We have analyzed the distribution of glycerol dialkyl glycerol tetraether lipids (GDGTs) in the Oligocene succession recovered by Integrated Ocean Drilling Program Expedition 342. The two studied sites, U1406 and U1411, penetrate a highly expanded section of the upper Eocene–Oligocene–lower Miocene succession. The branched isoprenoid tetraether (BIT) index varies between 0.2 and 0.85, implying that there was a moderate to high influx of soil organic matter to both sites. Furthermore, during the late Oligocene (Chattian) the influx was lower than during the early Oligocene (Rupelian). The methane index (MI) and %GDGT-0 index values suggest that methanotrophic Euryarchaeota and methanogenic archaea are not the main source of GDGTs, but rather marine Thaumarchaeota.
|Navn||Proceedings of the Integrated Ocean Drilling Program|
- Programområde 5: Natur og klima