Geological section

Geological studies include the study of the geological and tectonic structure of large regions (areas, work sites). In the course of research, stratigraphy (sequence of occurrence of geological formations), genesis (origin) and age of rocks composing the shell of the earth's chicken in the place of research is revealed.

The results of these studies are expressed in the form of geological maps. The geological map displays a geological structure of a section of the earth's crust in a horizontal plane in a specific studied place in a graphic form on a topographic basis on a certain scale. The actual geological information is applied to the map in full. Geological sections are extremely important in areas where rocks from above are covered by a powerful soil-vegetation layer, modern anthropogenic formations.

The geological cross-section is a graphical representation of a vertical section of the earth's crust into a depth opened by boreholes or mine workings. It is a compulsory addition to the geological map. The geological section illuminates the lithological section of the studied strata, the thickness of the layers, their position, the structure of the geological bodies, the age of the rocks, and the position of the groundwater level.

To obtain undistorted information of the geological structure in relation to the terrain, the values of the scales of the horizontal (map scale) and vertical (scale of the cut) should be the same. But for the design of construction projects (roads, dams, buildings), the vertical scale of the geological section is increased by tens, hundreds of times.

A geological section is built along the line of the cut, drawn on the map across the strike (across) the geological structures. The line is drawn at the points depicted in the wells on the map. For more complete information on the geological structure of the crustal strata in the region of investigations, the line of the geological section may be a broken line.

For the construction of the cut, a topographical profile is first built on millimeter paper , demolishing the characteristic altitude marks. The average height of the area is determined and a horizontal (zero) line is drawn at this height. The location of wells is applied to the profile and perpendiculars to the zero line are dropped through these points. Each perpendicular is the line on which to display the geological section of the well using its documentation. The cut line is also dotted, according to which there is documentation in the form of descriptions of natural outcrops of the earth's crust. Then a geological section is built, connecting the boundary lines (soles and roofs) of the rock layers, which are the same in lithology and age. To build a geological section correctly, carefully study the map, determining the structural elements, the type of occurrence of rocks, breaking disruptions.

The engineering-geological section differs from the geological one with additional information that characterizes the physical and mechanical properties of soils and the dynamics of processes. For engineering assessment of territories for the construction of buildings and facilities, not only geological information with the characteristics of rocks on their strength, water cut, but also information about changes in the geological environment-processes occurring on the territory and phenomena: frost punching of soil, karst formation, landslide processes, distribution of specific Groundwater regime, groundwater salinity, corrosive activity of soils and groundwater to concrete, steel, and much more. As a result of engineering and geological surveys, the measures that must be taken for the stability and durability of the erected structures are determined.