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1. Tonga Slab Morphology and Stress Variations Controlled by a Relic Slab: Implications for Deep Earthquakes in the Tonga‐Fiji Region

   https://doi.org/10.1029/2020GL091331  

   Liu, Hao ; Gurnis, Michael ; Leng, Wei ; Jia, Zhe ; Zhan, Zhongwen ( April 2021 , Geophysical Research Letters)

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2. Geochronology of the Wrangell Arc: Spatial-temporal evolution of slab-edge magmatism along a flat-slab, subduction-transform transition, Alaska-Yukon

   https://doi.org/10.1130/GES02417.1  

   Trop, Jeffrey M. ; Benowitz, Jeff A. ; Kirby, Carl S. ; Brueseke, Matthew E. ( December 2021 , Geosphere)

   Abstract The Wrangell Arc in Alaska (USA) and adjacent volcanic fields in the Yukon provide a long-term record of interrelations between flat-slab subduction of the Yakutat microplate, strike-slip translation along the Denali–Totschunda–Duke River fault system, and magmatism focused within and proximal to a Cretaceous suture zone. Detrital zircon (DZ) U-Pb (n = 2640) and volcanic lithic (DARL) 40Ar/39Ar dates (n = 2771) from 30 modern river sediment samples document the spatial-temporal evolution of Wrangell Arc magmatism, which includes construction of some of the largest Quaternary volcanoes on Earth. Mismatches in DZ and DARL date distributions highlight the impact of variables such as mineral fertility and downstream mixing/dilution on resulting provenance signatures. Geochronologic data document the initiation of Wrangell Arc magmatism at ca. 30–17 Ma along both sides of the Totschunda fault on the north flank of the Wrangell–St. Elias Mountains in Alaska, followed by southeastward progression of magmatism at ca. 17–10 Ma along the Duke River fault in the Yukon. This spatial-temporal evolution is attributable to dextral translation along intra-arc, strike-slip faults and a change in the geometry of the subducting slab (slab curling/steepening). Magmatism then progressed generally westward outboard of the Totschunda and Duke River faults at ca. 13–6 Ma along the southern flank of the Wrangell–St. Elias Mountains in Alaska and then northwestward from ca. 6 Ma to present in the western Wrangell Mountains. The 13 Ma to present spatial-temporal evolution is consistent with dextral translation along intra-arc, strike-slip faults and previously documented changes in plate boundary conditions, which include an increase in plate convergence rate and angle at ca. 6 Ma. Voluminous magmatism is attributed to shallow subduction-related flux melting and slab edge melting that is driven by asthenospheric upwelling along the lateral edge of the Yakutat flat slab. Magmatism was persistently focused within or adjacent to a remnant suture zone, which indicates that upper plate crustal heterogeneities influenced arc magmatism. Rivers sampled also yield subordinate Paleozoic–Mesozoic DZ and DARL age populations that reflect earlier episodes of magmatism within underlying accreted terranes and match magmatic flare-ups documented along the Cordilleran margin. 

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3. S -Wave Receiver Function Analysis of the Pampean Flat-Slab Region: Evidence for a Torn Slab

   https://doi.org/10.1029/2018GC007868  

   Haddon, A. ; Porter, R. ( October 2018 , Geochemistry, Geophysics, Geosystems)
4. Mantle flow through a tear in the Nazca slab inferred from shear wave splitting: SWS Slab Tear

   https://doi.org/10.1002/2017GL074312  

   Lynner, Colton ; Anderson, Megan L. ; Portner, Daniel E. ; Beck, Susan L. ; Gilbert, Hersh ( July 2017 , Geophysical Research Letters)
5. Slab Horizontal Subduction and Slab Tearing Beneath East Asia

   https://doi.org/10.1029/2018GL081703  

   Ma, Pengfei ; Liu, Shaofeng ; Gurnis, Michael ; Zhang, Bo ( May 2019 , Geophysical Research Letters)

   The present‐day architecture of subducted slabs in the mantle as inferred from seismic tomography is a record of plate tectonics through geological time. The unusually large slab that lies nearly horizontally above the 660‐km mantle discontinuity beneath East Asia is presumably from subduction of the Pacific plate. Numerical models have been used to explore the mechanical and geophysical factors that contribute to slab stagnation, but the evolution of this horizontal structure is not fully understood because of uncertainties in the plate‐tectonic history and mantle heterogeneity. Here we show that forward mantle‐flow models constrained by updated tectonic reconstructions can essentially fit major features in the seismic tomography beneath East Asia. Specifically, significant tearing propagated through the subducted western Pacific slab as the Philippine Sea plate rotated clockwise during the Miocene, leading to internal slab segmentation. We believe this tearing associated with Philippine Sea plate rotation also affects the horizontal configuration of slabs.

    

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