Palaeoproterozoic magnesite-stromatolite-dolomite-"red beds"assocation, Russian Karelia: palaeoenvironmental constraints on the 2.0 Ga positive carbon isotope shift.

Forkortet The ca. 2000 MA Tulomozerskaya Formation, Russian Karelia, representests the most 13C-rich carbonates (up to +18%)which have ever been reported. The implication of this excursion for our understanding of the coeval global geodynamic carbon cycle is not clear, but the interpretation of the maximum....