| title: | Correlation criteria and environmental changes at the boundaries of the global Ordovician stages in the East Baltic |
|---|---|
| reg no: | ETF5922 |
| project type: | Estonian Science Foundation research grant |
| subject: |
1.10. Geology |
| status: | accepted |
| institution: | Institute of Geology at Tallinn Technical University |
| head of project: | Jaak Nõlvak |
| duration: | 01.01.2004 - 31.12.2007 |
| description: | The main idea of the project is to integrate different approaches to the Ordovician stratigraphy and palaeontolgy in order to correlate the recently defined lower boundary levels of global series and stages and identify the corresponding environmental and biotic changes in the Baltic sequences. The boundaries of global units (series, global stages) are defined mainly in the sections of graptolite facies, but for their correlation in the Baltic carbonate facies different new criteria should be used, such as biozonal species among chitinozoans and conodonts. The biostratigraphical value of associated macrofossils and environmental changes should be estimated in the presumed boundary intervals. One possibility of achieving the best results in stratigraphy is the taxonomic study, based on detailed morphological research, and a revision of the palaeontological material considering the novel ideas of the palaeontological classification, especially the changes made recently on the genus and higher taxonomic levels. The taxonomic interpretation has direct influence on conclusions made by comparison of faunas from different regions, basins and areas. Due to the geological and palaeontological background and detailed stratigraphical correlation schemes available for the study area, the present project serves as a unique possibility of testing the usability of global boundaries in the limits of different environmental conditions of one and the same basin and to elaborate additional criteria which can be used in other basins with a similar depositional regime. A new aspect in the study of the Baltic palaeontological material will be specific problems, such as commensialism, symbiosis, bioerosion, mechanical injuries, giving information on the faunal associations and environments. The geochemistry and mineralogy of the phosphates in the Ordovician rocks (discontinuity surfaces) will be analysed to get additional data for the interpretation of environments. The studies of shell structure and mineralogy of lingulate brachiopods with phosphatic shells will be aimed at obtaining data about the Eh and pH conditions in the basin and their influence on the distribution of benthic faunas. . |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Linda Hints | TTÜ GI | osakonnajuhataja kt | |
| 2. | Dimitri Kaljo | TTÜ GI | juhataja | |
| 3. | Jüri Nemliher | TTÜ GI | vanemteadur | |
| 4. | Jaak Nõlvak | Institute of Geology at Tallinn Technical University | senior researcher | |
| 5. | Helje Pärnaste | TÜ GI | juhtivinsener; doktorant | |