Document Type
Article
Publication Date
2022
Digital Object Identifier (DOI)
https://doi.org/10.1038/s41467-022-28637-6
Abstract
How subduction-related magmatism starts at convergent plate margins is still poorly understood. Here we show that boron isotope variations in early-formed boninites from the Izu-Bonin arc, combined with radiogenic isotopes and elemental ratios document rapid (~0.5 to 1 Myr) changes in the sources and makeup of slab inputs as subduction begins. Heterogeneous hornblende-granulite facies melts from ocean crust gabbros ± basalts fluxed early melting to generate low silica boninites. Hydrous fluids from slab sediments and basalts later fluxed the low silica boninites mantle source to produce high silica boninites. Our results suggest that initially the uppermost parts of the slab were accreted near the nascent trench, perhaps related to early low-angle subduction. The rapid changes in slab inputs recorded in the boninites entail a steepening subduction angle and cooling of the plate interface, allowing for subduction of slab sediment and basalt, and generating hydrous fluids at lower slab temperatures.
Rights Information
This work is licensed under a Creative Commons Attribution 4.0 License.
Was this content written or created while at USF?
Yes
Citation / Publisher Attribution
Nature Communications, v. 13, art. 993
Scholar Commons Citation
Li, Hong-Yan; Li, Xiang; Ryan, Jeffrey G.; Zhang, Chao; and Xu, Yi-Gang, "Boron Isotopes in Boninites Document Rapid Changes in Slab Inputs during Subduction Initiation" (2022). School of Geosciences Faculty and Staff Publications. 2332.
https://digitalcommons.usf.edu/geo_facpub/2332
Supplementary Information
41467_2022_28637_MOESM3_ESM.pdf (2 kB)
Description of Additional Supplementary Files
41467_2022_28637_MOESM4_ESM.xlsx (36 kB)
Supplementary Data 1
