Geology of the Atlantis Massif (Mid-Atlantic Ridge, 30° N): Implications for the evolution of an ultramafic oceanic core complex

  title={Geology of the Atlantis Massif (Mid-Atlantic Ridge, 30° N): Implications for the evolution of an ultramafic oceanic core complex},
  author={Donna K. Blackman and Jeffrey A. Karson and Deborah S. Kelley and John R. Cann and Gretchen L. Fr{\"u}h-Green and Jeffrey S. Gee and Stephen D. Hurst and Barbara E. John and Jennifer Morgan and Scott L. Nooner and Daniel K. Ross and Timothy Schroeder and Elizabeth A. Williams},
  journal={Marine Geophysical Researches},
The oceanic core complex comprising Atlantis Massif was formed within the past 1.5–2 Myr at the intersection of the Mid-Atlantic Ridge, 30° N, and the Atlantis Transform Fault. The corrugated, striated central dome prominently displays morphologic and geophysical characteristics representative of an ultramafic core complex exposed via long-lived detachment faulting. Sparse volcanic features on the massif's central dome indicate that minor volcanics have penetrated the inferred footwall, which… Expand
Detachment shear zone of the Atlantis Massif core complex, Mid‐Atlantic Ridge, 30°N
Near-bottom investigations of the cross section of the Atlantis Massif exposed in a major tectonic escarpment provide an unprecedented view of the internal structure of the footwall domain of thisExpand
Seismic Velocity Variation within the Footwall of an Oceanic Core Complex – Atlantis Massif , Mid-Atlantic Ridge 30 ° N
The Atlantis Massif, an oceanic core complex (OCC) at 30oN on the Mid-Atlantic Ridge, is hypothesized to have formed via long-lived slip on a detachment fault. Due to unroofing that results from thisExpand
Drilling constraints on lithospheric accretion and evolution at Atlantis Massif, Mid‐Atlantic Ridge 30°N
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 theExpand
Mass transfer and fluid flow during detachment faulting and development of an oceanic core complex, Atlantis Massif (MAR 30°N)
The Atlantis Massif (Mid-Atlantic Ridge, 30°N) is an example of an oceanic core complex (OCC) exposed by a major fault system. Our integrated field and analytical study of mafic and ultramafic rocksExpand
Seismic reflection imaging of an oceanic detachment fault: Atlantis megamullion (Mid-Atlantic Ridge, 30°10′N)
Abstract We present multichannel seismic reflection data collected over the Atlantis megamullion, at the eastern ridge–transform intersection of Atlantis fracture zone on the northern Mid-AtlanticExpand
Fault rotation and core complex formation : significant processes in seafloor formation at slow-spreading mid-ocean ridges (Mid-Atlantic Ridge, 13°–15°N)
[1] The region of the Mid-Atlantic Ridge (MAR) between the Fifteen-Twenty and Marathon fracture zones displays the topographic characteristics of prevalent and vigorous tectonic extension. NormalExpand
Detachment Fault Control on Hydrothermal Circulation Systems: Interpreting the Subsurface Beneath The Tag Hydrothermal Field Using The Isotopic and Geological Evolution of Oceanic Core Complexes in The Atlantic
The geology and alteration history of two well-studied and very similar oceanic core complexes (OCCs) along the Mid-Atlantic Ridge are compared: the Atlantis Massif at 30°N (Integrated Ocean DrillingExpand
Seismicity of the Atlantis Massif detachment fault, 30°N at the Mid‐Atlantic Ridge
[1] At the oceanic core complex that forms the Atlantis Massif at 30°N on the Mid-Atlantic Ridge, slip along the detachment fault for the last 1.5–2 Ma has brought lower crust and mantle rocks to theExpand
A geophysical study of oceanic core complexes and surrounding terrain, Mid‐Atlantic Ridge 13°N–14°N
[1] We describe a geophysical study of oceanic core complexes (OCC) and surrounding seafloor on the Mid-Atlantic Ridge at 13°N–14°N and off-axis to ∼1.9 Myr. Data include a detailed, deep-towed sideExpand
Development and evolution of detachment faulting along 50 km of the Mid‐Atlantic Ridge near 16.5°N
A multifaceted study of the slow spreading Mid-Atlantic Ridge (MAR) at 16.5°N provides new insights into detachment faulting and its evolution through time. The survey included regional multibeamExpand


Origin of extensional core complexes: Evidence from the Mid‐Atlantic Ridge at Atlantis Fracture Zone
The contrast in geologic structure observed on opposing flanks of the Mid-Atlantic Ridge, where it is offset by the Atlantis transform fault, illustrates how significant differences in crustalExpand
Ultramafic and gabbroic exposures at the Mid-Atlantic Ridge: geological mapping in the 15°N region
Abstract The outcrops of mantle-derived ultramafic rocks in the 15°N region are the most extensive yet reported for the Mid-Atlantic Ridge. North of the Fifteen Twenty fracture zone, these outcropsExpand
Morphology and crustal structure of a small transform fault along the Mid-Atlantic Ridge: The Atlantis Fracture Zone
The Atlantis Fracture Zone (30° N) is one of the smallest transform faults along the Mid-Atlantic Ridge with a spatial offset of 70 km and an age offset of ~ 6 Ma. The morphology of the AtlantisExpand
Ultramafic exposures and the gravity signature of the lithosphere near the Fifteen-Twenty Fracture Zone (Mid-Atlantic Ridge, 14°–16.5°N)
Abstract We analyze geological and geophysical data near the Fifteen-Twenty Fracture Zone to constrain the processes of magmatic accretion and tectonic extension in the area, characterized byExpand
Megamullions and mullion structure defining oceanic metamorphic core complexes on the Mid-Atlantic Ridge
In a study of geological and geophysical data from the Mid-Atlantic Ridge, we have identified 17 large, domed edifices (megamullions) that have surfaces corrugated by distinctive mullion structureExpand
Submersible study of an oceanic megamullion in the central North Atlantic
Recently discovered megamullions on the seafloor have been interpreted to be the exhumed footwalls of long-lived detachment faults operating near the ends of spreading segments in slow spreadingExpand
A rifted inside corner massif on the Mid-Atlantic Ridge at 5°S
The structure of the Mid-Atlantic Ridge at 5°S was investigated during a recent cruise with the FS Meteor. A major dextral transform fault (hereafter the 5°S FZ) offsets the ridge left-laterally byExpand
Structure of oceanic core complexes: Constraints from seafloor gravity measurements made at the Atlantis Massif
[1] Using the DSV Alvin, the relative seafloor gravimeter ROVDOG was deployed at 18 sites on the Atlantis Massif (located at the ridge-transform intersection of the Mid-Atlantic Ridge and theExpand
Geometry and evolution of a mid-crustal extensional fault system: Chemehuevi Mountains, southeastern California
  • B. John
  • Geology
  • Geological Society, London, Special Publications
  • 1987
Summary The extensional fault system exposed in the Chemehuevi Mountains area of the southern Cordillera provides data on the mode of mid-crustal accommodation to continental extension. A stackedExpand
Geological investigation of a lineated massif at the Kane Transform Fault: implications for oceanic core complexes
  • J. Karson
  • Geology, Biology
  • Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences
  • 1999
Recent available new perspectives on the morphology of the sea–floor near the Mid–Atlantic Ridge reveal the widespread development of dome–like massifs with lineated upper surfaces, suggesting that these structures have formed over significant lengths of ridge axis and are not necessarily confined to any specific setting with respect to morphologic segmentation patterns. Expand