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CONCLUSIONS                          facies assemblages adjacent to the Western   Eberhart-Phillips, D., Reyners, M., Bannister, S.,
            The integration of surface and subsurface   Fiordland Orthogneiss in southwest Fiordland,   Chadwick, M., and Ellis, S., 2010, Establishing
          data sets from southwest New Zealand   New Zealand: Journal of Metamorphic   a versatile 3-D seismic velocity model for New
                                                                                  Zealand: Seismological Research Letters,
                                               Geology, v. 27, p. 349–369, https://doi.org/
          shows how the history of deformation,   10.1111/j.1525-1314.2009.00822.x.  v. 81, no. 6, p. 992–1000, https://doi.org/
          exhumation, and fault-related topographic   Allibone, A.H., Jongens, R., Turnbull, I.M., Milan,   10.1785/gssrl.81.6.992.
          growth above a young ocean-continent   L.A., Daczko, N.R., De Paoli, M.C., and   Haines, S., Lynch, E., Mulch, A., Valley, J.W.,
          subduction zone is linked to events   Tulloch, A.J., 2009b, Plutonic rocks of western   and Pluijm, B.V.D., 2016, Meteoric fluid
          occurring near the base of the continental   Fiordland, New Zealand: Field relations,   infiltration in crustal-scale normal fault
                                                                                  systems as indicated by d O and d H
                                               geochemistry, correlation, and nomenclature:
                                                                                                        2
                                                                                                  18
          lithosphere. New geologic mapping and   New Zealand Journal of Geology and   geochemistry and  Ar/ Ar dating of
                                                                                                 39
                                                                                              40
              39
          40 Ar/ Ar dates show that crustal-scale   Geophysics, v. 52, p. 379–415, https://doi.org/   neoformed clays in brittle fault rocks:
          reverse faults reactivated two ancient shear   10.1080/00288306.2009.9518465.  Lithosphere, v. 8, p. 587–600, https://doi.org/
                                                                                  10.1130/L483.1.
          zones at 8–7 Ma, placing an irregular slice   Andico, S., Schwartz, J.J., Tulloch, A., Turnbull,   Jiao, R., Herman, F., and Seward, D., 2017, Late
          of Cretaceous lower crust up and to the east   R., Klepeis, K., Miranda, E.A., Kitajima, K.,   Cenozoic exhumation model of New Zealand:
                                               and Ringwood, M.F., 2017, Oxygen isotope
          over the middle and upper crust. The size,   mapping reveals a crustal-scale structure   Impacts from tectonics and climate: Earth-
          age, location, and style of these faults   within the Median Batholith, Fiordland, New   Science Reviews, v. 166, p. 286–298,
          suggest that they formed as a direct   Zealand: Geological Society of America   https://doi.org/10.1016/j.earscirev.2017.01.003.
          consequence of a Late Miocene collision   Abstracts with Programs, v. 49, no. 6,    Kissling, E., and Schlunegger, F., 2018, Rollback
                                                                                  orogeny model for the evolution of the Swiss
                                               https://doi.org/10.1130/abs/2017AM-305151.
          between the leading edge of the subducting   Betka, P.M., and Klepeis, K.A., 2013, Three-  Alps: Tectonics, v. 37, p. 1097–1115,
          Australian Plate and previously subducted   stage evolution of lower crustal gneiss domes   https://doi.org/10.1002/2017TC004762.
          oceanic crust of the Cretaceous Hikurangi   at Breaksea Entrance, Fiordland, New   Klepeis, K.A., Schwartz, J., Stowell, H., and
          Plateau. This collision, which occurred at   Zealand: Tectonics, v. 32, p. 1084–1106,   Tulloch, A., 2016, Gneiss domes, vertical and
                                                                                  horizontal mass transfer, and the initiation of
          ~100 km depth, localized shortening and   https://doi.org/10.1002/tect.20068.  extension in the hot lower crustal root of a
          caused the subducting slab to steepen to   Bhattacharya, S., Kemp, A.I.S., and Collins,   continental arc, Fiordland, New Zealand:
                                               W.J., 2018, Response of zircon to melting and
          vertical. It also drove the reactivation of   metamorphism in deep arc crust, Fiordland   Lithosphere, v. 8, p. 116–140, https://doi.org/
          inherited structures, resulting in crustal   (New Zealand): Implications for zircon   10.1130/L490.1.
          imbrication and 12–15 km of vertical   inheritance in cordilleran granites:   Liu, L., 2015, The ups and downs of North
                                                                                  America: Evaluating the role of mantle
          motion. Integrated structural and    Contributions to Mineralogy and Petrology,   dynamic topography since the Mesozoic:
                                               v. 173, no. 28, p. 1–36.
          geochemical analyses suggest that the   Blattner, P., 1976, Replacement of hornblende by   Reviews of Geophysics, v. 53, p. 1022–1049,
          reverse faults penetrate the entire crust and   garnet in granulite facies assemblages near   https://doi.org/10.1002/2015RG000489.
          offset the Moho. The irregular geometry of   Milford Sound, New Zealand: Contributions   Liu, S., Gurnis, M., Ma, P., and Zhang, B., 2017,
          the Hikurangi Plateau at depth provides a   to Mineralogy and Petrology, v. 55, p. 181–190,   Reconstruction of northeast Asian
                                                                                  deformation integrated with western Pacific
          plausible explanation for why two ancient   https://doi.org/10.1007/BF00372225.  plate subduction since 200 Ma: Earth-Science
          shear zones were reactivated simultaneously   Bradshaw, J.Y., 1985, Geology of the northern   Reviews, v. 175, p. 114–142, https://doi.org/
                                               Franklin Mountains, northern Fiordland, New
          in different places at 8–7 Ma. For the first   Zealand, with emphasis on the origin and   10.1016/j.earscirev.2017.10.012.
          time, this study shows when, how, and why   evolution of Fiordland granulites [Ph.D.   Mao, X., Gurnis, M., and May, D.A., 2017,
                                                                                  Subduction initiation with vertical lithospheric
          Earth’s largest and deepest known exposure   thesis]: Dunedin, New Zealand, University of   heterogeneities and new fault formation:
          of lower crust from a Mesozoic continental   Otago, 379 p.              Geophysical Research Letters, v. 44,
          arc was uplifted, imbricated, and exhumed   Bradshaw, J.Y., 1990, Geology of crystalline   p. 11,349–11,356, https://doi.org/10.1002/
                                               rocks of northern Fiordland; details of the
          to the surface above the Puysegur    granulite facies western Fiordland Orthogneiss   2017GL075389.
          subduction zone. It also illustrates how   and associated rock units: New Zealand   Marcotte, S.B., Klepeis, K.A., Clarke, G.L.,
                                                                                  Gehrels, G., and Hollis, J.A., 2005, Intra-arc
          inherited zones of crustal weakness   Journal of Geology and Geophysics, v. 33,   transpression in the lower crust and its
          facilitate the transfer of displacements   p. 465–484, https://doi.org/10.1080/00288306   relationship to magmatism in a Mesozoic
                                               .1990.10425702.
          between Earth’s surface and the upper   Davy, B., 2014, Rotation and offset of the   magmatic arc: Tectonophysics, v. 407, p. 135–
                                                                                  163, https://doi.org/10.1016/j.tecto.2005.07.007.
          mantle during the early stages of subduction.  Gondwana convergent margin in the New   McCoy-West, J., Mortimer, N., and Ireland, T.R.,
                                               Zealand region following Cretaceous jamming   2014, U-Pb geochronology of Permian
          ACKNOWLEDGMENTS                      of Hikurangi Plateau large igneous province   plutonic rocks, Longwood Range, New
            We thank A. Tulloch and N. Mortimer at    subduction: Tectonics, v. 33, p. 1577–1595,   Zealand: Implications for Median Batholith–
          GNS (Dunedin) for discussions and assistance.   https://doi.org/10.1002/2014TC003629.  Brook Street Terrane relations: New Zealand
          D. Jones (Vermont) provided expertise and   Decker, M., Schwartz, J.J., Stowell, H.H.,   Journal of Geology and Geophysics, v. 57,
          assistance with the argon analyses. We thank the   Klepeis, K.A., Tulloch, A.J., Kitajima, K.,   no. 1, p. 65–85, https://doi.org/10.1080/
          Dept. of Conservation Te Anau office for access    Valley, J.W., and Kylander-Clark, A.R.C.,   00288306.2013.869235.
          and permission to sample and two anonymous   2017, Slab-triggered arc flare-up in the   Milan, L.A., Daczko, N.R., and Clarke, G.L.,
          reviewers for helping to improve the manuscript.   Cretaceous Median Batholith and the growth   2017, Cordillera Zealandia: A Mesozoic arc
          Financial support was provided by NSF grant   of lower arc crust, Fiordland, New Zealand:   flare-up on the palaeo-Pacific Gondwana
          EAR-1119248.                         Journal of Petrology, v. 58, no. 6, p. 1145–1171,   Margin: Scientific Reports, v. 7, no. 1, p. 261,
                                               https://doi.org/10.1093/petrology/egx049.  https://doi.org/10.1038/s41598-017-00347-w.
                                             Ducea, M.N., Saleeby, J.B., and Bergantz, G.,   Mortimer, N., Tulloch, A.J., Spark, R.N., Walker,
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