Co-variation of crenarchaeol and branched GDGTs in globally-distributed marine and freshwater sedimentary archives
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, while 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 that 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 After investigating 30 published and unpublished data sets from downcore and surface sediments as well as sediment traps from 19 distinct regions around the world, we found a widespread significant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.
Privacy & Cookies Policy
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.