Thematic maps of the Geological Base Map

Data points

An essential part of the Geological Base Map is the initial data, including the geological descriptions of the different data points (boreholes, wells, outcrops and other survey stations). Initial data are collected during revising the previous and new field studies. Well information originates from the EELIS database.

Quaternary

Data about the age, origin and lithological composition of the Quaternary sediments are shown. Map is supplemented with data of Quaternary thickness and geomorphology (landforms). 

For every map sheet, at least one cross-section penetrating the bedrock has been compiled. 

Bedrock 

Different types of bedrocks exposed on the ground surface or just beneath the Quaternary sediments are shown. Map is based on the stratigraphic schemes that  divide bedrocks according to their age into systems. Additionally, data about the bedrock faults and stratotype sections are given. Map is supplemented with bedrock relief data. 

For every map sheet, at least one cross-section penetrating the crystalline basement has been compiled.

Hydrogeology

Groundwater aquifer systems (rock bodies with similar water permeability) are shown, as well as data about the groundwater quality, consumption, flow direction, water table and other properties.

For every map sheet, at least one cross-section penetrating the crystalline basement has been compiled.

Groundwater vulnerability

An estimation of the potential contamination risk (originated from the ground surface) against the first bedrock aquifer is given.

Five groundwater vulnerability categories (  14.6 KB, 5.03.2010 ) are used.

The map provides information for planning the objects that may affect the natural environment extensively (gas stations, landfills, water protection zones).

Mineral resources

Perspective areas, discoveries and areas of mineral deposits are shown. A perspective area (prospect) is a deposit with preliminary resource estimations (not described in the Mineral Registry). Mineral occurrences (areas) are regions where resources may exist. They are determined during geological mapping or other surveys. Occurrences (points) are unspecified sites where sediments or rocks, suitable for extraction, have been found. 

Geophysics

Geophysical profiling and modelling provide knowledge about the composition of the subsurface, thus enable to plan further fieldworks.

Profiles

Profile networks established with different methods (electrical, georadar etc) and geologically interpreted results.

Anomalies

For mapping the gravity anomalies, the values of the acceleration of the planet's free fall (g) are needed. Later corrections are made for the measured values: geographic latitude, elevation and the Bouguer correction (2,3 g/cm3 refers to the average density of the sedimentary rocks).

For aeromagnetic anomalies, the total intensity (nT) of the planet's magnetic field is mapped. Data are corrected by subtracting temporal effects and global magnetic field values. 

The corrected data are used for generating the statistical surfaces. Variations in the anomalies can be expressed with isolines constructed from the surfaces.