The paper asserts the percent horizontal and vertical distribution of the main lithological components (the total organic matter, total carbonates and minerogenic clastic fraction) in the grab surface layer and core sediment samples of some fluvial - Danubian lakes. The study is corroborated on the analysis of 144 grab sampling stations and 6 Hydro-Bios sediment cores collected during 2010-2013. Evaluations of the above mentioned parameters considered in surface sediments, and in samples from distinct cores have been defined by Loss on Ignition (LOI) method. By using the total organic matter concentration results in the grab sediment, as a proxy, it was tried to be pursued the source of the organic matter input into the lakes during the recent period. Evaluating the mean areal distribution values of the total organic matter, the shallow water depth, and assuming the autochthonous input as a main contributing source, it was exhibited that the investigated lakes are over-supplied with organic material, passing through a continuous shallowing environments due to a strong siltation of the canals and streams. The assessment of the vertical distribution results reported a distinctive pattern with infrequent dominantly organic layers interposed with sequences of minerogenic clastic contents. These fluctuations indicate seasonal shifts that have repercussion on the depositional environment conditions on some moments in time. The results obtained by LOI method yields excellent, medium or small correlation between the variations in the investigated parameters.