Objective
The project will study one of the most remarkable and enigmatic Palaeoproterozoic phenomena: wide-spread isotopically heavy carbonate carbon. This phenomenon is related to a fundamental problem of the global carbon cycle, biological evolution and oxygenation of hydrosphere-atmosphere system in the Precambrian. It is still not clear what kind of mechanism this phenomenon could be attributed to and, therefore, the goal of the project is to reach at an understanding of ca. 2 billion-year-old positive anomaly of (13Ccarb, its significance and its driving forces. The main objectives are:
stable and radiogenic isotope systematics in 2.3 - 1.9 Ga-old sedimentary formations;
modelling of formation of anomalous heavy carbonate carbon occurred at around 2.3 - 2.1 Ga ago: global phenomenon versus local development.
The target area for this project is the Fennoscandian Shield where 2.3 - 2.1 Ga old 13C-rich carbonates were deposited over an area of more than 800,000 km2. The Fennoscandian Shield appears to be the largest and the most important province for the study of the Jatulian isotopic phenomenon. The high-(13C carbonates in this province have a very low metamorphic grade and are both extensively and intensively developed. Currently available time constraints for the period from 2.5 to 1.8 Ga are reliable on a mid-resolution time-scale.
The principal goals of the project will be achieved by using a multidisciplinary approach which will include an original study and compilation on: temporal and spatial variations of (13Corganic, (13Ccarbonate, (34Ssulphide, (34Ssulphate, initial 87Sr / 86Sr ratio; palaeotectonic, palaeogeographic, palaeobasinal, palaeoclimatic environments; dynamics of diversity and abundance of stromatolite taxa and their impact on carbon isotopes of Palaeoproterozoic carbonate precipitates; metamorphic and diagenetic impact on the carbonate carbon isotopes; direct Pb-Pb dating of 13C-rich carbonate rocks. The advantage of this project is its approach emphasizing how the carbon cycle was incorporated with concomitant sulphur, oxygen and strontium cycles and main events in biosphere and bios evolution.
The results are expected to be a new possibility for the modelling of the atmosphere-hydrosphere evolution in Precambrian; a better understanding of the contribution of biologically-produced and -induced events to Precambrian evolution of the Earth; a reconsideration of the regional Precambrian lithostratigraphy; and an independent tool for the regional, inter-regional, and global correlation of carbonate formations of that age. The new data related to heavy carbonate carbon phenomenon, and particularly those which will provide a new insight on the biological evolution of the ancient Earth, will be presented at international conferences and published in international journals.
Call for proposal
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7002 Trondheim
Norway