TY - JOUR
T1 - Molybdenum Isotopes Unmask Slab Dehydration and Melting Beneath the Mariana Arc
AU - Li, Hong-Yan
AU - Zhao, Rui-Peng
AU - Li, Jie
AU - Tamura, Yoshihiko
AU - Spencer, Christopher
AU - Stern, Robert J.
AU - Ryan, Jeffrey G.
AU - Xu, Yi-Gang
PY - 2021/1/1
Y1 - 2021/1/1
N2 - How serpentinites in the forearc mantle and subducted lithosphere become involved in enriching the subarc mantle source of arc magmas is controversial. Here we report molybdenum isotopes for primitive submarine lavas and serpentinites from active volcanoes and serpentinite mud volcanoes in the Mariana arc. These data, in combination with radiogenic isotopes and elemental ratios, allow development of a model whereby shallow, partially serpentinized and subducted forearc mantle transfers fluid and melt from the subducted slab into the subarc mantle. These entrained forearc mantle fragments are further metasomatized by slab fluids/melts derived from the dehydration of serpentinites in the subducted lithospheric slab. Multistage breakdown of serpentinites in the subduction channel ultimately releases fluids/melts that trigger Mariana volcanic front volcanism. Serpentinites dragged down from the forearc mantle are likely exhausted at >200 km depth, after which slab-derived serpentinites are responsible for generating slab melts.
AB - How serpentinites in the forearc mantle and subducted lithosphere become involved in enriching the subarc mantle source of arc magmas is controversial. Here we report molybdenum isotopes for primitive submarine lavas and serpentinites from active volcanoes and serpentinite mud volcanoes in the Mariana arc. These data, in combination with radiogenic isotopes and elemental ratios, allow development of a model whereby shallow, partially serpentinized and subducted forearc mantle transfers fluid and melt from the subducted slab into the subarc mantle. These entrained forearc mantle fragments are further metasomatized by slab fluids/melts derived from the dehydration of serpentinites in the subducted lithospheric slab. Multistage breakdown of serpentinites in the subduction channel ultimately releases fluids/melts that trigger Mariana volcanic front volcanism. Serpentinites dragged down from the forearc mantle are likely exhausted at >200 km depth, after which slab-derived serpentinites are responsible for generating slab melts.
UR - https://digitalcommons.usf.edu/geo_facpub/2334
U2 - 10.1038/s41467-021-26322-8
DO - 10.1038/s41467-021-26322-8
M3 - Article
C2 - 34650082
VL - 12
JO - Nature Communications
JF - Nature Communications
ER -