For a first overview, we analysed some samples from the Productive Series in Kirmaky Valley (Kirmaky Alti Suite, Kirmaky Suite, Post Kirmaky Sand Suite, Post Kirmaky Clay Suite, Balakhany Suite X) and in Yasamal Valley (Balakhany Suite VI - IX).
In Kirmaky Valley we could identify the four main clay mineral groups smectite, illite, chlorite and kaolinite in the sediments of the Productive Series. Illite concentrations range from 44% to 64%, smectite concentrations from 5% to 41%, chlorite concentrations from 14% to 29% and kaolinite concentrations from 4% to 9%. The quartz content is strongly fluctuating.
In Yasamal Valley the smectite concentrations fluctuate between 0.5 % and 24 %, with low concentrations in the Balakhany VII Suite and high concentrations in the Balakhany IX Suite and a sample from the Balakhany VI Suite. Illite concentrations range from 48 % to 75 %. Chlorite and kaolinite amounts fluctuate from 16% to 28% and from 6% to 17%, respectively. Quartz occurs in high amounts in the Balakhany IX Suite and the Balakhany VIII Suite. Below the Balakhany VIII Suite quartz contents slowly decrease.
The high contents of quartz and pyroxenes in the analysed samples indicate that the majority of the sediments is derived from the Russian Platform. They have been transported by the Paleo-Volga and may have been augmented by rivers draining the Greater Caucasus (Baturin, 1947; Reynolds et al., 1998). Illite and chlorite are the dominating clay minerals. They are detrital minerals, products of physical weathering processes, and possibly indicate a cool and dry climate of the period.