Co-variation of crenarchaeol and branched GDGTs in globally-distributed marine and freshwater sedimentary archives

Fietz, S. et al. (2012) Co-variation of crenarchaeol and branched GDGTs in globally-distributed marine and freshwater sedimentary archives. Global and Planetary Change, 92-93, pp. 275-285. (doi: 10.1016/j.gloplacha.2012.05.020)

Abstract

Two major types of glycerol dialkyl glycerol tetraethers (GDGTs) are commonly used in paleoecological and paleoclimatological reconstructions: isoprenoidal and branched GDGTs. In aquatic environments, it was originally assumed that isoprenoidal GDGTs, especially crenarchaeol, derive mainly from aquatic Thaumarchaeota, whilst branched GDGTs are an allochthonous input derived from soil Bacteria. Recently, direct co-variation of crenarchaeol and branched GDGTs has been described in two marine sedimentary records, and this observation suggests in situ production of branched GDGTs is possible at least in some aquatic environments. After investigating 30 published and unpublished data sets from downcore and surface sediments as well as sediment traps from 19 distinct regions around the world, we found a widespread significant correlation between concentrations of branched GDGTs and crenarchaeol (p < 0.01; r2 = 0.57-0.99), even when normalized against TOC, where available. These data sets include freshwater and marine environments with varying distances from the shore, varying redox conditions and different terrestrial matter input pathways. Our findings from this large-scale data set suggest that a common or mixed source for both GDGT types is actually commonplace in lacustrine and marine settings.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Jamieson, Mr Robert and Gallacher, Mr Christopher and Bendle, Dr James
• Authors: Fietz, S., Huguet, C., Bendle, J.A., Escala, M., Gallacher, C., Herfort, L., Jamieson, R., Martínez-Garcia, A., McClymont, E.L., Peck, V.L., Prahl, F.G., Rossi, S., Rueda, G., Sanson-Barrera, A., and Rosell-Melé, A.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Global and Planetary Change
• ISSN: 0921-8181
• Published Online: 02 June 2012