Modern nodules: mineralogical investigation and modelling experiments. Part 1. Sandstone formations with bacterial carbonate cement (settlement Volna, Krasnodar region)

The results of mineralogical investigation of nodule formations from modern deposits near Volna settlement (Krasnodar region) are presented in the article. Complex of modern investigating methods is used. Nodules are connected with zones of gaseous-fluid seepage. Presence in the nodules of bacterial films and bacteriomorphic carbonate formations, traces of biocorrosion and crustification of quartz grains by iron bacteria, mineralization of bacterial remains by iron oxides and hydroxides indicates high activity of procaryotic community developed near this seeps. Our data allow to prove early-diagenetic origin of nodules and to get information about peculiarities and conditions of paleobacterial community development.