The lithofacies analysis of the Mamon showed showed that secondary kaolin deposits, forming a new kaolin-bearing province in the southern part of the Voronezh anteklise, are associated with a complex of deluvial-proluvial, lacustrine-boggy, and floodplain-oxbow deposits. The main ore minerals are kaolinite, quartz and secondary iron oxides and gibbsite. The presence of both terrigenous and autistic kaolinite was revealed. An important role in the formation of the latter, as well as gibbsite, played an organic substance.