AUTHOREA
Log in
Sign Up
Browse Preprints
LOG IN
SIGN UP
Please note
: Importing new articles from Word documents is currently unavailable. We are working on fixing this issue soon and apologize for any inconvenience.
Mingdao Sun
Public Documents
1
Flare-up in Cordilleran arcs controlled by fluxes in subduction water budgets
Timothy Chapman
and 6 more
September 29, 2023
The tempo of subduction-related magmatic activity over geological time is episodic. Despite intense study and their importance in crustal addition, the fundamental driver of these episodes remains unclear. We demonstrate quantitatively a first order relationship between arc magmatic activity and subduction flux. The volume of oceanic lithosphere entering the mantle is the key parameter that regulates the proportion of H2O entering the sub-arc. New estimates of subduction zone H2O budgets over the last 150 million-years indicate a three- to five-fold increase in the proportion of H2O entering the sub-arc during the most recent global pulse of magmatism. Step changes in H2O flux enable proportionally greater partial melting in the sub-arc. Similar magmatic pulses in the ancient Earth could be related to variability in subduction flux associated with supercontinent cycles.