Open AccessThree‐dimensional seismic analysis of high‐amplitude anomalies in the shallow subsurface of the Northern Indus Fan: Sedimentary and/or fluid origin
Author(s) -
Calvès Gérôme,
Huuse Mads,
Schwab Anne,
Clift Peter
Publication year - 2008
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2008jb005666
Subject(s) - geology , indus , seismology , anticline , sedimentary rock , tectonics , submarine pipeline , reflection (computer programming) , submarine , geomorphology , paleontology , structural basin , geotechnical engineering , oceanography , computer science , programming language
We report on a detailed analysis of amplitude anomalies in three‐dimensional (3D) seismic reflection data and their surrounding strata in the shallow subsurface of the northern part of the Indus Submarine Fan, Arabian Sea. Our analysis reveals the presence of distributary lobe complexes and a relict fluid migration system, including a buried mud volcano, linked to contractional anticlines overlying deep‐seated strike‐slip faults buried below the Indus slope. Building on a regional tectonic and stratigraphic framework, we have used a 3D seismic survey to map in detail the occurrence of high‐amplitude anomalies in the shallow subsurface. We link these to gas hydrate and free gas accumulations hosted within distal distributary lobes deposited on the Indus slope and supplied by underlying focused fluid flow system along a fault zone. Our results suggest that the seismic amplitude anomalies may be classified as a weak “bottom‐simulating reflection” (BSR) formed during a paleofluid flow event in the northern Indus Fan (∼5–1.8 Ma). Present‐day fluid influx is low.