Evidence for carbon cycling in a large freshwater lake in the Balkans over the last 0.5 million years using the isotopic composition of bulk organic matter
In the DEEP core from the Lake Ohrid ICDP drilling project, the carbon isotope composition of bulk organic matter (?13CTOC) over the last 516 ka shows a negative correlation with total organic carbon (TOC) and total inorganic carbon (TIC). This relationship is marked by periods of lower ?13CTOC values corresponding to higher TIC and TOC. Along with TOC/TN, the correlation between ?13CTOC and ?13CTIC suggests that most of the organic matter in the core is from aquatic primary production within the lake.