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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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2
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German CR, Reeves EP, Türke A, Diehl A, Albers E, Bach W, Purser A, Ramalho SP, Suman S, Mertens C, Walter M, Ramirez-Llodra E, Schlindwein V, Bünz S, Boetius A. Volcanically hosted venting with indications of ultramafic influence at Aurora hydrothermal field on Gakkel Ridge. Nat Commun 2022; 13:6517. [PMID: 36316329 PMCID: PMC9622739 DOI: 10.1038/s41467-022-34014-0] [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: 03/30/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
Abstract
The Aurora hydrothermal system, Arctic Ocean, hosts active submarine venting within an extensive field of relict mineral deposits. Here we show the site is associated with a neovolcanic mound located within the Gakkel Ridge rift-valley floor, but deep-tow camera and sidescan surveys reveal the site to be ≥100 m across-unusually large for a volcanically hosted vent on a slow-spreading ridge and more comparable to tectonically hosted systems that require large time-integrated heat-fluxes to form. The hydrothermal plume emanating from Aurora exhibits much higher dissolved CH4/Mn values than typical basalt-hosted hydrothermal systems and, instead, closely resembles those of high-temperature ultramafic-influenced vents at slow-spreading ridges. We hypothesize that deep-penetrating fluid circulation may have sustained the prolonged venting evident at the Aurora hydrothermal field with a hydrothermal convection cell that can access ultramafic lithologies underlying anomalously thin ocean crust at this ultraslow spreading ridge setting. Our findings have implications for ultra-slow ridge cooling, global marine mineral distributions, and the diversity of geologic settings that can host abiotic organic synthesis - pertinent to the search for life beyond Earth.
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Affiliation(s)
- Christopher R. German
- grid.56466.370000 0004 0504 7510Woods Hole Oceanographic Institution, Woods Hole, USA
| | - Eoghan P. Reeves
- grid.7914.b0000 0004 1936 7443Department of Earth Science & Centre for Deep Sea Research, University of Bergen, Bergen, Norway
| | - Andreas Türke
- grid.7914.b0000 0004 1936 7443Department of Earth Science & Centre for Deep Sea Research, University of Bergen, Bergen, Norway ,grid.7704.40000 0001 2297 4381MARUM—Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany ,grid.7704.40000 0001 2297 4381Faculty of Geosciences, University of Bremen, Bremen, Germany
| | - Alexander Diehl
- grid.7704.40000 0001 2297 4381MARUM—Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany ,grid.7704.40000 0001 2297 4381Faculty of Geosciences, University of Bremen, Bremen, Germany
| | - Elmar Albers
- grid.7704.40000 0001 2297 4381Faculty of Geosciences, University of Bremen, Bremen, Germany
| | - Wolfgang Bach
- grid.7704.40000 0001 2297 4381MARUM—Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany ,grid.7704.40000 0001 2297 4381Faculty of Geosciences, University of Bremen, Bremen, Germany
| | - Autun Purser
- grid.10894.340000 0001 1033 7684Alfred Wegener Institute Helmholtz Centre for Polar & Marine Research, Bremerhaven, Germany
| | - Sofia P. Ramalho
- grid.7311.40000000123236065Centre for Environmental & Marine Studies (CESAM), Department of Biology, University of Aveiro, Aveiro, Portugal
| | - Stefano Suman
- grid.56466.370000 0004 0504 7510Woods Hole Oceanographic Institution, Woods Hole, USA
| | - Christian Mertens
- grid.7704.40000 0001 2297 4381MARUM—Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany ,grid.7704.40000 0001 2297 4381Institute of Environmental Physics, University of Bremen, Bremen, Germany
| | - Maren Walter
- grid.7704.40000 0001 2297 4381MARUM—Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany ,grid.7704.40000 0001 2297 4381Institute of Environmental Physics, University of Bremen, Bremen, Germany
| | - Eva Ramirez-Llodra
- grid.6407.50000 0004 0447 9960Norwegian Institute for Water Research (NIVA), Oslo, Norway ,REV Ocean, Lysaker, Norway
| | - Vera Schlindwein
- grid.7704.40000 0001 2297 4381MARUM—Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany ,grid.10894.340000 0001 1033 7684Alfred Wegener Institute Helmholtz Centre for Polar & Marine Research, Bremerhaven, Germany
| | - Stefan Bünz
- grid.10919.300000000122595234Centre for Arctic Gas Hydrate, Environment and Climate (CAGE), University of Tromso–The Arctic University of Norway, Tromsø, Norway
| | - Antje Boetius
- grid.7704.40000 0001 2297 4381MARUM—Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany ,grid.10894.340000 0001 1033 7684Alfred Wegener Institute Helmholtz Centre for Polar & Marine Research, Bremerhaven, Germany ,grid.419529.20000 0004 0491 3210Max Planck Institute for Marine Microbiology, Bremen, Germany
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Thermochemical anomalies in the upper mantle control Gakkel Ridge accretion. Nat Commun 2021; 12:6962. [PMID: 34845208 PMCID: PMC8630051 DOI: 10.1038/s41467-021-27058-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/15/2021] [Indexed: 11/30/2022] Open
Abstract
Despite progress in understanding seafloor accretion at ultraslow spreading ridges, the ultimate driving force is still unknown. Here we use 40Ar/39Ar isotopic dating of mid-ocean ridge basalts recovered at variable distances from the axis of the Gakkel Ridge to provide new constraints on the spatial and temporal distribution of volcanic eruptions at various sections of an ultraslow spreading ridge. Our age data show that magmatic-dominated sections of the Gakkel Ridge spread at a steady rate of ~11.1 ± 0.9 mm/yr whereas amagmatic sections have a more widely distributed melt supply yielding ambiguous spreading rate information. These variations in spreading rate and crustal accretion correlate with locations of hotter thermochemical anomalies in the asthenosphere beneath the ridge. We conclude therefore that seafloor generation in ultra-slow spreading centres broadly reflects the distribution of thermochemical anomalies in the upper mantle.
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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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Huybers P, Langmuir C, Katz RF, Ferguson D, Proistosescu C, Carbotte S. Comment on “Sensitivity of seafloor bathymetry to climate-driven fluctuations in mid-ocean ridge magma supply”. Science 2016; 352:1405. [DOI: 10.1126/science.aae0451] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 05/17/2016] [Indexed: 11/03/2022]
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6
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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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7
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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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Ultramafic-Mafic Plutonic Rock Suites Exposed Along the Mid-Atlantic Ridge (10°N-30°N). Symmetrical-Asymmetrical Distribution and Implications for Seafloor Spreading Processes. ACTA ACUST UNITED AC 2013. [DOI: 10.1029/gm106p0153] [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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9
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Structure of Modern Oceanic Crust and Ophiolites and Implications for Faulting and Magmatism at Oceanic Spreading Centers. ACTA ACUST UNITED AC 2013. [DOI: 10.1029/gm106p0219] [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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10
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Karson JA. Internal Structure of Oceanic Lithosphere: A Perspective from Tectonic Windows. FAULTING AND MAGMATISM AT MID-OCEAN RIDGES 2013. [DOI: 10.1029/gm106p0177] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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11
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Zhou H, Dick HJB. Thin crust as evidence for depleted mantle supporting the Marion Rise. Nature 2013; 494:195-200. [DOI: 10.1038/nature11842] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Accepted: 12/11/2012] [Indexed: 11/09/2022]
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12
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Escartín J, Lin J. Ridge offsets, normal faulting, and gravity anomalies of slow spreading ridges. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/94jb03267] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Ito GT, Lin J. Mantle temperature anomalies along the past and paleoaxes of the Galápagos spreading center as inferred from gravity analyses. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/94jb02594] [Citation(s) in RCA: 63] [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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14
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Wolfe CJ, Purdy GM, Toomey DR, Solomon SC. Microearthquake characteristics and crustal velocity structure at 29°N on the Mid-Atlantic Ridge: The architecture of a slow spreading segment. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/95jb02399] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Pariso JE, Sempéré JC, Rommevaux C. Temporal and spatial variations in crustal accretion along the Mid-Atlantic Ridge (29°-31°30′N) over the last 10 m.y.: Implications from a three-dimensional gravity study. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/95jb01146] [Citation(s) in RCA: 43] [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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16
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Minshull TA, Morris E, Detrick RS. Gravity anomalies and crustal structure at the Mesozoic Blake Spur Fracture Zone. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/95jb01692] [Citation(s) in RCA: 7] [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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17
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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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18
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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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19
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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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20
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Singh SC, Crawford WC, Carton H, Seher T, Combier V, Cannat M, Pablo Canales J, Düsünür D, Escartin J, Miranda JM. Discovery of a magma chamber and faults beneath a Mid-Atlantic Ridge hydrothermal field. Nature 2006; 442:1029-32. [PMID: 16943836 DOI: 10.1038/nature05105] [Citation(s) in RCA: 210] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Accepted: 07/18/2006] [Indexed: 11/09/2022]
Abstract
Crust at slow-spreading ridges is formed by a combination of magmatic and tectonic processes, with magmatic accretion possibly involving short-lived crustal magma chambers. The reflections of seismic waves from crustal magma chambers have been observed beneath intermediate and fast-spreading centres, but it has been difficult to image such magma chambers beneath slow-spreading centres, owing to rough seafloor topography and associated seafloor scattering. In the absence of any images of magma chambers or of subsurface near-axis faults, it has been difficult to characterize the interplay of magmatic and tectonic processes in crustal accretion and hydrothermal circulation at slow-spreading ridges. Here we report the presence of a crustal magma chamber beneath the slow-spreading Lucky Strike segment of the Mid-Atlantic Ridge. The reflection from the top of the magma chamber, centred beneath the Lucky Strike volcano and hydrothermal field, is approximately 3 km beneath the sea floor, 3-4 km wide and extends up to 7 km along-axis. We suggest that this magma chamber provides the heat for the active hydrothermal vent field above it. We also observe axial valley bounding faults that seem to penetrate down to the magma chamber depth as well as a set of inward-dipping faults cutting through the volcanic edifice, suggesting continuous interactions between tectonic and magmatic processes.
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Affiliation(s)
- Satish C Singh
- Laboratoire de Géosciences Marines, Institut de Physique du Globe de Paris, 4 Place Jussieu, 75252 Paris, France.
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21
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Miranda JM, Luis JF, Lourenço N, Santos FM. Identification of the magnetization low of the Lucky Strike hydrothermal vent using surface magnetic data. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jb003085] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- J. M. Miranda
- Centro de Geofísica; Universidade de Lisboa; Lisbon Portugal
| | - J. F. Luis
- Centro de Investigação Marinha e Ambiental; Universidade do Algarve; Faro Portugal
| | - N. Lourenço
- Centro de Geofísica; Universidade de Lisboa; Lisbon Portugal
- Centro de Investigação Marinha e Ambiental; Universidade do Algarve; Faro Portugal
| | - F. M. Santos
- Centro de Geofísica; Universidade de Lisboa; Lisbon Portugal
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22
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Dziak RP. Evidence of a recent magma dike intrusion at the slow spreading Lucky Strike segment, Mid-Atlantic Ridge. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004jb003141] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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23
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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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24
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Smith DK, Escartin J, Cannat M, Tolstoy M, Fox CG, Bohnenstiehl DR, Bazin S. Spatial and temporal distribution of seismicity along the northern Mid-Atlantic Ridge (15°-35°N). ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jb001964] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Deborah K. Smith
- Woods Hole Oceanographic Institution; Woods Hole Massachusetts USA
| | | | | | - Maya Tolstoy
- Lamont-Doherty Earth Observatory; Palisades New York USA
| | - Christopher G. Fox
- National Oceanic and Atmospheric Administration/Pacific Marine Environmental Laboratory; Newport Oregon USA
| | | | - Sara Bazin
- Institut de Physique du Globe de Paris; Paris France
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25
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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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26
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Asimow PD, Langmuir CH. The importance of water to oceanic mantle melting regimes. Nature 2003; 421:815-20. [PMID: 12594505 DOI: 10.1038/nature01429] [Citation(s) in RCA: 290] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2002] [Accepted: 01/14/2003] [Indexed: 11/09/2022]
Abstract
The formation of basaltic crust at mid-ocean ridges and ocean islands provides a window into the compositional and thermal state of the Earth's upper mantle. But the interpretation of geochemical and crustal-thickness data in terms of magma source parameters depends on our understanding of the melting, melt-extraction and differentiation processes that intervene between the magma source and the crust. Much of the quantitative theory developed to model these processes has neglected the role of water in the mantle and in magma, despite the observed presence of water in ocean-floor basalts. Here we extend two quantitative models of ridge melting, mixing and fractionation to show that the addition of water can cause an increase in total melt production and crustal thickness while causing a decrease in mean extent of melting. This may help to resolve several enigmatic observations in the major- and trace-element chemistry of both normal and hotspot-affected ridge basalts.
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Affiliation(s)
- P D Asimow
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA.
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27
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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]
|
29
|
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]
|
30
|
Hooft EEE, Detrick RS, Toomey DR, Collins JA, Lin J. Crustal thickness and structure along three contrasting spreading segments of the Mid-Atlantic Ridge, 33.5°-35°N. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/1999jb900442] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
31
|
Canales JP, Detrick RS, Lin J, Collins JA, Toomey DR. Crustal and upper mantle seismic structure beneath the rift mountains and across a nontransform offset at the Mid-Atlantic Ridge (35°N). ACTA ACUST UNITED AC 2000. [DOI: 10.1029/1999jb900379] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
32
|
Cannat M, Rommevaux-Jestin C, Sauter D, Deplus C, Mendel V. Formation of the axial relief at the very slow spreading Southwest Indian Ridge (49° to 69°E). ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1999jb900195] [Citation(s) in RCA: 145] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
33
|
Gràcia E, Bideau D, Hekinian R, Lagabrielle Y. Detailed geological mapping of two contrasting second-order segments of the Mid-Atlantic Ridge between Oceanographer and Hayes fracture zones (33°30′N-35°N). ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1999jb900161] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
34
|
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]
|
35
|
Ravilly M, Dyment J, Gente P, Thibaud R. Axial magnetic anomaly amplitude along the Mid-Atlantic Ridge between 20°N and 40°N. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/98jb01071] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
36
|
Thibaud R, Gente P, Maia M. A systematic analysis of the Mid-Atlantic Ridge morphology and gravity between 15°N and 40°N: Constraints of the thermal structure. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/97jb02934] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
37
|
Barclay AH, Toomey DR, Solomon SC. Seismic structure and crustal magmatism at the Mid-Atlantic Ridge, 35°N. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/98jb01275] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
38
|
Smith SE, Casey JR, Bryan WB, Dmitriev L, Silantyev S, Magakyan R. Geochemistry of basalts from the Hayes Transform region of the Mid-Atlantic Ridge. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/97jb03208] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
39
|
Maia M, Gente P. Three-dimensional gravity and bathymetry analysis of the Mid-Atlantic Ridge between 20°N and 24°N: Flow geometry and temporal evolution of the segmentation. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/97jb01635] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
40
|
Magde LS, Sparks DW. Three-dimensional mantle upwelling, melt generation, and melt migration beneath segment slow spreading ridges. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97jb01278] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
41
|
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]
|
42
|
Reynolds JR, Langmuir CH. Petrological systematics of the Mid-Atlantic Ridge south of Kane: Implications for ocean crust formation. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97jb00391] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
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Tucholke BE, Lin J, Kleinrock MC, Tivey MA, Reed TB, Goff J, Jaroslow GE. Segmentation and crustal structure of the western Mid-Atlantic Ridge flank, 25°25′-27°10′N and 0-29 m.y. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/96jb03896] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
44
|
Jung WY, Vogt PR. A gravity and magnetic anomaly study of the extinct Aegir Ridge, Norwegian Sea. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/96jb03915] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
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Chen YJ, Enriquez KD, Lonsdale P. Does the mid-ocean ridge propagate concurrently both on the seafloor and at depth? Implications from a gravity study of a large nontransform offset at 36.5°S, East Pacific Rise. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96jb02723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
46
|
Weiland CM, Macdonald KC. Geophysical study of the East Pacific Rise 15°N-17°N: An unusually robust segment. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96jb01756] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
47
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Nicolas A, Boudier F, Ildefonse B. Variable crustal thickness in the Oman ophiolite: Implication for oceanic crust. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96jb00195] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
48
|
Shaw WJ, Lin J. Models of ocean ridge lithospheric deformation: Dependence on crustal thickness, spreading rate, and segmentation. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96jb00949] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
49
|
Kincaid C, Sparks DW, Detrick R. The relative importance of plate-driven and buoyancy-driven flow at mid-ocean ridges. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96jb01184] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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