Solid knowledge about the bedrock

TU Darmstadt and its partners have created a hefty register for rock properties


In future, researchers will be able to access reliable information about the qualities and properties of rock strata more quickly and easily. This will be useful when producing region-specific simulations of the bedrock, for example, particularly in Europe. Support for this comes from a new database which has been compiled at TU Darmstadt in cooperation with the GFZ German Research Centre for Geosciences in Potsdam and the Fraunhofer Research Institution for Energy Infrastructures and Geothermal Systems IEG. The scientific paper has been published in the specialist journal Earth System Science Data.

A road section as a geological outcrop, as used for laboratory investigations and then recorded in the database.

They are not only different colours and shapes, but also have a range of geophysical properties and are therefore suitable to varying degrees for applications for the energy transition. Whether rocks could serve as hydrogen stores, thermal water deposits or raw material storage in future depends on their porosity, rigidity, permeability and several other properties.

Scientists who produce region-specific simulations of the bedrock, for example, have to invest a lot of effort in collecting the relevant data for their actual work. This will now change, thanks to a database which has been created at TU Darmstadt, under the leadership of Dr. Kristian Bär, in cooperation with Dr. Judith Bott from the GFZ Potsdam and Dr. Thomas Reinsch from the IEG within the scope of the EU project, IMAGE.

“What we know about geology increases every day,” says Dr. Kristian Bär from the Working group of Geothermal Science and Technology at the Institute of Applied Geosciences at TU Darmstadt. “Unfortunately, the aspects which are actually relevant for a particular piece of work are often spread across several data collections of publications, and not always well documented either.” In cooperation with partner institutions, Bär has now waded through the accessible specialist literature and compiled the most comprehensive, structured database to date for laboratory data on rock properties, the PetroPhysical Property Database (P3).

Data collection should be standardised

Typical rock drill core for laboratory tests.
Typical rock drill core for laboratory tests.

It was important to the researchers to not just document pure data, but also the way it was collected in a standardised way, as this information is an important interpretation aid when processing the data later on. Each measurement is supplemented by relevant meta-information such as the corresponding sampling location, sample size, petrographic description, chronostratigraphic age and original scientific citation. Additional information about measuring methods and conditions is also listed for quality assurance. This enables rock properties to be used better for simulating bedrock processes.

75,573 data points from 316 publications were included in the first version of the database. The current composition of the samples was created as part of the EU project IMAGE (Integrated Methods for Advanced Geothermal Exploration) and follows the four guiding principles for scientific data management: findability, accessibility, interoperability, and reusability – FAIR. The database can now be downloaded from the project page in a range of formats. In addition to continually expanding the number of datasets and the links to other databases, access via a web-based interface should also be made possible in the future. “We would be very pleased if our work forms the seed for standardised, comprehensive rock card indexes for the energy transition, which sprouts into the national and international research data infrastructure in future,” is what Bär, Bott and Reinsch hope for the future.

Further information

The database on the project page

The publication

Kristian Bär, Thomas Reinsch and Judith Bott: The PetroPhysical Property Database (P3) – a global compilation of lab-measured rock properties, Earth System Science Data, 13 October 2020.