Department 430 – Regional geology of sedimentary formations

Geological research on sedimentary and volcanic formations provides crucial information about the composition, physical properties and evolution of these rocks and is a prerequisite for understanding the factors governing risks associated with these rocks (e.g. landslides), the resources of potable water they contain, and their potential use for the storage of CO2 etc. Investigations are carried out in the Palaeozoic, Mesozoic and Caenozoic sedimentary basins and volcanic terrains of the Czech Republic. Because of growing public demand, emphasis is now being placed on investigations of Quaternary deposits, including their geomorphology and related environmental geofactors.

Section 431 – Quaternary research

The Quaternary period (approximately the last 3Ma) is the youngest period in the geological history of the Earth. During this time, the present landscape was created and human activity played a significant part in this. Quaternary deposits contain unique information about the most recent climatic changes, about the alternation of cold glacial periods and the warmer interglacial periods and about the development of relief and the geodynamic processes responsible. Quaternary deposits are an important reservoir of potable water as well as building materials (sand, gravel and clay).

The team from the Quaternary section studies the development of river networks and river terrace systems, and carries out analyses of geological hazards (landslides, floods, erosional processes). Palynological research is an important tool used to study the reaction of ecosystems to changes in climate, and also to assess the influence of human activities on the development of the landscape and vegetation. The information gathered by the scientists in this section provides a basis for the estimation of groundwater reserves and for the protection of water sources from contamination, as well as helping to minimize the damage and loss of life caused by natural catastrophes.

Contributions to the understanding of Quaternary deposits and their correlation in the Northern hemisphere were made by the CGS staff as part of the international program INQUA at the end of the last century,

Section 432 – Tertiary section

The geological development of sedimentary basins and volcanic areas in the territory of the Czech Republic during the Tertiary (between 65 and 3Ma) is being reconstructed using information obtained from sedimentological, volcanological, geochemical and palaeontological studies. The Tertiary brown coal basins were not only explored in detail to enable extraction of coal for generating energy, but they also provided unique information about the flora and fauna during this period of geological time. The details have been recorded in a number of monographic studies. In addition to their scientific significance, the results of research on the Tertiary formations have been used to solve problems of slope stability in areas of volcanic rocks, and to enable efficient and responsible extraction of raw materials.

Part of the work of the team is also the compilation of special geological maps for civil engineering projects, and areas at risk from geological hazards, and to enable the administration of nationally protected sites and landscapes. The tradition of research on the volcanic rocks in the Czech Republic goes back for more than two centuries. In the past, such personalities as Alexander von Humboldt and Johan Wolfgang Goethe were involved. Professor Josef Emanuel. Hibsch (1852-1940) initiated the compilation of geological maps of the Central Bohemian Mountains in the early days of the Geological Institute. Numerous hypotheses have been modified as a result of new insights provided by volcanological studies made during the last thirty years. The Doupov Mountains are no longer regarded as a single stratovolcanic edifice, but as a volcanic complex formed by a number of subsidiary volcanic centres.

Section433 – Cretaceous

The focus of geological investigation by this team is the largest sedimentary basin in the Czech Massif, the Czech Cretaceous Basin. The rugged terrain of Bohemian Switzerland, the Czech Paradise, the Adrspach-Teplice Crags, the Broumov Cliffs, the Podorlicko Hills and the Svitavy Upland are formed by the sandstone deposits of this basin, while the Central Bohemian Mountains and Elbe Lowlands are composed of marly limestones and claystones of Cretaceous age. The Czech Cretaceous Basin is the most important reservoir of potable ground water in the Republic. There are also significant deposits of uranium, glass sands, and raw materials for ceramics and building. The territory is a geotouristic attraction and many sites of outstanding natural beauty are protected.

By the 2nd half of the 19th Century, Professor Antonín Jan Frič (1832-1913), the Czech palaeontologist, biologist and geologist, later the director of the National Museum in Prague, had already studied the Cretaceous fauna and compiled the first stratigraphy of the Czech Cretaceous Basin where he discovered the only pterosaur so far known from the Czech Republic, Ornithocheirus? hlavatschi (found in 1880 near Choceň). The pterosaur was small with a wingspan of about 1,5m and lived during the Turonian.

At present detailed studies of the composition of the sediments, their origin and age are being carried out using modern techniques of basin analysis. Investigations are being carried out on surface exposures and in the subsurface down to a depth of several hundred meters. This has added much to the understanding of the geological history of the Czech Massif before about 100 Ma when the area was covered by a shallow subtropical sea.

Section 434 – Palaeozoic Section

This section carries out research on Palaeozoic marine (542-359 Ma) and continental (359-251 Ma) sedimentary basins. Using palaeontological, palynological, biostratigraphical, sedimentological, geochemical and volcanological evidence, the origin and evolution of these sedimentary basins in time and space is being reconstructed.

The results of this research are being applied to solve current problems, for instance by using 3D models of the sub-surface rock environment to identify repositories for the capture and storage of carbon dioxide (CCS) and to provide the information necessary for underground civil engineering projects. Detailed geological maps of areas of interest for underground engineering projects and areas at risk from geological hazards are compiled and information is supplied to the national and regional administrative authorities to help in planning land-use and the protection of sites of special scientific and recreational value.

Research on the Palaeozoic rocks of the Czech Massif has a distinguished tradition that goes back two centuries and is recognized internationally. Joachim Barrande studied the Palaeozoic sediments in the surroundings of Prague in the 19th Century. He named them the „Système Silurien du centre de la Bohême“. In the 1970s and 1980s of the 20th Century, thanks to the efforts of the CGS staff, international stratotypes (GSSP – Global Boundary Stratotype Section and Point) were agreed for the Ludlow/Přídolí boundary (Požáry, 418.7 Ma), for the Silurian/Devonian boundary at the base of the Lochkovian Stage (Klonk u Suchomast, 416 Ma), and for the boundary between the Lochkovian and Pragian Stages (Velká Chuch, 411 Ma). The names Přídolían (for the uppermost Stage of the Silurian), Lochkovian and Pragian (for Stages of the Lower Devonian) were adopted internationally at the same time.

The scientific work currently being undertaken by the Palaeozoic specialists at the CGS includes research on taxonomy, palaeoecology and palaeobiology that is published in international journals. Recent papers have discussed the use of biostratigraphy and geochemical methods to understand global climate change, the development of biodiversity and the geotectonic setting of volcanism in the Earth´s past