Assessing the fidelity of leaf wax signals in marine sediments: n-alkane sensitivity to change along a precipitation gradient

Abstract

Leaf wax n-alkanes are well known higher plant biomarkers. These molecules are widely found in geological archives, where their concentration, average chain length (ACL) and isotopic composition (δ 13 C alkanes and δ 2 H alkanes ) serve as proxies for changes in continental vegetation and hydroclimate. While mechanistic relationships of these proxies with climate and vegetation are relatively well understood, little is known about the transport of those biomarkers into geological archives. In marine sedimentary records, leaf wax biomarkers are often interpreted to represent the contiguous continental catchments, but few studies have examined the fidelity with which nalkanes in marine sediments record the corresponding continental conditions.