Lacustrine stratification

Because of their specificity for particular bacterial groups and environmental conditions, they make excellent biomarkers. Another steroidal biomarker is gammacerane (Figure 22.19b), which has six six-membered carbon rings. It is used as an indicator of water-column stratification in marine and lacustrine deposits. 

While the evidence (fossils, sediment type, stratification) supports a lacustrine environment for all the deposits, the monotonous sequence at Condor is unique. At Condor, a stratified lake system similar to that proposed by Smith and Lee (17) for density stratification in the Piceance Creek Basin may have developed. 

Notice that acid, represented here by C02 and water, is consumed and that sodium and bicarbonate ions are produced as albite alters to kaolinite. The material entering the lake as the stratification developed appears to have had two characteristic properties—easily hydrolyzed sodium and a limited content of halogens, particularly chlorine. Decomposition of organic matter furnished carbon dioxide. Concentration of sodium carbonates and other dissolved salts in solution in water of the stratified lake s lower layer built up, raising the water density. The evolution from normal lacustrine sediments to oil shale in the northwestern part of the Piceance Creek Basin is continuous... 

Thus ancient lacustrine deposits are often petroleum source beds. A similar stratification, with an upper... 

The upper Pleistocene lacustrine-glacial clay from the Novgorod region was taken as the object of study. The choice of this clay for the experiment was caused by a high rate of orientation of clay particles along stratification, which permitted us to classify these clays as natural model systems with marked anisotropy of properties. 

---