Geological research includes the study of the geological and tectonic structure of large regions (regions, work sites). In the course of the research, the stratigraphy (the sequence of occurrence of geological formations), the genesis (origin) and the age of the rocks that make up the shell of the earth's chicken at the research site are clarified.
The results of these studies are expressed in the form of geological maps. A geological map depicts in a graphical form on a topographic basis at a certain scale the geological structure of a section of the earth's crust in a horizontal plane in a particular studied place. The available actual geological information is put on the map in full. Geological sections are extremely important in areas where rocks are covered from above by a thick soil-vegetative layer, modern anthropogenic formations.
Geological section represents in graphical form a vertical section of the earth's crust to a depth opened by wells or mine workings. It is a must-have addition.geological map. The geological section illuminates the lithological section of the studied strata, the thickness of the layers, their position, the structure of geological bodies, the age of the rocks, the position of the groundwater level.
To obtain undistorted information of the geological structure in relation to the terrain, the values of the horizontal (map scale) and vertical (section scale) scales must be the same. But for the design of construction objects (roads, dams, buildings), the vertical scale of the geological section is increased by tens, hundreds of times.
A geological section is built along the section line drawn on the map across the strike (across) of geological structures. The line is drawn along the points that represent the wells on the map. For more complete information about the geological structure of the earth's crust in the study area, the line of the geological section can be broken.
To build a section, first, a topographic profile is built on graph paper, removing characteristic elevation marks. The average height of the area is determined and a horizontal (zero) line is drawn along this height. The locations of the wells are applied to the profile and perpendiculars to the zero line are lowered through these points. Each perpendicular is a line on which you want to display the geological section of the well using its documentation. Points for which there is documentation in the form of descriptions of natural outcrops of the earth's crust are also applied to the cut line. Then a geological section is built, connecting the boundaries with lines(soles and roofs) of rock layers identical in lithology and age. To build a geological section correctly, they carefully study the map, determining the structural elements, the type of rock occurrence, and faults.
An engineering-geological section differs from a geological one in that additional information that characterizes the physical and mechanical properties of soils and the dynamics of processes. For an engineering assessment of territories for the construction of buildings, structures, not only geological information is required with the characteristics of rocks about their strength, water content, but also information about changes in the geological environment - processes and phenomena occurring on the territory: frost heaving of soils, karst formation, landslide processes, the distribution of specific soils, groundwater regime, salinity of soils, corrosivity of soils and groundwater to concrete, steel, and much more. As a result of engineering and geological surveys, the measures that need to be taken for the stability and durability of the structures under construction are determined.
