There are several points of view on the conditions of layer formation. One group of researchers sees the main cause of layer formation in geotectonic fluctuations of the Earth's crust, which control the process of sediment accumulation. Other researchers consider the main cause of layer formation to be a change in the conditions of sediment formation as a result of changes in the physical-geographical regime; at the same time, they do not attribute significant importance to the geotectonic factor.

Fracture and displacement of the seam is a geological phenomenon that, in each specific case depending on the geological setting, possesses special geometric forms. Geometric classifications of fractures are numerous and their complexity is diverse, but all of them are only a way to make sense of the variety of fracture shapes. In order to search for the displaced part of the seam, data on not only the normal but also the displaced wing are needed. Therefore, geological setting data common to both wings are of particular importance for the search for the displaced part of the seam.

Insignificant changes in the occurrence of gently dipping seams often lead to losses of coal in the subsurface and sometimes create difficulties in the use of mining mechanisms; therefore, the refinement of hypsometry of gently dipping seams is one of the important tasks of mine geology.