Petrophysics

Petrophysics, gamma radiation

The product Petrophysics, gamma radiation contains data from field measurements of exposed bedrock from observed rock outcrops in Sweden. Assessment of rock types' Gamma radiation is often used to help characterize and classify rock types, and for building materials there are standards and guidelines that describe limit values for such radiation. Control and knowledge of gamma radiation in rock is important for mining and quarrying operations, but also for emplacement and deposition. Since measurement of gamma radiation assesses concentrations of radioactive isotopes, it provides genetic information and time information via the status of the decay chain.

Although ionizing radiation is strongly attenuated by only a few centimeters of soil cover, and the majority of the land surface is covered by soil material, measurements of gamma radiation on rock outcrops are a powerful tool for interpreting surface-covering radiation measurements. In addition, material transport following weathering processes and glaciations follows patterns that are documented and mapped in Quaternary geology.

Petrophysics, density and magnetic properties

The product Petrophysics, density and magnetic properties contains data from both laboratory and field measurements of rock samples from all over Sweden. This data is based on direct measurements or sampling, carried out on exposed bedrock, rock samples or drill cores.

Petrophysical data are used to identify and classify rock types and are important in modeling the Earth's geological structure in three dimensions, based on geophysical measurements and other observations. For example, petrophysical data can be used to assess whether deviations in the Earth's magnetic or gravity fields are caused by deep or shallow rock alteration. The information also contributes to understanding the geological processes that a rock type has undergone.

Classification and mapping of rock bodies is also done for engineering purposes, where petrophysical data forms the basis for volume calculations and assessments of mining methods, but also for decisions about suitability and quality related to infrastructure.