Facial Isotope Differences of Carbon and Global Photosynthesis in the Frames of Global Carbon Cycle

AA Ivlev

Abstract

Facial isotopic differences are usually regarded as the features of the carbon isotope composition of sedimentary organic matter, reflecting the conditions of formation and transformation in the location under study. In the present work it is shown that facial differences reflect the conditions of photosynthesis that took place in this location during the relevant period of geological time. These conditions are determined by the ratio of CO2 and O2 in the atmosphere, as well as by a set of other environmental parameters that affect on the ratio of these gases in photosynthesizing cells (illumination, water salinity, aeration, etc). The subsequent processes of organic matter transformation in the sediment do not significantly affect on the carbon isotope composition. The mechanism of formation of carbon isotope composition of photosynthetic part of “living matter” is suggested. The relationship of facial isotopic differences with isotope composition of photosynthetic biomass is traced.