TY - JOUR
T1 - Distributions of branched GDGTs in a tropical lake system
T2 - Implications for lacustrine application of the MBT/CBT paleoproxy
AU - Tierney, Jessica E.
AU - Russell, James M.
N1 - Funding Information:
We thank an anonymous reviewer and J. Weijers for constructive comments that greatly improved the manuscript. We also thank NSF-EAR (Grant # 0627803) for support, D. Haffner and D. Fowle for limnological data, the Indonesian Institute of Science for research permission, S. Bijaksana, N. Wattrus, P. Hehanussa, the International Nickel Company (INCO) and PT INCO Tbk (especially D. Tetradiono and L. Lubins) for field assistance and J.S. Sinninghe Damsté for helpful comments.
PY - 2009/9
Y1 - 2009/9
N2 - Branched glycerol dialkyl glycerol tetraether (GDGT) lipids are abundant and ubiquitous in lake sediments, potentially allowing for a paleolimnological application of the so-called MBT/CBT proxy (methylation index of branched tetraethers/cyclization ratio of branched tetraethers). To investigate the origin and characteristics of these compounds in lacustrine environments, we examined the distributions of GDGTs in soils, river sediments and lake sediments from Lake Towuti on the island of Sulawesi, Indonesia. We found significant differences in the degree of methylation and cyclization (expressed by way of the MBT and CBT indices) between the soil samples and the aquatic samples, suggesting that there may be in situ production of GDGTs in the aquatic environment. Based on these findings, we urge caution in the application of the MBT/CBT paleoproxy to lake sediments and encourage more rigorous study of these compounds in freshwater environments.
AB - Branched glycerol dialkyl glycerol tetraether (GDGT) lipids are abundant and ubiquitous in lake sediments, potentially allowing for a paleolimnological application of the so-called MBT/CBT proxy (methylation index of branched tetraethers/cyclization ratio of branched tetraethers). To investigate the origin and characteristics of these compounds in lacustrine environments, we examined the distributions of GDGTs in soils, river sediments and lake sediments from Lake Towuti on the island of Sulawesi, Indonesia. We found significant differences in the degree of methylation and cyclization (expressed by way of the MBT and CBT indices) between the soil samples and the aquatic samples, suggesting that there may be in situ production of GDGTs in the aquatic environment. Based on these findings, we urge caution in the application of the MBT/CBT paleoproxy to lake sediments and encourage more rigorous study of these compounds in freshwater environments.
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U2 - 10.1016/j.orggeochem.2009.04.014
DO - 10.1016/j.orggeochem.2009.04.014
M3 - Article
AN - SCOPUS:68749095059
SN - 0146-6380
VL - 40
SP - 1032
EP - 1036
JO - Organic Geochemistry
JF - Organic Geochemistry
IS - 9
ER -