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

Anderson, Melissa O., Chadwick, William W., Hannington, Mark D., Merle, Susan G., Resing, Joseph A., Baker, Edward T., Butterfield, David A., Walker, Sharon L. and Augustin, Nico (2017) Geological interpretation of volcanism and segmentation of the Mariana back-arc spreading center between 12.7°N and 18.3°N Geochemistry, Geophysics, Geosystems, 18 (6). pp. 2240-2274. DOI 10.1002/2017GC006813.

[img]
Preview
Text
Anderson_et_al-2017-Geochemistry,_Geophysics,_Geosystems.pdf - Published Version
Available under License ["licenses_description_cc_by_4.0" not defined].

Download (4Mb) | Preview

Supplementary data:

Abstract

The relationships between tectonic processes, magmatism, and hydrothermal venting along ∼600 km of the slow-spreading Mariana back-arc between 12.7°N and 18.3°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°N and 17.0°N segments. In contrast, cross-arc seismicity is associated with N-S extension and increased faulting along the 14.5°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.

Document Type: Article
Keywords: Mariana back-arc; ridge segmentation; axial morphology; cross-arc volcanism; hydrothermal venting; geological mapping; RV Falkor, FK151121, AUV Sentry, ROV Deep Discoverer, Okeanos Explorer, EX1605L1–2
Research affiliation: OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS Magmatic and Hydrothermal Systems > Marine Mineralische Rohstoffe
Kiel University
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS Magmatic and Hydrothermal Systems
Refereed: Yes
DOI etc.: 10.1002/2017GC006813
ISSN: 1525-2027
Date Deposited: 27 Jun 2017 12:27
Last Modified: 21 Aug 2017 08:57
URI: http://eprints.uni-kiel.de/id/eprint/38599

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...