Zircon Dates Long‐Lived Plume Dynamics in Oceanic Islands

Rojas‐Agramonte, Yamirka; Kaus, Boris; Piccolo, Andrea; Williams, Ian S.; Gerdes, Axel; Wong, J.; Xie, HangXian; Buhre, Stephan; Toulkeridis, Theofilos; Montero, P.; Garcia‐Casco, Antonio

doi:10.1029/2022gc010485

Cited by 5 publications

(3 citation statements)

References 154 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They interpret this finding, at a locality previously assumed to be solely igneous, as indicating at least some underlying continental crust. Zircons with ages from Triassic to Mesoarchean (~213-3000 Ma) have also been reported from the Galapagos Islands but assumed to be contamination 36 . That work could usefully also be followed up.…”

Section: Discussionmentioning

confidence: 97%

Seismic data and ancient zircons discovered on the Mendeleev Rise, Arctic Ocean, indicate continental crust

Nikishin,

Foulger,

Rodina

et al. 2023

Preprint

View full text Add to dashboard Cite

The Alpha-Mendeleev Rise is located in the Amerasia Basin. The work is based on a synthesis of interpretation of regional 2D MCS seismic profiles and data from rock sampling using special underwater vehicles on the slopes of seamounts. The Rise is represented by alternation of highs (horsts) and half-grabens. At the base of the horst cover, bright reflectors are distinguished, which are interpreted as volcanics. Half-graben sections are wedge-shaped and are similar in geometry to seaward-dipping reflectors (SDRs) of continental passive volcanic margins. Rock sampling has shown that the horsts are composed of sedimentary rocks of Paleozoic age, penetrated by intrusions. Aptian-Albian sections with volcanics (basalts, trachybasalts, trachyandesites) were identified on the horsts. U/Pb dating of igneous rocks showed that typical age of rocks is 110-114 Ma. Magmatic Cretaceous rocks contain zircons with ages ranging from pre-Barremian Mesozoic to Precambrian. The presence of these ancient zircons indicates that the Alpha-Mendeleev Rise is composed of continental crust. A model of the crustal structure of the Alpha-Mendeleev Rise is proposed. The upper and lower crust is approximately 20-30% saturated with intrusions of basic composition. At the base of the crust, a high-velocity layer up to 5 km thick is distinguished.

show abstract

Section: Discussionmentioning

confidence: 97%

Seismic data and ancient zircons discovered on the Mendeleev Rise, Arctic Ocean, indicate continental crust

Nikishin,

Foulger,

Rodina

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…This mantle source was partially sampled during the synextensional Karoo intraplate magmatism at ca. 186-176 Myr ago 12 , 25 , possibly caused by Karoo mantle plume plowing (e.g., 24 ) (Fig. 6 c).…”

Section: Discussionmentioning

confidence: 99%

“…According to Richter et al 16 , after subduction and mantle wedge melting ceased, the mélange remnants would remain neutrally buoyant in the area due to compositional and thermal re-equilibration of density differences with the ambient mantle. These stagnant mantle anomalies are then sampled during MOR overriding above these areas 13 , 14 , 16 or by other processes, such as plowing by continental edges 17 , or even during mantle plume impingement 24 .…”

Section: Introductionmentioning

confidence: 99%

Ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction

et al. 2023

View full text Add to dashboard Cite

The Southern Atlantic-Southwest Indian ridges (SASWIR) host mid-ocean ridge basalts with a residual subduction-related geochemical fingerprint (i.e., a ghost-arc signature) of unclear origin. Here, we show through an analysis of plate kinematic reconstructions and seismic tomography models that the SASWIR subduction-modified mantle source formed in the Jurassic close to the Georgia Islands slab (GI) and remained near-stationary in the mantle reference frame. In this analysis, the GI lies far inboard the Jurassic Patagonian-Antarctic Peninsula active margin. This was formerly attributed to a large-scale flat subduction event in the Late Triassic-Early Jurassic. We propose that during this flat slab stage, the subduction-modified mantle areas beneath the Mesozoic active margin and surrounding sutures zones may have been bulldozed inland by >2280 km. After the demise of the flat slab, this mantle anomaly remained near-stationary and was sampled by the Karoo mantle plume 183 Million years (Myr) ago and again since 55 Myr ago by the SASWIR. We refer to this process as asthenospheric anomaly telescoping. This study provides a hitherto unrecognized geodynamic effect of flat subduction, the viability of which we support through numerical modeling.

show abstract

Beyond zircon fingerprinting: Zircon and TiO2 polymorphs constrain genealogy and evolution of the New Caledonian ophiolite

Patias,

Zhou,

Aitchison

et al. 2024

Chemical Geology

View full text Add to dashboard Cite

Zircon Dates Long‐Lived Plume Dynamics in Oceanic Islands

Abstract: Global tomography and numerical models suggest that mantle plume occurrences are closely linked to the margins of large low-shear velocity provinces (

Cited by 5 publications

References 154 publications

Seismic data and ancient zircons discovered on the Mendeleev Rise, Arctic Ocean, indicate continental crust

Seismic data and ancient zircons discovered on the Mendeleev Rise, Arctic Ocean, indicate continental crust

Ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction

Beyond zircon fingerprinting: Zircon and TiO2 polymorphs constrain genealogy and evolution of the New Caledonian ophiolite

Contact Info

Product

Resources

About