Few studies have successfully identified bacteriohopanepolyols (BHPs) in continuous sedimentary records older than 100 ka. Here we expand significantly on previous work and report high resolution records of a variety of fully functionalised BHPs from ODP Site 1075 in the Congo deep sea fan BHPs are present throughout the core in sediments up to ca. 1 2 Ma, including composite and unsaturated homologues Although adenosylhopane, a proposed tracer for soil organic matter input, seems to undergo significant diagenesis with increasing depth below 65 m below the sea floor (mbsf), most BHPs appear to be relatively resilient to degradation, highlighting their potential as sedimentary tracers for past bacterial population distributions An unusual unsaturated BHT-cyclitol ether is present in high concentration between 500 and 600 ka and is interpreted as a possible biomarker for nitrogen-fixing Trichodesmium cyanobacteria. This previously unrecognised ecosystem change may have been partially driven by a decrease in nutrient supply to surface waters, resulting in more intense pelagic N fixation (C) 2010 Elsevier Ltd. All rights reserved.
|Number of pages||5|
|Publication status||Published - Sep 2010|
|Event||24th International Meeting on Organic Geochemistry 2009 - Bremen, Germany|
Duration: 6 Sep 2009 → 11 Sep 2009
- HOPANE SERIES
- SEDIMENTARY BACTERIOHOPANEPOLYOLS
- BACTERIAL TRITERPENOIDS
- TRICHODESMIUM SPP.