasbourg, France
| | - Marc Ulrich
- Institut Terre et Environnement de Strasbourg (ITES), Université de Strasbourg, 5 Rue Descartes, 67084, Strasbourg, France
| | | | - Dieter Franke
- Bundesanstalt für Geowissenschaften und Rohstoffe, Geozentrum Hannover, Stilleweg 2, 30655, Hannover, Deutschland
| | - Julia Autin
- Institut Terre et Environnement de Strasbourg (ITES), Université de Strasbourg, 5 Rue Descartes, 67084, Strasbourg, France
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Honing in on the climate signal in seafloor topography. Proc Natl Acad Sci U S A 2022; 119:e2209199119. [PMID: 35881780 PMCID: PMC9371738 DOI: 10.1073/pnas.2209199119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Influence of late Pleistocene sea-level variations on midocean ridge spacing in faulting simulations and a global analysis of bathymetry. Proc Natl Acad Sci U S A 2022; 119:e2204761119. [PMID: 35867751 PMCID: PMC9282452 DOI: 10.1073/pnas.2204761119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We address the hypothesis that changes in Pleistocene sea level have consequences for abyssal-hill bathymetry. A model illustrates how reductions in magma production caused by rising sea level could trigger faults at 100-ky intervals at intermediate spreading-rate ridges (>2.3 cm/y) and at 41-ky intervals at faster spreading-rate ridges (>3.8 cm/y). Analysis of 17 different regional ridge systems gives characteristic length scales that closely align with the predictions from the faulting model. Furthermore, a robust spectral peak is found at the 41-ky obliquity period at fast-spreading ridges. Together, these results constitute strong evidence for a pervasive influence of Pleistocene variations in glaciation and sea level on the pattern of abyssal hills. It is established that changes in sea level influence melt production at midocean ridges, but whether changes in melt production influence the pattern of bathymetry flanking midocean ridges has been debated on both theoretical and empirical grounds. To explore the dynamics that may give rise to a sea-level influence on bathymetry, we simulate abyssal hills using a faulting model with periodic variations in melt supply. For 100-ky melt-supply cycles, model results show that faults initiate during periods of amagmatic spreading at half-rates >2.3 cm/y and for 41-ky melt-supply cycles at half-rates >3.8 cm/y. Analysis of bathymetry across 17 midocean ridge regions shows characteristic wavelengths that closely align with the predictions from the faulting model. At intermediate-spreading ridges (half-rates >2.3 cm/y and ≤3.8 cm/y) abyssal hill spacing increases with spreading rate at 0.99 km/(cm/y) or 99 ky (n= 12; 95% CI, 87 to 110 ky), and at fast-spreading ridges (half-rates >3.8 cm/y) spacing increases at 38 ky (n= 5; 95% CI, 29 to 47 ky). Including previously published analyses of abyssal-hill spacing gives a more precise alignment with the primary periods of Pleistocene sea-level variability. Furthermore, analysis of bathymetry from fast-spreading ridges shows a highly statistically significant spectral peak (P < 0.01) at the 1/(41-ky) period of Earth’s variations in axial tilt. Faulting models and observations both support a linkage between glacially induced sea-level change and the fabric of the sea floor over the late Pleistocene.
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Olive JA, Behn MD, Ito G, Buck WR, Escartín J, Howell S. Response to Comment on "Sensitivity of seafloor bathymetry to climate-driven fluctuations in mid-ocean ridge magma supply". Science 2016; 353:229. [PMID: 27418498 DOI: 10.1126/science.aaf2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 06/08/2016] [Indexed: 11/02/2022]
Abstract
Tolstoy reports the existence of a characteristic 100 thousand year (ky) period in the bathymetry of fast-spreading seafloor but does not argue that sea level change is a first-order control on seafloor morphology worldwide. Upon evaluating the overlap between tectonic and Milankovitch periodicities across spreading rates, we reemphasize that fast-spreading ridges are the best potential recorders of a sea level signature in seafloor bathymetry.
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Affiliation(s)
- J-A Olive
- Lamont-Doherty Earth Observatory, Columbia University, Palisades NY, USA.
| | - M D Behn
- Woods Hole Oceanographic Institution, Woods Hole MA, USA
| | - G Ito
- University of Hawaii, Honolulu HI, USA
| | - W R Buck
- Lamont-Doherty Earth Observatory, Columbia University, Palisades NY, USA
| | - J Escartín
- CNRS, Institut de Physique du Globe de Paris, Paris, France
| | - S Howell
- University of Hawaii, Honolulu HI, USA
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Tolstoy M. Comment on "Sensitivity of seafloor bathymetry to climate-driven fluctuations in mid-ocean ridge magma supply". Science 2016; 353:229. [PMID: 27418497 DOI: 10.1126/science.aaf0625] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 06/08/2016] [Indexed: 11/02/2022]
Abstract
Olive et al (Reports, 16 October 2015, p. 310) and Goff (Technical Comment, 4 September 2015, p. 1065) raise important concerns with respect to recent findings of Milankovitch cycles in seafloor bathymetry. However, their results inherently support that the Southern East Pacific Rise is the optimum place to look for such signals and, in fact, models match those observations quite closely.
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Affiliation(s)
- Maya Tolstoy
- Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
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Olive JA, Behn MD, Ito G, Buck WR, Escartín J, Howell S. Response to Comment on "Sensitivity of seafloor bathymetry to climate-driven fluctuations in mid-ocean ridge magma supply". Science 2016; 352:1405. [PMID: 27313035 DOI: 10.1126/science.aaf2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 05/17/2016] [Indexed: 11/02/2022]
Abstract
Huybers et al present new bathymetric spectra from an intermediate-spreading ridge as evidence for a primary contribution of sea level cycles to the morphology of the seafloor. Although we acknowledge the possibility that sea level-modulated magmatic constructions may be superimposed on a first-order tectonic fabric, we emphasize the difficulty of deciphering these different contributions in the frequency domain alone.
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Affiliation(s)
- J-A Olive
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA.
| | - M D Behn
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - G Ito
- University of Hawaii, Honolulu, HI, USA
| | - W R Buck
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
| | - J Escartín
- CNRS, Institut de Physique du Globe de Paris, Paris, France
| | - S Howell
- University of Hawaii, Honolulu, HI, USA
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Olive JA, Behn MD, Ito G, Buck WR, Escartín J, Howell S. Sensitivity of seafloor bathymetry to climate-driven fluctuations in mid-ocean ridge magma supply. Science 2015; 350:310-3. [PMID: 26472905 DOI: 10.1126/science.aad0715] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Recent studies have proposed that the bathymetric fabric of the seafloor formed at mid-ocean ridges records rapid (23,000 to 100,000 years) fluctuations in ridge magma supply caused by sealevel changes that modulate melt production in the underlying mantle. Using quantitative models of faulting and magma emplacement, we demonstrate that, in fact, seafloor-shaping processes act as a low-pass filter on variations in magma supply, strongly damping fluctuations shorter than about 100,000 years. We show that the systematic decrease in dominant seafloor wavelengths with increasing spreading rate is best explained by a model of fault growth and abandonment under a steady magma input. This provides a robust framework for deciphering the footprint of mantle melting in the fabric of abyssal hills, the most common topographic feature on Earth.
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Affiliation(s)
- J-A Olive
- Lamont-Doherty Earth Observatory, Columbia University, Palisades NY, USA.
| | - M D Behn
- Woods Hole Oceanographic Institution, Woods Hole MA, USA
| | - G Ito
- University of Hawaii, Honolulu HI, USA
| | - W R Buck
- Lamont-Doherty Earth Observatory, Columbia University, Palisades NY, USA
| | - J Escartín
- CNRS, Institut de Physique du Globe de Paris, Paris, France
| | - S Howell
- University of Hawaii, Honolulu HI, USA
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Goff JA. Comment on “Glacial cycles drive variations in the production of oceanic crust”. Science 2015; 349:1065. [DOI: 10.1126/science.aab2350] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- John A. Goff
- Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, TX, USA
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Crowley JW, Katz RF, Huybers P, Langmuir CH, Park SH. Glacial cycles drive variations in the production of oceanic crust. Science 2015; 347:1237-40. [PMID: 25766231 DOI: 10.1126/science.1261508] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Glacial cycles redistribute water between oceans and continents, causing pressure changes in the upper mantle, with consequences for the melting of Earth's interior. Using Plio-Pleistocene sea-level variations as a forcing function, theoretical models of mid-ocean ridge dynamics that include melt transport predict temporal variations in crustal thickness of hundreds of meters. New bathymetry from the Australian-Antarctic ridge shows statistically significant spectral energy near the Milankovitch periods of 23, 41, and 100 thousand years, which is consistent with model predictions. These results suggest that abyssal hills, one of the most common bathymetric features on Earth, record the magmatic response to changes in sea level. The models and data support a link between glacial cycles at the surface and mantle melting at depth, recorded in the bathymetric fabric of the sea floor.
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Affiliation(s)
- John W Crowley
- Department of Earth Sciences, University of Oxford, Oxford, UK. Department of Earth and Planetary Sciences, Harvard University, Cambridge, USA
| | - Richard F Katz
- Department of Earth Sciences, University of Oxford, Oxford, UK.
| | - Peter Huybers
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, USA
| | - Charles H Langmuir
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, USA
| | - Sung-Hyun Park
- Division of Polar Earth-System Sciences, Korea Polar Research Institute, Incheon, Korea.
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Anderson BW, Coogan LA, Gillis KM. The role of outcrop-to-outcrop fluid flow in off-axis oceanic hydrothermal systems under abyssal sedimentation conditions. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jb009052] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Matthews KJ, Müller RD, Wessel P, Whittaker JM. The tectonic fabric of the ocean basins. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jb008413] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Scott RB, Goff JA, Naveira Garabato AC, Nurser AJG. Global rate and spectral characteristics of internal gravity wave generation by geostrophic flow over topography. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jc007005] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Goff JA. Global prediction of abyssal hill root-mean-square heights from small-scale altimetric gravity variability. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jb007867] [Citation(s) in RCA: 36] [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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Géli L, Cochran JR, Lee TC, Francheteau J, Labails C, Fouchet C, Christie D. Thermal regime of the Southeast Indian Ridge between 88°E and 140°E: Remarks on the subsidence of the ridge flanks. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jb004578] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Downey NJ, Stock JM, Clayton RW, Cande SC. History of the Cretaceous Osbourn spreading center. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jb004550] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nathan J. Downey
- Seismological Laboratory; California Institute of Technology; Pasadena California USA
| | - Joann M. Stock
- Seismological Laboratory; California Institute of Technology; Pasadena California USA
| | - Robert W. Clayton
- Seismological Laboratory; California Institute of Technology; Pasadena California USA
| | - Steven C. Cande
- Scripps Institution of Oceanography; La Jolla California USA
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Scheirer DS, Forsyth DW, Conder JA, Eberle MA, Hung SH, Johnson KTM, Graham DW. Anomalous seafloor spreading of the Southeast Indian Ridge near the Amsterdam-St. Paul Plateau. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/1999jb900407] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Escartín J, Cowie PA, Searle RC, Allerton S, Mitchell NC, MacLeod CJ, Slootweg AP. Quantifying tectonic strain and magmatic accretion at a slow spreading ridge segment, Mid-Atlantic Ridge, 29°N. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1998jb900097] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Ma LY, Cochran JR. Bathymetric roughness of the Southeast Indian Ridge: Implications for crustal accretion at intermediate spreading rate mid-ocean ridges. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97jb01280] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Cochran JR, Sempéré JC. The Southeast Indian Ridge between 88°E and 118°E: Gravity anomalies and crustal accretion at intermediate spreading rates. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97jb00511] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Sempéré JC, Cochran JR. The Southeast Indian Ridge between 88°E and 118°E: Variations in crustal accretion at constant spreading rate. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97jb00171] [Citation(s) in RCA: 57] [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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