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Bibliographic Details
Main Authors: Smith, Gemma L, McNeill, Lisa C, Henstock, Timothy J, Arraiz, Daniel, Spieß, Volkhard
Format: Dataset Open Access
Language:en
Published: PANGAEA 2014
Subjects:
Online Access:https://doi.org/10.1594/PANGAEA.840664
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author Smith, Gemma L
McNeill, Lisa C
Henstock, Timothy J
Arraiz, Daniel
Spieß, Volkhard
author_facet Smith, Gemma L
McNeill, Lisa C
Henstock, Timothy J
Arraiz, Daniel
Spieß, Volkhard
collection Datos científicos de ciencias marinas y ambientales
contents 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.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_840664
institution PANGAEA
language en
publishDate 2014
publisher PANGAEA
record_format pangaea
spellingShingle Common depth points and associated geographic coordinates
Smith, Gemma L
McNeill, Lisa C
Henstock, Timothy J
Arraiz, Daniel
Spieß, Volkhard
Center for Marine Environmental Sciences; Common depth point; CT; LATITUDE; LONGITUDE; M74/2; M74/2-track; MARUM; Meteor (1986); northwestern Indian Ocean; Underway cruise track measurements; UTM Easting, Universal Transverse Mercator; UTM Northing, Universal Transverse Mercator; UTM Zone, Universal Transverse Mercator
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.
title Common depth points and associated geographic coordinates
topic Center for Marine Environmental Sciences; Common depth point; CT; LATITUDE; LONGITUDE; M74/2; M74/2-track; MARUM; Meteor (1986); northwestern Indian Ocean; Underway cruise track measurements; UTM Easting, Universal Transverse Mercator; UTM Northing, Universal Transverse Mercator; UTM Zone, Universal Transverse Mercator
url https://doi.org/10.1594/PANGAEA.840664