Potassium Isotopic Composition of Low-Temperature Altered Oceanic Crust and its Impact on the Global K Cycle

Abstract

Abstract To constrain the behavior of K isotopes during the low-temperature alteration of oceanic crust and reveal its impact on the global K cycle, we measured the K isotopic compositions of 49 fresh and altered basalts recovered from the Integrated Ocean Drilling Program (IODP) Sites U1365 (∼100 Ma) and U1368 (∼13.5 Ma) in the South Pacific Ocean. The measured basalts representing the uppermost oceanic crust have been subjected to low-temperature (