Experimental evidence for the preservation of U-Pb isotope ratios in mantle-recycled crustal zircon grains.

ABSTRACT: Zircon of crustal origin found in mantle-derived rocks is of great interest because of the information it may provide about crust recycling and mantle dynamics. Consideration of this requires understanding of how mantle temperatures, notably higher than zircon crystallization temperatures, affected the recycled zircon grains, particularly their isotopic clocks. Since Pb²⁺ diffuses faster than U⁴⁺ and Th⁺⁴, it is generally believed that recycled zircon grains lose all radiogenic Pb after a few million years, thus limiting the time range over which they can be detected. Nonetheless, this might not be the case for zircon included in mantle minerals with low Pb²⁺ diffusivity and partitioning such as olivine and orthopyroxene because these may act as

SUBMITTER: Bea F 

PROVIDER: S-EPMC6110838 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature