@article{fdi:010074835,
  title = {{M}agmatism, serpentinization and life : {I}nsights through drilling the {A}tlantis {M}assif ({IODP} {E}xpedition 357)},
  author = {{F}ruh-{G}reen, {G}. {L}. and {O}rcutt, {B}. {N}. and {R}oumejon, {S}. and {L}illey, {M}. {D}. and {M}orono, {Y}. and {C}otterill, {C}. and {G}reen, {S}. and {E}scartin, {J}. and {J}ohn, {B}. {E}. and {M}c{C}aig, {A}. {M}. and {C}annat, {M}. and {M}enez, {B}. and {S}chwarzenbach, {E}. {M}. and {W}illiams, {M}. {J}. and {M}organ, {S}. and {L}ang, {S}. {Q}. and {S}chrenk, {M}. {O}. and {B}razelton, {W}. {J}. and {A}kizawa, {N}. and {B}oschi, {C}. and {D}unkel, {K}. {G}. and {Q}u{\'e}m{\'e}neur, {M}arianne and {W}hattam, {S}. {A}. and {M}ayhew, {L}. and {H}arris, {M}. and {B}ayrakci, {G}. and {B}ehrmann, {J}. {H}. and {H}errero-{B}ervera, {E}. and {H}esse, {K}. and {L}iu, {H}. {Q}. and {R}atnayake, {A}. {S}. and {T}wing, {K}. and {W}eis, {D}. and {Z}hao, {R}. and {B}ilenker, {L}.},
  editor = {},
  language = {{ENG}},
  abstract = {{IODP} {E}xpedition 357 used two seabed drills to core 17 shallow holes at 9 sites across {A}tlantis {M}assif ocean core complex ({M}id-{A}tlantic {R}idge 30 degrees {N}). {T}he goals of this expedition were to investigate serpentinization processes and microbial activity in the shallow subsurface of highly altered ultramafic and mafic sequences that have been uplifted to the seafloor along a major detachment fault zone. {M}ore than 57 m of core were recovered, with borehole penetration ranging from 1.3 to 16.4 meters below seafloor, and core recovery as high as 75% of total penetration in one borehole. {T}he cores show highly heterogeneous rock types and alteration associated with changes in bulk rock chemistry that reflect multiple phases of magmatism, fluid-rock interaction and mass transfer within the detachment fault zone. {R}ecovered ultramafic rocks are dominated by pervasively serpentinized harzburgite with intervals of serpentinized dunite and minor pyroxenite veins; gabbroic rocks occur as melt impregnations and veins. {D}olerite intrusions and basaltic rocks represent the latest magmatic activity. {T}he proportion of mafic rocks is volumetrically less than the amount of mafic rocks recovered previously by drilling the central dome of {A}tlantis {M}assif at {IODP} {S}ite {U}1309. {T}his suggests a different mode of melt accumulation in the mantle peridotites at the ridge-transform intersection and/or a tectonic transposition of rock types within a complex detachment fault zone. {T}he cores revealed a high degree of serpentinization and metasomatic alteration dominated by talc-amphibole-chlorite overprinting. {M}etasomatism is most prevalent at contacts between ultramafic and mafic domains (gabbroic and/or doleritic intrusions) and points to channeled fluid flow and silica mobility during exhumation along the detachment fault. {T}he presence of the mafic lenses within the serpentinites and their alteration to mechanically weak talc, serpentine and chlorite may also be critical in the development of the detachment fault zone and may aid in continued unroofing of the upper mantle peridotite/gabbro sequences. {N}ew technologies were also developed for the seabed drills to enable biogeochemical and microbiological characterization of the environment. {A}n in situ sensor package and water sampling system recorded real-time variations in dissolved methane, oxygen, p{H}, oxidation reduction potential ({E}h), and temperature and during drilling and sampled bottom water after drilling. {S}ystematic excursions in these parameters together with elevated hydrogen and methane concentrations in post-drilling fluids provide evidence for active serpentinization at all sites. {I}n addition, chemical tracers were delivered into the drilling fluids for contamination testing, and a borehole plug system was successfully deployed at some sites for future fluid sampling. {A} major achievement of {IODP} {E}xpedition 357 was to obtain microbiological samples along a west-east profile, which will provide a better understanding of how microbial communities evolve as ultramafic and mafic rocks are altered and emplaced on the seafloor. {S}trict sampling handling protocols allowed for very low limits of microbial cell detection, and our results show that the {A}tlantis {M}assif subsurface contains a relatively low density of microbial life.},
  keywords = {{IODP} {E}xpedition 357 ; {A}tlantis {M}assif ; {D}etachment faulting ; {S}erpentinization ; {S}i metasomatism ; {D}eep biosphere ; {ATLANTIQUE}},
  booktitle = {{S}pecial issue : {A}byss},
  journal = {{L}ithos},
  volume = {323},
  numero = {{N}o sp{\'e}cial},
  pages = {137--155},
  ISSN = {0024-4937},
  year = {2018},
  DOI = {10.1016/j.lithos.2018.09.012},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074835},
}