Expedition 357 summary

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doi: 10.14379/iodp.proc.357.101.2017
Author(s): Früh-Green, Gretchen L.; Orcutt, Beth N.; Green, Sophie; Cotterill, Carol; Morgan, Sally; Akizawa, Norikatsu; Bayrakci, Gaye; Behrmann, Jan-Hinrich; Herrero-Bervera, Emilio; Boschi, Chiara; Brazelton, William; Cannat, Mathilde; Dunkel, Kristina G.; Escartin, Javier; Harris, Michelle; Hesse, Kirsten; John, Barbara; Lang, Susan Q.; Lilley, Marvin; Liu Haiquan; Mayhew, Lisa; McCaig, Andrew; Menez, Benedicte; Morono, Yuki; Quéméneur, Marianne; Ratnayake, Amila Sandaruwan; Rouméjon, Stéphane; Schrenk, Matthew; Schwarzenbach, Esther; Twing, Katrina; Weis, Dominique; Whattam, Scott Andrew; Williams, Morgan; Zhao, Rui
International Ocean Discovery Program, Expedition 357 Scientists, College Station, TX
Author Affiliation(s): Primary:
Eidgenössische Technische Hochschule Zürich, Institute of Geochemistry and Petrology, Zurich, Switzerland
Other:
Bigelow Laboratory for Ocean Sciences, United States
British Geological Survey, United Kingdom
University of Leicester, United Kingdom
Kanazawa University, Japan
University of Southampton, United Kingdom
GEOMAR-Helmholtz Centre for Ocean Research Kiel, Germany
University of Hawaii at Manoa, United States
CNR, Institute of Geosciences and Earth Resources, Italy
University of Utah, United States
Université Paris Diderot, France
University of Oslo, Norway
Institut de Physique du Globe de Paris, France
Plymouth University, United Kingdom
Friedrich-Alexander University of Erlangen-Nuremberg, Germany
University of Wyoming, United States
University of South Carolina, United States
University of Washington, United States
Chinese Academy of Sciences, Guangzhou Institute of Geochemistry, China
University of Colorado at Boulder, United States
University of Leeds, United Kingdom
Japan Agency for Marine-Earth Science and Technology, Japan
Mediterranean Institute of Oceanography, France
Shimane University, Japan
Michigan State University, United States
Freie Universität Berlin, Germany
University of British Columbia, United States
Korea University, South Korea
Australian National University, Australia
University of Bergen, Norway
Volume Title: Proceedings of the International Ocean Discovery Program; Atlantis Massif serpentinization and life; Expedition 357 of the mission-specific drilling platform from and to Southampton, United Kingdom; Sites M0068-M0076, 26 October-11 December 2015
Volume Author(s): Früh-Green, Gretchen L.; Orcutt, Beth N.; Green, Sophie; Cotterill, Carol; Morgan, Sally; Akizawa, Norikatsu; Bayrakci, Gaye; Behrmann, Jan-Hinrich; Herrero-Bervera, Emilio; Boschi, Chiara; Brazelton, William; Cannat, Mathilde; Dunkel, Kristina G.; Escartin, Javier; Harris, Michelle; Hesse, Kirsten; John, Barbara; Lang, Susan Q.; Lilley, Marvin; Liu Haiquan; Mayhew, Lisa; McCaig, Andrew; Menez, Benedicte; Morono, Yuki; Quéméneur, Marianne; Ratnayake, Amila Sandaruwan; Rouméjon, Stéphane; Schrenk, Matthew; Schwarzenbach, Esther; Twing, Katrina; Weis, Dominique; Whattam, Scott Andrew; Williams, Morgan; Zhao, Rui
Source: Proceedings of the International Ocean Discovery Program; Atlantis Massif serpentinization and life; Expedition 357 of the mission-specific drilling platform from and to Southampton, United Kingdom; Sites M0068-M0076, 26 October-11 December 2015, Gretchen L. Früh-Green, Beth N. Orcutt, Sophie Green, Carol Cotterill, Sally Morgan, Norikatsu Akizawa, Gaye Bayrakci, Jan-Hinrich Behrmann, Emilio Herrero-Bervera, Chiara Boschi, William Brazelton, Mathilde Cannat, Kristina G. Dunkel, Javier Escartin, Michelle Harris, Kirsten Hesse, Barbara John, Susan Q. Lang, Marvin Lilley, Liu Haiquan, Lisa Mayhew, Andrew McCaig, Benedicte Menez, Yuki Morono, Marianne Quéméneur, Amila Sandaruwan Ratnayake, Stéphane Rouméjon, Matthew Schrenk, Esther Schwarzenbach, Katrina Twing, Dominique Weis, Scott Andrew Whattam, Morgan Williams and Rui Zhao; International Ocean Discovery Program, Expedition 357 Scientists, College Station, TX. Proceedings of the International Ocean Discovery Program, Expedition Reports, Vol.357. Publisher: International Ocean Discovery Program, Washington, DC, United States. ISSN: 2377-3189 CODEN: IDSDA6
Note: In English; illus., incl. 7 tables, sketch map
Summary: International Ocean Discovery Program (IODP) Expedition 357 successfully cored an east-west transect across the southern wall of Atlantis Massif on the western flank of the Mid-Atlantic Ridge (MAR) to study the links between 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. The primary goals of this expedition were to (1) examine the role of serpentinization in driving hydrothermal systems, sustaining microbial communities, and sequestering carbon; (2) characterize the tectonomagmatic processes that lead to lithospheric heterogeneities and detachment faulting; and (3) assess how abiotic and biotic processes change with variations in rock type and progressive exposure on the seafloor. To accomplish these objectives, we developed a coring and sampling strategy centered on the use of seabed drills-the first time that such systems have been used in the scientific ocean drilling programs. This technology was chosen in the hope of achieving high recovery of the carbonate cap sequences and intact contact and deformation relationships. The expedition plans also included several engineering developments to assess geochemical parameters during drilling; sample bottom water before, during, and after drilling; supply synthetic tracers during drilling for contamination assessment; acquire in situ electrical resistivity and magnetic susceptibility measurements for assessing fractures, fluid flow, and extent of serpentinization; and seal boreholes to provide opportunities for future experiments. Seventeen holes were drilled at nine sites across Atlantis Massif, with two sites on the eastern end of the southern wall (Sites M0068 and M0075), three sites in the central section of the southern wall north of the Lost City hydrothermal field (Sites M0069, M0072, and M0076), two sites on the western end (Sites M0071 and M0073), and two sites north of the southern wall in the direction of the central dome of the massif and Integrated Ocean Drilling Program Site U1309 (Sites M0070 and M0074). Use of seabed drills enabled collection of more than 57 m of core, with borehole penetration ranging from 1.30 to 16.44 meters below seafloor and core recoveries as high as 74.76% of total penetration. This high level of recovery of shallow mantle sequences is unprecedented in the history of ocean drilling. The cores recovered along the southern wall of Atlantis Massif have highly heterogeneous lithologies, types of alteration, and degrees of deformation. The ultramafic rocks are dominated by harzburgites with intervals of dunite and minor pyroxenite veins, as well as gabbroic rocks occurring as melt impregnations and veins, all of which provide information about early magmatic processes and the magmatic evolution in the southernmost portion of Atlantis Massif. Dolerite dikes and basaltic rocks represent the latest stage of magmatic activity. Overall, the ultramafic rocks recovered during Expedition 357 reveal a high degree of serpentinization, as well as metasomatic talc-amphibole-chlorite overprinting and local rodingitization. Metasomatism postdates an early phase of serpentinization but predates late-stage intrusion and alteration of dolerite dikes and the extrusion of basalt. The intensity of alteration is generally lower in the gabbroic and doleritic rocks.
Year of Publication: 2017
Research Program: IODP Integrated Ocean Drilling Program
IODP2 International Ocean Discovery Program
Key Words: 05 Petrology, Igneous and Metamorphic; 12 Stratigraphy, Historical Geology and Paleoecology; Aliphatic hydrocarbons; Alkanes; Atlantic Ocean; Atlantis Massif; Basalts; Boreholes; Brecciation; Carbon; Carbonate rocks; Circulation; Cores; Crust; Deep biosphere; Detachment faults; Diabase; Dikes; Dunite; Expedition 357; Faults; Gabbros; Harzburgite; Hydrocarbons; Hydrogen; Hydrothermal alteration; IODP Site M0068; IODP Site M0069; IODP Site M0070; IODP Site M0071; IODP Site M0072; IODP Site M0073; IODP Site M0074; IODP Site M0075; IODP Site M0076; Igneous rocks; International Ocean Discovery Program; Intrusions; Lithosphere; Lost City hydrothermal field; Metamorphic rocks; Metasomatism; Methane; Microorganisms; Mid-Atlantic Ridge; North Atlantic; Oceanic core complexes; Oceanic crust; Organic carbon; Organic compounds; Peridotites; Plutonic rocks; Schists; Sea water; Sedimentary rocks; Serpentinization; Ultramafics; Veins; Volcanic rocks; Water-rock interaction
Coordinates: N300730 N300730 W0420545 W0420545
N300756 N300756 W0420712 W0420712
N300832 N300833 W0420810 W0420811
N300742 N300743 W0420911 W0420913
N300747 N300747 W0420719 W0420719
N300754 N300754 W0421058 W0421058
N300952 N300952 W0420719 W0420719
N300739 N300740 W0420358 W0420359
N300737 N300737 W0420704 W0420705
Record ID: 2017020798
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