Common depth points and associated geographic coordinates


Fluids in subduction zones can influence seismogenic behaviour and prism morphology. The Eastern Makran subduction zone, offshore Pakistan, has a very thick incoming sediment section of up to 7.5 km, providing a large potential fluid source to the accretionary prism. A hydrate-related bottom simulating reflector (BSR), zones of high amplitude reflectivity, seafloor seep sites and reflective thrust faults are present across the accretionary prism, indicating the presence of fluids and suggesting active fluid migration. High amplitude free gas zones and seep sites are primarily associated with anticlinal hinge traps, and fluids here appear to be sourced from shallow biogenic sources and migrate to the seafloor along minor normal faults. There are no observed seep sites associated with the surface expression of the wedge thrust faults, potentially due to burial of the surface trace by failure of the steep thrust ridge slopes. Thrust fault reflectivity is restricted to the upper 3 km of sediment and the deeper décollement is non-reflective. We interpret that fluids and overpressure are not common in the deeper stratigraphic section. Thermal modelling of sediments at the deformation front suggests that the deeper sediment section is relatively dewatered and not currently contributing to fluid expulsion in the Makran accretionary prism.

Supplement to: Smith, Gemma L; McNeill, Lisa C; Henstock, Timothy J; Arraiz, Daniel; Spieß, Volkhard (2014): Fluid generation and distribution in the highest sediment input accretionary margin, the Makran. Earth and Planetary Science Letters, 403, 131-143

Related Identifier IsSupplementTo
Related Identifier IsDocumentedBy
Metadata Access
Creator Smith, Gemma L ORCID logo; McNeill, Lisa C ORCID logo; Henstock, Timothy J ORCID logo; Arraiz, Daniel; Spieß, Volkhard
Publisher PANGAEA
Publication Year 2014
Rights Creative Commons Attribution 3.0 Unported;
OpenAccess true
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 4204 data points
Discipline Earth System Research
Spatial Coverage (62.744W, 24.616S, 62.744E, 24.659N); northwestern Indian Ocean
Temporal Coverage Begin 2007-10-07T00:00:00Z
Temporal Coverage End 2007-10-28T00:00:00Z