Long term decrease in Proterozoic dynamo efficiency prior to inner core growth: Evaluation via single crystals

Wentao Huang1, Benjamin Thomas Crummins2, Tinghong Zhou3, Rory Danielle Cottrell4 and John Anthony Tarduno2, (1)University of Rochester, Rochester, NY, United States, (2)University of Rochester, Earth and Environmental Sciences, Rochester, NY, United States, (3)Peking University, School of Earth and Space Sciences, Beijing, China, (4)Univ of Rochester, Earth and Environmental Sciences, Rochester, NY, United States