Dear Colleagues, Benjamin Tutolo and I would like to invite you to submit an abstract to *Goldschmidt Session 8c: Seafloor hydrothermal processes on modern and ancient Earth: Implications for life, elemental budgets, and oxidation states of the lithosphere-hydrosphere-atmosphere system* (more info below). While we recognize that Goldschmidt in the time of COVID may lack many of the attributes we have come to know and love, the science must go on, *especially for the many early career researchers who are just now beginning to make connections that will lead to their future successes in the field of geochemistry*. Thus, Ben and I are committed to putting together a successful, engaging session at this summer’s Goldschmidt, and we are hoping that you will be join us in this effort by submitting an abstract to our session. The conference will be conducted in a *hybrid format* (more info <https://2021.goldschmidt.info/goldschmidt/2021/meetingapp.cgi/ModuleMeetingInfo/Format>), combining an onsite meeting in Lyon, France for delegates who can travel, with a reduced-price (€200 professional; €75 student/retired) online meeting for those who cannot, while aiming to promote as much interaction as possible between the two types of delegates. Participation from delegates in different time zones will be accommodated such that, as far as can be managed, no one is expected to join live meeting events too far outside of normal working hours. * The abstract submission deadline <https://2021.goldschmidt.info/goldschmidt/2021/cfp.cgi> will be 26 February.* We look forward to seeing your submissions! Ben and Drew *Theme 8:* Co-Evolution of Life and Environments Session Number 8c: Seafloor hydrothermal processes on modern and ancient Earth: Implications for life, elemental budgets, and oxidation states of the lithosphere-hydrosphere-atmosphere system *Conveners:* Benjamin Tutolo, Drew Syverson Invited Speaker(s): Desiree Roerdink *Provisional Keynote Speaker:* Geoff Wheat Seafloor hydrothermal systems have profoundly influenced the chemistry, biology, and oxidation state of Earth’s lithosphere-hydrosphere-atmosphere system throughout Earth history. However, their very nature within the oceanic crust drastically limits the temporal extent of direct geologic observations of their existence. Thus, attempts to correlate seafloor hydrothermal processes with biological evolution, global elemental budgets, and global redox states throughout Earth history generally require interdisciplinary studies that integrate studies of modern analogues, extrapolations of the geologic record, novel laboratory experiments, and numerical models. In this session, we intend to host a forum for presenting and integrating these various sets of observations in order to focus the community’s efforts on answering key questions regarding chemical budgets and oxidation states on modern and ancient Earth. In particular, we invite contributions focusing on seafloor measurements of modern hydrothermal systems; studies of recovered oceanic drill core, obducted oceanic lithosphere, or proxy records in ancient sedimentary rocks; experimental exploration of seafloor (bio)geochemical interactions; and integrative numerical models that expand the spatiotemporal scales of these field and experimental observations. Specific focuses could include the role of igneous oceanic crust alteration processes in the geologic carbon cycle, the contribution of submarine volcanism to the oxidation state of the early Earth, changes in ocean chemistry associated with the relative balance of continental weathering and seafloor hydrothermal fluxes, and the relation between these factors and tempos and milestones of biological evolution. Research Associate - Yale University email: drew.syverson@yale.edu ph: +1 (612) 475-0575 https://sites.google.com/view/drewsyverson/home