The lithological features of the Middle Cambrian sublittoral-littoral deposits of the Lower Evenki Member (Baykit Anteclise) have been refined. Four types of dolomites are identified: with stromatolitic texture, clotted-peloidal, replacement crystalline without preservation of the protolith primary structures, and replacement variably-crystalline with relict silt-pelitic structure. Post-sedimentary alterations of the rocks are associated with multi-stage dolomitization processes – early, syngenetic (in dolomite with stromatolitic texture and/or bacterial structures) and later (in replacement dolomites and silt-sandstones with dolomitic cement). The isotopic composition of carbon and oxygen in carbonates is analyzed. The elemental composition of carbonate, terrigenous-carbonate, carbonate-terrigenous, and terrigenous rocks is studied. A heat map with clustering was used to visualize the general pattern of enrichment by various elements. Carbonate lithology types are significantly enriched in Co, Cr, Sc, Rb and depleted in Cu, Zn, Li, Ba, Pb, and Sr in comparison with carbonate Clarke values. The nature of the positive Eu anomaly is investigated; its origin is attributed to Eu-bearing minerals in the terrigenous component of the rocks, rather than to hydrothermal solutions. No direct correlation is observed between the Rare Earth Element (REE) content and the amount of terrigenous admixture, thus the influence of reducing conditions or the composition of the dolomitizing fluid on the REE distribution cannot be ruled out. Terrigenous varieties are depleted in Cu, Zn, Pb, Ba, Th, U relative to the Clarke values for clays and clay shales. When normalized to PAAS, dolomitic argillites, dolomitic siltstones, sandstones, and silt-sandstones generally show enrichment in HREE relative to LREE. The source of the terrigenous clastic material was the Precambrian terranes of the Yenisei Ridge, formed by island-arc complexes, and recycled sedimentary material.