Role of upper-most crustal composition in the evolution of the Precambrian ocean-atmosphere system

- REE in matrix of black shales are used to determine composition of eroded rocks in the Precambrian.
- Mafic rocks have higher levels of nutrients and their erosion promotes biological evolution.
- Erosion of felsic crust, rich in K-Th-U-granites, led to nutrient poor oceans during Boring Billion.
- Atmosphere O2/CO2 are affected by composition of eroded continental rocks.