Publication Date:
2021-06-21
Description:
Sedimentary high molecular weight (HMW) n-alkyl lipids derived from the waxes of terrestrial plants are
common target compounds in biogeochemical and paleoenvironmental research. These plant waxes
derive predominantly from the epicuticular cover of vascular plant leaves and their relative and absolute
abundances and stable isotopic composition can be used as proxies to decipher, e.g., continental climate
and land-ocean carbon transfer processes. In marine sediments, however, compound-specific radiocarbon
analysis has revealed that plant waxes are often not syn-depositional, but instead are substantially
14C-depleted (‘pre-aged’) upon deposition. This 14C-depletion can be caused by various processes that
either promote retention of plant waxes during transport from source to sink such as storage in soils
or entrainment in deposition-resuspension loops in rivers and on continental shelves or, alternatively,
by processes that add HMW n-alkyl lipids from other sources (e.g., petrogenic inputs). Here, we review
the intrinsic and extrinsic processes affecting the sedimentary plant wax 14C composition (ranging from
chemical processes to continental-scale environmental conditions), how plant wax 14C compositions
translate into mean ages, and which processes control plant wax mean ages in marine sediments.
Finally, we use a compilation of available and new compound-specific plant wax 14C data to provide a
synthesis and evaluate the major controls on plant wax mean ages in marine sediments at the global
scale.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
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isiRev
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