This research used samples and **data** provided by the International Ocean Discovery Program (IODP) resulting from Expedition 349 (South China Sea Tectonics). The authors wish to thank the shipboard crew and scientific members of Expedition 349 for their essential contributions in collecting these samples. The authors also thank Sarah Turner and Elizabeth Weidner (UNH) for assistance with smear slide and TOC sample preparation. The manuscript was improved thanks to the contributions of reviewers. Funding for this research was provided through a Post-Expedition Award from the U.S. Science Support Program to FC and by a Center for Dark Energy Biosphere Investigations (C-DEBI) grant to FC and AT. Support for this research was also provided by the Deep Life Community, a part of the Deep Carbon Observatory.
