thumbnail

Extension in Mona Passage, Northeast Caribbean

Tectonophysics

By:
and
DOI: 10.1016/j.tecto.2010.07.002

Links

Abstract

As shown by the recent Mw 7.0 Haiti earthquake, intra-arc deformation, which accompanies the subduction process, can present seismic and tsunami hazards to nearby islands. Spatially-limited diffuse tectonic deformation within the Northeast Caribbean Plate Boundary Zone likely led to the development of the submerged Mona Passage between Puerto Rico and the Dominican Republic. GPS geodetic data and a moderate to high level of seismicity indicate that extension within the region is ongoing. Newly-collected high-resolution multibeam bathymetry and multi-channel seismic reflection profiles and previously-collected samples are used here to determine the tectonic evolution of the Mona Passage intra-arc region. The passage is floored almost completely by Oligocene-Pliocene carbonate platform strata, which have undergone submarine and subaerial erosion. Structurally, the passage is characterized by W- to NNW-trending normal faults that offset the entire thickness of the Oligo-Pliocene carbonate platform rocks. The orientation of these faults is compatible with the NE-oriented extension vector observed in GPS data. Fault geometry best fits an oblique extension model rather than previously proposed single-phase, poly-phase, bending-moment, or rotation extension models. The intersection of these generally NW-trending faults in Mona Passage with the N-S oriented faults of Mona Canyon may reflect differing responses of the brittle upper-crust, along an arc-forearc rheological boundary, to oblique subduction along the Puerto Rico trench. Several faults within the passage, if ruptured completely, are long enough to generate earthquakes with magnitudes on the order of Mw 6.5-7. ?? 2010.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Extension in Mona Passage, Northeast Caribbean
Series title:
Tectonophysics
DOI:
10.1016/j.tecto.2010.07.002
Volume
493
Issue:
1-2
Year Published:
2010
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Tectonophysics
First page:
74
Last page:
92
Number of Pages:
19