Blackman, D. K. et al. (2011): Drilling constraints on lithospheric accretion and evolution at Atlantis Massif, Mid-Atlantic Ridge 30 degrees N

Leg/Site/Hole:
IODP 304
IODP 305
IODP 304 U1309
IODP 305 U1309
IODP 340T U1309
IODP 304 U1310
IODP 304 U1311
Identifier:
2012-023645
georefid

10.1029/2010JB007931
doi

Creator:
Blackman, D. K.
Scripps Institution of Oceanography, La Jolla, CA, United States
author

Ildefonse, B.
Universite Montpellier II, France
author

John, B. E.
University of Wyoming, United States
author

Ohara, Y.
Ocean Research Laboratory, Japan
author

Miller, D. J.
Texas A&M University, United States
author

Abe, N.
Japan Agency for Marine-Earth Science and Technology, Japan
author

Abratis, M.
Friedrich Schiller University of Jena, Germany
author

Andal, E. S.
Philex Mining Corporation, Philippines
author

Andreani, M.
Universite Claude Bernard Lyon I, France
author

Awaji, S.
University of Tokyo, Japan
author

Beard, J. S.
Virginia Museum of Natural History, United States
author

Brunelli, D.
Universita Modena, Italy
author

Charney, A. B.
Oregon State University, United States
author

Christie, D. M.
University of Alaska Fairbanks, United States
author

Collins, J.
Woods Hole Oceanographic Institution, United States
author

Delacour, A. G.
Universite Toulouse, France
author

Delius, H.
University of Leicester, United Kingdom
author

Drouin, M.
Universite Reunion, France
author

Einaudi, F.
Institut de Physique du Globe, France
author

Escartin, J.
Eidgenoessische Technische Hochschule Zuerich, Switzerland
author

Frost, B. R.
University of Hawaii at Manoa, United States
author

Frueh-Green, G.
Mississippi State University, United States
author

Fryer, P. B.
Australian National University, Australia
author

Gee, J. S.
University of Bergen, Norway
author

Godard, M.
Norwich University, United States
author

Grimes, C. B.
Kanazawa University, Japan
author

Halfpenny, A.
University of Texas at Austin, United States
author

Hansen, H. E.
Brown University, United States
author

Harris, A. C.
Exxon-Mobile, United States
author

Tamura, A.
Baker Hughes, United States
author

Hayman, N. W.
Cardiff University, United Kingdom
author

Hellebrand, E.
Hokkaido University, Japan
author

Hirose, T.
Lawrence Berkeley National Laboratory, United States
author

Hirth, J. G.
University of Leeds, United Kingdom
author

Ishimaru, S.
Shizuoka University, Japan
author

Johnson, K. T. M.
University of Plymouth, United Kingdom
author

Karner, G. D.
Nihon University, Japan
author

Linek, M.
Okayama University, Japan
author

MacLeod, C. J.
GeoForschungsZentrum, Germany
author

Maeda, J.
Durham University, United Kingdom
author

Mason, O. U.
Universitat zu Koeln, Germany
author

McCaig, A. M.
University of Freiburg, Germany
author

Michibayashi, K.
University of California at Santa Cruz, United States
author

Morris, A.
author

Nakagawa, T.
author

Nozaka, T.
author

Rosner, M.
author

Searle, R. C.
author

Suhr, G.
author

Tominaga, M.
author

von der Handt, A.
author

Yamasaki, T.
author

Zhao, X.
author

Identification:
Drilling constraints on lithospheric accretion and evolution at Atlantis Massif, Mid-Atlantic Ridge 30 degrees N
2011
Journal of Geophysical Research
American Geophysical Union, Washington, DC, United States
116
B7
Expeditions 304 and 305 of the Integrated Ocean Drilling Program cored and logged a 1.4 km section of the domal core of Atlantis Massif. Postdrilling research results summarized here constrain the structure and lithology of the Central Dome of this oceanic core complex. The dominantly gabbroic sequence recovered contrasts with predrilling predictions; application of the ground truth in subsequent geophysical processing has produced self-consistent models for the Central Dome. The presence of many thin interfingered petrologic units indicates that the intrusions forming the domal core were emplaced over a minimum of 100-220 kyr, and not as a single magma pulse. Isotopic and mineralogical alteration is intense in the upper 100 m but decreases in intensity with depth. Below 800 m, alteration is restricted to narrow zones surrounding faults, veins, igneous contacts, and to an interval of locally intense serpentinization in olivine-rich troctolite. Hydration of the lithosphere occurred over the complete range of temperature conditions from granulite to zeolite facies, but was predominantly in the amphibolite and greenschist range. Deformation of the sequence was remarkably localized, despite paleomagnetic indications that the dome has undergone at least 45 degrees rotation, presumably during unroofing via detachment faulting. Both the deformation pattern and the lithology contrast with what is known from seafloor studies on the adjacent Southern Ridge of the massif. There, the detachment capping the domal core deformed a 100 m thick zone and serpentinized peridotite comprises approximately 70% of recovered samples. We develop a working model of the evolution of Atlantis Massif over the past 2 Myr, outlining several stages that could explain the observed similarities and differences between the Central Dome and the Southern Ridge.
English
Serial
Coverage:Geographic coordinates:
North:30.1200
West:-42.0700East: -42.0400
South:30.1000

Solid-earth geophysics; Applied geophysics; accretion; Atlantic Ocean; Atlantis Massif; cores; crust; Expedition 304; Expedition 305; Expeditions 304/305; gabbros; geophysical methods; geophysical surveys; igneous rocks; Integrated Ocean Drilling Program; IODP Site U1309; IODP Site U1310; IODP Site U1311; lithosphere; magmatism; Mid-Atlantic Ridge; mid-ocean ridges; North Atlantic; ocean floors; oceanic crust; oceanic lithosphere; plutonic rocks; refraction methods; seismic methods; surveys; tectonics;

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