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Projects / Programmes source: ARIS

Global changes of the Earth system and associated geochemical perturbations and biotic crises

Research activity

Code Science Field Subfield
1.06.00  Natural sciences and mathematics  Geology   

Code Science Field
P005  Natural sciences and mathematics  Geology, physical geography 
P006  Natural sciences and mathematics  Palaeontology 
Keywords
geo- and bio-boundary events, mass-extinction, geochemistry, stable isotopes, biomarkers
Evaluation (rules)
source: COBISS
Researchers (1)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  21372  PhD Matej Dolenec  Geology  Head  2007 - 2008  478 
Organisations (1)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  1555  University of Ljubljana, Faculty of Natural Sciences and Engeneering  Ljubljana  1627074  19,946 
Abstract
The proposed research program represents a continuation of complex fundamental investigations of biotic and a-biotic events in Earth history associated with short- term and long-term global perturbations of geochemical and isotopic records as well as with biotic crisis and mass extinctions. The project is focused on specific problems related to the end-Permian mass-extinction and associated perturbations of global Earth systems, terminal Cretaceous extinction and the Paleocene-Eocene transition in Slovenia (W. Tethys). Research includes biostratigraphy, stable isotope (O, C, H N, S) geochemistry, element chemistry (69 elements including REE), strontium isotopes, biomarkers and magnetostratigraphy.
Significance for science
The aim of these studies was to complete the previous investigations of global geo- and bio-events near the Permian-Triassic, Cretaceous-Tertirary and Paleocene-Eocene transition in the western Tethys especially with the results of complex geochemical (major, minor, trace elements, REE, PGM) and isotopic (O, C, H, N, S, Sr) studies in the year 2007 and 2008. Research also includes organic geochemical work (biomarkers), paleontology, biostratigraphy and magnetostratigraphy. The major objectives of the project were: The Permian-Triassic boundary events and related global geochemical and isotopic perturbations and mass-extinctions. This research was a continuation of complex investigations of P/Tr sedimentary boundary sequences in the western Slovenia and in the Karavanke Mountains where complete, undisturbed P/Tr boundary sections were identified. In the most regions of the world a general lack of the continuous sedimentation across the P/Tr boundary represent difficulties of global characterization of major geological, geochemical, climatic and bio-events at the P/Tr transition. The research results are relevant to the IGCP Project 386: "Response of the ocean/atmospheric system to past global changes". These results shows a major isotopic anomaily 50 cm below the paleontologicaly supposed P/T boundary in all profiles (Idrijca, Masore and Skopačnik). Beside the main global isotopic anomaly at the P/T boundary we found one even strongest anomaly 15-20 m above that. The preliminary geochemical analyses confirmed mentioned anomalies at the boundary and 15-20 m above the permo-triassic boundary. With the study of stable isotopes across the P/T transition we were able to identify Milanković cicles (20, 40, 80 and 100 ky.). These results were most helpfull for detail interpretations of accumulation rate for the upper permian sediments and duration of the severe mass extinction events. Dramatic changes in flora and fauna together with the global carbon isotope anomaly in our opinion occurred within 60.000 years perhaps even 8.000 years which shows catastrophic character of the event at the P/T boundary. Biotic (micro and macrofossils) and abiotic (isotopes, geochemistry, magnetostratigraphy, geochronology, and paleomagnetism) characterists of sedimentary rocks from the K/T boundary in the SW. and W. Slovenia. Preliminary geochemical and isotopical results in the Sopada profile shows strong anomalies (especially Ir) at the K/T transsition. These results will help us in interpretations of the events before and after the major meteorite impact at the K/T boundary. Our aim was also to go beyond the identification of geochemical and isotopic profiles and tentative interpretations especially at the P/T transition. Current research activities, will supply enough high-resolution geochemical and isotopic data, which will allow us to provide quantitative analyses of the parameters causing global changes at the end of the Permian. The research project results enable a progression towards a better understanding of the cause of the past global changes (volcanism, impact, sea level changes, changes in seawater chemistry, climatic changes etc.), which commonly, but not always, coincides with the collaps of the global ecosystem and biotic crisis. The results of geochemical (69 element including REE ) and stable isotope (C and O in carbonates, C and N in organic matter, S in sulphides) analyses as well as the biostratigraphic data together with the results of organic geochemical work provide new parameters which are very important for scientists who study the long-term and short-term global geochemical and biotic changes near the Permian-Triassic transition in the Tethys Sea. Owing to the exclusively fundamental character of the research project continuous research work is required.
Significance for the country
The results of the proposed project undoubtly represent a new contribution to the knowledge of the phenomena of global events and geochemical event markers. The results of exclusively fundamental studies are also an important part in education of students and young researchers for competent and continuous research work.
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