Employees of the Department of Geology deal with a wide range of geological research aimed at collecting data and constantly updating knowledge about the geological structure of the Republic of Croatia. The geological structure determines the soil's composition and fertility, the relief's formation and stability, and the existence of drinking water and mineral raw materials. Its understanding is one of the essential prerequisite for the sustainable use of natural resources and spatial planning, i.e. sustainable development. The employees of the Department of Geology carry out their activities through scientific research projects and the preparation of geological maps, as well as through cooperation with the economy. At the Department of Geology, sedimentological, stratigraphic, paleontological, mineralogical, petrological, geochemical, structural geological and geomorphological research is carried out. As support for geological research, geodetic (geomatic) research has recently been introduced into the department's activities. The synthesis of the research at the department are basic and thematic geological maps that serve as a basis for further, applied research.

The Department of Geology currently have 47 employees, among them 20 hold a scientific position, 6 hold associated positions, 14 hold professional positions, and 7 are administrative-technical personnel.

The Department of Geology's primary activity is preparing geological maps through geological research in Croatia. A geological map represents multidisciplinary scientific and professional research, including collecting and processing field, laboratory and cabinet data. Preparing the Basic Geological Map M 1:50,000 is an ongoing scientific research project with all the features of fundamental scientific work, which systematically builds on existing geological knowledge and discovers new ones. Employees also participate in scientific and/or professional projects financed from various sources like projects of the Croatian Science Foundation (HRZZ), projects of European (EU) and other international funds such as the Horizon2020 program, projects of national sources from ministries, agencies, local administrations and others public or private sector clients.

The research fields of the Department of Geology are related to basic geological, oil-geological, geochemical, geoarchaeological, geopedological and geomedical topics, as well as topics partly related to climate activity and the environment.

The Department of Geology undertakes investigations in several research groups:

1. Research of Quaternary sedimentary archives with an emphasis on paleoclimatic and paleoenvironmental reconstructions
2. Research of neotectonic and erosional processes and their impact on geomorphology
3. Investigation of the geodynamic evolution of the northwestern part of the Mesozoic Tethys
4. Research of the Dinaric karst area with an emphasis on the stratigraphy of the carbonate platform, the evolution of foothill basins and orogenesis
5. istraživanja područja dinarskoga krša s naglaskom na stratigrafiju karbonatne platforme, evoluciju predgorskih bazena i orogenezu
6. Petrochronological research of igneous and metamorphic rocks
7. Detailed reservoir modeling for mineral raw materials research, such as geothermal waters and hydrocarbons.
8. Detailed modeling of potential underground energy storages, aquifers (e.g. carbon dioxide storage) and geomechanical modeling.
9. Regional geochemical research to create geochemical atlases of the Republic of Croatia or its regions
10. Specialised geochemical research to define the ecological load (soil, water, recent sediments) with potentially toxic elements, i.e. all types of inorganic and organic pollutants.
11. Detection of active fault zones and other active geological processes
12. Geomatic research.

Most of the research fields are characterised by a multidisciplinary approach, enabling greater research efficiency and excellence through the joint cooperation of researchers from various scientific institutions and fields.