Publication Date:
2020-03-18
Description:
We reanalyzed 3D seismic reflection and logging-while-drilling data from the toe
of the northern Barbados accretionary prism to interpret structure, deformation, and fluid
flow related to subduction processes. The seafloor amplitude and coherence reveal an
abrupt change in the thrust orientation from NNE at the thrust front and north and NNW
about 5 km west of the thrust front. These thrust sets are separated by a triangular-shaped
quiet area, which may represent a zone of low strength. The northeast-trending band of
strong negative amplitude and high coherence in the décollement, known to be an interval
of arrested consolidation, overlaps the quiet area, suggesting that the arrested consolidation
may be related to the lack of thrust imbrication, and thus, vertical drainage for fluid
in the accretionary prism. Fractal analysis of the décollement and top of the subducting
oceanic basement indicates that the relief of the décollement correlates with the topography
of the oceanic basement. Differential compaction of the underthrust sediment overlying
the rugged oceanic basement, together with the basement faults that penetrate into the
décollement probably caused relief or even faulting in the décollement.
Type:
Article
,
PeerReviewed
Format:
text
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