In this paper, the stratigraphic occurrence of n-alkanes (C) is investigated in three peat cores (Mildred, JPH4 and McMurray) from the ombrotrophic peatlands in northeastern Alberta, Canada, to determine their origin, biomass input, and paleoclimatic significance. The molecular composition of n-alkanes is dominated by the > C-21 medium- to long-chain homologues, with a strong odd over even predominance. A number of n-alkane-based indices (e.g. predominant n-alkane, C-23/C-29, C-23/(C-27 + C-31), P-aq, ACL, and CPI), show changing conditions in the organic matter (OM) input from Sphagnum species or terrestrial vascular plants, which increasingly contributed upwards in the peat profiles, and through time. 13, and C-23/(C-27 + C-31) proxies are similar in the three cores, and allow us to infer vegetation variations that coincide with the climate alternations of the Medieval Warm Period (MWP), Little Ice Age (LIA), and modern Recent Warming (RW). The utilization of ACL-ket and (C-23 + C-25)/(C-27 + C-29 + C-31)-ket proxies, performed in comparison with n-alkane proxies, further support the biomarker-based reconstructions of paleoclimate variations over recent centuries. This study suggests that n-alkane homologues are sensitive to vegetation and climate changes and thus are reliable biomarkers for tracking past shifts in vegetation and climate variations in peat archives.
1.Univ Calgary, PRG, Calgary, AB T2N 1N4, Canada 2.CAGS, Inst Geophys & Geochem Explorat, Langfang 065000, Hebei, Peoples R China 3.China Univ Geosci, Sch Energy Resources, Beijing 100083, Peoples R China
Recommended Citation:
He, Dashuang,Huang, Haiping,Arismendi, Gabriela Gonzalez. n-Alkane distribution in ombrotrophic peatlands from the northeastern Alberta, Canada, and its paleoclimatic implications[J]. PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,2019-01-01,528:247-257