Constraints on melt movement beneath the East Pacific Rise from 230Th-238U disequilibrium.
We report 230Th-238U disequilibrium data on mid-ocean ridge basalts recovered 5 to 40 kilometers off the ridge axis near 9 degrees 30'N of the East Pacific Rise. These data indicate near-symmetrical eruptions of normal mid-ocean ridge basalts (NMORBs) and incompatible element-enriched mid-ocean ridge basalts (EMORBs) as far as 20 kilometers off axis. Our results suggest large-scale subsurface lateral transport of NMORB melt at 19 to 21 centimeters per year and also provide constraints on the petrogenesis of EMORBs of off-axis origin.
Zou
Haibo
H
Department of Earth and Space Sciences, University of California at Los Angeles, Los Angeles, CA 90095, USA. hzou@ess.ucla.edu
Zindler
Alan
A
Niu
Yaoling
Y