Abstract
In the study the applicability of some organic geochemical indices in paleoenvironment reconstruction in highly dynamic coastal basin was assessed. Within the frame of the study 9 samples from the profile Sa1/2, representative for Lake Sarbsko, were investigated. Bulk organic geochemical parameters (TOC/TN, TOC/TS, HI, 13CTOC) and molecular composition of selected hydrocarbons were used to recognize variations in paleosalinity, to determine origin of organic compounds as well as to demonstrate diagenetic alterations of the sediments. Fluctuations of salinity during the lake evolution are reflected by changesinTOC/TSandsteroid/hopanoidratiosaswellas 13CTOC values.Anoxicconditionsof sedimentation correlate with low values of pristane/phytane ratio and extended microbial acitivity is mirrored by elevated contribution of hopanoids in the samples. Organic matter in Lake Sarbsko sediments originated from both enhanced biological productivity in the water column and terrestrial sources. It was shown,that organic geochemical indices are a complementary methodforreconstruction of salinity, as there is satisfactory correlation between different organic and inorganic geochemical proxies. On the other hand, early diagenesis and complex mechanisms delivering organic matter to coastal basins hinder interpretations of origin of organic compounds.
| Translated title of the contribution | Organic matter composition as an indicator of genesis of Lake Sarbsko sediments |
|---|---|
| Original language | Polish |
| Pages (from-to) | 140-143 |
| Number of pages | 4 |
| Journal | Przeglad Geologiczny |
| Volume | 56.2008 |
| Issue number | 2 |
| Publication status | Published - 10 Apr 2008 |
| Externally published | Yes |
Keywords
- δC
- Biomarkers
- Coastal lake
- Sedimentary organic matter