@article {Kusch201635,
	title = {Factors influencing 14C concentrations of algal and archaeal lipids and their associated sea surface temperature proxies in the Black Sea},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {188},
	year = {2016},
	pages = {35 - 57},
	abstract = {Abstract Understanding the preservation and deposition history of organic molecules is crucial for the understanding of paleoenvironmental information contained in their abundance ratios such as Uk'37 and \{TEX86\} used as proxies for sea surface temperature (SST). Based on their relatively high refractivity, alkenones and glycerol dialkyl glycerol tetraethers (GDGTs) can survive postdepositional processes like lateral transport, potentially causing inferred \{SSTs\} to be misleading. Likewise, selective preservation of alkenones and \{GDGTs\} may cause biases of the \{SST\} proxies themselves and can lead to decoupling of both proxy records. Here we report compound-specific radiocarbon data of marine biomarkers including alkenones, GDGTs, and low molecular weight (LMW) n-fatty acids from Black Sea sediments deposited under different redox regimes to evaluate the potentially differential preservation of both biomarker classes and its effect on the \{SST\} indices Uk'37 and TEX86. The decadal Δ14C values of alkenones, GDGTs, and \{LMW\} n-fatty acids indicate similar preservation under oxic, suboxic, and anoxic redox regimes and no contribution of pre-aged compounds, e.g., by lateral supply. Moreover, similar 14C concentrations of crenarchaeol, alkenones, and \{LMW\} n-fatty acids imply that the thaumarchaeotal \{GDGTs\} preserved in these sediments are produced in the euphotic zone rather than in subsurface/thermocline waters. However, we observe biomarker-based \{SSTs\} that strongly deviate (ΔSST up to 8.4 {\textdegree}C) from in situ measured mean annual \{SSTs\} in the Black Sea. This is not due to redox-dependent differential biomarker preservation as implied by their Δ14C values and spatial \{SST\} pattern. Since contributions from different sources can largely be excluded, the deviation of the Uk'37 and \{TEX86\} proxy-derived \{SSTs\} from in situ \{SSTs\} requires further study of phylogenetic and other yet unknown environmental controls on alkenone and \{GDGT\} lipid distributions in the Black Sea.},
	keywords = {sea surface temperature proxies, TEX86, Uk37, Uk'37},
	issn = {0016-7037},
	doi = {http://doi.org/10.1016/j.gca.2016.05.025},
	url = {http://www.sciencedirect.com/science/article/pii/S001670371630268X},
	author = {Stephanie Kusch and Janet Rethemeyer and Ellen C. Hopmans and Lukas Wacker and Gesine Mollenhauer}
}
