Expedition 390/393 summary

• Main Authors: Coggon, R. M., Teagle, D. A. H., Sylvan, J. B., Reece, J., Estes, E. R., Williams, T. J., Christeson, G. L., Aizawa, M., Albers, E., Amadori, C., Belgrano, T. M., Borrelli, C., Bridges, J. D., Carter, E. J., D'Angelo, T., Dinarès-Turell, J., Doi, N., Estep, J. D., Evans, A., Gilhooly III, W. P., Grant, L. J. C., Guérin, G. M., Harris, M., Hojnacki, V. M., Hong, G., Jin, X., Jonnalagadda, M., Kaplan, M. R., Kempton, P. D., Kuwano, D., Labonte, J. M., Lam, A. R., Latas, M., Lowery, C. M., Lu, W., McIntyre, A., Moal-Darrigade, P., Pekar, S. F., Robustelli Test, C., Routledge, C. M., Ryan, J. G., Santiago Ramos, D., Shchepetkina, A., Slagle, A. L., Takada, M., Tamborrino, L., Villa, A., Wang, Y., Wee, S. Y., Widlansky, S. J., Yang, K., Kurz, W., Prakasam, M., Tian, L., Yu, T., Zhang, G.
• Other Authors: Coggon, R.M., Teagle, D.A.H., Sylvan, J.B., Reece, J., Estes, E.R., Williams, T.J., Christeson, G.L., Aizawa, M., Albers, E., Amadori, C., Belgrano, T.M., Borrelli, C., Bridges, J.D., Carter, E.J., D'Angelo, T., Dinarès-Turell, J., Doi, N., Estep, J.D., Evans, A., Gilhooly, W.P., III, Grant, L.J.C., Guérin, G.M., Harris, M., Hojnacki, V.M., Hong, G., Jin, X., Jonnalagadda, M., Kaplan, M.R., Kempton, P.D., Kuwano, D., Labonte, J.M., Lam, A.R., Latas, M., Lowery, C.M., Lu, W., McIntyre, A., Moal-Darrigade, P., Pekar, S.F., Robustelli Test, C., Routledge, C.M., Ryan, J.G., Santiago Ramos, D., Shchepetkina, A., Slagle, A.L., Takada, M., Tamborrino, L., Villa, A., Wang, Y., Wee, S.Y., Widlansky, S.J., Yang, K., Kurz, W., Prakasam, M., Tian, L., Yu, T., and Zhang, G., 2024. Expedition 390/393 summary. In Coggon, R.M., Teagle, D.A.H., Sylvan, J.B., Reece, J., Estes, E.R., Williams, T.J., Christeson, G.L., and the Expedition 390/393 Scientists, Mcintyre, A.
• Format: Book Part
• Language: English
• Published: 2024
• Subjects: Mid-Atlantic Ridge; South Atlantic Ocean
• Online Access: https://hdl.handle.net/11571/1500340; https://doi.org/10.14379/iodp.proc.390393.101.2024; http://publications.iodp.org/proceedings/390_393/101/390393_101.html

The South Atlantic Transect (SAT) is a multidisciplinary scientific ocean drilling experiment designed to investigate the evolution of the ocean crust and overlying sediments across the western flank of the Mid-Atlantic Ridge. This project comprises four International Ocean Discovery Program expeditions: fully staffed Expeditions 390 and 393 (April–August 2022) built on engineering preparations during Expeditions 390C and 395E (October–December 2020 and April–June 2021, respectively) that took place without science parties during the height of the Coronavirus Disease 2019 (COVID-19) pandemic. Through operations along a crustal flow line at ~31°S, the SAT recovered complete sedimentary sections and the upper ~40–340 m of the underlying ocean crust formed at a slow- to intermediate-spreading rate at the Mid-Atlantic Ridge over the past ~61 My. The sediments along this transect were originally spot cored more than 50 y ago during Deep Sea Drilling Project Leg 3 (December 1968–January 1969) to help verify the theories of seafloor spreading and plate tectonics. The SAT expeditions targeted six primary sites on 7, 15, 31, 49, and 61 Ma ocean crust that fill critical gaps in our sampling of intact in situ ocean crust with regard to crustal age, spreading rate, and sediment thickness. Drilling these sites was required to investigate the history, duration, and intensity of the low-temperature hydrothermal interactions between the aging ocean crust and the evolving South Atlantic Ocean. This knowledge will improve the quantification of past hydrothermal contributions to global biogeochemical cycles and help develop a predictive understanding of the impacts of variable hydrothermal processes and exchanges. Samples from the transect of the previously unexplored sediment- and basalt-hosted deep biosphere beneath the South Atlantic Gyre are essential to refine global biomass estimates and examine microbial ecosystems' responses to variable conditions in a low-energy gyre and aging ocean crust. The transect, located near World ...