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Data report: bitumen extracted from hydrothermally altered sediments encountered during Expedition 3311

Stephen A. Bowden,2 Jack Walker,2 Mateusz Ziolkowski,2 and Colin Taylor2


Drilling during Integrated Ocean Drilling Program Expedition 331 encountered sediments variably altered by hydrothermal activity. Site C0013 was highly altered, Site C0014 was hydrothermally altered below ~12 meters below seafloor (mbsf), and Site C0017 evidenced little hydrothermal alteration in near-surface sediments (to 90 mbsf) and more alteration at greater depths. Bitumen from these sites was variably altered, with the most thermally altered bitumen found in sediments close to the present-day hydrothermal mound (Site C0013). Similarly, deeper samples evidence more thermal alteration than their shallower counterparts for any given site. Despite these broad patterns, these trends are not clearly observed in many instances; thus, overall patterns of thermal alteration are complicated. This complication is likely because much of the bitumen present migrated into its present position during the movement of hydrothermal fluids, although it may also indicate complex circulation of fluids in the subsurface and temperature regimes that are spatially heterogeneous. The biomarker fingerprint of most of the bitumen is consistent with the hemipelagic nature of the sediments.

1 Bowden, S.A., Walker, J., Ziolkowski, M., and Taylor, C., 2016. Data report: bitumen extracted from hydrothermally altered sediments encountered during Expedition 331. In Takai, K., Mottl, M.J., Nielsen, S.H., and the Expedition 331 Scientists, Proceedings of the Integrated Ocean Drilling Program, 331: Tokyo (Integrated Ocean Drilling Program Management International, Inc.). doi:10.2204/iodp.proc.331.201.2016

2 Department of Geology and Petroleum Geology, School of Geoscience, University of Aberdeen, Aberdeen AB24 3UE, Scotland. Correspondence author:

Initial receipt: 6 June 2013
Acceptance: 21 January 2016
Publication: 9 May 2016
MS 331-201