Intra-Panthalassa Ocean subduction zones revealed by fossil arcs and mantle structure

Meer, Douwe G. van der; Torsvik, Trond H.; Spakman, Wim; Hinsbergen, Douwe J.J. van; Amaru, Maisha

doi:10.1038/ngeo1401

Cited by 109 publications

(113 citation statements)

References 25 publications

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“…A related question is how to interpret the different levels of velocity heterogeneity in the three sub-regions. One explanation is that the three sub-regions are from different paleo-slabs (OkuNiikappu, Kolyma-Omolon, and Anadyr-Koryak plate, from left to right), and these slabs may have different thermal and subduction histories, as Van der Meer et al (2012) have suggested.…”

Section: Origin Of the Scatterersmentioning

confidence: 99%

“…Based on geological and seismic tomographic data, Van der Meer et al (2012) reconstructed intra-oceanic arc subduction and suggested that a series of paleo-subduction zones subducted in the mid-Panthalasa ocean. Their reconstruction results show that the locations of the subduction zones $200 Myr ago overlap partly with the scatterer locations we find in the lowermost mantle.…”

Section: Origin Of the Scatterersmentioning

confidence: 99%

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Strong seismic scatterers near the core–mantle boundary north of the Pacific Anomaly

Sun

Wiens

et al. 2016

Physics of the Earth and Planetary Interiors

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a b s t r a c tTomographic images have shown that there are clear high-velocity heterogeneities to the north of the Pacific Anomaly near the core-mantle boundary (CMB), but the detailed structure and origin of these heterogeneities are poorly known. In this study, we analyze PKP precursors from earthquakes in the Aleutian Islands and Kamchatka Peninsula recorded by seismic arrays in Antarctica, and find that these heterogeneities extend $400 km above the CMB and are distributed between 30°and 45°N in latitude. The scatterers show the largest P-wave velocity perturbation of 1.0-1.2% in the center (160-180°E) and $0.5% to the west and east (140-160°E, 180-200°E). ScS-S differential travel-time residuals reveal similar features. We suggest that these seismic scatterers are the remnants of ancient subducted slab material. The lateral variations may be caused either by different slabs, or by variations in slab composition resulting from their segregation process.

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Section: Origin Of the Scatterersmentioning

confidence: 99%

Section: Origin Of the Scatterersmentioning

confidence: 99%

Strong seismic scatterers near the core–mantle boundary north of the Pacific Anomaly

Sun

Wiens

et al. 2016

Physics of the Earth and Planetary Interiors

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“…anomalies in the independent model S40RTS (22); Table S1], and geological records of mountain building of the past ∼250 My, the position and timing of past subduction episodes was determined for 28 major slabs mostly along the continental margins of Pangaea (15) These analyses implied a global average sinking velocity of slabs in the lower mantle of 1.2 ± 0.3 cm/y, yielding a "mantle memory" of subduction of some 250 My (15). Additionally, major intraoceanic subduction within the Panthalassa oceanic realm surrounding Pangaea was identified from the deep mantle structure below, and the geological records around the modern Pacific Ocean (16). These analyses combined resulted in a firstorder interpretation of global subduction history and show that all major elongated positive seismic velocity anomalies in the mantle can be consistently matched with former subduction zones, and vice versa.…”

Section: Subduction-zone Length Evolutionmentioning

confidence: 99%

“…Increasing total subductionzone length since the Triassic relates to breakup of Pangaea, when continuous subduction along the circum-Pacific continental margins was established (15,25,26) and intraoceanic subduction zones in the Panthalassa Ocean formed (16,27,28). Since the mid Jurassic, the total subduction-zone length decreased during collisions in the Tethys Ocean (15,29,30) and the MongolOkhotsk Ocean (15,26), and the demise of intraoceanic subduction zones in the Panthalassa Ocean (16), concomitant with growth of the Pacific plate (31,32).…”

Section: Subduction-zone Length Evolutionmentioning

confidence: 99%

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Plate tectonic controls on atmospheric CO₂levels since the Triassic

Meer

Zeebe

Hinsbergen

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

138

113

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Climate trends on timescales of 10s to 100s of millions of years are controlled by changes in solar luminosity, continent distribution, and atmosphere composition. Plate tectonics affect geography, but also atmosphere composition through volcanic degassing of CO 2 at subduction zones and midocean ridges. So far, such degassing estimates were based on reconstructions of ocean floor production for the last 150 My and indirectly, through sea level inversion before 150 My. Here we quantitatively estimate CO 2 degassing by reconstructing lithosphere subduction evolution, using recent advances in combining global plate reconstructions and present-day structure of the mantle. First, we estimate that since the Triassic (250-200 My) until the present, the total paleosubduction-zone length reached up to ∼200% of the present-day value. Comparing our subduction-zone lengths with previously reconstructed ocean-crust production rates over the past 140 My suggests average global subduction rates have been constant, ∼6 cm/y: Higher ocean-crust production is associated with longer total subduction length. We compute a strontium isotope record based on subduction-zone length, which agrees well with geological records supporting the validity of our approach: The total subduction-zone length is proportional to the summed arc and ridge volcanic CO 2 production and thereby to global volcanic degassing at plate boundaries. We therefore use our degassing curve as input for the GEOCARBSULF model to estimate atmospheric CO 2 levels since the Triassic. Our calculated CO 2 levels for the mid Mesozoic differ from previous modeling results and are more consistent with available proxy data.paleoclimate | carbon cycle | geodynamic V olcanism forms the most efficient mechanism to transfer carbon (C) from the mantle to the ocean-atmosphere system, the exogenic reservoir. At midocean ridges, mantle upwelling occurs between two diverging plates. At subduction zones, sinking oceanic plates lead to arc volcanism (1). A third type of volcanism, driven by mantle plumes, leads occasionally to large igneous provinces (LIPs) that typically last a few My (2, 3). Longterm (>>5 My) changes in volcanic output thus dominantly relate to the long-term plate tectonic processes. Constraints on volcanism-related degassing of CO 2 at subduction zones and midocean ridges hence derive from studies on lithosphere production/consumption (3-6). The quality of these constraints determines the mechanistic underpinning of climatic changes on timescales of 10 7 to 10 8 y. This is because on such timescales, volcanism is the major source of CO 2 to the atmosphere and thereby drives climate and the critical feedbacks in the carbon cycle, such as weathering. To date, estimates of CO 2 degassing through plate tectonic processes for the last 150 My are based on reconstructions of ocean-floor production (7), and for older periods indirect inferences were made through sea level inversion (8). An increasing body of work reveals major uncertainties in eustatic sea level reconstructi...

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Evidence for slab material under Greenland and links to Cretaceous High Arctic magmatism

Shephard

Trønnes

Spakman

et al. 2016

Geophysical Research Letters

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Understanding the evolution of extinct ocean basins through time and space demands the integration of surface kinematics and mantle dynamics. We explore the existence, origin, and implications of a proposed oceanic slab burial ground under Greenland through a comparison of seismic tomography, slab sinking rates, regional plate reconstructions, and satellite‐derived gravity gradients. Our preferred interpretation stipulates that anomalous, fast seismic velocities at 1000–1600 km depth imaged in independent global tomographic models, coupled with gravity gradient perturbations, represent paleo‐Arctic oceanic slabs that subducted in the Mesozoic. We suggest a novel connection between slab‐related arc mantle and geochemical signatures in some of the tholeiitic and mildly alkaline magmas of the Cretaceous High Arctic Large Igneous Province in the Sverdrup Basin. However, continental crustal contributions are noted in these evolved basaltic rocks. The integration of independent, yet complementary, data sets provides insight into present‐day mantle structure, magmatic events, and relict oceans.

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Intra-Panthalassa Ocean subduction zones revealed by fossil arcs and mantle structure

Cited by 109 publications

References 25 publications

Strong seismic scatterers near the core–mantle boundary north of the Pacific Anomaly

Strong seismic scatterers near the core–mantle boundary north of the Pacific Anomaly

Plate tectonic controls on atmospheric CO₂levels since the Triassic

Evidence for slab material under Greenland and links to Cretaceous High Arctic magmatism

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Intra-Panthalassa Ocean subduction zones revealed by fossil arcs and mantle structure

Cited by 109 publications

References 25 publications

Strong seismic scatterers near the core–mantle boundary north of the Pacific Anomaly

Strong seismic scatterers near the core–mantle boundary north of the Pacific Anomaly

Plate tectonic controls on atmospheric CO2levels since the Triassic

Evidence for slab material under Greenland and links to Cretaceous High Arctic magmatism

Contact Info

Product

Resources

About

Plate tectonic controls on atmospheric CO₂levels since the Triassic