An Early Cretaceous subduction-modified mantle underneath the ultraslow spreading Gakkel Ridge, Arctic Ocean

Earth’s upper mantle, as sampled by mid-ocean ridge basalts (MORBs) at oceanic spreading centers, has developed chemical and isotopic heterogeneity over billions of years through focused melt extraction and re-enrichment by recycled crustal components. Chemical and isotopic heterogeneity of MORB is dwarfed by the large compositional spectrum of lavas at convergent margins, identifying subduction zones as the major site for crustal recycling into and modification of the mantle. The fate of subduction-modified mantle and if this heterogeneity transmits into MORB chemistry remains elusive. Here, we investigate the origin of upper mantle chemical heterogeneity underneath the Western Gakkel Ridge region in the Arctic Ocean through MORB geochemistry and tectonic plate reconstruction. We find that seafloor lavas from the Western Gakkel Ridge region mirror geochemical signatures of an Early Cretaceous, paleo-subduction zone, and conclude that the upper mantle can preserve a long-lived, stationary geochemical memory of past geodynamic processes.

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A subduction influence on ocean ridge basalts outside the Pacific subduction shield

Nature Communications ◽

10.1038/s41467-021-25027-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

A. Y. Yang ◽

C. H. Langmuir ◽

Y. Cai ◽

P. Michael ◽

S. L. Goldstein ◽

...

Keyword(s):

Upper Mantle ◽

The Arctic ◽

Mantle Flow ◽

Mantle Heterogeneity ◽

Gakkel Ridge ◽

The Pacific ◽

Mid Ocean Ridge ◽

The Pacific Ocean ◽

Back Arc ◽

Ocean Ridge

AbstractThe plate tectonic cycle produces chemically distinct mid-ocean ridge basalts and arc volcanics, with the latter enriched in elements such as Ba, Rb, Th, Sr and Pb and depleted in Nb owing to the water-rich flux from the subducted slab. Basalts from back-arc basins, with intermediate compositions, show that such a slab flux can be transported behind the volcanic front of the arc and incorporated into mantle flow. Hence it is puzzling why melts of subduction-modified mantle have rarely been recognized in mid-ocean ridge basalts. Here we report the first mid-ocean ridge basalt samples with distinct arc signatures, akin to back-arc basin basalts, from the Arctic Gakkel Ridge. A new high precision dataset for 576 Gakkel samples suggests a pervasive subduction influence in this region. This influence can also be identified in Atlantic and Indian mid-ocean ridge basalts but is nearly absent in Pacific mid-ocean ridge basalts. Such a hemispheric-scale upper mantle heterogeneity reflects subduction modification of the asthenospheric mantle which is incorporated into mantle flow, and whose geographical distribution is controlled dominantly by a “subduction shield” that has surrounded the Pacific Ocean for 180 Myr. Simple modeling suggests that a slab flux equivalent to ~13% of the output at arcs is incorporated into the convecting upper mantle.

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Early Cretaceous magmatism and post-Early Cretaceous deformation on Ellef Ringnes Island, Canadian High Arctic, related to the formation of the Arctic Ocean

Circum-Arctic Structural Events: Tectonic Evolution of the Arctic Margins and Trans-Arctic Links with Adjacent Orogens ◽

10.1130/2018.2541(15) ◽

2019 ◽

Cited By ~ 1

Author(s):

Solveig Estrada ◽

Karsten Piepjohn

Keyword(s):

Arctic Ocean ◽

Early Cretaceous ◽

High Arctic ◽

The Arctic ◽

Canadian High Arctic ◽

The Arctic Ocean ◽

Ellef Ringnes Island ◽

Cretaceous Magmatism

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Non-chondritic HSE budget in Earth's upper mantle evidenced by abyssal peridotites from Gakkel ridge (Arctic Ocean)

Earth and Planetary Science Letters ◽

10.1016/j.epsl.2009.04.002 ◽

2009 ◽

Vol 283 (1-4) ◽

pp. 122-132 ◽

Cited By ~ 48

Author(s):

Chuan-Zhou Liu ◽

Jonathan E. Snow ◽

Gerhard Brügmann ◽

Eric Hellebrand ◽

Albrecht W. Hofmann

Keyword(s):

Arctic Ocean ◽

Upper Mantle ◽

Gakkel Ridge

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A synthesis of Jurassic and Early Cretaceous crustal evolution along the southern margin of the Arctic Alaska–Chukotka microplate and implications for defining tectonic boundaries active during opening of Arctic Ocean basins

Lithosphere ◽

10.1130/l471.1 ◽

2016 ◽

Vol 8 (3) ◽

pp. 219-237 ◽

Cited By ~ 16

Author(s):

Alison B. Till

Keyword(s):

Arctic Ocean ◽

Early Cretaceous ◽

The Arctic ◽

Crustal Evolution ◽

Southern Margin ◽

Arctic Alaska ◽

Tectonic Boundaries

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Compositions of dissolved organic matter in the ice-covered waters above the Aurora hydrothermal vent system, Gakkel Ridge, Arctic Ocean

10.5194/bg-2021-350 ◽

2022 ◽

Author(s):

Muhammed Fatih Sert ◽

Helge Niemann ◽

Eoghan P. Reeves ◽

Mats A. Granskog ◽

Kevin P. Hand ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Sea Ice ◽

Arctic Ocean ◽

Hydrothermal Vent ◽

Hydrothermal Vents ◽

The Arctic ◽

Buoyant Plume ◽

Gakkel Ridge ◽

Neutrally Buoyant

Abstract. Hydrothermal vents modify and displace subsurface dissolved organic matter (DOM) into the ocean. Once in the ocean, this DOM is transported together with elements, particles, dissolved gases, and biomass along with the neutrally buoyant plume layer. Considering the number and extent of actively venting hydrothermal sites in the oceans, their contribution to the oceanic DOM pool may be substantial. Here, we investigate the dynamics of DOM in relation to hydrothermal venting and related processes at the as-yet unexplored Aurora hydrothermal vent field within the ultraslow spreading Gakkel Ridge in the Arctic Ocean at 82.9° N. We examined the vertical distribution of DOM composition from sea ice to deep waters at six hydrocast stations distal to the active vent and its neutrally buoyant plume layer. In comparison to background seawater, we found that the DOM in waters directly affected by the hydrothermal plume was composed of lower numbers of molecular formulas and 5–10 % less abundant compositions associated with the molecular categories related to lipid and protein-like compounds. Samples that were not directly affected by the plume, on the other hand, were chemically more diverse and had a higher percentage of chemical formulas associated with the carbohydrate-like category. We suggest, therefore, that hydrothermal processes at Aurora may influence the DOM distribution in the bathypelagic ocean by spreading more thermally and/or chemically induced compositions, while DOM compositions in epipelagic and mesopelagic layers are mainly governed by the microbial carbon pump dynamics, and sea ice surface water interactions.

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The subduction influence on ocean ridge basalts and its significance

10.21203/rs.3.rs-132754/v1 ◽

2021 ◽

Author(s):

Alexandra Yang Yang ◽

Charles Langmuir ◽

Yue Cai ◽

Steven Goldstein ◽

Peter Michael ◽

...

Keyword(s):

Pacific Ocean ◽

Upper Mantle ◽

The Arctic ◽

Plate Tectonic ◽

Gakkel Ridge ◽

The Pacific ◽

Mid Ocean Ridge ◽

The Pacific Ocean ◽

Back Arc ◽

Ocean Ridge

Abstract The plate tectonic cycle produces chemically distinct mid-ocean ridge basalts (MORB) and arc volcanics, with the latter enriched in fluid-mobile elements and depleted in Nb owing to fluxes from the subducted slab. Basalts from back-arc basins (BABB), with intermediate compositions, show that the subduction flux can escape the arc. Hence it is puzzling why arc signatures have rarely been recognized in MORB. Here we report the first MORB samples with distinct arc signatures, akin to BABB, from the Arctic Gakkel Ridge. A new high precision dataset for 576 Gakkel samples suggests a pervasive subduction influence. This influence can also be identified in Atlantic and Indian MORB with a “BABB filter”, but is nearly absent in Pacific MORB. This global distribution reflects the control of a “subduction shield” that has surrounded the Pacific Ocean for 180Myr. Statistics suggest that a flux equivalent to ~ 13% of output at arcs is incorporated into the convecting upper mantle.

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Discovery of abundant hydrothermal venting on the ultraslow-spreading Gakkel ridge in the Arctic Ocean

Nature ◽

10.1038/nature01351 ◽

2003 ◽

Vol 421 (6920) ◽

pp. 252-256 ◽

Cited By ~ 137

Author(s):

H. N. Edmonds ◽

P. J. Michael ◽

E. T. Baker ◽

D. P. Connelly ◽

J. E. Snow ◽

...

Keyword(s):

Arctic Ocean ◽

The Arctic ◽

Gakkel Ridge ◽

The Arctic Ocean ◽

Hydrothermal Venting

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First Ocean Bottom Seismometer network underneath the ice-covered Arctic Ocean: Operational challenges and chances for monitoring the state of the sea ice cover

10.5194/egusphere-egu2020-6916 ◽

2020 ◽

Author(s):

Schlindwein Vera ◽

Kirk Henning ◽

Hiller Marc ◽

Scholz John-Robert ◽

Schmidt-Aursch Mechita

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Seismic Noise ◽

Ice Cover ◽

Wave Action ◽

The State ◽

The Arctic ◽

Ocean Bottom ◽

Gakkel Ridge ◽

Ocean Bottom Seismometers

Active and passive seismic monitoring of the cryosphere is mostly done with land seismometers on the surface of ice masses. Seismic monitoring beneath sea ice at the bottom of ice covered oceans has hardly been attempted, because ocean bottom seismometers (OBS) are difficult to recover in perennial sea ice. As a result, for example the tectonic activity of the Arctic mid-ocean ridge system is poorly known. Recently, the ambient seismic noise in long-term seismic records proved a useful tool to monitor the state of the sea ice cover. Since sea ice effectively dampens the formation of wave action, the power in the microseismic noise band, that is mostly generated by ocean wave action, shows seasonal variations which can be explored to study ocean wave climate in relation to the sea ice cover.From September 2018 - September 2019, we deployed for the first time a network of 4 broadband ocean bottom seismometers at distances of about 10 km at a water depth of roughly 4 km near Gakkel Deep on eastern Gakkel Ridge, Arctic Ocean, from board RV Polarstern. We modified the Lobster-type OBS to include a Posidonia transponder that allowed to accurately track the OBS during descent and ascent and when surfacing underneath an ice floe. We then carefully broke the ice floes until the OBSs appeared in open water and could be recovered.The network was designed to record local earthquakes along Gakkel Ridge, but it also yields valuable year-round data on the microseismic noise signal at the bottom of the Arctic Ocean in a marginal ice zone.A first inspection of the data shows a clearly reduced power in the microseismic noise band compared to the Norwegian-Greenland Sea and strongly time dependent noise levels, that may potentially be related to temporary wave action when sea ice retreats during summer. However, the modified OBS structure with a large head buoy fixed to the OBS structure may also be prone to vibrations caused by ocean bottom currents. We will present an initial analysis of the seasonal evolution of the ambient seismic noise that will help to discriminate noise sources and evaluate the potential of such records to monitor the state of the sea ice cover.

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