Message from IODP Expedition 399, Atlantis Massif

Published：2023-05-22 Views：573

Greetings from Atlantis Massif! Our deep life scientists Susan Lang (Woods Hole Oceanographic Institution; co-chief scientist of IODP Expedition 399), Fengping Wang (Shanghai JiaoTong University), William Brazelton (University of Utah), Jordyn Robare (Arizona State University) and Gordon Southam (University of Queensland) are sailing aboard the JOIDES Resolution. These microbiologists and organic geochemists are collaborating closely with the petrologists, geochemists, and structural geologists to explore the building blocks of life and the boundaries of life within the lithosphere. The samples collected during the expedition will be used to address a wide range of major scientific questions, including how the earliest life-forming processes on Earth developed and natural carbon sequestration processes. The expedition has been exceptionally successful by drilling a record-breaking hole: U1601C, located approximately 800 meters north of the Lost City Hydrothermal Field. As of day 40, we have drilled >950 meters into a peridotite-dominated system with incredibly high recovery, far surpassing the previous serpentinite drilling record of 201 meters. The scientific party is thrilled to see these exceptional rock cores and potential glimpses into the deep, serpentinite-hosted subseafloor biosphere. Highlights particularly linked with deep life exploration include:

Recovery of the freshest and most complete record of mantle ever collected by ocean drilling

Detection of highly elevated concentrations of molecular hydrogen in borehole fluids, recording active serpentinization.
Documentation of changing hydrothermal alteration of mantle rocks with depth, providing the opportunity to reconstruct the serpentinization process, including the formation of molecular hydrogen and abiotic synthesis of organic compounds.
Numerous, extensive examples of the relationships among peridotites, melt emplacement, fluid flow, and metal deposition, with profound importance for subseafloor habitability.

The successful drilling has provided an unprecedented opportunity for the microbiology group on the ship to preserve uncontaminated rock samples for on-ship and future on-shore analyses including cell and virus counting, lipid extraction, meta-omics analyses, single-cell activity assays, extremophilic crustal strain cultivation and bacteria-mineral interaction experiments. This expedition has provided tremendous research opportunities for onshore research for years to come, as well as a legacy borehole for future explorations of the subseafloor biosphere.