Geological interpretation of volcanism and segmentation of the Mariana back-arc spreading center between 12.7 degrees N and 18.3 degrees N

Details

• Journal Title:
  Geochemistry, Geophysics, Geosystems
• Personal Author:
  Anderson, Melissa O. ; Chadwick, William W. ; Hannington, Mark D. ; Merle, Susan G. ; Resing, Joseph A. ; Baker, Edward T. ; Butterfield, David A. ; Walker, Sharon L. ; Augustin, Nico
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research)
• Description:
  The relationships between tectonic processes, magmatism, and hydrothermal venting along similar to 600 km of the slow-spreading Mariana back-arc between 12.7 degrees N and 18.3 degrees N reveal a number of similarities and differences compared to slow-spreading mid-ocean ridges. Analysis of the volcanic geomorphology and structure highlights the complexity of the back-arc spreading center. Here, ridge segmentation is controlled by large-scale basement structures that appear to predate back-arc rifting. These structures also control the orientation of the chains of cross-arc volcanoes that characterize this region. Segment-scale faulting is oriented perpendicular to the spreading direction, allowing precise spreading directions to be determined. Four morphologically distinct segment types are identified: dominantly magmatic segments (Type I); magmatic segments currently undergoing tectonic extension (Type II); dominantly tectonic segments (Type III); and tectonic segments currently undergoing magmatic extension (Type IV). Variations in axial morphology (including eruption styles, neovolcanic eruption volumes, and faulting) reflect magma supply, which is locally enhanced by cross-arc volcanism associated with N-S compression along the 16.5 degrees N and 17.0 degrees N segments. In contrast, cross-arc seismicity is associated with N-S extension and increased faulting along the 14.5 degrees N segment, with structures that are interpreted to be oceanic core complexes-the first with high-resolution bathymetry described in an active back-arc basin. Hydrothermal venting associated with recent magmatism has been discovered along all segment types.
• Keywords:
  NOFO
• Source:
  Geochemistry Geophysics Geosystems, 18(6), 2240-2274.
• DOI:
  https://doi.org/10.1002/2017gc006813
• Document Type:
  Journal Article
• Funding:
  Grant no. NA10OAR4320148 ; Grant no. NA15OAR4320063
• Rights Information:
  Other
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha256:ec6c6daf08cf4cb461b82a72275695716bc4a975f35c3e6715aeabb24dd9100c
• Download URL:
  https://repository.library.noaa.gov/view/noaa/17971/noaa_17971_DS1.pdf
• File Type:
  [PDF - 4.78 MB ]