Lipid biomarker distributions in Oligocene and Miocene sediments from the Ross Sea region, Antarctica; implications for use of biomarker proxies in glacially-influenced settings

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doi: 10.1016/j.palaeo.2018.11.028
Author(s): Duncan, Bella; McKay, Robert; Bendle, James; Naish, Timothy; Inglis, Gordon N.; Moossen, Heiko; Levy, Richard; Ventura, G. Todd; Lewis, Adam; Chamberlain, Beth; Walker, Carrie
Author Affiliation(s): Primary:
Victoria University of Wellington, Antarctic Research Center, Wellington, New Zealand
University of Birmingham, United Kingdom
University of Bristol, United Kingdom
Geological and Nuclear Sciences, New Zealand
North Dakota State University, United States
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Vol.516, p.71-89. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 140 refs.; illus., incl. sketch map
Summary: Biomarker-based climate proxies enable climate and environmental reconstructions for regions where other paleoclimatic approaches are unsuitable. The Antarctic Cenozoic record consists of widely varying lithologies, deposited in rapidly changing depositional settings, with large lateral variations. Previous sedimentological and microfossil studies indicate that the incorporation of reworked older material frequently occurs in these sediments, highlighting the need for an assessment of biomarker distribution across a range of depositional settings and ages to assess the role reworking may have on biomarker-based reconstructions. Here, we compare sedimentary facies with the distribution of n-alkanes and hopanoids within a terrestrial outcrop, two glaciomarine cores and a deep sea core, spanning the Late Oligocene to Miocene in the Ross Sea. Comparisons are also made with n-alkane distributions in Eocene glacial erratics and Mesozoic Beacon Supergroup sediments, which are both potential sources of reworked material. The dominant n-alkane chain length shifts from n-C29 to n-C27 between the Late Eocene and the Oligocene. This shift is likely due to changing plant community composition and the plastic response of n-alkanes to climate cooling. Samples from glaciofluvial environments onshore, and subglacial and ice-proximal environments offshore are more likely to display reworked n-alkane distributions, whereas, samples from lower-energy, lacustrine and ice-distal marine environments predominantly yield immature/contemporaneous n-alkanes. These findings emphasise that careful comparisons with sedimentological and paleontological indicators are essential when applying and interpreting n-alkane-based and other biomarker-based proxies in glacially-influenced settings.
Year of Publication: 2019
Research Program: DSDP Deep Sea Drilling Project
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Aliphatic hydrocarbons; Alkanes; Aromatic hydrocarbons; Biomarkers; Cape Roberts Project; Cenozoic; Cores; DSDP Site 270; DSDP Site 274; Deep Sea Drilling Project; Eocene; Geochemistry; Hopanoids; Hydrocarbons; Leg 28; Lipids; Marine sediments; Minna Bluff; Miocene; Mount Boreas; Mount Discovery; N-alkanes; Neogene; Oligocene; Organic compounds; Paleoclimatology; Paleogene; Plantae; Ross Sea; Sedimentary rocks; Sediments; Southern Ocean; Tertiary; Triterpanes
Coordinates: S790000 S770000 E1700000 E1640000
S781200 S781200 E1651200 E1651200
S772629 S772629 W1783011 W1783011
S685949 S685949 E1732538 E1732538
Record ID: 2019033699
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands