Proterozoic Charnockites at 1.6 & 1.0 Ga in the Eastern Ghats Belt, India, Mirror Secular Evolution of Continental Crust

摘要

As the Earth continued to cool down, the chemistry of granitic rocks reflect the changing conditions &/or processes of continental crust formation. Compared to the 1.0 Ga charnockites, the 1.0 Ga charnockites in the Eastern Ghats Belt, are more potassium and Rubidium rich, with more negative Eu anomalies and show much less HREE fractionation. Thus the 1.0 Ga charnockites are more evolved in composition and this is consistent with secular evolution of the continental crust throughout the Proterozoic era.