Mantle processes
Investigating mantle flows
Investigating mantle outflows along a slab gap in the southern Marianas (Ribeiro et al., 2017, EPSL).
At subduction zones, sinking of the downgoing lithosphere is thought to enable a return flow of asthenospheric mantle around the slab edges. However, asthenospheric flow may also accommodate volumetric variations of shrinking or growing oceanic plates. Here, we seek to understand whether regional plate kinematics or local slab-mantle interactions determine the mantle flow in or out through slab gaps or tears using Hf-Nd isotopic ratios, and by examining the net area variations of the Philippine Sea plate.
Further readings
Ribeiro J.M., Stern R.J., Martinez F., Woodhead J., Chen M., Ohara Y. (2017) Asthenospheric outflow from the shrinking Philippine Sea Plate: Evidence from Hf-Nd isotopes of southern Mariana lavas, Earth and Planetary Science Letters.
Woodhead J., Stern R.J., Pearce J., Hergt J., Vervoort J. (2012) Hf-Nd isotope variation in Mariana Trough basalts: The importance of “ambient mantle” in the interpretation of subduction zone magmas, Geology, 40(6), 539-542, doi: 10.1130/G32963.1.
Woodhead J., Stern R.J., Pearce J., Hergt J., Vervoort J. (2012) Hf-Nd isotope variation in Mariana Trough basalts: The importance of “ambient mantle” in the interpretation of subduction zone magmas, Geology, 40(6), 539-542, doi: 10.1130/G32963.1.
