Tracing Holocene Weathering Input into the Kara Sea with Radiogenic Isotopes (Sr and Nd)
This Master thesis traces weathering input into the Kara Sea via the Yenisei and Ob Rivers, as the main suppliers for suspended and dissolved matter. With the use of Sr and Nd isotopes as tracers, potential sources of weathered material were complied for each river from the literature and based on p...
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| Format: | Thesis |
| Language: | English |
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2011
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| Online Access: | https://oceanrep.geomar.de/id/eprint/13256/ https://oceanrep.geomar.de/id/eprint/13256/1/2011_Filippova-Alexandra_MSc-Thesis.pdf |
| Summary: | This Master thesis traces weathering input into the Kara Sea via the Yenisei and Ob Rivers, as the main suppliers for suspended and dissolved matter. With the use of Sr and Nd isotopes as tracers, potential sources of weathered material were complied for each river from the literature and based on previously published work in this area possible ranges in Sr and Nd isotopes for each potential source were derived, which allowed to reconstruct the radiogenic isotope evolution of dissolved and particulate inputs into the Kara Sea. In this study, the signatures of these two radiogenic isotopes systems were analyzed in surface samples and two cores: one core BP99-04/7 from the Yenisei estuary area and one core BP00-07/7 from southern part of the Kara Sea. All samples were prepared in the clean laboratory using ion chromatography and were then measured on a Multi Collector-Inductively Coupled Plasma Mass Spectrometer (MC-ICP-MS). The obtained values were compared to the signatures of possible sources to evaluate their origin. Fluctuations within both cores were analyzed and compared. Ages were calculated for each depth interval based on the chronologies of Polyakova and Stein (2002). Furthermore, to determine, if there is any correlation between the variability of the signatures and changes in climatic conditions, the data were compared to the GISP-2 ice core from Greenland, as well as changes in temperature and precipitation over the Taimyr Peninsula over the past 10,000 years, changes in salinity in the Kara Sea and changes in precipitation over the Lake Baikal. The main goal of this master thesis was to identify the possible sources of input of weathered material into the Kara Sea from land and the relationship between weathering inputs via river discharge and climate change through Holocene times based on the Sr and Nd radiogenic isotope composition in Fe-Mn coatings and totally dissolved detrital material. |
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