What do electrical anomalies tell us about the structure and dynamics of the deep lithosphere?

Séminaire de Thomas Ferrand, Freie Universität Berlin.

In various contexts, the deep lithospheric mantle can reveal electrical conductivity anomalies, with values ≥ 10^-1 S m^-1 when average peridotites exhibit values as low as 10^-2 S m^-1. Recent experiments have shown that garnet-rich networks could explain the anomaly in the deep root of the Tanzanian craton (Ferrand & Chin, 2020), which could also apply to the anomaly within the Cocos Plate offshore Nicaragua, i.e. fossilized LAB (Ferrand, 2020b). Complementary experiments actually support solid-state lubrication at the LAB (Yamauchi & Takei, 2020; Ferrand & Deldicque, 2021).